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Biomedical subjects

P Stephenson

Publications and source records attributed to P Stephenson.

At least 55 records · Page 3Linked to original sources

Small intestinal plasma cells in coeliac disease.

Using a modified immunoperoxidase technique to achieve optimum staining and reproducible counts of plasma cells in paraffin embedded tissue, IgA, IgM, IgE, and IgG plasma cells were studied in small bowel biopsies from 20 controls, 23 untreated coeliac patients, 19 treated coeliac patients, and seven patients with Crohn's disease not involving duodenum or jejunum. In controls the ratio of the mean counts for IgA, IgM, IgE, and IgG plasma cells was 2.5:1:1:1 respectively. In patients with untreated coeliac disease, counts of all types of plasma cell were significantly increased approximately two-fold compared with controls although for IgG cells there was considerable overlap. The ratio of the mean plasma cell counts in the untreated coeliac patients was 3.5:1.5:2:1. Counts fell significantly after treatment with a gluten-free diet. There was no significant difference between counts in the controls and the Crohn's disease patients. The changes found in coeliac disease may simply be a non-specific response to mucosal damage. The increases in IgA and IgM plasma cells, however, suggest that the deposits of extracellular IgA and IgM observed in coeliac mucosa are locally produced, and the increase in IgE plasma cells raises the possibility that reaginic type hypersensitivity may be involved in coeliac disease.

Adolescent↗

The penetration of amoxycillin/clavulanic acid into peritoneal fluid.

Thirty patients undergoing elective abdominal surgery were given 1 g amoxycillin plus 0 . 2 g clavulanic acid as a single intravenous injection at varying times prior to the operation. Sterile assay discs were placed on the peritoneal surface in order to measure peritoneal fluid levels of each agent. Simultaneous serum levels were also measured. A total of 44 simultaneous serum and peritoneal samples were analysed. There was rapid penetration of both agents into peritoneal fluid. The mean peritoneal fluid levels of amoxycillin were 84% (S.D. 34) of the serum level and 66% 42) for clavulanic acid. The peritoneal levels of both agents declined in parallel to the serum levels (the half-lives all being about 1 h) and the ratio of amoxycillin: clavulanic acid in serum and peritoneal fluid was similar to that as administered.

Amoxicillin↗

Rectal mucosal plasma cells in inflammatory bowel disease.

To achieve optimum staining and reproducible counts of plasma cells in paraffin embedded tissue with the immunoperoxidase technique we have found it essential to obtain a plateau count by titration of antisera for each specimen. This modification was used to study IgA, IgM, IgE, and IgG plasma cells in rectal biopsies from 20 controls, 20 patients with ulcerative proctocolitis, 20 with Crohn's colitis, 20 with non-specific proctitis, 15 with bacterial colitis, and seven with Crohn's disease but no apparent large bowel involvement. Counts were correlated with the characteristic histological features of inflammatory bowel disease. In controls the ratio of the mean counts for IgA, IgM, IgE, and IgG plasma cells was 8:3:3:1. All types of plasma cells were very significantly increased in the patients with ulcerative proctocolitis, Crohn's colitis, and non-specific proctitis and counts correlated with the severity of inflammation. There was no significant difference between the counts in these three groups. All counts tended to be higher in bacterial colitis than in controls, the difference being significant for IgA and IgE. When matched for severity of inflammation there was no significant difference between the counts in bacterial colitis and inflammatory bowel disease. The counts in patients with Crohn's disease but no large bowel involvement were not significantly different from controls. These results suggest that changes in plasma cell counts in inflammatory bowel disease are a non-specific response to mucosal damage, possible by a luminal irritant, and do not differentiate the type of inflammatory bowel disease.

Adult↗

Sequence and location of the poly C tract in aphtho- and cardiovirus RNA.

The poly C tract in the RNA of the aphtho- and cardio viruses has been examined in several isolates of foot-and-mouth disease virus (FMDV) and encephalomyocarditis (EMC) virus. The length of the tract is variable, containing 100 to 170 bases in the FMDV isolates and 80 to 250 bases in the EMC virus isolates. Each poly C tract contains c. 10% A and U residues, located at the 5' end, i.e. most of the tract is a continuous run of C residues. The position of the tract on the genome was the same in each of the FMDV isolates, about 400 bases from the 5' end, whereas in the EMC virus isolates it was about 150 bases from the 5' end.

