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Biomedical subjects

J H Wallace

Publications and source records attributed to J H Wallace.

At least 19 recordsLinked to original sources
PubMed1989

Assessment of a method for immunochemical detection of antigen on nitrocellulose membranes.

Immunoblotting techniques are widely used for detection of antigen immobilized on nitrocellulose membranes. There are many immunolabeling methods and staining methods available to disclose the presence of antigen in such techniques. Five common staining methods each for alkaline phosphatase and horseradish peroxidase were examined. The staining methods with the highest sensitivity and the lowest background were selected for studies comparing five immunological labeling methods using human IgG as a model antigen. Results were evaluated on the basis of the least amount of detectable antigen and background staining. The most sensitive dot-blot method was then tested for its applicability to Western blots. For both dot-blots and Western blots, the immunoalkaline phosphatase methods are more sensitive than the corresponding immunoperoxidase methods. The use of biotinylated secondary antibodies and an avidin-enzyme conjugate is recommended. Disclosure of alkaline phosphate is best achieved with naphthol AS phosphate as substrate and fast blue BB as chromogen. Peroxidase is best stained using H2O2 and diaminobenzidine (DAB). Potential endogenous enzyme activities are demonstrable by blotting methods but can be inhibited by including levamisole in the disclosure reaction medium for calf intestinal alkaline phosphatase indicators, or by incubation of blots with sodium azide and hydrogen peroxide before immunolabeling when using horseradish peroxidase indicators.

Alkaline Phosphatase↗
PubMed1989

Differential regulation of the immune response to SRBC by monoclonal antibodies to interferon-gamma.

Three monoclonal antibodies against different epitopes of interferon-gamma (IFN-gamma) were used to assess its role as a normal immunomodulatory molecule. Two of these antibodies were able to reduce significantly the primary antibody response to sheep erythrocytes in an in vitro culture system. One of these two antibodies has been reported to suppress both the antiviral and macrophage activation factor activities of IFN-gamma by binding to its carboxyl terminus. These findings indicate that IFN-gamma is an important lymphokine for the maximum expression of the immune response and that it acts via the carboxyl terminus of the molecule. This antibody suppressed the immune response only when added at the initiation of culture, suggesting that the action of IFN-gamma is on an early component of the response. The third monoclonal antibody, which binds to the amino end of IFN-gamma, did not suppress the in vitro response. However, it was able to block the effects exerted by an immunosuppressive dosage of exogenous IFN-gamma on in vitro antibody production. These results indicate that the immunosuppression vitro antibody production. These results indicate that the immunosuppression induced by the addition of IFN-gamma to a primary antibody response and the role that it plays in that response are mediated through different sites on the molecule and, therefore, probably by different mechanisms.

Animals↗
PubMed1987

Regulation of oxygen radical release from murine peritoneal macrophages by pharmacologic doses of PGE2.

The ability of pharmacologic doses of PGE2 to alter the release of superoxide (O2-) and hydrogen peroxide (H2O2) from elicited peritoneal macrophages (M theta) was studied. Twice-daily administration of 200 or 100 micrograms of PGE2 to mice during accumulation of peritoneal M theta resulted in a significant reduction in M theta recovery and in the triggered release of H2O2, but not O2-. Cultivation of elicited M theta from normal mice with concentrations of PGE2 in excess of 10(-7) M for 24-48 h resulted in a significant reduction in the triggered release of H2O2, but not O2-. Cultivation for shorter periods of time or with lower concentrations of PGE2 failed to alter H2O2 release. This effect of PGE2 was reproduced by the phosphodiesterase inhibitor theophylline. The ability of PGE2 to inhibit H2O2 release in the presence of normal production of O2- was not prevented by the addition of superoxide dismutase. Cultivation of peritoneal M theta with 10(-5) M PGE2 for 48 h failed to increase intracellular catalase, although increased H2O2 scavenger activity was demonstrated. The inhibition of extracellular release of H2O2, but not O2-, by pharmacologic doses of PGE2 may be one mechanism for the anti-inflammatory action of this compound.

