Biomedical subjects

C J O'Brien

Publications and source records attributed to C J O'Brien.

At least 73 records · Page 4Linked to original sources

PubMed1989

Morphologic and immunophenotypic characterization of primary brain lymphomas using paraffin-embedded tissue.

Primary lymphomas of the brain constitute about 1% of all primary intracranial neoplasms, but recent studies suggest an increasing incidence. Most cases are associated with an immunosuppressed state. We reviewed 29 cases of primary brain lymphoma from the Yorkshire Health Authority Region between 1970 and 1988 and found a striking increase in incidence over this period. No overt evidence of immunosuppression was found in any case. All were non-Hodgkin's in type and were classified morphologically using Kiel criteria and immunophenotypically using a panel of antibodies. Cryo-preserved tissue was available in five cases for parallel immunophenotyping. The majority of tumours were high-grade lymphomas together with three of lymphoplasmacytoid type. Thirteen tumours showed a striking pleomorphic morphology with plasmacytoid features. A reactive, predominantly perivascular monomorphic T-cell population was seen in all tumours. Most tumours were of B-cell lineage. No cases of Hodgkin's disease, T-cell or histiocytic lymphoma were present. Light chain restriction was present in only 46% of cases. The results of tumour immunophenotyping on cryostat sections were comparable with those from paraffin blocks. Our study emphasizes the value of a panel of antibodies reactive in paraffin-embedded tissue, allowing simultaneous evaluation of morphology and immunophenotype, and suitable for small biopsies received from stereotactic procedures.

Adolescent↗

PubMed1989

Morphological and immunohistological study of testicular lymphomas.

We have studied normal testis, seminomas and malignant lymphomas of the testis using routine stains and a panel of antibodies directed against lymphoid and basement membrane antigens. The results show that normal testis contains, at most, a minor population of T-lymphocytes: seminomas contain mixed T- and B-cell populations with a predominance of B-lymphocytes; and most primary lymphomas are B-cell tumours of large centroblastic type. Solid testicular lymphomas presenting secondarily to acute lymphoblastic leukaemias showed intact seminiferous tubular basement membranes with predominantly interstitial lymphomatous infiltrates, whereas the tubules in primary cases were over-run by lymphoma cells and basement membranes were disrupted.

Antibodies, Monoclonal↗

PubMed1989

Association between CAM 5.2 and anti-CD1a reactivity in lymph nodes and gastrointestinal tract epithelium.

Immunocytochemical studies, using the antibodies CAM 5.2 and NA1/34 (CD1a), were performed on normal lymphoid tissue and malignant lymphomas. A population of dendritic cells in the paracortex of lymph nodes and in T cell lymphomas reacted with both antibodies. Colocalisation with antibodies was also found in gastrointestinal epithelium. Immune blotting shows that the likely basis of this reactivity is a 12 kilodalton peptide which is recognised by both antibodies. This is almost certainly the beta t peptide which has been described as the light chain of CD1a.

Antibodies, Monoclonal↗

PubMed1988

Total pharyngeal reconstruction using a pectoralis major myocutaneous tunnel.

Total pharyngeal reconstruction was performed using a pectoralis major myocutaneous flap. In this technique, the posterior wall of the neopharynx consists only of the prevertebral tissue, while the flap forms the anterior and lateral walls. The posterior wall heals by reepithelialization of the prevertebral fascia. Clinical experience with seven patients has shown that this technique provides a wide conduit and is not prone to develop stenosis.

Aged↗

PubMed1988

A new approach to the treatment of advanced high-grade non-Hodgkin's lymphoma--intensive two-phase chemotherapy.

