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T Kalland

Publications and source records attributed to T Kalland.

141 records · Page 8Linked to original sources
PubMed1979

Long-term effects of neonatal estrogen treatment on mitogen responsiveness of mouse spleen lymphocytes.

Neonatal female NMRI mice were given injections of olive oil (controls) or daily doses of corticosterone (10 micrograms), 17 beta-estradiol (10 micrograms), or diethylstilbestrol (DES) (0.01, 0.1, 1, or 5 micrograms) for the first 5 days after birth. The 5-micrograms dose of DES resulted in a persistently reduced in vitro mitogen response to concanavalin A or bacterial lipopolysaccharide of spleen lymphocytes from 6-, 10-, and 18-week-old or 17-month-old females. DES injections from day 6 through day 10 did not influence the later mitogen response. Treatment of ovariectomized 10-week-old females with 5 micrograms DES for 5 days resulted in a tendency to a reduced mitogen response (not statistically significant) 24 hours after the last DES injection. Four weeks later, the mitogen response was the same in experimental and control females. Different possible mechanisms for the persistent effect on the mitogen response are discussed. Neonatal DES treatment not only resulted in persistent changes in the cervicovaginal epithelium and in the hypothalamic-pituitary gland control system but also in the spleen lymphocyte mitogen response. The altered mitogen response should be a stimulus for a detailed analysis of the immune system in women exposed to DES during fetal life, some of whom develop later in life clear cell adenocarcinoma of the uterine cervix and vagina.

Animals↗
PubMed1978

Localization of 3H-estradiol-17beta in diethylstilbestrol-induced adenosis.

Treatment of neonatal mice with diethylstilbestrol results in the appearance of adenosis in the uterine cervix and upper part of the vagina in later life. Using dry mount autoradiography, the uptake and distribution of [3H]-estradiol in the same regions were studied after in vivo injections with [3H]-estradiol. It was demonstrated that the adenosis cells have the ability of uptake and nuclear concentration of estradiol and are thus target cells for estrogens. The importance of this finding for the development of malignancy is discussed in relation to the clear cell adenocarcinomas in young women exposed to diethylstilbestrol in utero.

Adenocarcinoma↗
PubMed1978

The isozyme pattern of cyclic AMP-dependent protein kinase and the distribution of a cervicovaginal antigen in experimental carcinoma of the cervix uteri of mice.

Tissue-sections from 12 methylcholanthrene-induced carcinomas of the cervix uteri of mice were tested for the presence of an antigen normally confined to the cervicovaginal epithelium. The antigen was detected in 10 of the 12 tumours investigated with indirect immunofluorescence, and in all 7 tumours studied with the more sensitive method of mixed hemagglutination. The concentration of the antigen was generally higher in the well-differentiated areas of the tumours, but it was also found associated with solitary tumour cells, apparently invading the stroma. The presence of CVA in the tumours suggests an origin of the tumour cells from the cervicovaginal epithelium. The cyclic AMP dependent protein kinase (EC 2. 7. 1. 37) in the tumour cytosols was studied by chromatography on agarose and DEAE-cellulose. The enzyme showed the same properties as that from normal vaginal epithelium. The tumour cells thus contain an apparently normal complement of this enzyme, which is believed to be responsible for most of the intracellular actions of cyclic AMP.

Animals↗
PubMed1977

A simple and rapid method to distinguish between rosettes and non-specific aggregation of erythrocytes in the rosette assay for human T-lymphocytes.

A method is described for rapid and simple visualization of lymphocytes in the rosette assay for human T-lymphocytes. A drop of acridine orange (pH 7.4) is added to the suspension of rosetted cells and allowed to incubate for 1 min on ice. Nucleic acids are then visualized in a fluorescence microscope by excitation at 430-500 micrometer. Simultaneous semi-illumination with light microscopy allows enumeration of total lymphocytes and the number of lymphocytes rosetted with sheep red blood cells. The central lymphocyte is clearly distinguishable even when it is crowded with red cells, and this makes the differentiation between rosettes and non-specific aggregation of cells easy.

Acridines↗
PubMed1976

The content of a specific cell product in the vaginal epithelium of normal and neonatally estrogenized mice: its dependence on an estradiol-prolactin interaction.

