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Biomedical subjects

N A Shepherd

Publications and source records attributed to N A Shepherd.

At least 37 records · Page 2Linked to original sources
PubMed2000

Misplacement of dysplastic epithelium in Peutz-Jeghers Polyps: the ultimate diagnostic pitfall?

Peutz-Jeghers syndrome is characterized by multiple polyps throughout the gastrointestinal tract in association with mucocutaneous pigmentation. Small bowel polyps in the syndrome may exhibit epithelial misplacement, into the submucosa, the muscularis propria, and even the subserosa. The authors demonstrate two patients in whom there is also misplacement of dysplastic epithelium into the submucosa and muscularis propria of the small bowel. Epithelial misplacement is recognized to mimic invasive malignancy. Such mimicry is heightened substantially when the misplaced epithelium is dysplastic. Correct interpretation of the histologic changes is aided by the use of special stains, which demonstrate the associated lamina propria and the lack of a desmoplastic response, and immunohistochemistry, which shows that the misplaced dysplastic epithelium is accompanied by non-neoplastic mucosa. There is an increased prevalence of gastrointestinal malignancy in Peutz-Jeghers syndrome. However, the presence of perplexing histologic features, caused by epithelial misplacement, especially when some of that epithelium is dysplastic, in small bowel polyps at least has the potential for the overdiagnosis of malignancy in the syndrome.

Adult↗
PubMed1999

Apoptotic and proliferative activity in the neoplastic progression of Barrett's oesophagus: a comparative study.

The balance between proliferation and apoptosis within a tissue is important in controlling its overall growth. When either or both are altered, uncontrolled cell proliferation can contribute to cancer. The aim of this study was to investigate apoptosis and proliferation in the progression from Barrett's oesophagus to adenocarcinoma. Fifty-one paraffin sections of Barrett's mucosa with both intestinal and gastric-type Barrett's mucosa, dysplasia, and adenocarcinoma, from 28 patients, were examined for apoptosis using haematoxylin and eosin (H&E)-stained sections counterstained immunohistochemically with CD45 to distinguish leucocytes from apoptotic bodies. Proliferation was detected by immunohistochemistry using the MIB-1 (Ki-67) antibody. There was an increase in proliferation in dysplastic and carcinomatous tissue compared with metaplastic tissue (p=0.0001). In dysplasia, proliferation was distributed throughout the basal-luminal axis, whereas in metaplasia, cell division was compartmentalized to the lower crypt (p<0.001). Conversely, there was a decrease in apoptosis in the upper crypt and luminal surface in dysplasia and adenocarcinoma compared with metaplasia (p<0.0008). There was a significant increase in apoptotic activity in intestinal-type Barrett's mucosa compared with gastric-type. There was a highly significant increase in the glandular proliferation to apoptosis ratio (GPAR) in the progression of metaplasia to dysplasia to adenocarcinoma (p=0.001). The shift in the GPAR in the progression of neoplastic change suggests that it may be a useful and sensitive marker of neoplastic change in Barrett's oesophagus, especially if the assessment of both apoptotic and proliferative activity in the mucosa can be made easier by more sophisticated technical methods.

Adenocarcinoma↗
PubMed1999

Regression of columnar-lined (Barrett's) oesophagus with omeprazole 40 mg daily: results of 5 years of continuous therapy.

BACKGROUND: We have previously reported the effect of 2 years of omeprazole 40 mg daily on columnar-lined (Barrett's) oesophagus (CLO). AIMS: In the present study, follow-up has been extended to 5 years to assess the macroscopic and microscopic effects of continuing therapy. PATIENTS AND METHODS: The 23 patients have been followed for up to a further 3 years. Endoscopy with multiple biopsies was performed at the end of years 3, 4 and 5. RESULTS: Although there had been a statistically significant regression in the length of CLO after 2 years, there was no overall further measurable change after 5 years. However, one patient showed complete macroscopic and microscopic regression. The number and size of macroscopic squamous islands within the CLO continued to increase, and there was a further increase in microscopic squamous re-epithelialization of surface mucosa, gland ducts and Barrett's gland tissue. Low-grade dysplasia was found consistently in one patient in biopsies taken up to the end of year 3 but it could not be detected thereafter. CONCLUSIONS: Omeprazole 40 mg daily appears to have beneficial effects on CLO, although it rarely induces a complete regression. Whether the benefits will reduce the risk of malignant transformation is unknown.