Animals↗

Reversible acute renal failure in the nephrotic syndrome with minimal glomerular pathology.

A case of minimal change glomerulonephritis, associated with the nephrotic syndrome and prolonged acute renal failure requiring two months of dialysis, is reported. Complete recovery of renal function occurred, but proteinuria recurred, responding to a course of steroids. Normal renal function without proteinuria has been observed for two years subsequently. The full return of renal function without specific therapy demonstrates that spontaneous recovery is possible in this rare complication of minimal change glomerulonephritis.

Acute Disease↗

Renomedullary antihypertensive function in accelerated (malignant) hypertension. Observations on renomedullary interstitial cells.

The antihypertensive function of the renal medulla was tested on accelerated (malignant) hypertension of the rabbit. A procedure for the development of accelerated hypertension of the rabbit of lethal proportions within 3 wk was established. This procedure consisted of the application of a rigid clip with a fixed and unyielding gap to the left renal artery and removal of the right kidney. Three additional manipulations, other than simple nephrectomy, were performed on the right kidney after application of the rigid clip to the left renal artery. These were: (a) a sham operation, (b) removal of the kidney and separation of the renal cortex and its autotransplantation in a fragmented state, and (c) removal of the kidney and separation of the renal medulla and its autotransplantation in a fragmented state. After the sham-operated kidney and autotransplanted renal medulla, the standardized accelerated hypertension did not develop, whereas after autotransplanted renal cortex it did. After a period of protection against accelerated hypertension, removal of either the sham-operated kidney or the renomedullary transplants was followed by a prompt rise in arterial pressure and death of the animal. Thus, the antihypertensive action of renomedullary tissue was similar to that of the whole kidney. The main cell type noted in the protective renomedullary transplants had the microscopic characteristics of the lipid-containing interstitial cells. These cells occurred in clusters, often were near capillaries, and appeared hyperplastic. It is suggested that the renomedullary interstitial cell is the most eligible cell for exertion of the renomedullary antihypertensive action. Since vasoactive lipids are extractable from the renal medulla and its interstitial cells, the hypothesis that interstitial cells secrete antihypertensive substance(s) is attractive.

Animals↗

Training needs of staff in Romanian institutions for young children.

In order to make adequate provision for staffing and staff training in leagane (long-term residential care institutions for preschool age children in Romania) a postal survey was conducted in the autumn of 1991 to ascertain the demographic characteristics, job titles and educational attainment of directors and staff, staffing needs and the kinds of positions currently filled, the numbers of directors and staff exposed to continuing education programmes within the last 2 years, and the opinions of directors and staff regarding their most important continuing educational needs. The bulk of the direct care workforce was less than 50 years old. Thirty-four per cent of the direct care staff had less than a high-school education. Sixty-seven per cent of the staff were health professionals or health care workers. There were few psychologists, physical therapists, teachers or social workers. In the last 2 years, directors and other physicians had been mostly exposed to courses in the areas of psycho-social care/management and paediatric medical care. Nurses had attended professional development courses. Infirmiera (nursing assistants) had also attended professional development courses such as those offered by foreign non-governmental organizations on the care of institutionalized children. Educators (teaching assistants) had attended courses in child development and rehabilitation. Directors and staff expressed clear opinions regarding their needs and preferences for additional training.

Adolescent↗

Recovery of Salmonella from shell eggs.

A preenrichment procedure and a direct selective enrichment procedure were compared for recovery of Salmonella artificially inoculated into liquid whole egg, egg yolk, and egg albumen. For liquid whole egg and egg yolk, the 2 procedures were comparable. With egg albumen, however, preenrichment in lactose broth gave significantly higher recoveries than did direct selective enrichment in either selenite cystine or tetrathlonate broths. The lactose preenrichment procedure was used to determine the survival of S. enteritidis in egg yolk and egg albumen over a period of 7 days. As shown by most probably number determinations, counts of S. enteritidis inoculated into egg albumen decreased by 3 log units, whereas those in egg yolk did not change significantly. It is recommended, therefore, that only the egg yolk be examined for this pathogen. In a comparison of 5 different preenrichment media (lactose broth, brain heart infusion broth, trypticase soy broth, buffered peptone water, and nutrient broth), lactose broth was somewhat less productive than the other 4 media for the recovery of Salmonella from egg yolks. Trypticase soy broth gave the highest recovery.

Culture Media↗