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Biomedical subjects

J C Houck

Publications and source records attributed to J C Houck.

At least 19 recordsLinked to original sources
PubMed1979

Permeability factor contaminating hyaluronidase preparations.

Both crude and highly purified testicular hyaluronidase preparations have been shown to contain a component which increases the permeability of the microcirculation in rat skin. This permeability activity had an isoelectric point of 7.4 while hyaluronidase was 9.4. It also could be separated from hyaluronidase by acrylamide gel electrophoresis. The permeability factor was not inhibited by serum and may explain previous observations that hyaluronidase preparations decrease the ischemia and necrosis appropriate to experimental myocardial infarction in vivo.

Animals↗
PubMed1979

Macromolecular, anionic pulmonary permeability factor.

Aqueous extracts of fresh or acetone-powdered calf lung have been found to contain a factor which increases the permeability of the microcirculation when injected into the skin of rats. This permeability factor, which is not found in similar extracts of muscle or kidney, was concentrated by Amicon ultrafiltration at a molecular weight range of between 50,000 and 100,000 daltons and via isoelectric focusing at an IEP of pH 4.2. After preparative acrylamide gel electrophoresis, this permeability factor was homogeneous by electrophoretic criteria and in SDS acrylamide gel electrophoresis had a molecular weight of approximately 82,000 daltons. This apparently homogeneous permeability factor from lung was inhibited by pepstatin, and yet possessed no acid proteolytic activity against any substrate. Its activity was completely inhibited by pretreatment of the animals with antihistamines. This pepstatin-inhibitable permeability factor was found largely in the lysosomal fraction of fresh lung and could also be obtained by extraction of large amounts of alveolar "washout" macrophages. Since macrophages, during phagocytosis, are known to leak significant quantities of their lysosomal contents, the fact that one of these components is a material which could release histamine from mast cells and thereby increase locally the permeability of the microcirculation may be of importance in the defense system of the lung.

Animals↗
PubMed1979

Pulmonary macrophage growth factor.

Pulmonary macrophage growth factor (MCF) can be purified from the "used" serum-free medium of cultures of mouse lung cells by concentration and dialysis over a 30,000-dalton Amicon ultrafilter and subjecting the retentate to isoelectric focusing. This yields a protein fraction with an isolelectric point of pH 4.2, which contains all the MGF activity. Upon electrophoresis of this fraction in analytical gels, one large and four small bands could be visualized. All bands were biologically active. This same "heterogenous" fraction ran as one band (mol wt 68,000) in SDS analytical gel electrophoresis, suggesting the ordered aggregation of this monomer. This was confirmed by reelectrophoresis of the first (and largest) band demonstrating the same 5-banded pattern as the initial material.

Animals↗
PubMed1979

The relevance of growth control (chalones) to the aging process.

A large amount of data suggests that a wide variety of cells and tissues contain cell-specific endogenous inhibitors of mitosis which are non species-specific. Increasingly, it appears that these chalone inhibitors are actually relatively small polypeptides capable of complexing with large molecular weight anionic molecules. The purification and chamical characterization of these inhibitors has been rendered extraordinarily difficult and the results have been very slow in forthcoming because of this ability to form complexes with anionic polyelectrolytes. Our recent understanding of this behavior should markedly accelerate our understanding and knowledge of chalone biochemistry in the future. If, in fact, chalones are ubiquitously important to the control of cell proliferation, then they will be important to our understanding of the development of post-mitotic cells and to our concepts of programmed senescence; both in turn might be important to our knowledge of the aging process.

Aging↗
PubMed1979

Kinetics and cell killing in dividing and nondividing leukemic cells in vitro and in vivo by natural splenic cytotoxic factor.

Ultrafiltered splenic extracts (30,000-50,000 daltons) were specifically cytotoxic in crowded cultures of murine leukemic lymphoblasts but were only inhibitory toward normal lymphocytes or sparse cultures of leukemic cells. This expression of cytotoxicity was quantitated by (i) vital dye exclusion, (ii) cytochemical metods, and (iii) the increased survival time of mice injected with L-1210 leukemic cells incubated in vitro with splenic extract. Selective cytotoxicity of splenic extract was not due to medium depletion or to complement-mediated cytolysis and could not be replicated using similar extracts of other lymphoid and nonlymphoid tissues. The selective effect of splenic extract on leukemic cells was characterized by the progressive shedding of cytochemically demonstrable RNA and the corresponding inhibition of 3H-uridine and 3H-thymidine incorporation. The comparison of progressive and gradual expression of cytotoxicity by splenic extract with the S phase specific inhibitor cytosine arabinoside suggests that the former is cytotoxic against leukemic cells predominantly in the G1 phase of the cell cycle.

