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Biomedical subjects

R Ford

Publications and source records attributed to R Ford.

At least 127 records · Page 7Linked to original sources
PubMed1983

Proliferation of human B lymphocytes mediated by a soluble factor.

Recent studies have established the ability of a proportion of activated human B lymphocytes to undergo G1 phase cell cycle progression and subsequent S phase entry on exposure to factor(s) present in lectin-stimulated mononuclear cell-conditioned media. One factor capable of stimulating activated human B lymphocyte proliferation may be separated from peripheral blood lymphocyte-conditioned media by successive ammonium sulfate precipitation, ion exchange, and gel filtration chromatography. The isolated factor is distinct from the other well-described cytokines, possesses a molecular weight of 12,000-13,000, has a mildly acidic isoelectric point (at pH 6.3-6.6), is protease sensitive, and is relatively heat sensitive. The human B cell mitogenic factor possesses functional and cellular specificity in that its action is restricted to B lymphocytes and its function is proliferative. The production of the B cell mitogenic factor by T lymphocytes is augmented by the presence of a macrophage and further stimulated by syngeneic B cells.

B-Lymphocytes↗
PubMed1982

Biochemical separation of a human B cell mitogenic factor.

Recent studies have established the ability of human B lymphocytes to undergo G1-phase cell cycle progression and subsequent DNA synthesis upon exposure to factor(s) present in media conditioned by lectin-stimulated mononuclear cells. Procedures for the isolation of such a cytokine have been the focus of the present investigation. Conditioned medium from cells stimulated by lectin for 72 hr was fractionated by ammonium sulfate precipitation, ion-exchange chromatography, and gel filtration chromatography. During the isolation procedure the proliferation-stimulating activity of the column fractions was assayed concurrently on purified human T cells, purified human B cells, and murine thymocytes. T cell and B cell stimulatory factors present in the initial conditioned medium were found to copurify during ammonium sulfate precipitation, DEAE-Sephadex chromatography, and Bio-Gel P-30 gel filtration. However, partial separation of these two activities was achieved after Bio-Gel P-100 gel filtration. Analytic polyacrylamide gel electrophoresis of radiolabeled Bio-Gel P-100 column fractions demonstrated a distinct protein band of 14,000-15,000 daltons in those column fractions predominantly supporting T cell growth and a distinct protein band of 12,000-13,000 daltons for those fractions predominantly supporting B cell growth. The fractions associated with B cell mitogenic activity induced B cell S-phase entry in a proportion of B lymphocytes in the absence of any detectable IgM secretion.

B-Lymphocytes↗
PubMed1981

Fibronectin production by human mammary cells.

Human mammary cells were examined for the presence of the high-molecular-weight surface glycoprotein fibronectin. Early passage mammary epithelial cell and fibroblast cultures from both carcinomas and normal tissues were tested for the presence of cell-associated fibronectin by immunofluorescence microscopy and for the synthesis and secretion of fibronectin by specific immunoprecipitation of metabolically labeled protein. In vivo frozen sections of primary carcinomas and normal tissues were tested for the localization of fibronectin by immunofluorescence microscopy. In contrast to the extensive fibrillar networks of fibronectin found in the fibroblast cultures, the epithelial cell cultures from both tissue sources displayed a pattern of cell-associated fibronectin characterized by powdery, punctate staining. However, the cultured epithelial cells, as well as the fibroblasts, secreted large quantities of fibronectin into the medium. Putative myoepithelial cells also displayed extensive fibrillar networks of fibronectin. The difference in cell-associated fibronectin distribution between the epithelial cells and the fibroblasts and putative myoepithelial cells provided a simple means of quantitating stromal and myoepithelial cell contamination of the mammary epithelial cells in culture. In vivo, normal tissues showed fibronectin primarily localized in the basement membrane surrounding the epithelial cells and in the stroma. Most primary carcinomas displayed powdery, punctate staining on the epithelial cells in addition to the fibronectin present in the surrounding stroma.

Basement Membrane↗
PubMed1980

Deaths from asphyxia among fisherman.

On July 19, 1978, two crewmen aboard a shrimp trawler died and the captain was hospitalized after being exposed to a toxic atmosphere in the ship's hold. Examination of the Coast Guard records of deaths at sea since 1970 led to the identification of 11 incidents involving 32 deaths by asphyxia. All deaths occurred in the unventilated holds of ships in warm waters and during warm months of the year. Asphyxia in the unventilated holds of ships is an underrecognized hazard. We recommend that fishermen be informed of this hazard, that ships' holds be ventilated before they are entered, and that safety protocols be provided to rescuers of persons found unconscious in a ship's hold.

