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Biomedical subjects

D O Hourihane

Publications and source records attributed to D O Hourihane.

At least 19 recordsLinked to original sources
PubMed1992

DNA quantification of squamous cell carcinoma of the oesophagus by flow cytometry and cytophotometric image analysis using formalin fixed paraffin embedded tissue.

This is the first comparative study of DNA quantification of oesophageal squamous cell carcinoma by flow cytometry (FCM) and image cytometry (ICM) using formalin fixed paraffin embedded tissue. The potential advantages of ICM include the identification of a reliable control cell population; avoidance of non-tumour stromal and inflammatory cell nuclei, nuclear fragments, degenerate cell nuclei and doublets, triplets etc., which are not possible with FCM using archival tissue. Twenty-eight cases, all of the same stage (stage 2a) and similar grade (well or moderately differentiated) were analysed. The cases were separated into two groups, those that had succumbed to tumour in less than 18 months (group A) and those that were tumour free at least 18 months post-resection (group B). Using ICM all 28 tumours yielded interpretable histograms by comparison to 25 of 28 using FCM. Aneuploidy was identified in 100% of cases in group A using ICM (in comparison to 73% by FCM) and in 73% of group B using ICM (in comparison to 44% by FCM). Any tumour aneuploid by FCM was also aneuploid by ICM. Nine cases aneuploid by ICM were euploid by FCM. The mean 5C exceeding rate (% of cells whose nuclei contain a DNA mass equivalent to > 5 sets of 23 chromosomes) was 21% in group A and 14% in group B (P < 0.01). Euploidy was confined to tumours of those patients disease free for more than 18 months. The conclusions of this study are that: firstly, ICM is superior in its yield of interpretable histograms to FCM using formalin fixed paraffin embedded tissue; secondly, ICM is more sensitive in the identification of aneuploid stemlines than FCM; and thirdly, euploid tumours (as detected by ICM) appear to have a better prognosis than aneuploid tumours of similar stage and grade.

Adult↗
PubMed1992

Colo-rectal carcinoma 1975 and 1990: no improvement in the stage of disease at resection.

There is no overall consensus as to what screening patterns should be adopted for individuals of average risk for colo-rectal carcinoma. The single most important prognostic factor in survival is the stage of the colo-rectal neoplasm at the time of resection. Consequently significant resources have been directed to early detection while the disease is at a curative stage. To assess the impact of widespread availability of faecal occult blood testing and large bowel endoscopy we prospectively examined all large intestine specimens resected for carcinoma in 1990 and compared them with specimens resected for colonic carcinoma in 1975. We excluded adenomatous polyps with malignant change which had been treated by snaring at colonoscopy, without subsequent colectomy, as their precise Duke's staging was so difficult. In any event, their numbers were small (> 5 in 1990). Our study shows that despite the resources targeted at early diagnosis of colo-rectal carcinoma resection of tumours at a prognostically favourable stage has not been improved in the 25 years since 1975.

Adenocarcinoma↗
PubMed1992

DNA ploidy in squamous oesophageal carcinoma.

The role of DNA ploidy in the management of oesophageal carcinoma is unclear. Most studies have employed flow cytometry (FC) for DNA analysis but some have used image analysis (IA) of tissue sections. In this study aneuploidy rates in stage IIa squamous tumours were determined by both FC and IA of cell suspensions and results were compared with outcome in two patient subgroups. Group 1 (n = 15) were patients who died from tumour recurrence within 1 year of surgery while Group 2 (n = 21) were patients who survived tumour free for at least 1 year. Aneuploidy rates differed significantly between techniques; 29 of 36 tumours (81%) were aneuploid by IA compared with 19 of 34 (56%) by FC (P < 0.05). Aneuploidy rates differed significantly between groups 1 and 2 as determined by FC (79%) versus 40%) (P < 0.05) but not by IA (93% versus 71%) (P = ns). Euploid status was a good prognostic indicator; 6 of 7 (86%) patients with euploid tumours by IA and 12 of 15 (80%) by FC (P < 0.05) survived more than 1 year. The sensitivity and specificity of euploidy was 93% and 28.6% for IA compared with 78.6% and 60% for FC. Since 33 (92%) of these tumours exhibited a marked peritumoral desmoplastic or chronic inflammatory reaction IA, being more sensitive to subtle nuclear change, may be a more appropriate technique than FC for evaluation of the role of ploidy in such tumours.

