Shared decision-making needs, barriers, and facilitators of patients with newly diagnosed advanced cancer in the hospital: a multi-level, mixed-methods study.

PURPOSE: Little is known about the shared decision-making (SDM) needs, barriers, and facilitators of patients with newly diagnosed advanced cancer in the hospital. Understanding this may improve SDM and cancer care quality in this vulnerable population. METHODS: A single-site, mixed-methods study of hospitalized patients with newly diagnosed advanced cancer, caregivers, and oncologists was conducted. After discharge, patient ± caregiver semi-structured interviews exploring SDM needs, barriers, and facilitators regarding their most important upcoming cancer-related decision were conducted. Oncologists were surveyed about patient knowledge and SDM needs using closed- and open-ended questions, respectively. Thematic analysis was performed for qualitative data with a focus on themes unique to or amplified by hospitalization. Descriptive statistics and the Chi-squared test were performed for quantitative data. RESULTS: Patients and caregivers reported high SDM needs surrounding treatment and prognostic information, leading to decisional conflict. Eight themes emerged: anticipated cancer treatment decisions, variable control preferences in decision-making, high cancer-related information needs and uncertainty, barriers and facilitators to information gathering during and post hospitalization, and decision-making facilitators. Among 32 oncologists, most (56%) reported patients were poorly informed about treatment and prognosis. Oncologists reported variable expectations about patient knowledge after hospitalization, facilitators to patient decision-making, and patient uncertainty while awaiting an outpatient oncologist appointment. CONCLUSION: Patients newly diagnosed with advanced cancer in the hospital have high SDM needs and experience decisional conflict. This may be due to barriers unique to or exacerbated by hospitalization. Further research is needed to develop strategies to address these barriers and enhance the facilitators identified in this study.

Identification of (+)-erythro-mefloquine as an active enantiomer with greater efficacy than mefloquine against Mycobacterium avium infection in mice.

Infection caused by Mycobacterium avium is common in AIDS patients who do not receive treatment with highly active antiretroviral therapy (HAART) or who develop resistance to anti-HIV therapy. Mefloquine, a racemic mixture used for malaria prophylaxis and treatment, is bactericidal against M. avium in mice. MICs of (+)-erythro-, (-)-erythro-, (+)-threo-, and (-)-threo-mefloquine were 32 µg/ml, 32 µg/ml, 64 µg/ml, and 64 µg/ml, respectively. The postantibiotic effect for (+)-erythro-mefloquine was 36 h (MIC) and 41 h for a concentration of 4× MIC. The mefloquine postantibiotic effect was 25 h (MIC and 4× MIC). After baseline infection was established (7 days), the (+)- and (-)-isomers of the diastereomeric threo- and erythro-α-(2-piperidyl)-2,8-bis(trifluoromethyl)-4-quinolinemethanol were individually used to orally treat C57BL/6 bg(+)/bg(+) beige mice that were infected intravenously with M. avium. Mice were also treated with commercial mefloquine and diluent as controls. After 4 weeks of treatment, the mice were harvested, and the number of bacteria in spleen and liver was determined. Mice receiving (+)- or (-)-threo-mefloquine or (-)-erythro-mefloquine had numbers of bacterial load in tissues similar to those of untreated control mice at 4 weeks. Commercial mefloquine had a bactericidal effect. However, mice given the (+)-erythro-enantiomer for 4 weeks had a significantly greater reduction of bacterial load than those given mefloquine. Thus, (+)-erythro-mefloquine is the active enantiomer of mefloquine against M. avium and perhaps other mycobacteria.

Peyer's patch-deficient mice demonstrate that Mycobacterium avium subsp. paratuberculosis translocates across the mucosal barrier via both M cells and enterocytes but has inefficient dissemination.

Mycobacterium avium subsp. paratuberculosis, the agent of Johne's disease, infects ruminant hosts by translocation through the intestinal mucosa. A number of studies have suggested that M. avium subsp. paratuberculosis interacts with M cells in the Peyer's patches of the small intestine. The invasion of the intestinal mucosa by M. avium subsp. paratuberculosis and Mycobacterium avium subsp. hominissuis, a pathogen known to interact with intestinal cells, was compared. M. avium subsp. paratuberculosis was capable of invading the mucosa, but it was significantly less efficient at dissemination than M. avium subsp. hominissuis. B-cell knockout (KO) mice, which lack Peyer's patches, were used to demonstrate that M. avium subsp. paratuberculosis enters the intestinal mucosa through enterocytes in the absence of M cells. In addition, the results indicated that M. avium subsp. paratuberculosis had equal abilities to cross the mucosa in both Peyer's patch and non-Peyer's patch segments of normal mice. M. avium subsp. paratuberculosis was also shown to interact with epithelial cells by an alpha(5)beta(1) integrin-independent pathway. Upon translocation, dendritic cells ingest M. avium subsp. paratuberculosis, but this process does not lead to efficient dissemination of the infection. In summary, M. avium subsp. paratuberculosis interacts with the intestinal mucosa by crossing both Peyer's patches and non-Peyer's patch areas but does not translocate or disseminate efficiently.

