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Biomedical subjects

D S Chi

Publications and source records attributed to D S Chi.

At least 19 recordsLinked to original sources
PubMed1992

Effects of MPTP and vitamin E treatments on immune function in mice.

The effects of treatment with the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and vitamin E, an antioxidant, on immune functions were examined. Male C57/B1 mice were fed daily with natural vitamin E for 12 weeks, subsequently injected i.p. with MPTP or its vehicle, and sacrificed 1 week later. Control mice received the stripped corn oil vehicle daily, in place of vitamin E. Oral vitamin E feeding increased cerebral vitamin E content by 60% (P = 0.05). However, MPTP attenuated this rise in cerebral vitamin E content when measured 1 week after treatment with the neurotoxin (P = 0.05). MPTP also produced an 80-90% reduction in striatal dopamine content in both the stripped corn oil control group and the vitamin E-treated group (P = 0.0000). One week after MPTP injection, the numbers of peripheral blood lymphocytes and the percent of spleen T-cells, but not B-cells, were decreased in those groups receiving MPTP alone or MPTP plus vitamin E (P less than 0.05 and 0.02, respectively). The Con A-induced IL-2 production of spleen cells was decreased in all treated groups (P less than 0.005). There was no difference in the mitogenic stimulative response to PHA, Con A or LPS. However, the response to PWM was increased in both MPTP and MPTP plus vitamin E-treated groups (P less than 0.05 and 0.001, respectively). On the other hand, the one-way mixed lymphocyte response of the splenocytes from the MPTP-treated group was increased (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Failure of Met-enkephalin to enhance natural killer cell activity.

Several papers have reported the enhancing effects of opiate peptides, like Met-enkephalin, on natural killer (NK) cell activity. We examined the actions of Met-enkephalin on NK activity in blood obtained from 18 different donors, of different ages, many of them on several occasions, at several ratios of effector to target cells, several concentrations of peptide, in several types of flasks, with the purity and identity of the pentapeptide verified by chromatography, in a system responsive to interferon, and with results calculated in different ways. No significant increase was found for the peptide for any ratio of cells, any concentration of peptide, or any single subject, even when the subjects with the lowest baseline NK cell activity were used or when the subjects were more than 60 years old. Instead of an increase, the combined results for all subjects at all ratios at all concentrations of Met-enkephalin showed an overall decrease of 31.3% specific cytotoxicity. These results fail to support the reports of an enhancing effect of Met-enkephalin on NK cell activity.

Adult↗
PubMed1991

Relationship between blood groups and behavior patterns in men who have had myocardial infarction.

Consistent correlations have been found between physical dysfunctional states and blood factors. Some of these disorders have possible psychosomatic components (eg, duodenal ulcer, myocardial infarction). This study focused on the relationship between blood types and various indices of behavior patterns (eg, type A behavior scores, anger ratings) in young patients who had had an initial myocardial infarction. Patients with blood type O scored significantly higher on type A behavior scales and related indices than those having blood type A. Those with blood group B responded on several scales between those with types A and O. We discuss the utility of blood groupings in future research in the prediction of myocardial infarction, methodologic limitations, the relationship of these results to temperament studies, Jenkins Activity Survey subtest patterns, anti-H reactivity pattern, and hypotheses relating blood factors and behavioral traits in patients with psychosomatic disorders.

ABO Blood-Group System↗
PubMed1990

Antibody response to P-protein in patients with Branhamella catarrhalis infections.

Branhamella catarrhalis is now recognized as an important cause of lower respiratory tract infections, especially in the elderly. In most instances, pathogenicity is presumed by recovery of the organism in a sputum culture, a method that is less than conclusive. In order to better diagnose B. catarrhalis infections, an enzyme-linked immunoassay has been developed using P-protein as antigen to measure antibodies to B. catarrhalis. In 17 elderly patients with B. catarrhalis pneumonia and 12 with tracheobronchitis, acute-phase serum antibody titers to P-protein were found to be significantly increased when compared with those of normal subjects (both p less than 0.02). There were no differences in antibody titers between patients with pneumonia and tracheobronchitis. Antibody titers of convalescent-phase sera increased over those of acute-phase sera in 46 percent of pneumonia patients and 50 percent of tracheobronchitis patients. The results demonstrated that lower respiratory tract infections with B. catarrhalis promote a significant elevation in antibody response to P-protein of B. catarrhalis.

Aged↗
PubMed1990

Effect of exercise on complement activity.

