Induction of atherosclerosis in Brown Norway rats by immunization with ovalbumin.
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A study was carried out to establish an animal model that would be suitable for evaluating the role of the diet in immune cell-mediated atherogenesis. Brown Norway rats were initially treated with hypervitamin D2 for 4 days and then fed on an atherogenic diet for 3 months, during which period the rats were either immunized with ovalubumin plus Al(OH)3 (OVA group) or with Al(OH)3 alone (control group) every 3 weeks. Aortic lesions were mainly composed of foam cells, the lesions evaluated by the intimal thickness of the ascending aorta being more severe in the OVA group than in the control group. The OVA group, in comparison with the control group, showed prominently increased serum levels of OVA-specific IgG and rat chymase, an indicator of mast cell degranulation. The intimal thickness was positively correlated with the level of chymase. Immunization had no effect on the serum lipid levels. These results support the hypothesis that mast cells play a role in the early stage of atherosclerosis and suggest that this animal model could be useful for evaluating the role of the diet in immune-related atherogenesis. (+info)
Pharmacokinetics of gatifloxacin and interaction with an antacid containing aluminum and magnesium.
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The pharmacokinetics of gatifloxacin (400 mg orally) and the influence of the antacid aluminum magnesium hydroxide (20 ml of Maalox 70) on the bioavailability of gatifloxacin in 24 healthy volunteers were assessed. In an open, randomized, six-period crossover study, the volunteers received either gatifloxacin alone (treatments A and D); aluminum magnesium hydroxide concomitant with gatifloxacin (treatment C); or aluminum magnesium hydroxide 2 h before (treatment B), 2 h after (treatment E), or 4 h after gatifloxacin administration (treatment F). Gatifloxacin concentrations were measured by a validated bioassay and high-performance liquid chromatography. Pharmacokinetics of a single 400-mg dose of gatifloxacin alone were characterized as follows (mean +/- standard deviation): peak concentration (Cmax), 3.8 +/- 0. 5 (treatment A) and 3.4 +/- 0.9 (treatment D) microgram/ml; time to Cmax, 1.4 +/- 0.8 (treatment A) and 1.7 +/- 0.7 (treatment D) h; area under the curve from time zero to infinity (AUC0-infinity), 33. 5 +/- 5.9 (treatment A) and 31.4 +/- 3.4 (treatment D) microgram. h/ml; urine recovery, (83 +/- 6)% (treatment A) and (84 +/- 8)% (treatment D). Comparison of the results obtained by bioassay showed a good correlation. Aluminum magnesium hydroxide administration 2 h before (treatment B) or concomitant with (treatment C) gatifloxacin decreased the Cmax by 45% (2.1 +/- 1.2 microgram/ml) or even 68% (1.2 +/- 0.4 microgram/ml) highly significantly (P < 0.01). AUC0-infinity was significantly reduced from 33.5 +/- 5.9 to 19.4 +/- 6.9 microgram. h/ml (by 42%) or even to 11.9 +/- 3.3 microgram. h/ml (by 64%) (P < 0. 01). If aluminum magnesium hydroxide was given 2 h after gatifloxacin (treatment E), there was no significant reduction of concentration in serum but AUC0-infinity was significantly reduced from 31.4 +/- 3.4 to 25.9 +/- 5.3 microgram. h/ml (18%) (P < 0.01). Aluminum magnesium hydroxide given 4 h after gatifloxacin (treatment F) showed no influence on the gatifloxacin pharmacokinetics. Therefore, the optimal time between gatifloxacin application and the intake of an aluminum-containing antacid should be 4 h. (+info)
Clinical and immune responses in resected colon cancer patients treated with anti-idiotype monoclonal antibody vaccine that mimics the carcinoembryonic antigen.
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PURPOSE: We generated an anti-idiotype antibody, designated CeaVac, that is an internal image of the carcinoembryonic antigen (CEA). We previously demonstrated that the majority of patients with advanced colorectal cancer generate specific anti-CEA responses. The purpose of the current study was to treat patients with surgically resected colon cancer with CeaVac to determine the immune response and clinical outcome to treatment with vaccine. We also compared the immune responses between patients treated with fluorouracil (5-FU) chemotherapy regimens plus vaccine versus vaccine alone. PATIENTS AND METHODS: Thirty-two patients with resected Dukes' B, C, and D, and incompletely resected Dukes' D disease were treated with 2 mg of CeaVac every other week for four injections and then monthly until tumor recurrence or progression. Fourteen patients were treated concurrently with 5-FU chemotherapy regimens. RESULTS: All 32 patients entered onto this trial generated high-titer immunoglobulin G and T-cell proliferative immune responses against CEA. The 5-FU regimens did not have a qualitative or quantitative effect on the immune response. Three of 15 patients with Dukes' B and C disease progressed at 19, 24, and 35 months. Seven of eight patients with completely resected Dukes' D disease remained on study from 12 to 33 months; one patient with resected Dukes' D disease relapsed at 9 months. One patient with incompletely resected Dukes' D disease remained on study at 14 months without evidence of progression; eight experienced disease progression at 6 to 31 months. CONCLUSION: CeaVac consistently generated a potent anti-CEA humoral and cellular immune response in all 32 patients entered onto this trial. A number of very high-risk patients continue on study. 5-FU regimens, which are the standard of care for patients with Dukes' C disease, did not affect the immune response. These data warrant a phase III trial for patients with resected colon cancer. (+info)
Large subcutaneous calcification in systemic lupus erythematosus: treatment with oral aluminum hydroxide administration followed by surgical excision.