Adult↗
PubMed1991

Bleeding due to colorectal atheroembolism. Diagnosis by biopsy of adenomatous polyps or of ischemic ulcer.

Atheroembolism, although not infrequent at autopsy, is seldom identified in life, when it may present as a multisystem disease involving lower limbs, kidney, and gastrointestinal (GI) tract. Diagnosis of isolated GI involvement usually requires examination of surgically resected tissue, because recognition by endoscopic GI biopsy is exceptional. We diagnosed colorectal atheroembolism by biopsy in four patients. All were elderly (68-80 years old) and had generalized atheroma, including aortic aneurysms. Three patients had sudden onset of frank rectal bleeding with clots or bloody diarrhea, lower abdominal discomfort, and tenderness. Biopsy revealed atheroemboli in a rectal ischemic ulcer and in colorectal adenomatous polyps. In all three, disease resolved on conservative management and did not recur during the period of follow-up. In the fourth patient, asymptomatic atheroembolism was identified in an adenomatous polyp at the splenic flexure. Extraintestinal disease attributable to atheroembolism was not present in any of the patients. Atheroembolism with manifestations confined to the colon may sometimes be diagnosed by biopsy, appears to be more frequent than currently recognized, and may present a diagnostic challenge as a self-limited episode of rectal bleeding.

Aged↗
PubMed1991

Histologic characteristics of carotid artery plaque.

Carotid plaque characteristics associated with the production of symptoms were identified with quantification of carotid plaque constituents in high-grade stenotic asymptomatic (n = 8) and symptomatic (n = 44) plaques. Asymptomatic plaques contained significantly more fibrous/collagen material (88%) than symptomatic plaques (66%) (p less than 0.05). Hemorrhage constituted 2% and 1% of asymptomatic and symptomatic plaques, respectively. The predominant nonfibrous material was a pink amorphous material mixed with cholesterol, which composed 7% of asymptomatic and 27% of symptomatic plaques (p less than 0.05). No relationship was found between plaque composition and the number of ipsilateral ischemic neurologic events, nor was there evidence of a healing process. B-mode ultrasound scanning had a sensitivity of 94% in identifying plaque with greater than 80% fibrous content. We believe that plaque composition may be a useful discriminating factor in selecting asymptomatic patients for carotid endarterectomy.

Arteriosclerosis↗
PubMed1990

"Haemorrhagic" carotid plaque does not contain haemorrhage.

The presence of haemorrhage in carotid bifurcation atheromatous plaques is widely believed to be associated with the production of ischaemic neurological events. This study set out to characterise plaque composition in symptomatic (SYM) and asymptomatic (ASYM) patients and to identify, if possible, the origin of intra-plaque haemorrhage. Fifty-nine plaques (50 SYM and 9 ASYM) were serially sectioned and examined for haemorrhage, haemosiderin, fibrin, cholesterol and collagen. Immunoperoxidase and electron microscopy studies were carried out on sections from five plaques in order to identify blood breakdown products. Intra-plaque haemorrhage was identified in 40 (68%) plaques and was similar in SYM and ASYM plaques. In only one did it constitute more than 15% of plaque content, and in the remainder it consisted of small collections of erythrocytes constituting greater than 1% of plaque content in only 21 (35%) plaques. The predominant non-fibrous component was a pink amorphous material mixed with cholesterol. Apart from traces of platelet breakdown products there was no evidence of haemorrhage in this pink material. Plaque roof rupture or ulceration was seen in 39 (66%) and in almost all cases overlay the amorphous/cholesterol material. Blood vessels were identified in 51 87%) plaques but were in close proximity to haemorrhage in only nine (15%).

Arteriosclerosis↗
PubMed1989

Quality assurance programme for necropsies.

One hundred and eight consecutive necropsies were entered into a quality assessment of the necropsy service in this hospital using a previously published American protocol. Our results were similar to those of the American series, with confirmation of the major clinical diagnosis in 75%, but a higher rate of unsuspected diagnosis (44%). Necropsy was helpful in 58% of cases. The presentation of selected cases at a monthly conference on causes of death was valuable in correlating clinical and pathological findings, and in helping integrate both services.

