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Biomedical subjects

K L Erickson

Publications and source records attributed to K L Erickson.

At least 109 records · Page 6Linked to original sources
PubMed1983

Dietary lipid modulation of immune responsiveness.

The influence of dietary fat concentration and saturation on blastogenesis, cytotoxicity, antibody response and fatty acid composition of murine splenic lymphocytes was studied. Blastogenesis of lymphocytes from dietarily manipulated mice in response to alloantigens from control mice was significantly greater for those mice fed a diet containing minimal essential fatty acids (EFA) as the only fat source (EFA control) than those fed an EFA-deficient diet. When the dietary fat concentration was increased, blastogenic response decreased compared to the EFA control diet. Lymphocyte-mediated cytotoxicity against allogeneic melanoma cells was greater for mice receiving diets with EFA only than for those deficient in EFA. However, cytotoxicity responses of mice fed additional polyunsaturated fat (PUF) decreased as concentration increased, whereas responses of mice fet the saturated fat (SF) diets decreased only when the dietary fat concentration was greater than 8%. As compared to diets with EFA control, direct plaque-forming cell (PFC) response was decreased for mice fed high levels of PUF and increased for mice fed high levels of SF; however, no difference in the percentage of IgM-positive cells was observed. These changes in PFC response were inversely related to the levels of linoleic acid in the lymphocyte. Thus, high levels of dietary fat, and particularly PUF, suppress lymphocyte functions when EFA requirements are met, whereas low levels (EFA control) intensify these responses. EFA deficiency, however, suppress some lymphocyte responses. Thus, dietary lipids differentially modulate the levels of T- and B-cell responsiveness.

Animals↗
PubMed1983

Effects of dietary zinc on melanoma growth and experimental metastasis.

These studies were designed to determine the effects of zinc on in vitro melanoma cell growth and in vivo metastasis. Cultured P51 mouse melanoma cells were larger, had longer doubling times and a decreased rate of tritiated-thymidine uptake when grown in zinc depleted compared to standard medium. Experimental metastasis was evaluated using intravenously injected, radiolabelled melanoma cells. Cell distribution and survival were determined 1, 3 and 21 days post-injection in C57BL/6 mice fed low zinc (0.5 and 4.0 mg Zn/kg) or stock diets. Altered organ distribution and survival of melanoma cells were observed in the zinc depleted dietary groups compared to the stock diet group. After 21 days of tumor growth, lungs of mice fed diets low in zinc contained up to 50% fewer labelled tumor cells than those of mice fed the stock diet. Livers of mice in the 0.5 mg Zn/kg group contained a greater percentage of tumor cells 21 days post-injection than those of mice fed the stock diet. Thus, dietary zinc can influence experimental tumor metastasis through modification in organ distribution of tumor cells and their subsequent survival.

Animals↗
PubMed1983

Effects of supplemental zinc on melanoma metastasis in mice.

The influence of a single intraperitoneal injection of zinc (0.5, 1.5 and 4.5 mg/kg) on the metastasis and subsequent growth of radiolabelled melanoma cells was examined in mice receiving tumor cells s.c. or i.v. 24 h following zinc treatment. Parenteral zinc resulted in increased tumor cell survival in the liver, spleen and lungs of zinc-treated mice 1 day post-injection, while 21-day cell survival was enhanced in the spleens of s.c. injected, zinc-treated mice. Regardless of zinc exposure, relative numbers of s.c. injected tumor cells decreased with time in the lungs and spleen, while increasing in the liver and kidneys. A single dose of zinc can modify the organ distribution and viability of metastatic tumor cells in mice.

Animals↗
PubMed1983

Effect of dietary triglycerides on lymphocyte transformation in rats.