Animals↗
PubMed1979

Cytochemical and ultrastructural alteration of leukemic cells by a naturally cytotoxic factor from spleen.

Experiments were carried out to delineate the differences in cytocidal modality of natural splenic cytotoxic factor (30,000-50,000 daltons) and cyto-A against normal and human leukemic lymphocytes in vitro. It was found that the differences in the cytocidal action effected by cyto-A and splenic isolate were as follows: (1) the killing effect of cyto-A against leukemic cells was very rapid in contrast to the slowly acting spleen factor as evaluated by cytochemical and ultrastructural studies; (2) spleen factor was not cytotoxic against normal lymphocytes in contrast to the indiscriminatory cytotoxic cyto-A.

Cell Transformation, Neoplastic↗
PubMed1978

The biochemistry of lymphocyte-derived mediators of immunological inflammation.

Evidence is presented to indicate that there exists in lymphoid tissue, as a result of transforming lymphocytes, a new lymphokine which is chemotactically specific for lymphocytes, called 'lymphotactin'. Lymphotactin has been purified to electrophoretic homogeneity; has a molecular weight of 10,500 D and an isoelectric point of 5.9. Its role in amplifying the immune defense system by recruitment of naive lymphocytes into propinquity with the challenging antigens is suggested. Purification of macrophage migration inhibitory factor from thymus extracts to electrophoretic homogeneity leads to a compound of molecular weight of 36,500 D and an IEP of 6.9. Chemically it contains sialic acid and o-methyl glucopyranoside as its only carbohydrates. Purified MIF activates the macrophage phagocytically. Skin reactive factor and lymph node permeability factor have been isolated and purified and are found to be inhibited by pepstatin and antihistamine and to have an isoelectric point of pH 4.2 and a molecular weight of 50,000--100,000 D. It is believed that this anionic permeability increasing agent actually arises from the lysosomes of macrophages and lymphoblasts (the normal small lymphocyte having essentially no lysosomal organelles). The mononuclear cell infiltration characteristic of crude SRF and LNPF may proceed from their being contaminated with lymphotactin.

Animals↗
PubMed1977

Lymphocyte and fibroblast chalones: some chemical properties.

Experiments with lymphocyte and fibroblast chalones indicate that they are complexed strongly with RNA in tissue extracts; have a molecular weight of less than 10,000 and more than 1,000 daltons, and probably about 5,000 daltons; are strongly cationically charged; and contain mannose and perhaps other carbohydrates.

Cell Division↗
PubMed1977

The purification and characterization of a lymphokine chemotactic for lymphocytes--lymphotactin.

Aqueous extracts of the thymus from vaccinated calves contain a protein specifically chemotactic for lymphocytes (lymphotactin). Lymphotactin has been isolated and purified by ethanol fractionation, ultrafiltration, isoelectric focusing, and preparative acrylamide gel electrophoresis. Its isoelectric point is 5.9, and the molecular weight by both SDS electrophoresis and exclusion chromatography is about 10,500. The purified sialoprotein is homogeneous at three different pH's in acrylamide gel electrophoresis. As little as 1 microgram of this material intraperitoneally wlll produce massive lymphocyte infiltration within 4 h in vivo.

Animals↗
PubMed1977

In vitro inhibition of human peripheral blood lymphocyte transformation by an extract of Pseudomonas putida.

An extract prepared from a psychrophilic strain of Pseudomonas putida was found to cause a dose-dependent inhibition of [H3]TdR incorporation into human peripheral blood lymphocytes stimulated with PHA, ConA, PWM, or in a mixed lymphocyte reaction. The inhibition was found not to be the result of cytotoxicity, culture medium depletion of a component necessary for lymphocyte transformation, or interference with label uptake by blast lymphocytes. The extract was most effective when added prior to 48 h of mitogen stimulation. The inhibitory material was photeolytic enzyme degradable, heat-stable and non-dialyzable.

Cell Extracts↗
PubMed1976

Evidence of morphological and physiological transformation of mammalian cells by strong magnetic fields.

