NRU :: Browsing by Author "Johnson, John L."

Browsing by Author "Johnson, John L."

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Capacity Building For The Clinical Investigation Of AIDS Malignancy In East Africa
(Cancer Detection and Prevention, 2005) Orem, Jackson; Otieno, Mwanda W.; Banura, Cecily; Mbidde, Edward Katongole; Johnson, John L.; Ayers, Leona; Ghannoum, Mahmoud; Fu, Pingfu; Feigal, Ellen G.; Black, Jodi; Whalen, Christopher; Lederman, Michael; Remick, Scot C.
To build capacity in the resource-poor setting to support the clinical investigation and treatment of AIDS-related malignancies in a region of the world hardest hit by the AIDS pandemic.An initial MEDLINE database search for international collaborative partnerships dedicated to AIDS malignancies in developing countries failed to identify any leads. This search prompted us to report progress on our collaboration in this aspect of the epidemic. Building on the formal Uganda-Case Western Reserve University (Case) Research Collaboration dating back to 1987, established NIH-supported centers of research excellence at Case, and expanding activities in Kenya, scientific and training initiatives, research capital amongst our institutions are emerging to sustain a international research enterprise focused on AIDS and other viral-related malignancies.A platform of clinical research trials with pragmatic design has been developed to further enhance clinical care and sustain training initiatives with partners in East Africa and the United States. An oral chemotherapy feasibility trial in AIDS lymphoma is near completion; a second lymphoma trial of byrostatin and vincristine is anticipated and a feasibility trial of indinavir for endemic Kaposi's sarcoma is planned.In the absence of published reports of evolving international partnerships dedicated to AIDS malignancy in resource constrained settings, we feel it important for such progress on similar or related international collaborative pursuits to be published. The success of this effort is realized by the long-term international commitment of the collaborating investigators and institutions to sustain this effort in keeping with ethical and NIH standards for the conduct of research; the provision of formal training of investigators and research personnel on clinical problems our East African partners are faced with in practice and the development of pragmatic clinical trials and therapeutic intervention to facilitate technology transfer and enhance clinical practice.
Comparison of MGIT and Myco/F Lytic Liquid-Based Blood Culture Systems for Recovery of Mycobacterium tuberculosis from Pleural Fluid
(Journal of clinical microbiology, 2015) Harausz, Elizabeth; Kafuluma Lusiba, John; Nsereko, Mary; Johnson, John L.; Toossi, Zahra; Ogwang, Sam; Boom, Henry; Joloba, Moses L.
Tuberculosis (TB) is the most frequent cause of exudative pleural effusions in areas of high TB incidence. Studies have shown that Mycobacterium tuberculosis is the causative agent in up to 44% of HIV-seronegative people hospitalized with a pleural effusion (1–3), and the percentage is higher in HIV-seropositive people (4). Pleural TB is a paucibacillary disease. The pathogenesis of a tuberculous pleural effusion is likely due to a delayed hypersensitivity reaction to M. tuberculosis proteins (for a review, see reference 5) and not to a large burden of organisms. The scarcity of organisms makes it difficult to isolate M. tuberculosis from pleural fluid samples, leading to low rates of culture confirmation. Rich culture media are generally more sensitive in detecting M. tuberculosis in sputum and other clinical samples (6). Few studies have compared different liquid media and examined their potential role in combination with solid media for the diagnosis of tuberculous pleurisy. In this study, we compared the Bactec 9120 Myco/F lytic blood culture system (Myco/F lytic) to the Bactec mycobacterial growth indicator tube (MGIT) 960 system (Becton Dickinson, Sparks, MD) (with each liquid system used in conjunction with locally prepared Middlebrook 7H11 solid medium) with respect to time to positivity (TTP), sensitivity, specificity, and percent culture yield of M. tuberculosis isolates from pleural fluid.