A total of 110 patients with high-grade non-Hodgkin's lymphoma (NHL) not previously treated by chemotherapy or by radiotherapy at more than one site of disease underwent a regimen comprising an intensive 6-week initial, induction phase using vincristine, adriamycin, methotrexate, and prednisolone (VAMP) followed by the non-cross-resistant combination cyclophosphamide, etoposide, and vindesine (EEE). The median age of patients was 54 years, the majority having stage IV disease. The median follow-up was 34 months and all patients have completed treatment. The overall complete remission (CR) rate for all patients was 68%. The initial phase of treatment produced a CR rate of 49%. The full regimen was completed by 87 patients, and of these, 66 (76%) achieved CR. Of those achieving CR, 72% were relapse-free, on an actuarial basis, at 2 years. Overall 2-year survival was 53%, with a median survival of 31 months. The survival of older patients and those with lymphoblastic histology was comparable to that of other groups. The survival prospects of patients with stage IV disease was not as good as that of other patients, with a significant trend to shorter survival in patients with more advanced disease. Toxicity was predictable and manageable for both phases of the regimen, although it was more severe for the initial phase. Dose-limiting toxicities were neutropenia and mucositis. This regimen is active in the treatment of advanced high-grade NHL with acceptable toxicity. These results have encouraged us to continue the study of weekly chemotherapy, which we will compare with standard cyclical chemotherapy in a prospective, randomized trial.

Adolescent↗

PubMed1988

Controlled trials of charcoal hemoperfusion and prognostic factors in fulminant hepatic failure.

One hundred thirty-seven patients with fulminant hepatic failure were entered into two controlled trials of charcoal hemoperfusion carried out concurrently. In trial A, 75 patients with grade 3 encephalopathy were randomized to receive 5 or 10 h of hemoperfusion daily. Overall survival rates for the two groups were similar (51.3% vs. 50.0%) as was the frequency of major complications including cerebral edema and renal failure. In trial B, in which 62 patients with established grade 4 encephalopathy on admission were randomized to a no-perfusion group or to have 10 h of hemoperfusion daily, overall survival rates for the two groups were again similar (39.3% and 34.5%, respectively). There was in both trials a significant relationship between survival and etiology quite independent of the use or duration of hemoperfusion. Thus, percentage survival for the acetaminophen-overdose cases was 52.9%, for hepatitis A 66.7%, for hepatitis B 38.9%, for presumed non-A, non-B hepatitis 20%, and for halothane or drug reaction 12.5%. Within the etiologic subgroups survival was also influenced by the three major complications that developed, being inversely related to their frequency and combination, except in the non-A, non-B hepatitis and halothane or drug reaction subgroups, which had a high mortality throughout. In the latter cases particularly, orthotopic liver transplantation merits early consideration and in the group with better "intrinsic" survival (acetaminophen, hepatitis A and B) intensive management of complications (rather than charcoal hemoperfusion) would appear to be of major importance.

Acetaminophen↗

PubMed1988

In vitro effect of TP-1 (a calf thymic extract) on suppressor T-cell function of patients with autoimmune chronic active hepatitis.

Concanavalin A-activated T-lymphocyte suppression of IgG production was found to be significantly impaired in patients with untreated active autoimmune chronic hepatitis when compared to normals or patients with inactive disease. When the dose-response effect of TP-1, a calf thymic extract, on in vitro suppressor cell activity was assessed, lymphocytes from six out of eight patients with previously reduced suppressor cell function showed a significant improvement, while over a similar range the suppressor cell activity of most normal controls declined. These results support the possibility that defective immunoregulation in patients with autoimmune chronic active hepatitis may be related to a deficiency in thymic hormone levels.

Adjuvants, Immunologic↗

PubMed1988

Metastatic Staphylococcus aureus endophthalmitis: a case report.

A case of bilateral metastatic Staphylococcus aureus endophthalmitis is presented. It evolved over a two-week period, causing some diagnostic confusion. Treatment with fusidic acid and benzylpenicillin resulted in the retention of useful vision in one eye and good vision in the other.

Endophthalmitis↗

PubMed1988

Hodgkin's disease: a flow cytometric study.