Asphyxia↗
PubMed1980

An inhibitor of thymic hormone activity in serum from patients with lymphoblastic leukemia.

Serum from 21 patients with lymphoblastic leukemia, five with myeloblastic leukemia and 30 age matched control subjects tested for thymic hormone activity in an assay that measures the induction of T cell surface antigen. This activity was subnormal in serum from 10 of 16 patients with untreated lymphoblastic leukemia (p less than 0.001) but was within the normal range when the leukemia was in remission. Low inductive activity was associated with an inhibitor of T cell induction which was less than 30,000 daltons in molecular size and interfered with induction by purified thymopoietin plus a high concentration of ubiquitin or by normal serum alone.

Antigens, Surface↗
PubMed1980

Spectrum of immunodeficiencies with Hodgkin's disease.

The role of six suppressor mechanisms upon T and B cell responses was studied on 17 untreated patients with Hodgkin's disease. Proliferative hyporesponsiveness to mitogen was greatly impaired in 8 of the 13 patients. 10 of these patients had an excessive degree of suppression by cells that adhered to foreign surfaces. Suppression by adherent cells correlated with impairment of proliferative responses and, in some instances, suppression was largely inhibited with indomethacin. Likewise, adherent cells suppressed immunoglobulin synthesis. A correlation was evident between suppression of T and B cell responses by adherent mononuclear leukocytes from individual patients. This suppression coincided with elevated percentages of monocytes in the patient mononuclear cell preparations. This excess of monocytes was not the result of a circulating monocytosis. The monocyte excess may have been acquired during isopyknic cell separation. A second form of suppression was observed in 5 of the 11 patients affected by a lymphocyte that neither adhered to glass wool nor required preactivation. It did not inhibit allogeneic lymphocytes, which contrasts with the suppressor abnormality of monocytoid cells.

Adolescent↗
PubMed1979

ABH and Lewis antigens on lymphocytes: screening of pregnant women's sera with the B-cell cytotoxicity test.

Five phenotypes related to the ABH-Lewis substances were defined by the B-cell lymphocytotoxic test. These five antigens are built up in a stepwise fashion by the action of the glycosyl transferases specified by the Le, H, and the A, B genes onto the same ABO percursor molecules. The comparison of their chemical structures with the cluster analysis obtained by cytotoxicity suggests that antibodies reacting with large antigenic structures (pentasaccharides) have a more restricted specificity than antibodies reacting only with smaller antigenic determinants (trisaccharides).

ABO Blood-Group System↗
PubMedDate not supplied

A prospective study of complications in Hickman right-atrial catheters in marrow transplant patients.

One hundred forty-three large bore right-atrial catheters (RACs) in 111 bone marrow transplant recipients were prospectively analyzed for the incidence of complications interfering with catheter function. Of the 143 RACs, 108 (76%) were patent on departure from Seattle or death. Infectious complications occurred in 63 (44%) of the catheters, resulting in 18 (13%) removals. Noninfectious complications occurred with 54 (38%) of the catheters, resulting in 17 (12%) removals. Successful interventions included catheter repair, dissolving precipitates with ammonium chloride solution, and declotting catheter lumens with heparin and/or urokinase. We conclude that RACs continue to be reliable and safe devices to use in marrow transplant patients. Complications interfering with catheter function are frequent; however, most can be resolved without the need to remove the catheter.

Adolescent↗
PubMedDate not supplied

Mental health facilitators in primary care.

In the context of the National Primary Care Facilitation Programme, the Sainsbury Centre for Mental Health has reviewed the membership of the Mental Health in Primary Care Network, and explored members' roles; the findings of the review are reported in this article. Researchers examined the activities undertaken by network members, and identified the proportion working directly with primary health care teams and those working strategically within health authorities. Education and training, health promotion, and liaison and linkworking were undertaken by many staff, while a few worked at a more strategic level. In order to increase the effectiveness of this model, a more focused approach is recommended, targeting those with responsibility for implementing changes and developing mental health care in primary care settings. Learning sets which involve primary care and mental health teams, and strategic work with health authorities, are also recommended.

Attitude of Health Personnel↗