Aged↗
PubMed1998

The histopathology of treated Barrett's esophagus: squamous reepithelialization after acid suppression and laser and photodynamic therapy.

Columnar metaplasia of the lower esophageal epithelium (Barrett's esophagus) occurs in response to acid reflux, and its most important long-term complication is malignancy. In view of this, techniques are being explored for the eradication of Barrett's esophagus, and histopathologists will increasingly be required to assess response to these therapies in esophageal biopsy samples. The histopathologic features before and after treatment were studied in biopsy samples from 16 patients receiving omeprazole only, 10 treated by KTP laser photoablation, and five who underwent photodynamic therapy. All the treatment modalities resulted in histologic changes with at least partial squamous reepithelialization of the metaplastic columnar epithelium. The histologic findings suggest three main mechanisms for this: encroachment of adjacent squamous epithelium at the squamocolumnar junction, extension of epithelium from the submucosal gland duct to form squamous islands, and squamous metaplasia within the Barrett's columnar mucosa itself. The latter mechanism implies the existence of pluripotential stem cells within Barrett's mucosa. A relatively common finding was residual glandular mucosa, nonneoplastic and dysplastic, beneath squamous epithelium indicating the requirement for histologic confirmation of endoscopically suspected complete squamous reepithelialization with sufficiently deep biopsies.

Aged↗
PubMed1997

The prognostic importance of peritoneal involvement in colonic cancer: a prospective evaluation.

BACKGROUND & AIMS: Prognostic parameters specific to the colon have been somewhat neglected compared with the rectum. This study was instituted to assess the influence of local peritoneal involvement (LPI) on pelvic and intraperitoneal recurrence and prognosis in an unselected, prospective series of colonic cancer resections. METHODS: Meticulous examination of 412 resections included evaluation of the relation of the tumor to the peritoneal surface. Histological assessment was as follows: 1, peritoneal involvement absent (81 resections, 20%); 2, inflammatory reaction with tumor close but not present at the surface (89 resections, 22%); 3, peritoneal surface unequivocally infiltrated (112 resections, 27%); and 4, peritoneal involvement with ulceration and tumor cells lying apparently free in the peritoneum (130 resections, 32%). RESULTS: LPI showed strong independent prognostic influence in both curative surgery groups and in all patients. In multivariate analysis in curative surgery, LPI was the most powerful prognostic indicator. It was significantly associated with palliative surgery, extent of local spread, and mucinous subtype and predicted cases with subsequent intraperitoneal recurrence and/or persistence. CONCLUSIONS: LPI is a common event in colonic cancer and is a consistent predictor of subsequent intraperitoneal recurrence. It is an important independent pathological prognostic parameter and may supersede other parameters in current usage in colonic cancer prognosis.

Adult↗
PubMed1997

p53 and Rb1 protein expression: are they prognostically useful in colorectal cancer?