Animals↗
PubMed1986

Measurement of gastric emptying rate in humans by real-time ultrasound.

Simultaneous studies of gastric emptying by ultrasound and scintigraphy were performed in 14 subjects to assess the use of ultrasound for the measurement of gastric emptying rate. The presence of air in the stomach prevented the acquisition of gastric emptying data by ultrasound in 3 of the 14 subjects. In the remaining 11 subjects there was no significant difference between values for the half-time (t1/2) of gastric emptying obtained by scintigraphy [for anterior imaging, mean t1/2 = 20.9 +/- 9.9 min (+/- SD); for anterior and posterior imaging, geometric mean t1/2 = 21.1 +/- 10.5 min (+/- SD)] compared with those derived by ultrasound [mean t1/2 = 20.2 +/- 10.0 min (+/- SD), p greater than 0.05 for each comparison]. A significant correlation between the t1/2 of gastric emptying derived by scintigraphy (anterior scanning and geometric mean of counts obtained by anterior and posterior scanning) and the t1/2 measured by ultrasound was obtained (r2 = 0.7, 0.69, respectively). These results imply that ultrasound can be used for the valid assessment of the gastric emptying rate in humans.

Adult↗
PubMed1986

Variable susceptibility to immune complex glomerulonephritis among mice sharing the same major histocompatibility complex.

Three inbred strains of mice were identified which demonstrated different susceptibilities to induction of immune complex glomerulonephritis (ICGN) despite sharing the same major histocompatibility complex haplotype (H-2k). Groups of mice from each of these three strains, B10.BR, CBA and C3H/HeJ, were injected with one of two different dose schedules of horse apoferritin (HAF) for 4 weeks, after which glomerular morphology, immunoglobulin deposition, and serum anti-HAF antibody levels were examined. With either dose schedule, only those mice which demonstrated a high level antibody response developed ICGN and glomerular immunoglobulin deposition. These results suggest that susceptibility to ICGN in this model is related to the level of antigen exposure and to the magnitude of the antibody response, which is not under strict control of the major histocompatibility complex.

Animals↗
PubMed1985

Alterations in serum antibody and peripheral T-lymphocyte subsets resulting from treatment of murine immune complex glomerulonephritis with PGE2.

The effects of treatment with 16,16-dimethyl prostaglandin E2 (DMPGE2) on histologic damage, glomerular immune complex deposition, serum total IgG subclass levels, anti-apoferritin IgG levels, and peripheral blood T-lymphocyte subsets were determined in apoferritin-induced immune complex glomerulonephritis of mice. The results demonstrate that doses of DMPGE2 ranging from 2.5 to 10 micrograms twice daily significantly reduced the degree of glomerular damage in a dose-dependent manner. Similarly, these doses of DMPGE2 reduced the amount of immunoglobulin deposition along peripheral capillary loops. Total IgM, IgG1, IgG2a, and IgG2b were unaffected by DMPGE2 administration. Serum anti-apoferritin IgG levels were significantly reduced in mice receiving DMPGE2 at doses of 5 and 10 micrograms twice daily. Nephrotic mice had significantly reduced peripheral blood total T lymphocytes (Lyt-1+) and a reduction of T-suppressor (Lyt-2+) cells. Administration of DMPGE2 at doses of 5 and 10 micrograms twice daily prevented these T-lymphocyte alterations. These studies indicate that treatment of mice receiving apoferritin with DMPGE2 may prevent glomerulonephritis by altering both cellular and humoral immune responses.

16,16-Dimethylprostaglandin E2↗
PubMed1985

Serial changes in humoral and cellular immunity induced by prostaglandin E2 treatment of murine immune complex glomerulonephritis.