Mycobacterium avium infection of macrophages results in progressive suppression of interleukin-12 production in vitro and in vivo.

Interleukin-12 (IL-12) has been shown to have an important role in the host defense against Mycobacterium avium. We sought to determine if human monocyte-derived macrophages produce IL-12 upon M. avium infection. Although IL-12 can be measured in supernatants of M. avium-infected macrophages at 24, 48, and 72 h following infection, intracellular staining showed that 24 to 48 h after infection, IL-12 was synthesized chiefly by uninfected macrophages in the monolayer, suggesting that M. avium infection inhibits IL-12 production. In addition, the data also suggest that the longer macrophage monolayers were infected, the less IL-12 they were able to produce. Stimulation of macrophages with IFN-gamma prior to infection with M. avium resulted in greater production of IL-12 compared with unstimulated macrophages. Culture supernatant of M. avium-infected macrophage monolayers, but not control macrophages, partially inhibited IL-12 production by IFN-gamma-stimulated macrophages. This partial inhibition was not reversed by anti-interleukin-10 (anti-IL-10) and anti-transforming growth factor beta 1 (anti-TGF beta 1)-neutralizing antibodies. M. avium infection of macrophages in vitro also suppressed IL-12 synthesis induced by Listeria monocytogenes infection. Immunohistochemistry staining of spleen of infected mice showed that IL-12 production by splenic macrophages was more pronounced in the beginning of the infection but decreased later. Our data indicate that M. avium infection of macrophages suppresses IL-12 production by infected cells and that the suppression was not a result of the presence of IL-10 and TGF beta 1 in the culture supernatant.

Identification of virulence determinants of Mycobacterium avium that impact on the ability to resist host killing mechanisms.

Mycobacterium avium is an opportunistic pathogen associated with pulmonary disease in non-AIDS patients and disseminated infection in patients with AIDS. The chief route of infection is by colonization and invasion of the mucosa of the gastrointestinal tract, but infection through the respiratory route also occurs. After crossing the mucosa, M. avium infects and replicates within tissue macrophages. To identify M. avium genes required for survival in vivo, a library of signature-tagged transposon mutants was constructed and screened for clones attenuated in mice. Thirty-two clones were found to be attenuated for their virulence, from which eleven were sequenced and tested further. All the mutants studied grew similarly in vitro to the wild-type MAC104. Ten mutants were tested individually in mice, confirming the attenuated phenotype. MAV_2450, a polyketide synthase homologue to Mycobacterium tuberculosis pks12, was identified. STM5 and STM10 genes (encoding two hypothetical proteins MAV_4292 and MAV_4012) were associated with susceptibility to oxidative products. Mutants MAV_2450, MAV_4292, MAV_0385 and MAV_4264 live in macrophage vacuoles with acidic pH (below 6.9). Mutants MAV_4292, MAV_0385 and MAV_4264 were susceptible to nitric oxide in vitro. The study of individual mutants can potentially lead to new knowledge about M. avium pathogenic mechanisms.

The ability to form biofilm influences Mycobacterium avium invasion and translocation of bronchial epithelial cells.

Organisms of the Mycobacterium avium complex (MAC) are widely distributed in the environment, form biofilms in water pipes and potable water tanks, and cause chronic lung infections in patients with chronic obstructive pulmonary disease and cystic fibrosis. Pathological studies in patients with pulmonary MAC infection revealed granulomatous inflammation around bronchi and bronchioles. BEAS-2B human bronchial epithelial cell line was used to study MAC invasion. MAC strain A5 entered polarized BEAS-2B cells with an efficiency of 0.1 +/- 0.03% in 2 h and 11.3 +/- 4.0% in 24 h. In contrast, biofilm-deficient transposon mutants 5G4, 6H9 and 9B5 showed impaired invasion. Bacteria exposed to BEAS-2B cells for 24 h had greater ability to invade BEAS-2B cells compared with bacteria incubated in broth. M. avium had no impact on the monolayer transmembrane resistance. Scanning electron microscopy showed that MAC A5 forms aggregates on the surface of BEAS-2B cell monolayers, and transmission electron microscopy evidenced MAC within vacuoles in BEAS-2B cells. Cells infected with the 5G4 mutant, however, showed significantly fewer bacteria and no aggregates on the cell surface. Mutants had impaired ability to cause infection in mice, as well. The ability to form biofilm appeared to be associated with the invasiveness of MAC A5.

