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Biomedical subjects

A L Moore

Publications and source records attributed to A L Moore.

At least 109 records · Page 6Linked to original sources
PubMed1984

Specific antibody synthesis in vitro. I. Technical considerations.

Previously described methods for measuring specific antibody production in vitro are complex and frequently require the addition of a non-specific mitogen and 2 or more separate steps including a lymphocyte culture and then an antibody assay. In this report we present further details regarding a 1-step, non-mitogen requiring assay for specific antibody synthesis combining microculture and enzyme-linked immunoassay techniques. Peripheral blood mononuclear cells from recently immunized subjects are cultured in antigen-coated plastic wells and the specific antibody produced and adhered to the solid-phase antigen is measured in an enzyme-linked immunoassay. The production of specific antibody in vitro did not occur in lymphocyte preparations that were frozen, thawed and incubated, nor did it occur in cultures containing puromycin. T cell separation and remixture experiments indicated that T cells provide significant augmentation under the conditions of this assay. It is apparent that the antibody measured was synthesized in vitro and that cell-cell interactions are operant. The assay may prove useful in the assessment of immune competence and in determining in vitro the effect of certain biologic response modifiers on antibody production.

Antibodies, Bacterial↗
PubMed1984

Trifluoperazine inhibition of electron transport and adenosine triphosphatase in plant mitochondria.

Trifluoperazine inhibits ADP-stimulated respiration in mung bean (Phaseolus aureus) mitochondria when either NADH, malate, or succinate serve as substrates (IC50 values of 56, 59, and 55 microM, respectively). Succinate:ferricyanide oxidoreductase activity of these mitochondria was inhibited to a similar extent. The oxidation of ascorbate/TMPD was also sensitive to the phenothiazine (IC50 = 65 microM). Oxidation of exogenous NADH was inhibited by trifluoperazine even in the presence of excess EGTA [ethylene glycol bis(beta-aminoethyl ether)-N,N'-tetraacetic acid] (IC50 = 60 microM), indicating an interaction with the electron transport chain rather than with the dehydrogenase itself. In contrast, substrate oxidation in Voodoo lily (Sauromatum guttatum) mitochondria was relatively insensitive to the phenothiazine. The results suggest the bc1 complex to be a major site of inhibition. The membrane potential of energized mung bean mitochondria was depressed by micromolar concentrations of trifluoperazine, suggesting an effect on the proton-pumping capability of these mitochondria. Membrane-bound and soluble ATPases were equally sensitive to trifluoperazine (IC50 of 28 microM for both), implying the site of inhibition to be on the F1. Inhibition of the soluble ATPase was not affected by EGTA, CaCl2, or exogenous calmodulin. Trifluoperazine inhibition of electron transport and phosphorylation in plant mitochondria appears to be due to an interaction with a protein of the organelle that is not calmodulin.

Adenosine Diphosphate↗
PubMed1984

Influenza and aging: age-related changes and the effects of thymosin on the antibody response to influenza vaccine.

Despite massive immunization programs, influenza remains a major cause of morbidity and mortality for elderly people. This may occur because immune senescent recipients may respond to vaccination with inadequate antibody production. We measured antibody response to the trivalent 1983-1984 influenza vaccine in young and elderly volunteers and found a significantly reduced response in the latter. The age-associated decreased antibody production was also observed in lymphocyte cultures in which specific antiinfluenza antibody synthesis was measured. In these cultures, however, the addition of a thymic hormone preparation (either thymosin fraction 5 or thymosin alpha 1) was shown to enhance specific antibody synthesis to a greater extent in the cultures established from the elderly volunteers. If this in vitro observation of thymosin induced increased antibody production reflects what might occur in a clinical trial in which elderly subjects receive thymosin coincident with vaccine, greater protection against influenza infection may result.

Adult↗
PubMed1984

Specific antibody synthesis in vitro. II. Age-associated thymosin enhancement of antitetanus antibody synthesis.

