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Biomedical subjects

D Wallace

Publications and source records attributed to D Wallace.

At least 145 records · Page 8Linked to original sources
PubMed1984

Physiology of IgD. IV. Enhancement of antibody production in mice bearing IgD-secreting plasmacytomas.

Immune responses to trinitrophenylated hemocyanin (TNP-KLH), Ficoll (TNP-Ficoll), and Brucella abortus (TNP-BA) were examined in BALB/c mice bearing subcutaneous transplants of TEPC-1017 and TEPC-1033, the two known IgD-secreting BALB/c plasmacytomas. Both primary and secondary 19S and 7S splenic plaque-forming cell (PFC) responses in spleen to intravenously injected TNP-KLH were enhanced three to fivefold. Primary responses to TNP-Ficoll were 1.5-2 times higher than in control mice (particularly the 7S PFC response). Primary responses to TNP-BA were enhanced by TEPC-1017 but suppressed by TEPC-1033, while secondary responses to TNP-BA were enhanced three to sevenfold by both tumors. Intraperitoneal injections of ascites fluid from mice bearing TEPC-1017 or TEPC-1033, or of IgD isolated from such ascites fluid, caused a similar enhancement of the primary response to TNP-KLH, as did the tumor itself, particularly when injected approximately 1 wk before antigen injection. IgD-containing ascites fluid had no effect on the response of athymic (nu/nu) BALB/c mice to TNP-KLH. These findings suggest the existence of an IgD-responsive immunoregulatory T cell.

Animals↗
PubMed1983

Comparison of the transport of chlorozotocin and CCNU in L1210 leukemia and murine bone marrow cells in vitro.

The uptake of radiolabeled CLZ and CCNU by L1210 leukemia and murine bone marrow cells was investigated to determine whether the preferential ratio of alkylation of L1210 DNA to murine bone marrow DNA of 1.3 by 0.1 mM CLZ, as against a ratio of 0.6 by equimolar CCNU, is secondary to differences in uptake. The concentration of intact CLZ was determined in the medium and the intracellular water space. The cell: medium ratio (intracellular concentration/medium concentration) of CLZ in bone marrow cells was greater than that seen for L1210 cells. However, the intracellular CLZ concentration generally remained constant in both cell types at 37 degrees C, between 7.0 and 10.0 pmole/microliters. The L1210: murine bone marrow cell ratio of intracellular CLZ concentrations was approximately 1.0 from 10 to 60 min. The intracellular CCNU concentration during the uptake of 0.1 mM (chloroethyl-U-14C) CCNU at 37 degrees C was constant at 85 pmol/microliters from 10 to 60 min in L1210 cells, but slowly decreased from 66 pmole/microliters at 20 min to 43 pmole/microliters at 60 min in bone marrow cells. The L1210: murine bone marrow cell ratio of intracellular CCNU concentrations ranged from 1.45 to 1.98 from 20 to 60 min. Thus, it appears that the preferential ratio of alkylation of L1210 DNA to murine bone marrow DNA by CLZ compared with equimolar CCNU cannot be explained by differences in uptake of the two agents by the two cell types. The uptake of 0.1 mM CLZ at 37 degrees C by L1210 cells in McCoy's 5A medium containing 300 mg% glucose was not affected by the addition of 5 mM cold drug, nor was it affected by the absence of glucose in the medium, with or without cold drug. This suggests that CLZ uptake into L1210 cells is via passive diffusion and that CLZ does not enter these cells via the glucose transport mechanism.

Animals↗
PubMed1982

Dangers of collapsible ventricular drainage systems. Technical note.

Ventricular drainage systems employing a collapsible plastic bag for fluid collection were postulated to cause an increasing back-pressure produced in part by the elasticity of the bag. This postulate was shown to be correct in an experimental situation. There was a logarithmic rise in cerebrospinal fluid pressure as the bag filled. By increasing the size of the bag, the problem was overcome.

Cerebral Ventricles↗
PubMed1982

Accessory splenectomy for idiopathic thrombocytopenic purpura.

Not all patients who undergo splenectomy for idiopathic thrombocytopenic purpura (ITP) respond to operation. This may be due to the presence of an accessory spleen. This is a report of three patients who underwent successful accessory splenectomy after relapse of their disease. Each patient initially experienced a complete response to splenectomy, but recurrence occurred months to years later. All of the patients had persistent Howell-Jolly bodies on peripheral blood smear, yet two of the patients had complete and sustained remissions of their disease after accessory splenectomy. Intraoperative localization of an accessory spleen may be exceedingly difficult in the patient who has undergone a previous operation. However, localization of accessory splenic tissue is greatly facilitated by use of a sterile isotopic detector probe intraoperatively after the injection of technetium-99m-labeled red blood cells. Given the morbidity and mortality rates of refractory ITP, patients who have a relapse after, or who fail to respond to, splenectomy should be evaluated for the presence of an accessory spleen, even if Howell-Jolly bodies are present on peripheral blood smear.

Adult↗
PubMed1981

The effect of chemical agents, beverages, and spinach on the in vitro solubilization of iron from cooked pinto beans.

The solubilization of iron from cooked pinto beans was examined using an improved in vitro methodology. The iron content of the beans was found to exist in three populations: 1) that which is spontaneously soluble upon incubation; 2) that which can be mobilized by chelating or reducing agents; and 3) that which is more firmly bound to the insoluble bean residue. These fractions constitute approximately 25, 45, and 30%, respectively, of the bean iron content when using consecutive 30-min incubations at pH 2 and 6. Ascorbic acid is maximally effective in iron mobilization under acidic conditions and acts via iron reduction. Citric acid is maximally effective near pH 6. The combination of ascorbic acid and citric acid leads to the solubilization of 70% of the iron content of the beans. Orange juice also leads to maximal soluble iron, predominantly in the Fe2+ state. Tea severely decreases iron solubility in the system. Only 3% of the iron content of spinach is solubilized by 10 mM ascorbic acid. Whole spinach suspension and the insoluble spinach residue are able to remove iron from solution that was previously solubilized from beans.

Beverages↗
PubMed1980

Comparison of venom and whole-body rast and intradermal testing in vespid-sensitive patients.

14 patients clinically hypersensitive to vespid sting by history, 6 patients with large local reactions and 10 control subjects were skin tested with serial two- and tenfold dilutions of venom and whole-body extract of yellow jacket, wasp, and white-faced hornet antigens. Radioallergosorbent test determinations with the same antigens were also made. Determination of minimal reactive dose by skin testing distinguished control and hypersensitive patients groups for all three antigens using either venom or whole body extract. Yellow jacket venom skin testing detected 12 of 14 patients considered clinically hypersensitive. This was not the case with the other two venoms, possibly because most of the patients were yellow jacket sensitive, or any of the whole-body extracts. The Radioallergosorbent test was less useful than venom skin testing in detecting patients considered clinically sensitive.

Adult↗
PubMed1979

Clinical comparison of skin testing and the radioallergosorbent test in dog-sensitive patients using mixed and breed-specific antigens.

A study of clinical history, intradermal test end points and RAST values with six different dog antigens was made in 20 patients and 5 control subjects. Skin testing was found to be more useful clinically than the RAST. Considerable variability among mixed epidermal extracts was noted. There was no apparent advantage to testing with three individual-breed extracts studied, compared to the most potent mixed epidermal antigen. The results of this study suggest that further efforts toward standardization of potency, methods of preparation and, possibly, breed composition of dog allergenic extracts are required to develop improved allergens for clinical use.

Animals↗