Flow cytometry was performed on paraffin embedded tissue from 115 cases of Hodgkin's disease. Thirteen (11%) tumours were aneuploid with no significant difference between the histological subgroups. The median proliferative index was 14%, and the highest values were found in the NS2 (16.4%) and lymphocyte depleted (16.0%) subgroups. The difference in proliferative index approached significance when the NS2 subgroup was compared with the NS1 subgroup (p less than or equal to 0.11) and when the lymphocyte depleted and NS2 subgroups combined were compared with the mixed cellularity, lymphocyte predominance, and NS1 subgroups combined (p less than or equal to 0.07). There was a trend towards better survival for patients with aneuploid tumours and those cases with a proliferative index below 15%, but neither of these trends was significant.

Adolescent↗

PubMed1988

Techniques for obtaining differential cell counts from bone marrow trephine biopsy specimens.

Differential cell counts were performed on 200 paired bone marrow aspirates and trephine biopsy specimens to compare the distribution of cell types. Relatively more immature myeloid cells were found in the trephine biopsy specimens and relatively more polymorphs and lymphocytes in the aspirates. Two methods for sampling areas of the trephine biopsy specimens for counting were assessed, and the differences between aspirates and trephine specimens were found to be more consistent when the second, more extensive, sampling method was used. This method also permitted quantitation of some features of bone marrow topography and provided information that would not normally be obtainable from aspirated material. The techniques were easy to apply and took relatively little time to perform. They could offer useful information in the study of bone marrow disorders, particularly those such as myelodysplastic syndromes in which disturbances of marrow architecture are prominent.

Biopsy↗

PubMed1988

Prognostic indicators in centroblastic-centrocytic lymphoma.

The prognostic importance of ploidy and proliferative index (%S + G2) assessed by flow cytometry, mitotic and centroblast counts, and histological growth pattern were evaluated in biopsy specimens taken before treatment from 60 cases of centroblastic-centrocytic non-Hodgkin's lymphoma. Cases with a high proliferative index (greater than or equal to 18%) or DNA aneuploidy showed significantly poorer survival than those with a low proliferative index (less than 18%). A high mitotic count was also associated with a poor prognosis. On multiple regression analysis the flow cytometric assessments and mitotic counts were significant predictors of survival. Assessments of proliferative activity clearly have prognostic potential in centroblastic-centrocytic lymphoma and may permit more accurate characterisation of individual tumours.

Adult↗

PubMed1988

Identification of human herpesvirus 6-specific DNA sequences in two patients with non-Hodgkin's lymphoma.

Human herpesvirus 6 (HHV-6) is a recently discovered virus which has not been causally linked to any particular disease. In order to investigate the possible role of this virus in the pathogenesis of lymphoid malignancies, we examined tissue samples from 117 patients for the presence of HHV-6-specific DNA sequences. Two cases of non-Hodgkin's lymphoma were found to be positive. One patient had a T cell lymphoma and a preceding history of angioimmunoblastic lymphadenopathy; the other had a B cell lymphoma occurring in the context of Sjögren's syndrome. HHV-6 has been isolated previously from a patient with angioimmunoblastic lymphadenopathy, and viral sequences have been identified in another patient with Sjögren's syndrome and B cell lymphoma. The relationship between HHV-6 and these conditions therefore warrants further investigation.

Aged↗

PubMed1987

Prospective study of cellular immunity to hepatitis-B-virus antigens from the early incubation phase of acute hepatitis B.

Cellular immunity to hepatitis-B-virus (HBV) antigens was followed prospectively in five patients who were identified in the early incubation phase of acute HBV infection, between 30 and 70 days before the onset of liver damage. Cellular immunity to pre-S antigens was the first detectable immune response, appearing 30 days before the first rise in serum aminotransferases in every case. T-cell sensitisation to HBcAg followed, with IgM anti-HBc appearing 10 days later. A cellular immune response to HBsAg was the last to appear, 10 days before the onset of liver damage. These cellular immune responses are the earliest host responses to the virus infection and could be critical in initiating and directing the processes of liver damage and viral clearance.

Acute Disease↗

PubMed1987

Thermal desorption-gas chromatography of plasma isovaleraldehyde in hepatic encephalopathy in man.