A decline in T cell function accounts for many of the observed age-related deficient immune responses. Specific antibody response to many antigens requires T cell cooperation, and deficient antibody response to such antigens has been demonstrated with aging. In an effort to assess the potential reconstitutive capacity of Thymosin Fraction 5, in vitro antitetanus antibody production was measured in tetanus toxoid booster-immunized young and old volunteers. 22 young and 12 old volunteers were immunized with tetanus toxoid and plasma antitetanus antibody and in vitro lymphocyte production of antitetanus antibody was measured. Plasma antitetanus antibody response was significantly greater in the young. In vitro antitetanus antibody synthesis was negligible prior to immunization and peaked in cultures established 1 week after immunization from both young and old. When Thymosin Fraction 5 was added to the cultures, however, there was a dose-related enhancement of antibody synthesis in 7 of 10 from the group of elderly volunteers, but only 3 of 12 from the younger group. Our data indicate that specific antibody response is deficient in the elderly, but can be enhanced in vitro by thymosin. A future clinical trial of thymosin as an adjuvant to active immunization for the elderly is warranted.

Adjuvants, Immunologic↗
PubMed1984

Experimental tumors and aging: local factors that may account for the observed age advantage in the B16 murine melanoma model.

In the B16 murine melanoma model tumor growth has been shown to be slower in animals of advanced age. One feature associated with this slower growth has been prominent fibrosis demonstrated in biopsies of the tumor in older animals. We have performed experiments to examine the fibrotic response in young and old mice. In non-tumor bearing animals the capacity to regain skin strength after surgical laceration and healing by primary intention was greater in old mice. Histologic preparations suggested a more prominent fibrosis at the wound site. The animals who were injected subcutaneously with B16 melanoma and treated with L 3,4-dehydroproline (an inhibitor of collagen synthesis) local tumor growth was significantly enhanced only for the old animals. Although this inhibition of collagen synthesis produced a differential growth enhancement, there remained a significant difference in tumor volume between young and old animals. We conclude that fibrogenesis is an important host defense for containing local tumor growth and that this mechanism is preserved if not enhanced in mice of advanced age. Nevertheless other factors are needed to account completely for the observed age-advantage in the B16 melanoma model.

Aging↗
PubMed1984

B16 murine melanoma and aging: slower growth and longer survival in old mice.

The growth characteristics and colonization potential of a transplantable melanoma administered to young (3 mo) and old (24 mo) C57BL/6 mice were investigated. After sc injection of B16-F10 melanoma cells, tumor growth was slower, and final tumor volume was less in the older mice. Furthermore, after iv injection of B16-F1 melanoma cells, the number of pulmonary colonies was also less, and the survival was greater in the older mice. These findings indicate an age advantage in this experimental tumor model that may be attributed to either physical or immunologic factors.

Aging↗
PubMed1984

Transfer of age-associated restrained tumor growth in mice by old-to-young bone marrow transplantation.

B16 melanoma and Lewis lung carcinoma grow more slowly in aged mice. Immunesenescent changes may account for this age-related difference. To test for the effect of immune deficiency on the growth of these tumors, we treated young mice with an immunosuppressive dose of radiation and then observed tumor growth. We also radiated young mice to a higher (lethal) dose and then rescued them with either young or old bone marrow transfusion. Tumors grew more slowly in radiated mice than controls and in those reconstituted with old bone marrow. These findings support the concept of immunesenescent-related reduced tumor growth.

Aging↗
PubMed1983

Phosphate dependent, ruthenium red insensitive CA2+ uptake in mung bean mitochondria.

Energy linked Ca2+ uptake into mung bean mitochondria has been studied. Using arsenazo III as a monitor of extramitochondrial Ca2+, we observe a respiration-linked uptake of Ca2+ which requires phosphate and is insensitive to ruthenium red. The rate of uptake is of the order of 5 nmol/mg protein/min. Acetate, sulphate and thiosulphate are unable to support Ca2+ uptake. The results suggest that although plant mitochondria accumulate Ca2+ in an energy dependent fashion, it is not via a simple electrophoretic uniport mechanism.