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A 32-year-old woman with a long-standing systemic lupus erythematosus had multiple subcutaneous nodules on her axillae, iliac crests and limbs. Three years ago, these nodules began to appear and slowly became larger. Some of them amassed to form a large, fungating, lobulated mass on her right iliac crest. Roentgenographic and histological examination showed that they were calcium deposits. She was initially treated with aluminum hydroxide administration for nine months, which resulted in moderate decrease in size and softening in consistency, but not complete resolution. Then, the mass on the right iliac crest was excised, with an excellent early result. (+info)
Repeated antigen inhalations alter chemical mediators that cause asthmatic obstruction in guinea pigs.
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The contributions of histamine, cysteinyl leukotrienes (CysLTs) and thromboxane A2 (TXA2) to the asthmatic responses and the magnitudes of blood and lung eosinophilia at acute and chronic stages of our asthmatic model were comparatively determined. Guinea pigs were alternately sensitized/challenged by inhalation with ovalbumin+Al(OH)3 and ovalbumin, once every 2 weeks. Effects of mepyramine, pranlukast (a CysLT antagonist) and seratrodast (a TXA2 antagonist) on the early (EAR) and/or the late asthmatic response (LAR) were assessed at the second and fourth antigen challenges. The second challenge caused EAR but not LAR. Although the EAR was decreased at the fourth challenge, a substantial LAR was seen. Both mepyramine and seratrodast inhibited the EAR at the second challenge by approximately 50%. However, at the fourth challenge, these drugs did not inhibit the EAR. The LAR at the fourth challenge was attenuated by pranlukast and seratrodast by 45% and 40%, respectively. Both the blood and lung eosinophilia were modestly and markedly induced 5 h after the second and fourth challenges, respectively. These results strongly suggest that repetition of antigen challenge induces quantitative alterations of chemical mediators participating in the asthmatic responses and a change of the body state under which eosinophils exhibit enhanced migratory activities. (+info)
Aluminium hydroxide adjuvant initiates strong antigen-specific Th2 responses in the absence of IL-4- or IL-13-mediated signaling.
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Previous studies demonstrate that aluminium hydroxide adjuvant (alum) produces increased Th1 responses in IL-4-deficient mice compared with wild-type animals, although the continued production of IL-5 by spleen cells from these mice also indicates that Th2 responses are induced. In the present study, we demonstrate that alum can induce Th2-associated IL-4 and IL-5 production in the absence of IL-4 signaling in mice deficient in either IL-4Ralpha or Stat6. The Th2 responses observed could not be due to IL-13 as IL-13 responses are also impaired in IL-4Ralpha- and Stat6-deficient mice. We also detected higher levels of IL-4 in IL-4Ralpha gene-deficient, though not Stat6-deficient, mice compared with their wild-type counterparts. The increased levels of IL-4 could be explained by the IL-4R being unavailable to neutralize this cytokine in IL-4Ralpha-deficient mice. While levels of IL-5 production in IL-4Ralpha- or Stat6-deficient mice were similar to IL-4-deficient and wild-type mice, other type 2-associated responses, which are largely or wholly IL-4 dependent, such as the production of IgG1 or IgE Abs, were either reduced or absent. We conclude that alum adjuvants can induce IL-4 production and Th2 responses independently of IL-4 or IL-13, negating the requirement for an early source of IL-4 in the Th2 response induced by this adjuvant. (+info)
Onset of action during on-demand treatment with maalox suspension or low-dose ranitidine for heartburn.
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AIM: To compare the onset of action of the local antacid Maalox and the systemic H2-antagonist ranitidine, during 'on demand' ambulant treatment of a single heartburn episode, using a randomized, parallel group, double-blind, double-dummy design. METHODS: Subjects with self-perceived heartburn without known gastrointestinal disease or interfering treatments were selected with questionnaires. The study was performed unsupervised, whenever heartburn required medication. An electronic patient diary gave instructions when to take study medication, and provided visual analogue scales and five-item relief ratings for heartburn, at frequent time intervals activated by an alarm-clock. RESULTS: After a study of the natural history of heartburn and the feasibility of the study procedures in 23 patients, 49 subjects took Maalox and 45 ranitidine. Half of these experienced meaningful heartburn relief within 19 min after Maalox, and within 70 min after ranitidine. One hour after intake, the average heartburn relief score was 3.43 in the Maalox group and 3.04 in the ranitidine group (3 means 'slight improvement' and 4 'strong improvement'). Heartburn was similar in both groups after 3 h. CONCLUSIONS: Maalox provides faster relief of heartburn than ranitidine. Heartburn can be assessed frequently and reliably under ambulant conditions using an electronic patient diary. (+info)
A new, surface-antigen-adsorbed influenza virus vaccine. I. Studies on immunogenicity in hamsters.
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The ability of a new, surface-antigen-adsorbed influenza virus vaccine to induce serum antibody in hamsters, and to protect these hamsters against subsequent homologous virus challenge, is reported. In addition, similar studies in hamsters have also been carried out using the surface antigen material prior to adsorption to the aluminium hydroxide carrier. The new, adsorbed vaccine is at least as effective as inactivated saline influenza virus vaccine in inducing serum antibody and protection in hamsters; the unadsorbed surface antigen material, however, did not confer protection to hamsters challenged subsequently with homologous virus. (+info)