Search PubMed⌕ Search

Biomedical subjects

J Spencer

Publications and source records attributed to J Spencer.

At least 307 records · Page 17Linked to original sources
PubMed1987

Malignant lymphoma of mucosa-associated lymphoid tissue.

Lymphomas of the gastrointestinal tract, salivary glands, lung and thyroid are grouped together as tumours arising in mucosa-associated lymphoid tissue. The great majority of them are of B-cell origin but distinctive T-cell lymphomas are also recognized in the gastrointestinal tract. These lymphomas tend to remain localized for prolonged periods but, whereas the B-cell group respond favourably to local therapy, the T-cell group are associated with severe morbidity and their overall prognosis is extremely poor. Accepted histological classifications of non-Hodgkin's lymphomas are difficult to apply to these tumours. In this paper their morphological features are reviewed; recent findings based on immunohistochemistry and DNA analysis are presented; and the biological behaviour of these tumours is discussed insofar as they offer insight into mucosal immunological mechanisms.

B-Lymphocytes↗
PubMed1987

Specialist investigation of obscure gastrointestinal bleeding.

The investigation and treatment of 131 patients with 'obscure' gastrointestinal bleeding has been reviewed. One hundred and six patients were assessed electively for recurrent haemorrhage, 25 presented as emergencies. The major presenting feature was melaena (55 patients), anaemia (35), rectal bleeding (34), haematemesis (six) and ileostomy bleeding (one). The lesions responsible for haemorrhage were colonic angiodysplasia (52 patients), small bowel vascular anomalies (16), Meckel's diverticula (nine), small bowel smooth muscle tumours (seven), gastric vascular anomalies (four), chronic pancreatitis (three), colonic diverticular disease (three) and 16 other miscellaneous lesions. No lesion was found in 21 cases. Lesions were first shown by visceral angiography (69 patients), at laparotomy (23), on endoscopy (11), on gastrointestinal contrast radiological studies (four), and at ERCP (three). Lesions which were undetectable at operation increased markedly with age (p less than 0.0001). Expert visceral angiography is strongly recommended before surgery in patients over 45 years of age and after laparotomy when no cause has been found. Exploratory laparotomy is recommended at an early stage for younger patients, and for older patients after non-diagnostic angiography.

Adolescent↗
PubMed1987

Splenectomy in advanced chronic lymphocytic leukaemia.

A group of 20 patients with stage C chronic lymphocytic leukaemia (CLL) and marked splenomegaly refractory to anti-leukaemia treatment was evaluated in relation to clinical course and survival after splenectomy, and compared with a control group of non-splenectomised CLL patients at the same disease stage. Patients in the former group showed a significant clinical improvement after splenectomy, being reallocated to, and maintained in, stages A (85%) or B (10%) for more than 24 months. Ten patients were still alive 24-135 months after splenectomy. The 10 deaths observed in the group of splenectomised patients occurred 4-69 months after surgery, due to disease progression and/or immunoblastic transformation (4 cases), infectious complications (3 cases) and unrelated causes (3 cases). Analysis of survival from diagnosis showed a significantly better prognosis for patients in the splenectomised group (median survival 10 years, as compared to 3.5 years for the control group). The same statistical difference, p less than 0.001, with better life expectancy for splenectomised patients, was observed when the survival was calculated from the time of progression to stage C. These results strongly suggest a beneficial role for splenectomy in advanced CLL with significant splenomegaly, when the accumulation of resistant lymphoid cells precludes an adequate control of the disease by conventional forms of treatment.

Evaluation Studies as Topic↗
PubMed1987

Tricuspid stenosis in prosthetic valve endocarditis. Diagnosis by Doppler echocardiography.

Valvular stenosis is an uncommon finding in bacterial endocarditis involving native cardiac valves. Prosthetic valve endocarditis, however, is more commonly associated with obstruction. Bioprosthetic cardiac valves may be particularly prone to this complication. A case of bioprosthetic tricuspid valve endocarditis with stenosis diagnosed by Doppler echocardiography and confirmed by operative findings is presented.

Adult↗
PubMed1987

Heterogeneity of non-lymphoid cells expressing HLA-D region antigens in human fetal gut.