CD4+ T cells but Not CD8+ or gammadelta+ lymphocytes are required for host protection against Mycobacterium avium infection and dissemination through the intestinal route.

Disseminated Mycobacterium avium infection is common in AIDS patients that do not receive anti-AIDS therapy and in patients for whom therapy fails. M. avium is commonly acquired by ingestion, and a large number of AIDS patients have M. avium in their intestinal tracts. To better understand the dynamics of the infection in patients with AIDS, we studied orally infected mice. To determine if immunocompetent mice challenged orally with M. avium can develop protection against the infection, and if so, which cell population(s) is responsible for the protection, we exposed wild-type as well as CD4(-/-), CD8(-/-), and gammadelta(-/-) knockout mice to low concentrations of M. avium strain 101 given orally, followed by treatment with azithromycin. After 1 month, the mice were challenged with kanamycin-resistant M. avium 104. Only CD4(+) T cells appeared to be required for protection against the second challenge. Both CD4(+) and CD8(+) T cells produced comparable amounts of gamma interferon after the first exposure to the bacterium. Tumor necrosis factor alpha was elevated in CD4(+) T cells but not in CD8(+) T cells. Following exposure to a small inoculum of mycobacteria orally, wild-type mice did not develop disseminated infection for approximately 4 months, although viable bacteria could be observed in the mesenteric lymph nodes. The ingestion of small numbers of M. avium cells induces a protective immune response in the intestines against subsequent infection. However, the bacteria remain viable in intestinal lymph nodes and might disseminate later.

A Mycobacterium avium PPE gene is associated with the ability of the bacterium to grow in macrophages and virulence in mice.

PPE and PE gene families, which encode numerous proteins of unknown function, account for 10% of Mycobacterium tuberculosis genome. Mycobacterium avium genome has similar PPE and PE gene families. Using a temperature-sensitive phage phAE94 transposon mutagenesis system, a M. avium transposon library was created in the strain MAC109. Screening of individual mutants in human U937 macrophages for the ability to replicate intracellularly, we identified several attenuated clones. One of them, the 2D6 mutant, has a transposon interrupting a PPE gene (52% homologous to Rv 1787 in M. tuberculosis) was identified. The mutant and the wild-type strain had comparable ability to enter macrophages. Challenge of mice with the 2D6 mutant resulted in approximately 1 log and 2 log fewer bacteria in the spleen, at 1 and 3 weeks after infection, compared with the wild-type bacterium. The 2D6 mutant grows like the wild-type bacterium in vitro. Vacuoles containing the 2D6 mutant acidified to pH 4.8; whereas, vacuoles containing wild-type bacterium were only slightly acidic. It was also observed that, in contrast to the wild-type bacterium, the 2D6 mutant did not prevent phagosome-lysosome fusion, and it is only expressed within macrophage but not in 7H9 broth. These results revealed a role for this PPE gene in the growth of M. avium in macrophages and in virulence in mice.

Intracellular phenotype of Mycobacterium avium enters macrophages primarily by a macropinocytosis-like mechanism and survives in a compartment that differs from that with extracellular phenotype.

Mycobacterium avium uptake by human macrophages differs between the phenotypes of bacterium grown in laboratory media (extracellular growth, EG) and bacterium grown within macrophages (intracellular growth, IG). Studies in vivo have confirmed that, when spreading, pathogenic mycobacteria enter macrophages by a complement receptor 3-independent pathway, in contrast to mycobacteria uptake in vitro. M. avium, grown in macrophages (IG) for 3 or more days, invade fresh macrophages by a macropinocytosis-like mechanism, in contrast to bacteria grown in media (EG), confirmed by the inhibitory effect of wortmannin, an inhibitor of phosphoinoside-3-kinase, on the uptake of IG, but not EG, by macrophages. The IG phenotype was seen in vacuoles with lower pH than those inhabited by the EG phenotype. Incubation of macrophages with bafilomycin A1, an inhibitor of vacuole acidification, decreased the viability of intracellular IG, but not EG, phenotype, suggesting the importance of an acidic environment for the regulation of IG genes. In addition, the percentage of vacuoles that incorporate and retain LAMP-1 is smaller with EG than with IG bacteria. The formation of M. avium macropinosomes was also shown to be independent of microtubules. These data suggest that uptake of extracellular fluid is part of M. avium IG phenotype uptake by macrophages, and that the IG phenotype inhabits a slightly different vacuole than that of EG.

Mycobacterium tuberculosis uptake by recipient host macrophages is influenced by environmental conditions in the granuloma of the infectious individual and is associated with impaired production of interleukin-12 and tumor necrosis factor alpha.

