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Biomedical subjects

C H Kirkpatrick

Publications and source records attributed to C H Kirkpatrick.

At least 91 records · Page 5Linked to original sources

The E-rosette augmenting factor (E-RAF): aspects of clinical application.

It has recently been demonstrated that antigen- or mitogen-stimulated normal lymphocytes release a soluble E-rosette augmenting factor (E-RAF) which enhances E-rosette formation. Using this enhanced E-rosette formation as an immunologic marker, we studied lymphocytes from twelve normal volunteers, ten patients with chronic mucocutaneous candidiasis and one male patient with severe combined immune deficiency (SCID). These studies confirmed the observation that lymphocytes from normal donors respond to mitogen or specific antigen stimulation by release of E-RAF and increased E-rosette formation. Lymphocytes from the SCID patient were unable to release the soluble factor following mitogenic stimulation and increased E-rosette formation did not occur. Furthermore, our data indicated that short-term incubation (18 hr) of normal lymphocytes in mitogen (PHA or Con A)-derived supernatant fluids containing the soluble factor may offer a reliable and highly reproducible assay technique for total E-rosettes.

Antigens↗

Immunosuppressive activity of cord blood leukocytes.

The in vitro effects of cord blood cells from term and preterm infants on cell-mediated immune responses by adult lymphocytes were studied. The experiments showed that cord blood cells were potent suppressors of antigen- and mitogen-induced proliferation of adult T cells. In contrast to the previously reported observations with adult suppressor cells, the cord blood cells did not require mitogenic activation to exert their suppressive activity. It was also found that a similar, if not identical, suppressive activity was released into the fluid phase when cord blood cells were placed in tissue culture for three to five days. Studies with subpopulations of cord blood cells showed that the suppressive factor was released from rosette-forming T lymphocytes, but not from cell populations that were depleted of T cells. In addition, the production of and the action of the soluble suppressive factor was inhibited by indomethacin.

Antigens↗

Mucocutaneous candidiasis and thymoma.

The clinical, pathologic and immunologic features of 27 patients with chronic mucocutaneous candidiasis and thymic tumors are reviewed. This form of chronic candidiasis is unique in that the infections do not occur until after the third decade and, in contrast to patients in whom candidiasis develops during infancy or childhood, it is not accompanied by failure of endocrine organs. Instead, the patients have the disorders that often accompany thymoma, such as myasthenia gravis, hypogammaglobulinemia, and abnormalities of the bone marrow and circulating blood elements. Evidence of impaired cell-mediated immunity was found in 16 of the 21 patients in whom studies were made. The pathogenesis of the immunodeficiency in these patients is unknown. Immunosuppressive activities in the plasma of four patients were found, but none of the five patients in whom the appropriate studies were made was found to have suppressor cells. The features of this disorder are unique enough that it should be considered a syndrome, and patients in whom candidiasis develops during their adult years should be studied for the presence of thymoma.

Adult↗

Age-related and thymus-dependent rejection of adenovirus 2-transformed cell tumors in the Syrian hamster.

Adenovirus type 2-transformed hamster cell-induced newborn tumor lines were usually rejected when transplanted s.c. into 21-day-old syngeneic, weanling hamsters. The tumor-inducing capacity of two of these lines (Ad2HTL3 and Ad2HTL6) was tested in intact and neonatally thymectomized hosts. After s.c. injection of suspensions prepared from these lines, none of the weaning hamsters developed tumors while 100% of the newborns and 35.2% of neonatally thymectomized, weanling hamsters developed progressively enlarging neoplasms. The susceptibility of neonatally thymectomized hamsters to tumor challenge was directly related to the degree of immunosuppression observed following thymectomy as indicated by the amplitude of the in vitro response of blood leukocytes to concanavalin A. Pretreatment of thymectomized weanlings with syngeneic adult lymphoid cells (i.p.) resulted in a significant reduction in tumor susceptibility (p = 0.03). These findings suggest that acquisition of resistance to adenovirus type 2-transformed cells during the first 21 days of life may be a thymus-dependent cellular immune process.

Adenoviridae↗

Rejection of adenovirus 2-transformed cell tumors and immune responsiveness in Syrian hamsters.

Transplantation of adenovirus type 2-transformed cell-induced newborn tumor lines to different aged hamsters revealed that the cell-mediated host defenses responsible for tumor graft rejection matured early in the second week of life. When light microscopic examinations were performed during the course of tumor development, the primary histopathological difference between progressing tumors removed from newborn or thymectomized weanling hamsters and regressing lesions from normal weanlings was the lack of an early, mononuclear cell infiltrate in neoplasms from newborn and thymectomized hosts. These results suggest that the maturation of cellular immunity determines resistance to tumor transplantation in this system. This conclusion was supported by the in vitro detection of concanavalin A-responsive lymphocytes in spleens from tumor-resistant suckling but not tumor-susceptible neonatal hamsters. Although the incomplete seeding of thymus-dependent lymphocytes to the peripheral lymphoid tissues of newborn hamsters may partially explain the deficient concanavalin A responses of neonatal spleen cells, there appears to be an additional requirement for a radioresistant, adherent accessory cell population. These findings suggest that the development of a cell-mediated immune response is necessary for the rejection of adenovirus type 2-transformed cells and transformed cell-induced tumors and that this response requires the interaction of T-cells and accessory cell populations.

Adenoviridae↗

Release of E-rosette augmenting factor (E-RAF) after stimulation of human leukocytes with mitogens or antigens.

Stimulation of human peripheral blood leukocytes (HPBL) with mitogens such as phytohemagglutinin or concanavalin A increases the total number of lymphocytes that form rosettes with sheep erythrocytes. A similar effect is seen when HPBL from skin test-positive, but not skin test-negative, donors are stimulated by a specific antigen. It was also found that the culture fluids from mitogen-stimulated lymphocytes contained a substance that significantly increased the percentage of E-rosette forming cells (85 to 95%) over that of control culture fluids (40%). A similar phenomenon was also observed with supernatant fluids derived from antigenic stimulation of cells from skin test-positive donors, but not from skin test-negative subjects. The factor that produces this effect has been designated E-rosette augmenting factor (E-RAF). It is nondialyzable; it appears in the supernatants of antigen or mitogen-stimulated cells within 12 hr; and its production is not blocked by mitomycin C. It is produced by cells that do not adhere to glass wool columns and by mitogen-stimulated thymocytes. Sephadex G-100 chromatography showed that mitogen-induced E-RAF eluted from the column in advance of antigen-induced E-RAF. E-RAF has many properties that are characteristic of lymphokines.

Antigens↗

Treatment of chronic oral candidiasis with clotrimazole troches. A controlled clinical trial.

Twenty patients with chronic oral candidiasis were assigned by random allocation to a two-week course of either 10-mg clotrimazole buccal troches or placebo taken five times daily in a double-blind clinical trial. Each of the 10 recipients of clotrimazole had marked regression of symptoms and mucosal lesions, and in nine patients potassium hydroxide preparations and cultures of mucosal scrapings gave no evidence of candidiasis. In contrast, only one of the 10 patients receiving placebo showed any improvement. The clinical outcome in the clotrimazole-treated group was significantly more favorable (P less than 0.001) than in the group receiving placebo. No adverse reactions to the drug were observed. After the blind phase of their trial, 15 patients were treated with clotrimazole troches in an open trial. One to three troches per day were found adequate to sustain remissions. We conclude that clotrimazole is highly effective treatment for chronic oral candidiasis.

Adolescent↗