To examine the mechanism by which prostaglandin E2 (PGE2) inhibits the development of apoferritin (HAF)-induced immune complex glomerulonephritis (ICGN), weekly determinations of glomerular histologic conditions, blood urea nitrogen (BUN), total immunoglobulin levels, anti-HAF antibody, peripheral blood and splenic T cell subsets, and splenic suppressor cell activity were compared between mice receiving HAF and mice additionally treated with PGE2. PGE2 therapy prevented the development of glomerular hypercellularity and the increase in BUN concentration. Administration of PGE2 reduced anti-HAF IgG levels, but total IgM and IgG1, IgG2a, and IgG2b levels were unchanged. Mice receiving HAF alone demonstrated serial reductions in phenotypically identified peripheral blood pan-T cells and suppressor-cytotoxic T cells. PGE2-treated mice maintained normal levels of peripheral blood T cell subsets. Significant reductions in splenic total T cells and suppressor-cytotoxic cells occurred in mice receiving HAF as compared with normal mice. This reduction was offset by an increase in splenic B cells. PGE2 therapy prevented the decrease in splenic T cells at week 1, but not at week 4. Nonspecific suppressor cell activity, as measured by the ability of spleen cells from experimental mice to suppress a mixed lymphocyte reaction (MLR) or to suppress MLR-induced polyclonal IgG synthesis, was not different between the two groups. We conclude that prevention of HAF-ICGN by PGE2 is associated with a reduction in nephritogenic antibody production without an alteration in total immunoglobulin synthesis or the generation of nonspecific suppressor T cells. Changes in the percent of peripheral blood and splenic T cells and B cells may represent an effect of PGE2 on antigen-stimulated B cell proliferation.

Animals↗
PubMed1985

Ultrasonography in the diagnosis of thyroid lymphoma.

Lymphoma of the thyroid is a rare condition, classically occurring in elderly caucasian women, presenting as a rapidly enlarging, symptomatic mass. Almost all examples are due to non-Hodgkin's lymphoma, and the lesion is commonly superimposed on pre-existing Hashimoto's thyroiditis. Prognosis is best if the disease is diagnosed early and while confined to the thyroid region, there being a favourable response to radiotherapy alone. Unfortunately, lymphoma is rarely considered in the differential diagnosis of thyroid masses, often leading to unnecessary, excessive surgery. Ultrasonography of five patients was analysed to determine if any common diagnostic features were present. All had a similar pattern, with a large, circumscribed, solid hypoechoic mass. Although nonspecific, this appearance, with awareness of a rapidly growing mass, should alert the radiologist and attending clinician to the possibility of lymphoma.

Adolescent↗
PubMed1984

Monoclonal antibody analysis of responder and stimulator cells in the human autologous mixed lymphocyte reaction.

Responder and stimulator cell subpopulations in the autologous mixed lymphocyte reaction (AMLR) were determined with the OK series of monoclonal antibodies. Mitomycin-C-treated, monocyte-enriched cell populations were used as stimulator cells in the AMLR. Treatment of these monocytes with either OKM and/or OKI monoclonal antibodies and complement resulted in a marked loss of ability of these cells to act as stimulators in the AMLR. Removal of OKT3+ and OKT4+ cells diminished the proliferative responses of AMLR cultures. Interaction of T cells with autologous monocytes resulted in generation of cells capable of suppressing both MLR and AMLR cultures. The suppressor activity of these cells was diminished by treatment with OKI , OKT4 or OKT8 monoclonal antibodies. No cytotoxic activity to autologous or allogeneic monocytes was observed. Additional studies showed an increased number of OKT9 + and OKI + as well as OKT8+ T cells in the AMLR responder cell population. This study indicates that cultures of T lymphocytes with autologous monocytes yield T cell subset(s) which suppress MLR and AMLR reactivity.

Antibodies, Monoclonal↗
PubMed1983

Treatment of murine immune complex glomerulonephritis with prostaglandin E2: dose--response of immune complex deposition, antibody synthesis, and glomerular damage.

