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Biomedical subjects

D W Ou

Publications and source records attributed to D W Ou.

9 recordsLinked to original sources

Effects of cannabinoids and cocaine on the mitogen-induced transformations of lymphocytes of human and mouse origins.

The effects of delta 9-tetrahydrocannabinol (d9THC), delta 6-tetrahydrocannabinol (d6THC), and cocaine on the mitogen-induced transformations of lymphocytes of human and mouse origins were examined in an in vitro system. None of the three compounds is mitogenic in nature. The effects of the two components of marijuana on the mitogen-induced transformation are biphasic. Both compounds stimulated the lymphocyte transformation at low concentrations and inhibited mitogenesis at high concentrations. Cocaine, on the other hand, neither affected mitogen-induced lymphocyte transformations nor altered d9THC's transformation effects when both compounds were added together. Human lymphocytes and mouse splenocytes appeared to respond in similar patterns.

Animals

Immunomopharmacological effects of polysaccharides from Acanthopanax senticosus on experimental animals.

Polysaccharides PES isolated from a common Oriental herb Acanthopanax senticosus were found to have a wide spectrum of immunomodulatory activities on experimental animals. The potential usefulness of these polysaccharides is suggested in the observations that PES inhibited transplanted tumor growths and ameliorated toxicities of the toxic substances in experimental animals. Of most interest is the observations that they suppressed human TB propagation in mice and guinea pigs, as evaluated by lymph node responses and OT skin tests in the guinea pig model, and the quantitation of the TB in the lungs in the mouse model.

Animals

The effects of pH and temperature on the in vitro bindings of delta-9-tetrahydrocannabinol and other cannabinoids to bovine serum albumin.

Albumin is a major carrier of drugs and fatty acids in biological fluids. These protein-drug complexes serve to solubilize, transport these compounds to sites of action, and have been associated with increased half-life for these compounds. The authors are interested in the pH and temperature effects of the binding of delta-9-tetrahydrocannabinol to albumin. Ultrafiltration techniques were used in the separation of free to bound compounds. Cannabinoids bind to bovine serum albumin rapidly. The cannabinoid binding sites are more sensitive to temperature changes (37-47 degrees C) than changes in pH with 37 degrees C and pH 7.4 resulting in optimal binding. These conditions would result in the greatest viability in the cells, while allowing for the use of a variety of compounds in in vitro studies for the administration of compounds to isolated cells and cell lines.

Binding Sites

Effects of cocaine on the immune system of Balb/C mice.

Cocaine was given to Balb/C mice by intramuscular injection to assess the effects of the drug on their immune system. An injection of 5 mg/kg of cocaine 24 hr before assay suppressed phagocytic activity of peritoneal macrophages and decreased the numbers of thymocytes and white blood cells in a dose-dependent manner. The suppression appeared to be reversible. Tumor-implanted mice received 10 consecutive days of injections of smaller doses of cocaine (0.05, 0.25, or 5 mg/kg), also resulting in a dose-dependent suppression of phagocytosis 24 hr after the last injection. Cocaine decreased the number of plaque-forming cells when 5 mg/kg of cocaine was injected on the day of immunization but no inhibition was detected if the drug was given later. The size of tumors appeared to be increased in mice injected with cocaine for 10 consecutive days in comparison to the control mice. The effects were concentration dependent. Our study showed that cocaine had general suppressive effects on the mouse immune system.

Animals

Confirmation of drugs of abuse in urine drug screens by direct exposure probe mass spectrometry.

A direct exposure probe (DEP) mass spectrometric method was developed to confirm the presence of cocaine (C), phencyclidine (P), benzoyl ecognine (BE) and 11-norcarboxy tetrahydrocannabinol (11-nor-c-THC) in previously screened urine specimens. Essentially, a urine sample is lyophilized overnight and reconstituted in 30 microliters of a 3:1 mixture of ethyl acetate:methanol. One microliter is placed on a rhenium filament and left to air dry. The specimen was analyzed by negative ion chemical ionization DEP using ammonia as reagent gas at 0.20 Torr with an ion source temperature of 100 degrees C. An electronics setting of 1700 V (EM), 0.30 mA filament current, and 100 eV with scanning at m/z 100-650 (1 sec/SCAN) resulted in simple spectra with easily identifiable molecular ions for C, BE, P and 11-nor-c-THC. The sensitivity of the assay was 1 ng for the drugs of abuse. The method was validated by analyzing 50 urine samples that have been previously screened and confirmed for drugs at the University of Illinois Toxicology Laboratory. The results showed that the DEP method confirmed 87%, 71%, 100%, and 85% of the BE, C, P and 11-nor-c-THC. In summary, a rapid and sensitive DEP method for the confirmation of drugs of abuse in urine has been developed which can serve as a useful adjunct to gas chromatographic/mass spectrometric confirmation.

Cocaine

Variable response to intravenous gamma-globulin therapy in a patient with autoimmune neutropenia, thrombocytopenia, and pemphigoid.

Intravenous high-dose gamma-globulin has been shown to be useful in some patients with immune thrombocytopenia or neutropenia. In the case we have reported, this regimen elevated the platelet but not the neutrophil count. This observation emphasizes the heterogeneity in patients with immune cytopenia, and shows that treatment outcome is likely to be influenced by a number of pathogenetic variables.

Aged

Acute-phase decrease of T lymphocyte subsets in rhinovirus infection.

Populations of peripheral blood leukocytes were enumerated in 15 volunteers challenged by intranasal inoculation with rhinovirus serotype 25. The results demonstrated a significant decrease in total lymphocyte count among infected persons on the third day after challenge with the virus (P less than .01). The change in lymphocyte count was associated with a significant decrease in total T cells, as determined by monoclonal antibodies (both T11+ and T3+, P less than .02), but not in B cells (B7+). Among the subsets of T cells, T4+ (T helper/inducer) and T8+ (T suppressor/cytotoxic) lymphocytes both declined in number, but only the change in the T4+ subset was significant. For each of the lymphocyte populations that decreased significantly (T3+, T11+, and T4+) there was a strong correlation with increased severity of symptoms. Persons who had the greatest decrease in total lymphocyte count also shed virus most frequently. The number of nonlymphocyte leukocytes increased with the severity of the symptoms. These data show that T lymphocytes (particularly the T4+ population) are related to both the progression of infection and the symptoms of the rhinovirus common cold.

Adult