Human fetal ileum contains an abundance of cells expressing HLA-D region (HLA-DR) antigens. In this study we characterized the HLA-DR positive cellular infiltrate in fetal ileum using a panel of monoclonal antibodies against cells of the macrophage/monocyte lineage. As well as anti-HLA-DR, the whole infiltrate was recognized by three of the antibodies in the panel studied: RFD1, reported to be an antibody to 'dendritic cells', leu3a which recognizes CD4 (an antigen expressed on helper/inducer T cells and macrophages), and PD7/26 which recognizes the leukocyte common antigen. The macrophage specific antibodies RFD7 and 3.9 stained fewer cells than the anti-HLA-DR. By sequential staining it was clear that most of the RFD7 positive macrophages in the fetal gut lamina propria were not recognized by 3.9 which is a broad specificity antimacrophage antibody in adult tissue. In contrast to this, more of the macrophages within the Peyer's patches of the fetal gut were recognized by 3.9 than by RFD7. In fetal lamina propria not all of the HLA-D region positive cells expressed macrophage markers and some expressed both markers associated with macrophages and 'dendritic' cells. Macrophages with different surface phenotypes were differentially distributed between the lamina propria and the primitive Peyer's patches; RFD7+, 3.9- macrophages were concentrated in the lamina propria whereas RFD7-, 3.9+ macrophages were abundant in Peyer's patches. Within the Peyer's patch lymphoid tissue RFD7+, 3.9- cells were present in the T cell zone whereas RFD7-, 3.9+ cells were concentrated in the dome region as they are in the adult. This suggests that functional heterogeneity of organized macrophage populations may occur in fetal ileum which is free of dietary and bacterial antigens.

Fetus↗
PubMed1987

Selective visceral angiography in obscure postoperative gastrointestinal bleeding.

Postoperative gastrointestinal bleeding may be difficult to diagnose and treat. Selective visceral angiography localised the bleeding site in seven out of ten episodes of obscure postoperative gastrointestinal haemorrhage, and in two cases radiological embolisation was used successfully to control the bleeding. Angiography, preferably during an episode of haemorrhage, is recommended whenever possible for patients with undiagnosed postoperative gastrointestinal bleeding.

Aged↗
PubMed1987

Remaining indications for vagotomy with drainage or antrectomy in duodenal ulcer.

Proximal gastric vagotomy (PGV) consists of denervation of the body and fundus of the stomach, the antral nerve supply being left intact. It has a low operative morbidity and mortality and there are few postvagotomy side effects. However, the recurrent ulcer rate may be higher than with other operations for duodenal ulcer. Nevertheless it is usually easier to treat post-PGV recurrence than the complications of other gastric acid lowering operations. This study defines those patients in whom we have not performed a PGV. Of 110 operations for duodenal ulcer since 1980, 70 were PGVs while 40 consisted of truncal or selective vagotomy combined either with a drainage procedure or antrectomy. It is our practice not to perform a PGV in those patients with prepyloric ulcers, pyloric stenosis, bleeding or perforated ulcers and recurrent ulcers.

Adult↗
PubMed1987

Observations on community screening for alcohol problems: a pilot project to assess the feasibility of identifying heavy drinkers in a community setting.

Using a standard computerised alcohol screening questionnaire including the CAGE and SMAST instruments, 122 subjects in a suburban shopping centre in Perth, Western Australia, were screened in an attempt to estimate the prevalence of hazardous drinking and to investigate knowledge of and attitudes to safe and heavy alcohol consumption.

Alcohol Drinking↗
PubMed1986

Tests of association of immunoglobulin allotype genes and viral oncogenesis in chickens.

Chickens from Regional Poultry Research Laboratory (RPRL) inbred line 6(3) are resistant to virally-induced Marek's disease (MD) and lymphoid leukosis (LL) and are relatively strong regressors of virally-induced Rous sarcomas. In contrast, RPRL line 100 chickens are highly susceptible to MD and LL and are weaker regressors of Rous sarcomas than line 6(3). RPRL lines 100 and 6(3) differ for alleles at the IgG-1 (G-1) allotype locus, but have identical IgM-1 (M-1) allotype alleles. To test the possible association of the G-1 locus with variations in resistance to virally-induced tumors, homozygous and heterozygous genotypes among F3 crosses were infected. F3 chickens with different G-1 types were comparable in their resistance to MD tumors following inoculation with the JM strain of the MD virus, and for their ability to regress Rous sarcoma tumors induced by the Rous sarcoma virus (RSV) RAV-1. However, following RAV-1 virus infection a smaller proportion of G-1a/G-1aF3 or F4 birds developed LL tumors than G-1a/G-1e and G-1e/G-1e birds. Genes determining immunoglobulin heavy chains were therefore associated with a recessive resistance to B-cell lymphomagenesis in chickens.

Animals↗
PubMed1986

Granulocyte migration in uncomplicated intestinal anastomosis in man.