Biological Transport, Active↗
PubMed1983

Evidence for a Ca2+ gradient across the plasma membrane of wheat protoplasts.

Fluxes of Ca2+ across the plasma membrane of isolated wheat protoplasts have been measured both as net accumulation and as uptake under steady-state conditions. The ATPase inhibitors, orthovanadate and diethylstibesterol, and the divalent cation ionophore, A23187, were all found to enhance net Ca2+ accumulation by protoplasts. The uptake of Ca2+ under steady-state conditions was also stimulated by A23187 but relatively unaffected by a range of plant hormones or by red or far red light. Light treatments were compared to dark controls with protoplasts isolated from etiolated wheat. The results suggest that plant cells maintain a Ca2+ gradient across their plasma membrane but it appears not to be under phytochrome control.

Calcimycin↗
PubMed1983

Cimetidine and the immune response. I. In vivo augmentation of nonspecific and specific immune response.

Cimetidine is a commonly prescribed histamine antagonist useful in the treatment of peptic ulcer disease. Histamine receptors are found on suppressor T cells and therefore we expected to observe enhanced immune responsiveness in animals treated with this drug. Mice given daily subcutaneous injections of cimetidine (25 or 100 mg/kg) were found to produce approximately twice as much specific antibody in response to tetanus toxoid immunization. Furthermore, mitogen-stimulated splenocytes from cimetidine-treated animals proliferated to a greater extent and produced more immunoglobulin in vitro than controls. These observations offer direct in vivo evidence for immunomodulation by cimetidine.

Animals↗
PubMed1983

Immunoblastic lymphadenopathy: failure of, rather than lack of immunoregulation.

The lymphoid proliferation characteristic of immunoblastic lymphadenopathy is polyclonal and of B cell lineage. This proliferation of B cells could result from an inherent B cell defect, prolonged and pronounced antigenic stimulation, or inadequate immunoregulation. We recently evaluated a patient with this disorder and found excessive T cell mediated in vitro suppression of both the autologous and allogeneic blastogenic response to mitogen. This enhanced in vitro suppression suggests that the clinically observed lymphoid proliferation in this patient occurred because of autonomous or excessively stimulated B cells and not because of a lack of functional suppressor cells.

Aged↗
PubMed1982

Measurements of membrane potentials in plant mitochondria with the safranine method.

The positively charged dye, safranine, has been used as an indicator of membrane potentials in mung bean (Phaseolus aureus) and Voodoo lily (Sauromatum guttatum) mitochondria under a variety of metabolic conditions. The spectral response of safranine has been calibrated with respect to a K(+) diffusion potential and was found to be linearly related to the developed potential within the range of 50 to 160 millivolts. Both respiration and ATP hydrolysis gave rise to a membrane potential of approximately 135 millivolts. Respiratory inhibitors such as cyanide and antimycin depolarized the potential, whereas rotenone has little effect. No potentials were developed during NADH supported cyanide insensitive respiration. It is concluded that safranine may be a useful spectrophotometric probe of the mitochondrial membrane potential.

Journal Article↗
PubMed1982

Specific in vivo and in vitro antibody response to tetanus toxoid immunization.

Booster immunization of normal individuals with soluble tetanus toxoid (TT) produced significant levels of plasma anti-tetanus IgG and IgM detectable by an enzyme linked immunosorbent assay (ELISA). Similar changes in circulating anti-TT antibody were found in mice following primary immunization. There was. however, no correlation observed between circulating anti-TT antibody response and the proliferative response of peripheral blood mononuclear cells exposed to soluble TT in the immunized individuals. The capacity of the peripheral blood mononuclear cells to produce specific anti-TT antibody in vitro was evaluated using a new microculture antibody synthesis enzyme-linked assay (MASELA). It was observed that the production of specific antibody in vitro correlated with the circulating anti-TT antibody level and not with the proliferative response. Peripheral blood mononuclear cells from these recently secondary immunized individuals produced greater specific anti-TT antibody when cultured in TT coated plastic wells than did controls. The potential utility of this technique in assessing response to immunization and basic immune competence is discussed.

