Search PubMed⌕ Search

Biomedical subjects

R Lea

Publications and source records attributed to R Lea.

8 recordsLinked to original sources
PubMed1991

Granulocyte/macrophage colony-stimulating factor (GM-CSF) gene expression by eosinophils in nasal polyposis.

Nasal polyposis is a chronic inflammatory condition of the upper airways characterized by infiltration of activated inflammatory cells, particularly eosinophils. Granulocyte/macrophage colony-stimulating factor (GM-CSF) is a cytokine with powerful biologic effects including the regulation of survival, proliferation, and activation of granulocytes as well as differentiation of hemopoietic cells. To examine the potential role of GM-CSF in the pathogenesis of this condition, we investigated gene expression and production of GM-CSF in nasal polyp tissues as well as in the normal nasal mucosa. Immunoreactive GM-CSF was detected by enzyme-linked immunosorbent assay in the 24-h supernatant of nasal polyp tissues placed in culture. By Northern blot analysis and Southern blot analysis following a reverse-transcription polymerase chain reaction using a human GM-CSF cDNA probe, we detected GM-CSF mRNA in nasal polyp tissues, as well as in the tissue from a patient with allergic rhinitis, but not in the normal nasal mucosa. By in situ hybridization using the same probe, cells expressing mRNA specific for GM-CSF were observed in nasal polyp tissues and in the allergic nasal mucosa. In addition, by the combination of in situ hybridization and counterstaining with chromotrope 2R, we demonstrated that approximately 30% of eosinophils infiltrating the polyp tissue express the GM-CSF gene. These results suggest a novel mechanism by which eosinophils may contribute to the pathogenesis of chronic inflammatory diseases such as nasal polyposis, allergic rhinitis, and, by implication, asthma.

Base Sequence↗
PubMed1987

Surgery after initial chemotherapy for localized small-cell carcinoma of the lung.

Despite the high response rates induced by chemotherapy, many patients with limited small-cell lung cancer (SCLC) relapse at the site of primary disease. Failure of radiotherapy to overcome this has led to the use of surgery as part of a combined modality approach. Between December 1981 and December 1985, 189 patients with SCLC were assessed for suitability for surgery after an initial three cycles of chemotherapy (doxorubicin, cyclophosphamide, and etoposide). Fifty-seven were found to have limited disease, and of these, 19 were ineligible or unfit for surgery. Of the 38 eligible patients, 84% had an objective response to three cycles of chemotherapy and 25 were deemed suitable for surgery after restaging. At thoracotomy, four were inoperable, nine had a lobectomy, and 12 had a pneumonectomy. There was no evidence of viable SCLC in four resection specimens (one stage 1, two stage 2, one stage 3 at presentation), no viable SCLC but an entirely separate focus of viable poorly differentiated squamous carcinoma (SqLC) in one, and the remaining specimens contained viable SCLC. Survival of patients selected to undergo tumor resection was excellent (median survival, 33 months; plateau phase, 48% alive at 3 to 5 years), but survival of the entire group with limited SCLC was not dissimilar from that reported in previous series of limited-stage tumor treated with chemotherapy alone. Long-term survival appeared to be largely restricted to those with no evidence of viable SCLC at surgery (no viable SCLC, zero of five relapsed; viable SCLC, 13 of 16 relapsed and/or died). This prospective study confirms the feasibility of the combined modality approach, but suggests that any improvement in overall survival is likely to be small. Until the results from multicenter randomized trials are available, surgery, as part of a combined modality program, should be regarded as experimental.

Actuarial Analysis↗
PubMed1978

B- and T-cell markers in lymphoproliferative disorders with blood and bone marrow involvement.

B- and T-cell surface markers were determined in 26 adult patients with lymphoproliferative malignancies who had bone marrow and blood involvement. The patients in whom more than 60% of the abnormal cells were immunoglobulin-bearing cells were considered to have B-cell lymphoproliferative malignancy. The diagnosis of a T-cell disorder was made in those patients in whom more than 70% of the cells formed E rosettes (T cells). Those patients in whom 30% and more of the abnormal cells did not show B- and T-cell surface markers were regarded as suffering from "null" cell disorder. The B-cell type of lymphoproliferative malignancy was the most commonly encountered (63%) with an equal male to female ratio. In addition, 4 male patients with "hairy-cell" leukaemia were shown to have a B-cell disorder. T-cell disorders were found in 3 male patients; 1 patient had acute lymphoblastic leukaemia and in the other 2 the histopathological diagnosis was well-differentiated lymphoma and Sternberg sarcoma. Four patients with "null" cell lymphoma were found, the histopathological diagnoses in all were poorly-differentiated lymphocytic lymphoma, and 3 of the 4 patients were males. Further haematological investigations of the B-cell and the non-B-cell disorders showed that although the bone marrow was equally extensively infiltrated in both groups, the non-B-cell disroders were more commonly associated with complications of anemia and thrombocytopenia. It is therefore postulated that the abnormal lymphoid cell involved in B-cell disorders is an end-stage cell and not the haemopoietic stem cell.

Adult↗
PubMed1976

Separation of pesticide residues from lipids prior to gas-liquid chromatographic analysis.

Lipids are separated from dieldrin, endrin, and p,p'-DDE residues by saponification in ethanolic sodium hydroxide, acidification with dilute sulfuric acid, and adsorption chromatography on deactivated alumina, using petroleum ether as the eluant. Dieldrin, endrin, and p,p'-DDE are efficiently recovered (95-102%), and p,p'-DDT is converted to p,p'-DDE, which is then recovered with high yield (90-96%). Extremely low lipid carryover (less than 0.3-0.5%) is observed for 0.5-1.0 g samples of chicken fat.

Adsorption↗