Dose-Modified Oral Chemotherapy in the Treatment of AIDS-Related Non-Hodgkin’s Lymphoma in East Africa
(2009-05-26) Mwanda, Walter O; Orem, Jackson; Fu, Pingfu; Banura, Cecilia; Kakembo, Joweria; Onyango, Caren Auma; Ness, Anne; Reynolds, Sherrie; Johnson, John L.; Subbiah, Vivek; Bako, Jacob; Wabinga, Henry; Abdallah, Fatuma K.; Meyerson, Howard J.; Whalen, Christopher C.; Lederman, Michael M.; Black, Jodi; Ayers, Leona W.; Ayers, Leona W.; Katongole-Mbidde, Edward; C., Scot; Remick, Scot C.
Purpose Africa is burdened by the AIDS epidemic and attendant increase in HIV/AIDS-related malignancies. Pragmatic approaches to therapeutic intervention could be of great value. Dose-modified oral chemotherapy for AIDS-related non-Hodgkin's lymphoma is one such approach. Patients and Methods The oral regimen consisted of lomustine 50 mg/m2 on day 1 (cycle 1 only), etoposide 100 mg/m2 on days 1 to 3, and cyclophosphamide/procarbazine 50 mg/m2 each on days 22 to 26 at 6-week intervals (one cycle) for two total cycles in HIV-infected patients with biopsy-proven non-Hodgkin's lymphoma. Results Forty-nine patients (21 in Uganda and 28 in Kenya) were treated. The majority of patients were female (59%) and had a poor performance status (63%); 69% of patients had advanced-stage disease; and 18 patients (37%) had access to antiretroviral therapy. In total, 79.5 cycles of therapy were administered. The regimen was well tolerated, had modest effects (decline) on CD4+ lymphocyte counts (P = .077), and had negligible effects on HIV-1 viral replication. Four febrile neutropenia episodes and three treatment-related deaths (6% mortality rate) occurred. The overall objective response rate was 78% (95% CI, 62% to 88%); median follow-up time was 8.2 months (range, 0.1 to 71 months); median event-free and overall survival times were 7.9 months (95% CI, 3.3 to 13.0 months) and 12.3 months (95% CI, 4.9 to 32.4 months), respectively; and 33% of patients survived 5 years. Conclusion Dose-modified oral chemotherapy is efficacious, has comparable outcome to that in the United States in the pre–highly active antiretroviral therapy setting, has an acceptable safety profile, and is pragmatic in sub-Saharan Africa. The international collaboration has been highly successful, and subsequent projects should focus on strategies to optimize combination antiretroviral therapy and chemotherapy and follow-up tissue correlative studies.
Drug Tolerance in Mycobacterium tuberculosis
(Antimicrobial agents and chemotherapy, 1999) Wallis, Robert S.; Patil, Shripad; Cheon, Seon-Hee; Edmonds, Kay; Phillips, Manijeh; Perkins, Mark D.; Joloba, Moses; Namale, Alice; Johnson, John L.; Teixeira, Lucileia; Dietze, Reynaldo; Siddiqi, Salman; Mugerwa, Roy D.; Eisenach, Kathleen; Ellner, Jerrold J.
Although Mycobacterium tuberculosis is eradicated rapidly during therapy in some patients with pulmonary tuberculosis, it can persist for many months in others. This study examined the relationship between mycobacterial drug tolerance (delayed killing in vitro), persistence, and relapse. It was performed with 39 fully drug-susceptible isolates from a prospective trial of standard short-course antituberculous therapy with sputum smear-positive, human immunodeficiency virus-uninfected subjects with pulmonary tuberculosis in Brazil and Uganda. The rate of killing in vitro was determined by monitoring the growth index (GI) in BACTEC 12B medium after addition of drug to established cultures and was measured as the number of days required for 99% sterilization. Drugs differed significantly in bactericidal activity, in the following order from greatest to least, rifampin > isoniazid-ethambutol > ethambutol (P < 0.001). Isolates from subjects who had relapses (n 5 2) or in whom persistence was prolonged (n 5 1) were significantly more tolerant of isoniazidethambutol and rifampin than isolates from other subjects (P < 0.01).