A model of immune complex glomerulonephritis (ICGN) produced in mice by the daily injection of apoferritin was employed to study the effect of treatment with various doses of prostaglandin E2 (PGE2) on glomerular damage, immune complex deposition, proteinuria, and serum anti-apoferritin antibody. Administration of PGE2, 200 micrograms twice daily, resulted in a significant decrease in glomerular damage and immune complex deposition, prevented the development of proteinuria, and significantly reduced serum levels of anti-apoferritin antibody. PGE2, 100 micrograms twice daily, resulted in a decrease in immune complex deposition as assessed by immunofluorescence microscopy, but this dosage did not significantly alter glomerular damage, proteinuria, or antibody levels. PGE2 dosages of 50 and 25 micrograms twice daily had no effect on any of these parameters. The protective effect of PGE2 on the development of ICGN occurred only at dosages that were associated with decreased anti-apoferritin antibody.

Animals↗
PubMed1983

Phenotype of the hairy cells of leukemic reticuloendotheliosis defined by monoclonal antibodies.

Hairy cell populations of greater than 90 purity were prepared from six samples obtained from four patients with leukemic reticuloendotheliosis (LRE). These then were analyzed for surface immunoglobulin (SIg) and antigens specified by a panel of monoclonal antibodies. The hairy cells from all patients displayed SIg and antigens reactive with OKIa-1 and OKM-1 antibodies; these markers often were expressed simultaneously. T-cell-specific antigens were not displayed on the surface of hairy cells. The simultaneous expression of SIg and OKM-1 which ordinarily are unique for B cells or myeloid cells, respectively, suggests that hairy cells may represent an aberrant form of either cell type with defective regulation of antigen expression. It alternatively suggests the possibility that B cells and myeloid elements develop along a common pathway and that the hairy cell is a component of such a pathway.

Adult↗
PubMed1982

Generalized monocyte deficiency in leukaemic reticuloendotheliosis.

Examination of the blood of 40 patients with leukaemic reticuloendotheliosis (LRE) revealed a drastic reduction in monocyte numbers (mean 74/microliter) when compared to a normal group of 33 (mean 442/microliter). Repeated blood studies in 8 LRE patients were made over periods of 2 months to 5 years and monocytopenia was observed to be a persistent phenomenon. Similarly, tissues from 29 patients showed an overall decrease in numbers of monocytes/ histiocytes when compared with those of 73 control subjects. Skin window examinations in all 11 patients so studied showed marked reduction or absence of monocyte response to inflammation. 2 exceptional cases to this trend are noted. In one, circulating monocyte levels remained normal over a 14-month period while examinations of blood and marrow in this case showed few hairy cells. In another case, severe and persistent monocyte deficiency was noted during a 2-year period of unsuccessful treatment. When he eventually responded to low dose chlorambucil and his Hb rose from 40-140 g/l and WBC became normal, the number of circulating monocytes also became normal.

Esterases↗
PubMed1981

The prickly lettuce agglutinin. II. Immunobiological properties.

The prickly lettuce agglutinin (PLA), extracted from leaves of the plant Lactuca scariole, was tested for immunomodulatory effects on C57BL/6 mice. When administered with antigen in vivo, 50 micrograms PLA caused an enhancement of the primary splenic plaque-forming cell (PFC) response to the helper T cell-dependent antigens sheep red blood cells and trinitrophenyl-keyhole limpet hemocyanin; higher doses of PLA (200 micrograms) resulted in depressed responses to these antigens. Similarly, 50 micrograms PLA enhanced the B cell response to SIII, a helper T cell-independent antigen, but higher doses did not cause significant depression of the SIII-specific PFC response. When PLA (less than 25 micrograms) was coincubated with spleen cells and antigen, sheep red blood cells or SIII, in vitro the primary PFC response was enhanced; higher doses of PLA (greater than or equal to 25 micrograms) depressed cell culture viability and also depressed the resultant PFC responses. In the in vitro studies, stimulatory doses of PLA were effective only when added to cultures before or with antigen. In tests for mitogenic effects of PLA on spleen cells, PLA was found to be nonstimulatory. On the basis of these observations, we suggest that PLA may modulate murine splenic primary B cell responses by providing a stimulatory signal to B cells. The nature of the suppressive effect in vivo is unknown but may be attributable to antigenic competition.

Animals↗