Cultures of L-929 and WI-38 cells, frozen to 4.2 degrees K and exposed for 4 to 8 hours to 5000-oersted magnetic fields, were markedly inhibited in their growth as compared to controls. In cultures grown on cover slips, approximately 7 days after exposure, morphologically distinct cells emerged and were propagated from generation to generation; 3 weeks later, in flask cultures, contact inhibition was abolished. It is concluded that under certain experimental conditions, strong magnetic fields induce morphological and physiological transformations of target cells.

Cell Division↗
PubMed1976

Evidence for a colon chalone.

The molecular weight fractions of 10,000-50,000 daltons prepared from "used" medium obtained during cultivation of human colon carcinoma cells (SW-48) in vitro inhibited the proliferation and DNA synthesis of these cells. Fractions exceeding 50,000 daltons were not inhibitory; those less than 10,000 daltons were cytotoxic. The inhibitory fraction did not affect either proliferation of human fibroblasts or transformation of human lymphocytes in vitro. Similar fractions from the colon mucosa of other species inhibited the proliferation of SW-48 cells, whereas extracts of dog jejunum or lung did not. This mitotic inhibition was completely reversible and could be destroyed by preincubation with trypsin. Therefore, colon cells appear to contain a cell- (but not species) specific, endogenous mitotic inhibitor or chalone.

Animals↗
PubMed1976

Inflammation: a quarter century of progress.

This report summarizes the progress of studies on inflammation during the past quarter century; it is a personal overview of the most important and salient accomplishments in this field. Except for a few references to review articles and textbooks in the field, much of the literature surveyed is not cited.

Acute Disease↗
PubMed1976

Circulating factors controlling cell proliferation.

Dipolid human fibroblast-rich tissues contain a macromolecule with a molecular weight between 30,000 and 50,000 daltons which will inhibit the proliferation of fibroblasts in the G1 phase of the cell cycle (i.e., inhibit both 3H-thymidine uptake as well as the normal increase in cell number). The inhibitor is destroyed by trypsin but not by ribonuclease or deoxyribonuclease, and it is thermolabile. It has an acid IEP. It is not cytotoxic, and its inhibitory activity appears to be completely reversible. This fibroblast endogenous inhibitor does not interfere with the proliferation of DNA synthesis by human lymphocytes, bronchial carcinoma cells, or HeLa cells. The activity does not appear to be species specific. Therefore, we suggest that it is quite possible that the control of fibroblast proliferation resides in a fibroblast chalone. Diploid human fibroblasts, in contrast to chicken or mouse fibroblasts or heteroploid fibroblasts in general, stringently require serum for their proliferation. All of this mitogenic activity of calf serum can be concentrated in a molecular weight range around 100,000 daltons by ultrafiltration. All of the mitogenic activity within this molecular weight class can be concentrated at a pH of 5.2 via isoelectric focusing, and all of the activity at this isoelectric point can be concentrated in one peak on preparative polyacrylamide gel electrophoresis. This latter material is homogeneous at three different pH's in analytical gel electrophoresis as well as in SDS electrophoresis. This purified serum mitogen for diploid human fibroblasts in vitro also works in vivo and represents as much as 0.5% of calf serum protein, albeit there is much less of this protein in adult cow or horse. It is composed of two equal subunits weighing about 60,000 daltons each and contains about 2 moles of sialic acid, one S-S bond, and 6 moles of hexose per subunit. There is a reciprocal relationship between the biological activity of fibroblast inhibitor and serum mitogen, but there is no apparent direct interaction between these two proteins. Addition of pure serum mitogen to diploid human fibroblasts in vitro results in the release of commensurable chalone activity into the medium and a reciprocal loss of mitogen from the medium. Therefore, we propose that serum contains a single macromolecule which competes with endogenous chalone on the surface of diploid human fibroblasts and that this functions as an anti-chalone for the fibroblast.

Cells, Cultured↗
PubMed1975

Lymphocyte chalone concentrates and their effects upon leukemic cells in vitro.

Lymphocyte chalone is a cell-specific but not species-specific noncytotoxic and endogenous inhibitor of the transformation and mitotic activity of normal lymphocytes stimulated in vitro by either lectins or antigens. However, human- and mouse-established lymphoblastic cell lines were killed and their uptake of thymidine was inhibited after incubation for almost one complete mitotic cell cycle. The chalone lymphocytotoxicity effect was also demonstrated, using primary cultures of EL-4 lymphoma cells. Lymphocyte chalone was highly cytotoxic to leukemic cells under crowded condition (cells in G1-G0) in contrast to S phase chemotherapeutic agents. Finally, thymus chalone lymphocytotoxicity appears to be specific for T versus B lymphoblastic cell lines.

Animals↗