The amount of an immunological marker (CVA) in mucified cells of the mouse vaginal epithelium was quantified by a mixed hemagglutination technique for tissue sections. Immature mice, adult mice which had been estrogenized neonatally (5 mug diethylstilbestrol daily for the first five days after birth), and adult non-estrogenized mice were studied. All adult animals were castrated 7-10 days before starting the experiments. Injections of 5 mug estradiol-17beta (48 and 24 h before killing the animals) increased the amount of CVA in all three groups of animals, but most markedly in the neonatally estrogenized mice. The amount of CVA found following estradiol treatment was decreased in adult animals injected with the ergot alkaloid CB154 (0.5 mg twice daily for 6 days) in addition to the hormone. This partial block of the estradiol-induced CVA response by CB154 was relieved by exogenous rat prolactin. The CVA content in immature animals was not influenced by CB154, given alone or together with estradiol. Combined treatment with estradiol and rat prolactin (3 mug every 8 h for 6 days) increased more efficiently than estradiol alone the amount of CVA in immature and adult nonestrogenized animals. Prolactin injected alone had no effect on the CVA content. These data strongly suggest a synergistic action of estradiol and prolactin in augmenting the epithelial CVA content. Explants of the vaginal wall from normal and neonatally estrogenized mice were grafted into the thigh muscles of newborn mice, every host carrying one graft from both types of animals. The CVA content in the epithelium of the two grafts increased to the same level in response to estradiol. When the hosts were injected with estradiol and prolactin, the CVA content was higher in grafts from estrogenized donors than in those from nonestrogenized animals. Our results demonstrate that the mucified vaginal cells in adult, neonatally estrogenized mice have a content of CVA which is higher than in nonestrogenized animals. This difference may be ascribed to hormonal factors (estradiol-prolactin) as well as to persistent effects in the vaginal cells as a result of the neonatal estrogen treatment.

Age Factors↗
PubMedDate not supplied

Targeting of superantigens.

The bacterial superantigen staphylococcal enterotoxin A (SEA) is an extremely potent activator of T lymphocytes when presented on MHC class II antigens. In order to induce T lymphocytes to reject a tumor, we substituted the specificity of SEA for MHC class II molecules with specificity for tumor cells by combining SEA with a MAb recognizing colon carcinomas. Chemical conjugates or recombinant fusion proteins of the MAb C215 and SEA retained excellent antigen binding properties whereas the binding to MHC class II was markedly reduced. The hybrid proteins directed SEA responsive T cells to tumors with specificity determined by the specificity of the MAb. Significant tumor cell killing was obtained at picomolar concentrations of the hybrid proteins and was the result of direct cell mediated by cytotoxicity as well as production of tumoricidal cytokines by T cells. Targeting of superantigens represents a novel approach to specific immunomodulation and deserves further study as a potential therapy for malignant disease.

Antibodies, Monoclonal↗
PubMedDate not supplied

Preparation and characterization of conjugates of monoclonal antibodies and staphylococcal enterotoxin A using a new hydrophilic cross-linker.

Conjugates between monoclonal antibodies recognizing human cancer cells and the superantigen staphylococcal enterotoxin A (mAb-SEA) represent a potential novel approach to tumor therapy. Such mAb-SEA conjugates direct T-cells to lyse colon carcinoma cells in vitro. The synthesis of mAb-SEA conjugates which were prepared by introducing thiol groups on SEA and iodoacetyl or maleimide groups on mAb forming a stable thioether linkage between SEA and mAb is described. A hydrophilic spacer, composed of repeated ethylene oxide units, was constructed to increase the distance between SEA and mAb, preserving biological activity of both proteins. The degree of modification of mAb with SEA was determined with SDS-PAGE. Variables influencing the composition of the conjugates and their effect on the tumor-cell cytotoxicity were studied and optimal conditions for the synthesis were established. Functionally active mAb-SEA conjugates were prepared from a panel of different mAb and T-cell-dependent cytotoxicity against several human cancer types including colon, ovarial, breast, and renal cancer was obtained. This suggests that mAb-SEA conjugates may be of value in the treatment of human neoplastic disease.

Antibodies, Monoclonal↗