TIC injections extended throughout the intensification and maintenance periods are superior to IDM pulses for prevention of CNS leukemia. Our results with TIC seem comparable with those achieved with other contemporary methods of CNS preventative therapy. Thus, extended TIC affords a reasonable alternative to CNS irradiation plus upfront IT MTX for patients with B-progenitor ALL.

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A bacterial adherence assay using swine nasal turbinate fragments was established. Turbinate fragments were incubated with Bordetella bronchiseptica or Pasteurella multocida type D at different concentrations or for different inbucation times at 37°C on a shaker at 120 rev/min. B. bronchiseptica phase I strains exhibited strong adherence to swine nasal ciliated epithelial cells. The number of adherent bacteria per cell increased when the bacterial concentration or incubation time increased (0, 15, 30, and 60 min); however, the number of adherent bacteria decreased after 3 or 6 hours' incubation due to the loss of cilia from cells. The optimal bacterial concentration and incubation time were 1 times 109 organisms/ml and one hour respectively, which resulted in 7.48 ± 0.66 (Mean ± SEM; B. bronchiseptica strain 03) and 9.31 ± 0.54 (B. bronchiseptica strain 013) adherent bacteria per cell. In contrast to B. bronchiseptica phase I strains, rough phase strains of B. bronchiseptica and all P. multocida strains tested showed no adherence to swine nasal ciliated epithelial cells. All B. bronchiseptica phase I strains could agglutinate calf RBC but rough phase strains could not. Furthermore, pretreatment of B. bronchiseptica phase I organisms with 1 mg/ml or 2 mg/ml of trypsin significantly inhibited the adherence of B. bronchiseptica to ciliated epithelial cells; however, trypsin (2 mg/ml) treatment of bacteria did not decrease their ability to agglutinate calf RBC. From these results we conclude that, in addition to hemagglutinin, other proteinaceous components exist on the surface of virulent B. bronchiseptica that are sensitive to 2 mg/ml trypsin; these are suggested to be the adhesins for the adherence of B. bronchiseptica to swine nasal ciliatd epithelial cells.

Abstract. Bronchoalveolar lavages (BALs) were performed with a bronchoscope on 5-and 7.5-week-old, anesthetized, high health status pigs (n ϭ 14). At 10 weeks of age, pigs (n ϭ 28) were necropsied, lungs were removed, and BAL samples were collected from the right diaphragmatic lobe with a modified 12-Fr (4-mm) Foley catheter. Peripheral blood was sampled from all pigs (n ϭ 28) before each BAL procedure. Peripheral blood and BAL samples were collected according to a similar study design at 5, 7.5, and 10 weeks of age from 12 low health status pigs, which were raised according to standard farm procedures (n ϭ 6) or as segregated early weaned pigs (n ϭ 6). Bronchoalveolar lavage cytology and hematologic 95% confidence intervals were determined for 5-, 7.5-, and 10-week-old high (group A) and low health status pigs (groups B and C). The results were compared between the different groups. Repeated BALs were easily performed in all pigs, making this an additional tool for evaluation of respiratory health. Total numbers of cells and neutrophils in peripheral blood and BAL samples were greater in low health status pigs than in high health status pigs. Hematologic results paralleled the findings in BAL fluid. Segregated early weaning of low health status pigs in a less challenging environment mainly reduced the number of neutrophils in BAL samples and peripheral blood.Respiratory diseases in pigs are of great concern for the swine industry worldwide. 19 New large-scale confinement systems, such as multisite, off-site, segregated early weaning (SEW) facilities, have not had a major impact on lowering the incidence and cost of swine respiratory disease. 7 On the contrary, a marked increase has occurred in respiratory diseases in growingfinishing pigs, which are now described as the porcine respiratory disease complex (PRDC). 19 This name implies multifactorial causes including viruses, bacteria, and environmental factors. Mycoplasma hyopneumoniae and porcine reproductive and respiratory syndrome virus (PRRSV) are infectious agents that are important in the development of PRDC. 19 Both organisms target the alveolar macrophages (AMs), which are the resident mononuclear phagocytes in the airways and play a primary role in the clearance of bacteria and particles. 13,17 Mycoplasma infection suppresses AM function and increases concentration of several inflammatory mediators in bronchoalveolar lavage (BAL) fluid, 2 whereas PRRSV replicates in AMs. 13 A total understanding of all etiologic and host factors, in particular those in the lung tissue, is needed to truly understand the pathogenesis of PRDC.Repeated bronchoscopy and bronchoalveolar lavag- Received for publication June 28, 1999. es have been used in pigs as a research tool to study normal cytology in the airways and changes due to respiratory diseases. 2,4,8,13,18,20,24 Recently, researchers have reported that when comparing virus isolation from serum or AMs at selected time points after exposure to PRRSV, AMs were the most consistent PRRSV-positive sample. 13 These f...

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