The expression of the p53 and Rb1 proteins was examined in an unselected consecutive series of 250 primary operable colorectal carcinomas with a mean follow-up of 4.3 years (range 43-77 months). The overall cancer-specific mortality was 34.8%, with 87 cancer deaths and 35 deaths as the result of other causes. Expression of p53 protein was identified in 152 of 250 (60.8%) cases, with expression of Rb1 protein in 207 of 250 (82.8%) cases. There was no association of p53 or Rb protein expression with patient age, sex, tumour site, tumour size, tumour type, tumour grade, peritumoral fibrosis, tumour lymphocytic infiltrate, nature of the tumour margin, extramural vascular invasion, number of lymph nodes or high apical lymph node involved or local peritoneal infiltration by tumour, Dukes' stage or Jass group. There was no difference in overall survival or recurrence-free survival for those cases that showed p53 expression or Rb1 protein expression compared with those cases showing absence of p53 or Rb1 protein expression, although patients with tumours showing aberrant (reduced) Rb1 protein expression demonstrated shorter recurrence-free survival and overall survival. The effect of 'aberrant' Rb1 protein expression and shorter recurrence-free and overall survival did not, however, achieve independent statistical significance. The results from this study would suggest that expression of p53 and Rb1 proteins does not appear be useful in determining the prognosis of operable colorectal cancer.

Adult↗
PubMed1997

Gastrointestinal tumour masses due to multiple myeloma: a pathological mimic of malignant lymphoma.

AIMS: To describe and evaluate two cases of gastrointestinal involvement by multiple myeloma. METHODS AND RESULTS: Clinical details were obtained from patients records and routine histopathological sections were correlated with haematological and immunohistochemical investigations. As shown in the accompanying illustrations, myeloma manifests as large, atypical, non-cohesive cells which may mimic high-grade lymphoma. CONCLUSIONS: Extraskeletal spread of multiple myeloma occurs more frequently than is currently recognized, but clinical involvement of gut is rarely reported. Gut involvement may occur soon after initial diagnosis of myeloma and may be of serious clinical consequence. Histologically, it may mimic high-grade lymphoma. Failure to recognize myelomatous involvement of gut may result in inappropriate surgery or oncological therapy.

Aged↗
PubMed1997

Photothermal laser ablation of Barrett's oesophagus: endoscopic and histological evidence of squamous re-epithelialisation.

BACKGROUND: Barrett's oesophagus is acquired by severe gastro-oesophageal reflux and is a premalignant condition. Acid suppression or anti-reflux surgery alone do not cause significant regression of the metaplastic mucosa nor reduce the malignant potential. Recent reports have suggested that the combination of mucosal ablation with acid suppression may result in squamous regeneration. AIMS: To destroy Barrett's mucosa by thermal ablation (in the setting of acid suppression) and so induce squamous regeneration. PATIENTS: Sixteen patients with non-dysplastic Barrett's oesophagus were recruited from a surveillance programme. All had been on a proton pump inhibitor. METHODS: At intervals, non-circumferential areas of columnar mucosa were ablated using the KTP laser. Acid suppression was obtained with 40 mg omeprazole daily. Multiple biopsy specimens were obtained for histological examination from ablated areas. RESULTS: Ablation of all areas of glandular mucosa resulted in squamous regeneration. The number of treatments required depended on the length of the Barrett's segment. In 11 patients there was evidence of squamous regeneration over remaining Barrett's glands (in some of the post-treatment biopsy specimens) whilst in nine patients squamous metaplasia was seen within Barrett's glands. CONCLUSION: Mucosal ablation of Barrett's oesophagus by laser, in the setting of acid suppression, results in squamous regeneration (though some burying of Barrett's glands did occur).

Adult↗
PubMed1997

Gastric cancer below the age of 55: implications for screening patients with uncomplicated dyspepsia.

