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J D Lundgren

Publications and source records attributed to J D Lundgren.

167 records · Page 10Linked to original sources
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Effects of inhibitors of arachidonic acid metabolism on serotonin release from rat basophilic leukemia cells.

Mast cells can release arachidonic acid (AA) metabolites as well as preformed mediators with IgE mediated stimulation, and these mediators are considered to play an important role in allergic reactions. The coincident release of preformed mediators and AA metabolites suggests that AA metabolism is related to mast cell degranulation. To clarify the relationship between mast cell degranulation and AA metabolism, the effects of various A cascade inhibitors on rat basophilic leukemia cell (RBL) mediator release induced by either anti-IgE or A23187 were examined. 5,8,11,14-eicosatetraynoic acid (ETYA) inhibited both PGD2 and LTC4/D4 generation, and partially inhibited serotonin release. Nordihydroguaiaretic acid (NDGA) caused complete inhibition of LTC4/D4 generation, and partial inhibition of PGD2 generation and serotonin release. The cyclooxygenase inhibitor, indomethacin, and the specific 5-lipoxygenase inhibitor, L-651,392 completely inhibited PGD2 and LTC4/D4 generation, respectively, without affecting release of other mediators. Both PGD2 and LTC4/D4 generation were abolished by the combination of indomethacin and L-651,392, however, serotonin release remained intact. HPLC analysis showed that no shift to other AA metabolites occurred after the treatment with these inhibitors. Mepacrine, a phospholipase A2 inhibitor, completely inhibited PGD2 and LTC4/D4 generation, as well as AA release itself, without affecting serotonin release. Therefore, neither AA metabolism nor AA release is necessary for RBL degranulation.

5,8,11,14-Eicosatetraynoic Acid↗
PubMedDate not supplied

The insufficient suppression of viral load by saquinavir hard gel is reversible: a retrospective cohort study.

PURPOSE: To assess the effect of changing antiretroviral therapy in patients initially treated with saquinavir hard gel capsule (hgc). METHOD: A retrospective cohort study comparing the virological and immunological responses in antiretroviral-naïve patients initially treated with a regimen of saquinavir-hgc, zidovudine, and lamivudine, with patients receiving either ritonavir or indinavir on a background of zidovudine and lamivudine. RESULTS: Twenty-nine patients starting with saquinavir-hgc as the protease inhibitor (PI) component were compared to 58 patients starting with ritonavir (n = 16) or indinavir (n = 42). Median follow-up time was 30 and 33 months, respectively. Twelve, 18, 24, and 30 months after starting a regimen including saquinavir-hgc, 72%, 50%, 4%, and 0% of patients still received this PI. At these time points, 35%, 24%, 59%, and 74% of the patients in the saquinavir group obtained an HIV-RNA <500 copies/mL compared to 76%, 72%, 66%, and 65% in the indinavir/ritonavir group. No significant difference in CD4 count between the two groups was observed. CONCLUSION: We found that saquinavir-hgc, in combination with nucleoside reverse transcriptase inhibitors, suppressed viral load insufficiently in HIV patients naïve to antiretroviral therapy. However, the suboptimal effect of saquinavir-hgc seems reversible after optimizing the antiretroviral regimen, at least for the short term.

Adult↗
PubMedDate not supplied

Platelet-activating factor stimulates eicosanoid production in cultured feline tracheal explants.

Eicosanoids have been shown to be major mediators of airway inflammation. Platelet-activating factor (PAF), a potent bronchoconstrictor and stimulator of respiratory mucous secretion, may mediate some of its effects via eicosanoid production. To explore eicosanoid generation by cultured feline tracheal explants, eicosanoids were measured following PAF stimulation. After labeling the explants with [3H]arachidonic acid, supernatant from control and PAF treated explants was fractionated by reverse phase high-performance liquid chromatography (HPLC). The resulting elution pattern suggested the release of arachidonic acid (AA), 15-hydroxyeicosatetraenoic acid (HETE), leukotriene (LT)B4, C4, prostaglandin (PG) D2/E2/F2 alpha, and 6-keto-PGF1 alpha. Radioimmunoassay (RIA) following HPLC resolution confirmed that PAF induced a significantly increased release of peptido-leukotrienes, PGD2, PGE2, PGF2 alpha, LTB4, and 5-HETE, as well as thromboxane (TX) B2. The most remarkable increase was LTC4/D4/E4 (15 x control) and PGD2 (4 x control). The PAF antagonist Ro 19-3704 had an inhibitory effect on the PAF-stimulated release of peptido-leukotrienes. We conclude that PAF stimulates the production of a variety of lipoxygenase and cyclooxygenase pathway metabolites in feline airways.

Animals↗