Induction of the Antigen 85 Complex of Mycobacterium tuberculosis in Sputum: A Determinant of Outcome in Pulmonary Tuberculosis Treatment
(The Journal of infectious diseases, 1998) Wallis, Robert S.; Perkins, Mark; Phillips, Manijeh; Joloba, Moses; Demchuk, Barbara; Namale, Alice; Johnson, John L.; Williams, Donna; Wolski, Kathy; Dietze, Reynaldo; Mugerwa, Roy D.; Eisenach, Kathleen; Ellner, Jerrold J.
Sputum quantitative culture, acid-fast smear, days-to-positive by BACTEC, and Mycobacterium tuberculosis antigen 85 complex were monitored during therapy in 42 patients with pulmonary tuberculosis (TB). By BACTEC, 4 patients were persistently positive on days 90–180, and treatment ultimately failed in 2 of these. Antigen 85 expression increased in subjects in whom disease persisted (persisters) from days 0 to 14 when the difference between persisters and nonpersisters was statistically significant (P .002). Only antigen 85 complex values at day 14 suggested TB persistence at or after day 90. All subjects with day 14 antigen 85 complex values 60 pg/mL responded rapidly to treatment and were cured. Of those with values 60 pg/mL, in 33% TB persisted at or after day 90 and treatment failed in 17%. Biologic factors expressed early in therapy, not related to compliance or resistance, may exert a substantial influence on outcome. The antigen 85 complex is critical in cell wall biosynthesis and is induced by isoniazid in vitro. Its induction may represent an adaptive transition to a persistent state during therapy
Mycobacterium tuberculosis Specific CD8+ T Cells Rapidly Decline with Antituberculosis Treatment
(PLoS One, 2013) Nyendak, Melissa R.; Park, Byung; Null, Megan D.; Baseke, Joy; Swarbrick, Gwendolyn; Mayanja-Kizza4, Harriet; Nsereko, Mary; Johnson, Denise F.; Gitta, Phineas; Okwera, Alphonse; Goldberg, Stefan; Bozeman, Lorna; Johnson, John L.; Boom, W. Henry; Lewinsohn, Deborah A.; Lewinsohn, David M.; the Tuberculosis Research Unit and the Tuberculosis Trials Consortium
Biomarkers associated with response to therapy in tuberculosis could have broad clinical utility. We postulated that the frequency of Mycobacterium tuberculosis (Mtb) specific CD8+ T cells, by virtue of detecting intracellular infection, could be a surrogate marker of response to therapy and would decrease during effective antituberculosis treatment. We sought to determine the relationship of Mtb specific CD4+ T cells and CD8+ T cells with duration of antituberculosis treatment. We performed a prospective cohort study, enrolling between June 2008 and August 2010, of HIV-uninfected Ugandan adults (n = 50) with acid-fast bacillus smear-positive, culture confirmed pulmonary TB at the onset of antituberculosis treatment and the Mtb specific CD4+ and CD8+ T cell responses to ESAT-6 and CFP-10 were measured by IFN-γ ELISPOT at enrollment, week 8 and 24.There was a significant difference in the Mtb specific CD8+ T response, but not the CD4+ T cell response, over 24 weeks of antituberculosis treatment (p<0.0001), with an early difference observed at 8 weeks of therapy (p = 0.023). At 24 weeks, the estimated Mtb specific CD8+ T cell response decreased by 58%. In contrast, there was no significant difference in the Mtb specific CD4+ T cell during the treatment. The Mtb specific CD4+ T cell response, but not the CD8+ response, was negatively impacted by the body mass index.Our data provide evidence that the Mtb specific CD8+ T cell response declines with antituberculosis treatment and could be a surrogate marker of response to therapy. Additional research is needed to determine if the Mtb specific CD8+ T cell response can detect early treatment failure, relapse, or to predict disease progression.