Complement measurements of C1, C1q, C2, C3, C4, C5; the anaphylatoxins, C3a, C4a, and C5a; and total hemolytic activity of the classical and alternative pathways were made in 26 experienced adult runners before and after shortterm aerobic exercise. The baseline results were compared with those of nonexercising age-matched controls. In most subjects tested, running resulted in nanogram increases in C3a and C4a with corresponding decreases in the hemolytic activity of C4 (C4H). Baseline values of C3 and C4H were decreased significantly in runners when compared with nonexercising controls. Preliminary studies measuring the effect of exercise on C3a levels were also done in three asthmatic runners. Mean resting and postexercise levels, and exercise-induced increases in C3a anaphylatoxin in the asthmatic subjects were significantly higher than in the nonasthmatic subjects. The findings indicate that short-term exercise results in the activation of C3 and C4 and subsequent generation of C3a and C4a anaphylatoxins, and suggest that both activation of the classical pathway of complement and a selective downregulation of C3 production may occur in persons regularly engaged in aerobic exercise. The exaggerated generation of C3a by asthmatic subjects during exercise raises the possibility that anaphylatoxins play an etiologic role in exercise-induced asthma.

Adult↗
PubMed1989

In vitro studies of Tyr-MIF-1 with human lymphocytes.

Our previous report showed that the brain peptide Tyr-MIF-1 (Tyr-Pro-Leu-Gly-NH2) blocks the inhibitory effect of morphine sulfate on E-rosette formation by human peripheral blood lymphocytes (PBL). In this study, additional in vitro effects of Tyr-MIF-1 on human PBL were studied. The percentages of positive cells for CD 2, a sheep erythrocyte receptor, CD 4 and CD 8 were unchanged after incubation of PBL with morphine or morphine plus Tyr-MIF-1. Tyr-MIF-1 was not mitogenic by itself. The addition of Tyr-MIF-1 did not increase the proliferative response of PBL to Con A, although morphine did. Tyr-MIF-1 did not activate PBL to produce IL 2 nor did it affect the production of IL 2 by Con A-stimulated PBL. The results suggest that Tyr-MIF-1 does not directly modulate CD 2, CD 4 and CD 8 expression, does not alter the proliferative response of PBL, and does not affect the production of IL 2.

Antigens, CD↗
PubMed1989

Disseminated echovirus infection in a patient with multiple myeloma and a functional defect in complement. Treatment with intravenous immunoglobulin.

A man with IgG1 multiple myeloma developed fever, confusion, and progressive muscle weakness resulting in paralysis. Echovirus type 11 was isolated from cerebrospinal fluid, pleura, pleural fluid, and muscle, and muscle biopsy disclosed changes consistent with viral myositis. Immunologic evaluation revealed low serum levels of polyclonal IgG subtypes 1 and 3, reduced blood levels of T-helper/inducer and T-suppressor/cytotoxic cells, and a complement abnormality involving the function of the classical pathway C3 convertase, C4b2a. Therapy with intravenous immunoglobulin was associated with clinical recovery. This is the first reported case of disseminated central nervous system enteroviral infection in an adult with a B-cell malignancy, and in association with a documented complement abnormality. The findings suggest the efficacy of immunotherapy in this disease.

Complement Activation↗
PubMed1988

Effect of hepatectomy on the reticuloendothelial system of septic rats.

The purpose of this study was to evaluate the function of the reticuloendothelial system (RES) of sham hepatectomy and 20% and 50% partial hepatectomy (PH 20%, PH 50%), with or without cecal ligation and puncture-induced sepsis. The animals were injected with 51Chromium sheep red blood cells (SRBC) at 72 hours. SRBC half life (T1/2) was measured as an index of RES function and the percentage distribution of SRBC in liver, lung, and spleen was calculated. T1/2 was significantly prolonged in PH 50% rats and was associated with decreased radioactive uptake by the liver. Mortality was nil in the control groups and markedly increased in the presence of sepsis. The results suggest that decreased RES function following hepatectomy is dependent upon the proportion of liver removed and that sepsis further increased the mortality of hepatectomized animals.

Animals↗
PubMed1988

Significance of IgE level in amniotic fluid and cord blood for the prediction of allergy.

Intrauterine sensitization has been reported in animal and clinical studies. One study suggests that the amniotic fluid (AF) IgE level might be useful in predicting infant allergy. We followed for 1 year 83 newborns on whom we had 78 samples of AF, 82 of cord serum (CS), and 83 of maternal serum (MS). All infants were delivered by C-section at term. Amniotic fluid samples were aspirated through the exposed myometrium. Sanguineous specimens were excluded. Amniotic fluid, CS, and MS were tested for total IgE level and IgE RAST to three foods: cow's milk, egg white, and peanut. Data on family medical history, feeding history, and allergy symptoms were collected for 12 months. By 1 year 23% had probable allergy: recurrent wheezing = 8, food related G.I. symptoms = 7, and atopic dermatitis = 4. Allergy in formula-fed infants occurred more often than in those breast-fed for greater than 6 months. IgE in AF was greater than or equal to 0.5 IU/mL in 21/78 (27%); range = 0.5 to 5.9 and geometric mean = 0.76. No correlation was noted between AF total IgE and the appearance of allergy. RAST was equivocally positive in 1.2% AF. Cord serum total IgE was greater than or equal to 0.5 IU/mL in 6/82 (7%); range = 0.5 to 2.6 and geometric mean = 0.72. Allergy appeared in 67% of infants with CS total IgE greater than or equal to 0.5 IU/mL. RAST was negative in all CS samples. In this limited series, AF IgE did not seem to have predictive value of allergy in infancy.