Adult↗
PubMed1981

A comparison of the phosphorylation potential and electrochemical proton gradient in mung bean mitochondria and phosphorylating sub-mitochondrial particles.

The phosphorylation potential (delta Gp) and the electrochemical proton gradient (delta muH+) normally maintained during respiration or ATP hydrolysis by mung bean hypocotyl mitochondria and phosphorylating sub-mitochondrial particles have been investigated. Phosphorylation potential experiments using safranine and oxonol-VI, as membrane potential markers for mitochondria and sub-mitochondrial particles, respectively, suggest that the 'null point' delta Gp (i.e., the phosphorylation potential at which no change in optical signal occurred) corresponds to a value of 15.2 +/- 0.7 kcal/mol in mitochondria and 11.2 +/- 0.3 kcal/mol in sub-mitochondrial particles. The value of delta muH+ generated by the hydrolysis of ATP was estimated using ion distribution techniques. In each case a rapid centrifugation technique was used to separate the organelle from the suspending medium. The total delta muH+ generated in each case was approx. 200 mV being composed of both membrane potential and pH components. A comparison of delta muH+ with delta Gp indicates that the apparent H+/ATP ratio in mung bean mitochondria is 3.4 +/- 0.2 while in phosphorylating sub-mitochondrial particles it is 2.2 +/- 0.1.

Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone↗
PubMed1981

Amplified lymphokine production phenomenon confirmed by a macrophage 2-D-[3H]deoxyglucose transport assay.

The amplified lymphokine production phenomenon was confirmed by using an improved macrophage 2-d-[(3)H]deoxyglucose uptake assay as an indicator of lymphokine activity. Amplified lymphokine titers were determined in supernatants derived from tuberculin-sensitive, antigen (purified protein derivative)-stimulated, guinea pig peritoneal exudate and spleen cell suspensions after the cells were allowed to sediment into a pellicle in a conical culture tube. The deoxyglucose uptake assay, which probably measured an effect on the macrophage cell membrane, was easy to perform, and the prozone phenomenon observed with other lymphokine assay systems did not occur. The deoxyglucose uptake-enhancing moiety was stable at 56 degrees C for 1 h and had a molecular weight of between 50,000 and 100,000, as defined by Amicon ultrafiltration. Exposure of macrophages to the lymphokine-containing supernatants did not increase macrophage deoxyglucose uptake significantly until after 9 h of incubation had elapsed. The effect on deoxyglucose uptake was to increase the V(max) without changing the K(m) value. Deoxyglucose uptake also involved a stereospecific carrier-facilitated transport system both in the presence and in the absence of lymphokine. The increased deoxyglucose transport induced by the lymphokine-containing supernatants was reversible. A migration inhibitory factor activity of similar molecular weight and heat stability was also present in these supernatants, but in titers lower than the titers of the deoxyglucose uptake-enhancing activity. Consequently, in the absence of a complete biochemical characterization, the two effects cannot be ascribed to the same molecular species at this time. Such a characterization, along with studies of lymphokine production and action, should be facilitated greatly by the availability of very high-titer supernatants derived by this geometric culture method.

Animals↗
PubMed1981

A lymphokine resembling transfer factor that stimulates MIF production by nonsensitive lymphocytes.

High potency preparations of a new heat-labile, low m.w. (less than 5000) lymphokine (LMWL) were obtained by culturing tuberculin-sensitive guinea pig peritoneal exudate cells (PEC) with PPD in geometric conditions that promote amplified lymphokine production. This LMWL has the ability, in the presence of PPD, to stimulate nonsensitive PEC to produce a heat-stable molecule(s) resembling MIF with a m.w. in the range 50,000 to 100,000. The effects of the LMWL (less than 5000 daltons) and the MIF-like molecule(s) (50,000 to 100,000 daltons) were defined by the indirect macrophage migration assay and a macrophage deoxyglucose uptake assay. It is possible that LMWL represents a form of transfer factor with the ability to recruit unsensitized lymphocytes to produce MIF.

Animals↗