Aged↗
PubMed1987

Histological changes associated with wheat protein antibodies in the absence of villous atrophy.

A retrospective study was conducted to assess the association of alpha-gliadin antibodies with intraepithelial lymphocyte counts. Twelve subjects with apparently normal small intestinal histology and raised alpha-gliadin antibody titres had significantly increased intraepithelial lymphocyte counts (42 (SEM) 5.9) when compared with 16 subjects with normal alpha-gliadin antibody titres (17 (3.2); p less than 0.001). These findings show that in the absence of gross pathology raised alpha-gliadin antibody titres are associated with increased numbers of intraepithelial lymphocytes and may reflect continuous immunological processes in the small intestine.

Antibodies↗
PubMed1974

Coeliac disease during the teenage period: the value of serial serum folate estimations.

A group of teenage coeliac patients has been followed at three monthly intervals in the Outpatient Department to assess their progress and also to monitor their ability to maintain a gluten-free diet. After a follow-up period of four to six years a detailed reassessment was carried out in hospital on 10 patients, only five of whom had persevered with a gluten-free diet. The jejunal mucosal histology of those patients who did not persist with a gluten-free diet remained ;flat' although these patients appeared to have remitted clinically. Those subjects who did persist with a gluten-free regime had a normal or near normal mucosal histology. It was difficult on the basis of clinical, haematological, or biochemical criteria to separate the two groups. The best single assessment of whether these patients were maintaining a gluten-free diet was serial serum folate estimations. It is often extremely difficult to say whether teenage coeliac patients are keeping to their diet unless repeated jejunal biopsies are obtained, and this study suggests that serial serum folate estimations can act as a reasonable criterion of whether subjects are maintaining a gluten-free regime.

Adolescent↗
PubMed1972

Ectopic Enterobius vermicularis.

Enterobius vermicularis (the pinworm) commonly infests the lumen of the intestine but on rare occasions has been found in the wall or in the tissues outside the gastrointestinal tract. Three such patients have been encountered in whom Enterobius vermicularis was found in the wall of the colon, in the retrocaecal tissues, and on the peritoneum. The pathological lesions and their relationship to the clinical features are discussed. A brief review of the literature is given. It is concluded that Enterobius vermicularis can only penetrate the wall of the gastrointestinal tract if this is diseased. Once in the tissues the worms can cause an inflammatory reaction simulating carcinoma and Crohn's disease, and, by perforation of the intestine, cause a generalized peritonitis.

Cecal Diseases↗
PubMed1972

Ischaemic lesions of the alimentary tract.

The clinical and pathological findings in 23 patients with ischaemic lesions of the alimentary tract (ischaemic enterocolitis) are described. These are compared with findings in 13 patients with occlusive thrombosis of the superior mesenteric artery. The pathological features distinguishing the two conditions are discussed. Ischaemic enterocolitis was found to be a relatively common condition (0.6% of necropsies). The occurrence of mucosal fibrosis (a hitherto undescribed feature) has been of help in the biopsy diagnosis of ischaemic lesions of the gut.

Adult↗
PubMed1970

Suppression of erythropoiesis by alcohol.

Serial measurements in alcoholic subjects showed a profound fall of serum iron for three days after withdrawal of alcohol and a reversion of abnormal accumulation of erythroblastic haemosiderin to normal. These findings suggest an interference in normal haem synthesis, most probably by a direct effect.

Adult↗
PubMed1970

Infected infarcts of the testis: a study of 18 cases preceded by pyogenic epididymoorchitis.

Eighteen cases of infected infarcts of the testis are presented, and evidence is put forward that these result from venous occlusions in the epididymis and cord. The venous lesions probably result from thrombosis during the course of an attack of epididymoorchitis. Granulomatous orchitis was present in some part of half of the orchidectomy specimens, and the clinical histories, bacteriological findings, and histological data all suggest that this form of inflammation results from pyogenic infection of the testicle. What the factor is which determines whether the inflammation is granulomatous or not is unknown.

Adult↗