Weanling rats were fed casein-based diets containing purified and mixed triglycerides to evaluate the effect of these lipids on mitogen-induced lymphocyte transformation, lymphoid organ weights, and fatty acid profiles of the total lipid in plasma, spleen, and thymus. Test lipids were added at a level of 8 g per 100 g of diet. All diets contained 0.82 g of safflower oil per 100 g. The digestibility coefficients for tristearin, tripalmitin, and trimyristin were 20, 37, and 85%, respectively. Digestibility coefficients for all remaining triglycerides were 90% or greater. The differences in mitogen-induced lymphocyte transformation among rats fed the various dietary lipids were unrelated to saturation of the lipid and correlated negatively with total lipid absorbed. Except for tripalmitin and tristearin, dietary lipids significantly altered the fatty acid profiles of the total lipids in plasma, spleen and thymus. It was concluded that the fatty acid profiles of the total lipid in plasma, spleen and thymus can be altered without accompanying major changes in mitogen-induced blood lymphocyte transformation. It was further concluded that mitogen-induced lymphocyte transformation was unrelated to saturation of dietary lipid and appeared to be associated negatively and weakly with the quantity of dietary lipid absorbed.

Animals↗
PubMed1983

Macrophage-mediated inhibition of melanoma cell growth in nude mice.

The effects of macrophages or sera from tumor-transplanted or control syngeneic and allogeneic mice on the latency and growth rate of P51 murine melanoma cells were determined after transplantation into congenitally athymic (nude) mice (tumor neutralization test). Syngeneic macrophages from tumor-bearing mice (TBM) inhibited melanoma growth in the nude mouse more than control macrophages, additionally macrophages from sensitized allogeneic mice inhibited melanoma growth to a greater degree than did allogeneic control macrophages. Sera from TBM inhibited melanoma growth as compared to control cells alone. Macrophages obtained after 14 days were also cytolytic towards the melanoma target in vitro. Despite the growth of large local masses, no evidence of distant metastases was found. The nude mouse thus provides an appropriate model for this tumor to portray in vivo immunotherapy.

Animals↗
PubMed1983

Modulation of murine lymphocyte and macrophage proliferation by parenteral zinc.

The effects of a single i.p. injection of zinc (0.7, 1.3, 4.0 or 12.0 mg/kg), 24 h prior to sacrifice, on lymphocyte blastogenesis as well as lymphocyte and macrophage progenitor cell proliferation were examined using cells from adult BALB/c mice. Splenic lymphocyte blastogenesis in response to T cell mitogens decreased for mice receiving the highest zinc dosage while responses to B cell mitogens were initially depressed, subsequently increased, and finally declined sharply as the LD50 was approached. Splenic B cell colony formation decreased linearly in relation to zinc dosage with a 50% suppression of colony formation observed at approximately 8.0 mg/kg. In contrast, bone marrow granulocyte-macrophage colonies were enhanced at higher dosages (greater than or equal to 2.5 mg/kg) of zinc. These results indicate that zinc exposure at dosages less than the LD50 can influence lymphocyte blastogenesis and clonal expansion of both B cell and macrophage progenitors.

Animals↗
PubMed1983

Activation of tumoricidal properties in human blood monocytes by liposomes containing lipophilic muramyl tripeptide.

Peripheral blood monocytes were isolated from normal human donors by separation on a continuous Percoll gradient and adherence to yield preparations of blood monocytes with a high degree of purity (greater than 99%). The monocytes were incubated in vitro with medium alone or with multilamellar liposomes that contained either a lipophilic derivative of muramyl dipeptide, muramyl tripeptide (MTP-PE), or medium. The cytotoxic properties of the monocytes were assessed by an in vitro radioisotope release assay against various allogeneic targets. Monocytes that have phagocytosed liposomes containing MTP-PE were rendered tumoricidal. These monocytes lysed cells of three different tumorigenic lines but not cells of two nontumorigenic lines. The ability of MTP-PE-activated human blood monocytes to recognize and selectively lyse neoplastic cells was also demonstrated under cocultivation conditions. We conclude that human blood monocytes can be rendered tumoricidal after interaction with liposomes containing MTP-PE.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1982

Clonal proliferation of peritoneal exudate cells from New Zealand black mice: age-related changes.

