methylcellulose and Tuberculosis

Panel testing, blinded cross rechecking and on-site evaluation are the three methods for external quality assessment (EQA) of acid-fast bacilli (AFB) smear microscopy. Panel testing can provide data on laboratory capabilities prior to implementing a rechecking programme, assess the current status of laboratory performance and detect problems associated with diagnostic performance. Thus far, two methods for preparing panel test slides have been reported: these use real AFB-positive and -negative sputum treated with sodium hydroxide (NaOH) or N-acetyl-L-cysteine (NALC).. To evaluate the above methods and to develop a new method to prepare panel test slides with artificial sputum.. Panel test slides were prepared using the NaOH and NALC methods. New artificial sputum preparation methods were developed and examined using a cultured monocyte cell line, cultured avirulent mycobacteria and methylcellulose or polyacrylamide gel as substrate. Smears prepared by the four methods were compared.. Panel test slides prepared with NaOH and NALC methods are not macroscopically or microscopically similar to real smears. Our new artificial sputum is similar to real sputum in viscosity and macroscopic and microscopic appearance; it is also consistent in panel positivity grades.. The artificial sputum described here could contribute to the EQA and training in tuberculosis laboratories or microscopy centres.

Topics: Acetylcysteine; Acrylic Resins; Bacteriological Techniques; Caustics; Cells, Cultured; Cytodiagnosis; Expectorants; Humans; Methylcellulose; Microscopy; Monocytes; Mycobacterium tuberculosis; Reproducibility of Results; Sodium Hydroxide; Specimen Handling; Sputum; Staining and Labeling; Tuberculosis; Viscosity

Susceptible BALB/c mice were infected iv with a strain of Mycobacterium avium and infused with different biological response modifiers (BRM) in a gel delivery system so as to modify the progression of the infection in a beneficial fashion. Infusion of IL-2 or IL-4 in hydrophobic gels led to no significant enhancement of resistance. Infusion of muramyl dipeptide in hypromellose led to a significant enhancement of resistance against the M. avium, as seen by a significant reduction of colony-forming units (CFU) in the spleens of infected mice. Similarly, infusion of interleukin-1 beta in hypromellose in infected mice led to a significant reduction in CFU counts in the organs of mice. The mechanism(s) responsible for this enhanced resistance was studied further. It was found that infected mice developed profound immunosuppression, as judged by mitogenic and antigenic stimulation. Mice infused with MDP/hypromellose developed a similar immuno-suppression, suggesting that this adjuvant immunotherapy did not act by stimulating a T-cell response or by abrogating a putative suppressive phenomenon. Macrophages from mice infused with MDP alone were no more bacteriostatic for a virulent M. avium than control cells. However, macrophages from infected mice infused with MDP/hypromellose were more bacteriostatic for M. avium than cells from mice infected with M. avium and infused with the hydrophobic gel only. Overall, these results suggest that adjuvant immunotherapy is beneficial in M. avium infections.

Topics: Acetylmuramyl-Alanyl-Isoglutamine; Animals; Cellulose; Drug Combinations; Gels; Hypromellose Derivatives; Immunologic Factors; Interleukin-1; Interleukin-2; Interleukin-4; Lymphocyte Activation; Macrophages; Methylcellulose; Mice; Mice, Inbred BALB C; Mycobacterium avium; Pharmaceutical Vehicles; Recombinant Proteins; Spleen; Tuberculosis

Topics: Barium Sulfate; Bronchography; Cysts; Humans; Infections; Lidocaine; Lung; Lung Abscess; Lung Diseases; Macrophages; Methylcellulose; Pathology; Phagocytosis; Tuberculosis; Tuberculosis, Pulmonary

Topics: Dihydrostreptomycin Sulfate; Empyema, Tuberculous; Excipients; Methylcellulose; Streptomycin; Tuberculosis; Tuberculosis, Pulmonary