AIMS: To test the hypothesis that gastric cancer presenting with uncomplicated dyspepsia is rare below the age of 55. PATIENTS AND METHODS: The area studied was the postcode defined catchment area of a district general hospital (Gloucestershire Royal) serving a population of 280,500. An open access endoscopy service has been available in this district for more than 17 years. All cases of gastric cancer during a seven year period (1986-92) were drawn from the local pathology database. The database of the neighbouring hospital and the South West Cancer Registry were searched for missed cases from the postcoded area. Hospital and general practitioner records were retrospectively reviewed with respect to duration of symptoms, and previous consultation and investigation for dyspepsia; and alarming symptoms and signs suggestive of underlying malignancy (unexplained recent weight loss, dysphagia, haematemesis or melaena, anaemia, previous gastric surgery, palpable mass, and perforation). RESULTS: Twenty five of 319 cases of gastric cancer detected during the seven year period were aged less than 55. Twenty four of these 25 patients presented with one or more suspicious symptoms or signs. Only one patient (4%) aged less than 55 presented with uncomplicated dyspepsia. In two patients there was a delay in diagnosis of more than six months after first presenting to the general practitioner. Both these patients had significant symptoms at presentation. CONCLUSION: Gastric cancer is rare below the of 55 (7.8% of all cases) and, even in the presence of established open access endoscopy, presents with suspicious symptoms or signs in 96% of cases. The age limit for screening uncomplicated dyspepsia can be raised safely to 55.

Age Distribution↗
PubMed1996

Eradication of high-grade dysplasia in columnar-lined (Barrett's) oesophagus by photodynamic therapy with endogenously generated protoporphyrin IX.

BACKGROUND: High-grade dysplasia in columnar-lined (Barrett's) oesophagus presents a difficult therapeutic dilemma. Choices for management are endoscopic surveillance to detect a cancer or oesophagectomy. One carries the risk of missing invasive cancer, the other carries worrying morbidity and mortality. We have used endoscopic photodynamic therapy to eradicate high-grade dysplasia. METHODS: After the oral administration of 5-aminolaevulinic acid, the accumulation of the endogenously generated photosensitiser protoporphyrin IX was measured with quantitative fluorescence microscopy. Five patients with histologically confirmed high-grade dysplasia were treated with endoscopic photodynamic therapy with 630 nm laser light to activate the photosensitiser. FINDINGS: Protoporphyrin IX accumulated in the dysplastic epithelium rather than the adjacent stroma. Selective necrosis of the dysplastic epithelium in columnar-lined oesophagus occurred after light activation. High-grade dysplasia was eradicated in all patients and squamous regeneration occurred after acid suppression with a protonpump inhibitor. There were no complications or recurrence of dysplasia after 26-44 months' endoscopic and histological follow-up. In two cases we saw non-dysplastic Barrett's epithelium underneath regenerative squamous mucosa. INTERPRETATION: High-grade dysplasia in columnar-lined oesophagus can be eradicated by endoscopic photodynamic therapy with endogenously generated PpIX. Remaining non-dysplastic Barrett's epithelium will require surveillance, but overall the technique has interrupted or delayed the worsening of the dysplasia through to carcinoma. This technique may prevent the need for surgical excision in these patients.

Aged↗
PubMed1996

Is saliva serology useful for the diagnosis of Helicobacter pylori?

BACKGROUND: The Cortecs Diagnostics Helisal Assay test is a quantitative immunoassay for salivary IgG antibodies against Helicobacter pylori. Saliva can be obtained simply with the kit in the general practitioners surgery. AIMS: To compare the new saliva serological test for H pylori with 'gold standard' evidence of H pylori infection (antral biopsy specimens for histology, culture, and urease test) and a new serum serological test. PATIENTS: Eighty six unselected dyspeptic patients undergoing endoscopy. METHODS: Each patient provided saliva and serum before endoscopy for H pylori serology, which was compared against 'gold standard' evidence of infection. RESULTS: Thirty two patients were H pylori positive by the 'gold standard' tests. At a cut off value of 0.15 EU/ml the saliva test had a sensitivity of 88% and a specificity of 71%, with a negative predictive value of 90%. If patients who were taking omeprazole or had recent antibiotics are excluded, the sensitivity is unchanged but the specificity increases to 79%. The serum test had a similar sensitivity of 85% but better specificity of 78%. CONCLUSION: Serum testing remains the best serological test for H pylori in the hospital setting. Saliva testing may have a role in epidemiological studies and in screening dyspeptic patients in general practice, especially in children in whom venesection is more difficult.

Antibodies, Bacterial↗