Proliferation and differentiation of peritoneal exudate colony-forming cells (PE-CFC) were examined in BALB/c, C57BL/6, and NZB mice; NZB mice provided an experimental animal model for studies of autoimmunity. At 1 and 12 months of age, the number of PE-CFC from NZB mice was significantly less than the number of PE-CFC for other tested strains, whereas the number of clusters formed was reduced only in the older NZB mice. In contrast, 1- to 12-month-old BALB/c and C57BL/6 mice showed no significant age or strain-dependent alterations in PE-CFC. Although the latency period preceding colony growth remained constant for all strains and ages, significant variation in colony size was observed for NZB mice; the largest colonies were noted in the oldest group. We also observed age-associated variations in colony morphology; therefore, age- and strain-dependent differences may exist in the differentiation or functional attributes of PE-CFC subpopulations. The results specifically indicate that NZB mice have age-related alterations in PEC proliferative and differentiation capacities.

Aging↗
PubMed1982

Inherited 7S immunoglobulin deficiency of chickens is associated with bursal degeneration anomalies.

Partially inbred line UCD 140 chickens develop an age dependent inherited 7S immunoglobulin deficiency with features similar to acquired human agammaglobulinemia. Serial and developmental observations in line UCD 140 and control lines 440 and 444 reveal a significant progressive premature involution of the bursa of Fabricius. These bursal changes are characterized by epithelial and medullary degeneration, reduced follicular bursacyte mitosis, and decreased follicular plasma cells. These abnormalities have not been previously described in other avian systems and suggest that this immune deficiency is due to a primary bursal disease.

Agammaglobulinemia↗
PubMed1981

Current concepts in the surgical treatment of patients with myasthenia gravis.

Patients undergoing surgical treatment often have concurrent diseases. An in-depth understanding of such diseases permits the dentist to initiate treatment with minimal risk to the patient. Myasthenia gravis (MG) is one such disease; it is characterized by various degrees of muscle weakness and fatigue. Many of the physical signs and symptoms affect the oral and facial musculature. A review of the symptoms, etiology, and treatment of myasthenia gravis, with special reference to the patient undergoing surgical treatment, is presented.

Adult↗
PubMed1980

Influence of dietary fat concentration and saturation on immune ontogeny in mice.

Dietary fat modulation of immune responsiveness was studied using a murine model subjected to prenatal and postnatal dietary manipulation. The weight of lymphoid associated organs, particularly the spleen, thymus and liver were significantly influenced by dietary fat saturation and concentration whereas other organs studied were not influenced by this manipulation. The serum immunoglobulins IgG1 and IgG2, but not IgM or IgA, increased in mice fed the polyunsaturated fat (PUF) diet as compared to the levels in those mice fed the saturated fat (SF) diet. While dietary manipulation generally did not influence the peripheral differential blood cell counts, the percentage of immunoglobulin positive splenic cells changed with dietary manipulation; the percentage of T cells, however, was not influenced by the experimental diets. In contrast, T-cell blastogenesis was influenced by both saturation and concentration of dietary fat whereas B-cell transformation was influenced by neither variable. Changes in T-cell responses were manifested through changes in the lymphocytes, and not cell numbers; PUF, particularly high levels, suppresses lymphocyte blastogenesis whereas low levels or a deficiency of PUF intensify this response. It is concluded that dietary fats influence the modulation and level of immune function.

Animals↗
PubMed1979

Effects of low dietary protein concentration and energy deprivation on lymphocyte transformation in melanoma-bearing mice.

Temporal changes in lymphocyte blastogenesis were studied using spleen cells from syngeneic melanoma-bearing and control mice fed various levels of purified diets containing 6, 10 or 30% casein. T-cell blastogenesis was stimulated by the presence of the tumor and these responses changed with the duration of feeding. In addition, protein concentration did not affect T-cell transformation but the level of energy intake influenced concanavalin A induced DNA synthesis. In contrast, the growing melanoma did not influence B-cell transformation whereas a very low level of dietary protein, a low level of energy intake and duration of the dietary manipulation influenced these cells. Tumor weights were generally not affected by the diet except in mice receiving a very low level of energy intake. Thus, we have found that B-cell responses were affected more than those of T-cells and that moderate protein deficiency did not enhance cellular immune responses in syngeneic tumor-bearing and control mice.