Adult↗
PubMed1985

Enhancement of in vitro antibody responses by human serum proteins cleaved by trypsin.

Tryptic cleavage of human serum proteins remarkably enhanced in vitro plaque-forming cell (PFC) responses of mouse spleen cells primed with sheep erythrocytes (SE). Moreover, trypsin cleaved proteins could mimic the activity of T-cells in immune responses of SE-primed B cells. Eluted with 6 M guanidine-HCl on a Sepharose 6B-CL Column, the activity was found in the fraction corresponding to the molecular weight greater than 100,000. The results suggest that tryptic cleavage of human serum proteins produced a factor(s) that resembled the T-cell augmentation of B-cell immune responses.

Animals↗
PubMed1984

Defective bursa regeneration after irradiation of young thymectomized chickens.

The ability of the bursa of Fabricius to regenerate after gamma-irradiation and bone marrow reconstitution was examined in chickens thymectomized (TX) immediately after hatching. Irradiation (2 X 500 R) 3 weeks after hatching was followed by impaired bursa regeneration, as judged both by bursa/body weight ratios and by bursa follicle development 3-6 weeks later in TX as compared to control birds. Germinal center formation in the spleen was deficient, and immune responses to sheep erythrocytes (SRBC) and B. abortus (BA) were moderately reduced in the TX as compared to control birds irradiated at 3 weeks but not in TX birds irradiated at 5 weeks of age.

Animals↗
PubMed1984

Effect of temperature and lymphokines on mixed lymphocyte and mitogen responses of chicken lymphoid cells in vitro.

The effect of temperature on T cell mitogen and mixed lymphocyte responses (MLR) of chicken lymphoid cells in vitro was examined. Responses at 40 degrees C were much higher than at 37 degrees C. This difference did not appear to be due only to faster kinetics of the responses at 40 degrees C. At the lower temperature the MLR could be enhanced by polyethylene glycol (PEG) for spleen cells and by Con A induced lymphokines for peripheral blood cells (PBL). The positive effect of PEG on the chicken spleen cell MLR appeared to be determined at the stimulator cell level. Responses to mitogens at 37 degrees C of both spleen cells and PBL were enhanced by lymphokines.

Animals↗
PubMed1984

Effect of temperature on suppressor cells in chicken spleen cell cultures.

The plaque forming cell (PFC) response of in vivo primed chicken spleen cells to sheep erythrocytes (SRBC) at 37 degrees C in vitro was much higher when antigen was added on Day 2 of culture than on Day 0, at the initiation of the incubation period. No such difference was observed when the cells were cultured at 40 degrees C, in which case both responses were low. As shown previously the effect of delayed exposure to SRBC at 37 degrees C was due to a disappearance of suppressor T cells in the absence of antigen, which did not occur at 40 degrees C. Addition of concanavalin A on Day 0 could, even in the absence of SRBC, maintain the suppressor cell activity at 37 degrees C. The results suggest that suppressor cell activity is very temperature dependent.

Animals↗
PubMed1980

Antigen-induced helper and suppressor T cells in normal and agammaglobulinemic chickens.

Spleen cells from chickens injected with sheep erythrocytes (SE) intravenously 2 to 14 days prior to culture were found to give faster and higher plaque-forming cell responses upon addition of antigen on day 2 rather than on day 0 of culture. Cell mixture experiments showed that this was due to the induction of suppressor T cells upon re-exposure to SE on day 0 of culture. Spleen cells taken on days 2 or 14, but not between days 4 and 7 after priming to SE were sensitive to suppression. The suppressor cells were resistant to gamma irradiation (1000 rd) and to mitomycin C, but were apparently lost after 2 days of culture in the absence of antigen. Pokeweed mitogen addition on day 0 of culture also induced suppressor cells, both in SE immune and in normal spleen. Similar suppressor cells were induced in cultures of primed spleen cells taken from agammaglobulinemic chickens. The response to Brucella abortus in vitro was not affected by induction of suppression for the anti-SE response. Suppression could also be shown after transfer of cell mixtures to irradiated recipients. Helper cell activity for the anti-SE response could readily be shown, both in vivo and in vitro, in primed spleen cells precultured for 2 days in the absence of antigen, and was also resistant to 1000 rd gamma irradiation and to mitomycin C.

Agammaglobulinemia↗