Mycobacterium tuberculosis Specific CD8+ T Cells Rapidly Decline with Antituberculosis Treatment
(PLoS ONE, 2013) Nyendak, Melissa R.; Byung, Park; Null, Megan D.; Baseke, Joy; Swarbrick, Gwendolyn; Mayanja-Kizza, Harriet; Nsereko, Mary; Johnson, Denise F.; Gitta, Phineas; Okwera, Alphonse; Goldberg, Stefan; Bozeman, Lorna; Johnson, John L.; Boom, W. Henry
Biomarkers associated with response to therapy in tuberculosis could have broad clinical utility. We postulated that the frequency of Mycobacterium tuberculosis (Mtb) specific CD8+ T cells, by virtue of detecting intracellular infection, could be a surrogate marker of response to therapy and would decrease during effective antituberculosis treatment. Objectives: We sought to determine the relationship of Mtb specific CD4+ T cells and CD8+ T cells with duration of antituberculosis treatment. Materials and Methods: We performed a prospective cohort study, enrolling between June 2008 and August 2010, of HIV uninfected Ugandan adults (n = 50) with acid-fast bacillus smear-positive, culture confirmed pulmonary TB at the onset of antituberculosis treatment and the Mtb specific CD4+ and CD8+ T cell responses to ESAT-6 and CFP-10 were measured by IFN-c ELISPOT at enrollment, week 8 and 24. Results: There was a significant difference in the Mtb specific CD8+ T response, but not the CD4+ T cell response, over 24 weeks of antituberculosis treatment (p,0.0001), with an early difference observed at 8 weeks of therapy (p = 0.023). At 24 weeks, the estimated Mtb specific CD8+ T cell response decreased by 58%. In contrast, there was no significant difference in the Mtb specific CD4+ T cell during the treatment. The Mtb specific CD4+ T cell response, but not the CD8+ response, was negatively impacted by the body mass index. Conclusions: Our data provide evidence that the Mtb specific CD8+ T cell response declines with antituberculosis treatment and could be a surrogate marker of response to therapy. Additional research is needed to determine if the Mtb specific CD8+ T cell response can detect early treatment failure, relapse, or to predict disease progression.
Therapeutic Challenges of AIDS-Related Non-Hodgkin’s Lymphoma in the United States and East Africa
(2002-05) Otieno, Mwanda W.; Banura, Cecily; Katongole-Mbidde, Edward; Johnson, John L.; Dowlati, Afshin; Renne, Rolf; Arts, Eric; Whalen, Christopher; Lederman, Michael M.; Remick, Scot C.
Abstract Non-Hodgkin's lymphoma (NHL) remains the second most common malignant complication in patients with human immunodeficiency virus (HIV) infection. As we enter the third decade of the acquired immunodeficiency syndrome (AIDS) epidemic, it is apparent that the evolution of antiretroviral therapy and the emergence of combination antiviral strategies have greatly affected the natural history of HIV infection and its neoplastic complications. For example, there may be a trend for declining incidence of AIDS-related lymphoma in the United States for the first time. However, in regions of the world where the burden of HIV infection is greatest, such as in East Africa, AIDS-related lymphoma is an increasing cause of morbidity and mortality. Treatment of lymphoma has evolved coincident with improvements in antiretroviral therapy. Infusional chemotherapy regimens may offer advantages over other regimens and schedules, but comparative trials have not been done. Clinical trial data are available on which to develop therapeutic strategies to treat this disease in East Africa where pragmatic approaches are needed. Both the differences in manifestations of HIV infection and the inherent difficulties in administering cytotoxic chemotherapy in this part of the world must be taken into consideration in planning therapeutic strategies. Improved understanding of the pathogenesis of HIV infection and lymphoma will likely yield improved therapeutic interventions as well.

Browsing by Author "Johnson, John L."

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