Animals↗
PubMed1979

The influence of dietary protein concentration and energy intake on mitogen response and tumor growth in melanoma-bearing mice.

The effects of energy deprivation and low or high dietary protein levels upon lymphocyte transformation of spleen cells from syngeneic tumor-bearing and control mice were studied in a murine model of malignant melanoma. Both T- and B-lymphocyte transformation were significantly stimulated by the presence of a growing melanoma. T-cell responses however, were dependent only upon dietary protein concentrations, not the level of energy intake; whereas, the converse was true for B cells. Moreover, mice fed stock diet had the lowest response to mitogens of all diets tested. Except for mice receiving a 15% casein diet, tumor weights were generally not affected by level of intake or the amount of dietary protein. Others have demonstrated that melanoma cells have a greater need for tyrosine or phenylalanine than other tumor cells; thus we hypothesized that lymphocyte transformation may be depressed by relatively low phenylalanine or tyrosine levels in the diet when protein intakes are limited by either a low dietary concentration a restricted intake of a diet containing adequate protein, or both.

Animals↗
PubMed1979

Microspectrofluorometric analysis of surface antigens of murine melanoma and hamster peritoneal cell hybrids: comparisons of species antigenicity, chromosome number, and tumorigenicity.

Somatic cell hybrids from viral fusions of murine melanoma (PAZG) X Chinese hamster peritoneal cells (CH) were compared with respect to surface antigenicity, karyotype and tumorigenicity. One line, F57-(9), which arose from the hybridization of two CH cells and one PAZG cell, had slight (6%) CH chromosome loss but 80%PAZG chromosome loss after 10 months in culture. These cells expressed CH antigens strongly and PAZG antigens weakly. In comparison, another hybrid, F57-(7), formed from one CH and one PAZG cell, lost 20% of its chromosomes after 10 months in vitro. These cells had a stronger expression of PAZG antigens and weaker expression of CH antigens than F57-(9). These findings indicate a direct relationship between chromosome number and antigenicity; tumorigenicity, however, does not appear to depend on the chromosome numbers of the parental cells.

Animals↗
PubMed1979

Cell interactions in the initial contact between cultured melanoma cells and syngeneic macrophages.

Thioglycolate-induces peritoneal macrophages from melanoma-bearing mice (immune macrophages) or from control mice (control macrophages) were cultured with syngeneic melanoma cells (P51) to determine the surface characteristics of the effector cells during interaction and destruction of the target cells. After a short culture period (3 hours), immune macrophages had extensive connections via filopodia and ruffled membranes to the surfaces of the melanoma cells; control macrophages did not exhibit the same behavior. A dense region in the cytoplasm immediately beneath the macrophage plasmalemma was observed at the point of contact with the target tumor cell. With longer periods of culture (24 hours), effector cells began phagocytosis of the target cells; immune macrophages, however, had more fine filopodial connections and were more cytostatic than were controls. These observations indicate that one of the initial mechanisms of tumor cell destruction was contact-induced lysis, with phagocytosis playing a minor part.

Animals↗
PubMed1976

The use of ultraviolet light to induce melanogenesis in the epidermis of the rhesus monkey: an ultrastructural and biochemical study.

The general body epidermis of the rhesus monkey (Macaca mulatta) contains no discernible melanocytes, but after repeated ultraviolet irradiation DOPA-positive melanocytes appear and increase numerically up to 30 exposures. With continued irradiation, however, the number again declines. Experiments to determine how melanogenic activity, assayed by the incorporation of labeled DOPA or tyrosine, is related to DOPA positivity indicated that biochemical activity corresponded to the histochemical pattern. Ultrastructural studies demonstrated that after the exposure to ultraviolet light a pool of indeterminate cells in the skin of rhesus monkeys developed into malanocytes. The melanosomes formed by these cells, however, differed from the eumelanin melanosomes described in other species; they had no internal filamentous matrix with periodicity but appeared similar to phaeomelanin melanosomes. Long term ultraviolet light irradiation may damage keratinocytes and render them incapable of phagocytizing melanosomes.

Animals↗