We have investigated the presence, duration, and clinical significance of granulocyte accumulation, using indium-111 granulocyte scanning, in patients following uncomplicated intestinal anastomosis. Eight patients underwent intestinal resection and anastomosis (right hemicolectomy, 5; sigmoid colectomy, 2; ileal resection, 1) for carcinoma, angiodysplasia, or perforation. All patients had an uneventful postoperative course, with no evidence of any leakage or infection. Indium-111 granulocyte scan and abdominal ultrasound were performed 7-20 days (12 +/- 4.7 means +/- SD) following surgery. Indium-111 granulocyte scan showed the presence of labeled granulocytes at the site of anastomosis in all patients. In three of eight, cells subsequently passed into the lumen of the bowel. In contrast, granulocytes were not visualized along the abdominal incision. Thus, in contrast to skin wounds, granulocytes continue migrating into the intestinal wall in areas of anastomosis for at least up to 20 days following surgical trauma. They may play a significant role both in healing the anastomosis and in preventing systemic bacterial infection. Moreover, indium-111 granulocyte scans following intestinal surgery should be interpreted with care, and the presence of labeled granulocytes around anastomoses does not necessarily indicate abscess formation.

Aged↗
PubMed1986

A comparative study of the gut-associated lymphoid tissue of primates and rodents.

Previous studies have suggested that the gut-associated lymphoid tissue (GALT) of man is distinct from that of laboratory animals, but it is not clear whether this is due to environmental or true species difference. We have made a comparative study of rats and baboons because, like rats, baboons are herbivorous and relatively unhygienic but they are phylogenetically much more closely related to man. The Peyer's patches of rats, baboons and man are morphologically very similar in all three species but phenotypically those of man and baboons are different to those of rats. Cells with irregular nuclei ("centrocyte-like" cells) surround the mantle zone in all three species. While these cells express surface IgD and IgM in rats, in man and baboons they express surface IgM or IgA. A population of immunoblasts which express cytoplasmic IgA are present in association with the high endothelial venules of rat Peyer's patches. These cells are not present to the same extent in man or baboons. This suggests that the events between the antigenic stimulation of Peyer's patches and the ultimate seeding of the lamina propria with IgA secreting plasma cells may be different in rodents and primates.

Animals↗
PubMed1986

Primary B-cell gastric lymphoma.

A detailed clinicopathologic and immunocytochemical study was performed in 12 cases of primary gastric lymphoma in which fresh tissue was available for study. The patients ranged in age from 18 to 76 years; persistent epigastric symptoms had led to endoscopy (often on multiple occasions) and biopsy in each case. The endoscopic appearances rarely suggested malignancy. The histologic appearances of the gastrectomy specimens covered a spectrum, from changes normally considered characteristic of "pseudolymphoma" to those of florid malignant lymphoma, with evidence of extragastric spread in four cases. Formation of follicular centers characterized each case, and diffuse interfollicular infiltrates of centrocyte-like cells were also present. Plasma cells were also consistently present. Immunocytochemical studies showed the same light chain restriction of follicular center cells and centrocyte-like cells in all cases and of plasma cells in five cases. Follicular center cells and centrocyte-like cells were otherwise phenotypically distinct. This study yielded criteria for the objective diagnosis of gastric B-cell lymphoma in biopsy and resection specimens; the results suggest that the term pseudolymphoma should no longer be used.

Adolescent↗
PubMed1986

Expression of HLA-DR antigens on epithelium associated with lymphoid tissue in the human gastrointestinal tract.

Mucosa from human stomach, terminal ileum, appendix, and colon was studied for epithelial HLA-DR expression using an immunoperoxidase technique with a monoclonal antibody that detects HLA-DR antigens in paraffin embedded tissues. Expression of HLA-DR by epithelial cells was studied with particular reference to the effect of adjacent lymphoid tissue or surrounding chronic inflammation. In the stomach, epithelial HLA-DR appeared to be induced by chronic inflammation. Where lymphoid nodules were present only that epithelium directly adjacent to the lymphoid tissue expressed HLA-DR. Expression was independent of cell type. Epithelium adjacent to normal lymphoid tissue in the terminal ileum, appendix, and colon also expressed HLA-DR, the relationship between expression and proximity to lymphoid tissue being remarkably precise. Expression of HLA-DR by gastrointestinal epithelium appears to be an effect of adjacent lymphocytes, whether part of an inflammatory response or normal tissue. This must be taken into account when assessing HLA-DR expression by gastrointestinal epithelium.

Appendix↗