The validation of a new assay for the leucine degradion product isovaleraldehyde in biological fluids is described. A gas purge technique was used with trapping of volatile constituents in a Tenax cartridge followed by automated thermal desorption and gas chromatographic analysis. The concentration of isovaleraldehyde during the course of hepatic encephalopathy (80 observations in 48 patients; 25 cirrhotic, 23 fulminant hepatic failure) was significantly increased compared to control subjects (0.58 +/- 0.08 compared to 0.17 +/- 0.02 mol/l; p less than 0.001). However, concentrations in grades 3-4 coma (37 observations) and grades 1-2 coma (30 observations) were similar and were not significantly different from values when encephalopathy was absent (grade 0; 13 observations). These results do not support an important role for isovaleraldehyde in the pathogenesis of hepatic encephalopathy.

Aldehydes↗

PubMed1987

T-cell inducers of suppressor lymphocytes control liver-directed autoreactivity.

The sensitisation of helper T cells of patients with autoimmune chronic active hepatitis to a liver-cell membrane-expressed asialoglycoprotein receptor protein is shown to be associated with a defect of T cells that specifically induce suppressor lymphocytes. These lymphocytes are found in an activated state in the peripheral blood of healthy people and may form part of an immunoregulatory network which actively prevents autoimmunity.

Adult↗

PubMed1987

Is modified radical neck dissection only a staging procedure?

This retrospective study evaluates the clinical benefit of modified radical neck dissection among patients with squamous carcinoma of the upper aerodigestive tract. Ninety-eight modified neck dissections were performed in 86 patients over a 5-year period. The procedure entailed removal of the submaxillary and jugular chain nodes while the posterior triangle was not dissected. Thirty-two patients received postoperative radiotherapy. Lymph nodes were histologically positive in 55 of 98 dissections (56%). Among 72 determinate patients, recurrence in the dissected neck occurred in 8 of 38 with positive nodes and none of 34 with negative nodes (P less than 0.05). These recurrences occurred in patients who had clinically palpable nodes preoperatively. Postoperative radiotherapy did not significantly alter the overall recurrence rate or survival of patients with positive nodes. Cumulative disease-free survival at 5 years was 70% overall. It is concluded that the modified neck dissection described is appropriate in the clinically negative neck or when regional disease is early (i.e., N1) and located in the submandibular triangle. Postoperative radiotherapy should be given if more than one node is involved histologically or if extracapsular spread is present.

Adult↗

PubMed1987

Modified radical neck dissection. Terminology, technique, and indications.

The terminology relating to the various modifications of radical neck dissection is loose and confusing. A simple system of nomenclature has been suggested which allows specification of the node levels dissected and the structures preserved. A technique of modified neck dissection, which excludes dissection of the posterior triangle and spares the sternocleidomastoid muscle and spinal accessory nerve, has been described. We believe this operation is appropriate when local disease is advanced and clinically uninvolved neck nodes are likely to harbor occult metastatic disease, when resection of the primary tumor is through the neck, or when clinical disease in the neck is minimal. Patients with multiple palpable nodes, patients with nodes larger than 3 cm in diameter, patients with disease in the posterior triangle, and patients in whom radiotherapy to the neck has failed may be better served by radical neck dissection.

Head and Neck Neoplasms↗

PubMed1987

Squamous cell carcinoma of the buccal mucosa: analysis of prognostic factors.

Although the TNM system is the accepted standard for head and neck tumor classification, there are often discrepancies between tumor size and survival. This retrospective analysis of 89 patients with squamous cell carcinoma of the buccal mucosa was carried out to evaluate tumor thickness and depth of invasion as prognostic variables and to compare them to the standard parameters. Recurrence rates increased with tumor size, clinical stage, thickness, and depth of invasion. In univariate analysis, sex, clinical stage, thickness, and depth of invasion were significantly related to survival (p less than 0.10). Multivariate analysis revealed that only thickness was an independent variable (p less than 0.0001). Patients with tumors less than 6 mm in thickness had a significantly better survival rate compared with those patients with tumors greater than 6 mm in thickness, regardless of the tumor stage. Measurement of tumor thickness should be included in estimating prognosis, planning therapy, and comparing results in patients with squamous cell carcinoma of the buccal mucosa.

Adult↗