Transmission of Mycobacterium tuberculosis from one individual to another usually is associated with episodes of coughing. The bacteria leave the environment of the lung cavity of the infected person and travel in droplets to reach the recipient's respiratory tract. Therefore, at the time that the bacteria encounter alveolar cells (macrophages and epithelial cells) in the new host, they express virulence determinants that are regulated by the environmental conditions in the infected person. To determine if those environmental conditions encountered in the lung cavity (hyperosmolarity, acidic pH, and low oxygen tension, among others) would influence the uptake of M. tuberculosis by the recipient's alveolar macrophages, M. tuberculosis H37Rv was incubated under several conditions for different periods of time, washed at 4 degrees C, and used to infect human monocyte-derived macrophages. While increased osmolarity had no effect on M. tuberculosis uptake compared to the uptake of bacteria grown on 7H10 Middlebrook medium, both acidic pH and anaerobiosis increased the uptake of the H37Rv strain four- to sixfold. Using anti-CD11b receptor blocking antibodies or mannoside to inhibit the uptake of M. tuberculosis by macrophages, we determined that while uptake of M. tuberculosis cultured on 7H10 medium was inhibited 77% +/- 6% in the presence of anti-CD11b antibody, the antibody had no effect on the uptake of M. tuberculosis incubated at pH 6.0 and was associated with 27% inhibition of M. tuberculosis previously exposed to anaerobic conditions. The mannose receptor was also not involved with invasion after exposure to acidic conditions, and mannoside resulted in only 32% inhibition of uptake by macrophages of M. tuberculosis exposed to anaerobiosis. Uptake by macrophages also resulted in the secretion of significantly lower amounts of interleukin-12 and tumor necrosis factor alpha than that by macrophages infected with a strain cultured under laboratory conditions. M. tuberculosis cultured under the pH and oxygen concentration found in the granuloma expresses a large number of proteins that are different from the proteins expressed by bacteria grown under laboratory conditions. The results suggest that M. tuberculosis in vivo may be adapted to gain access to the intracellular environment in a very efficient fashion and may do so by using different receptors from the complement and mannose receptors.

The efficiency of the translocation of Mycobacterium tuberculosis across a bilayer of epithelial and endothelial cells as a model of the alveolar wall is a consequence of transport within mononuclear phagocytes and invasion of alveolar epithelial cells.

The mechanism(s) by which Mycobacterium tuberculosis crosses the alveolar wall to establish infection in the lung is not well known. In an attempt to better understand the mechanism of translocation and create a model to study the different stages of bacterial crossing through the alveolar wall, we established a two-layer transwell system. M. tuberculosis H37Rv was evaluated regarding the ability to cross and disrupt the membrane. M. tuberculosis invaded A549 type II alveolar cells with an efficiency of 2 to 3% of the initial inoculum, although it was not efficient in invading endothelial cells. However, bacteria that invaded A549 cells were subsequently able to be taken up by endothelial cells with an efficiency of 5 to 6% of the inoculum. When incubated with a bicellular transwell monolayer (epithelial and endothelial cells), M. tuberculosis translocated into the lower chamber with efficiency (3 to 4%). M. tuberculosis was also able to efficiently translocate across the bicellular layer when inside monocytes. Infected monocytes crossed the barrier with greater efficiency when A549 alveolar cells were infected with M. tuberculosis than when A549 cells were not infected. We identified two potential mechanisms by which M. tuberculosis gains access to deeper tissues, by translocating across epithelial cells and by traveling into the blood vessels within monocytes.

SRI-286, a thiosemicarbazole, in combination with mefloquine and moxifloxacin for treatment of murine Mycobacterium avium complex disease.

Treatment of Mycobacterium avium disease remains challenging when macrolide resistance develops. We infected C57 beige mice and treated them with mefloquine, SRI-286, and moxifloxacin. SRI-286 (80 mg/kg) was bactericidal in the liver. Mefloquine plus moxifloxacin or mefloquine plus SRI-286 were better than mefloquine alone.

Mefloquine, moxifloxacin, and ethambutol are a triple-drug alternative to macrolide-containing regimens for treatment of Mycobacterium avium disease.

Macrolides are the core of effective drug regimens for the treatment of Mycobacterium avium complex (MAC) disease. Mefloquine (MFQ), moxifloxacin (MXF), and ethambutol (EMB), in combination, were evaluated against both clarithromycin-resistant (CLR-R) and CLR-susceptible (CLR-S) MAC; MFQ (40 mg/kg), MXF (100 mg/kg), or EMB (100 mg/kg/day) was given to mice for 4 weeks. MFQ was bactericidal, whereas MXF and EMB were bacteriostatic against both MAC 101 CLR-S and CLR-R. The combination of MFQ and EMB reduced (P<.05, for comparison with controls), and the combination of MFQ and MXF significantly reduced, the load of CLR-R in both the liver and the spleen. Treatment with all 3 drugs was associated with approximately 1-log reduction of CLR-R after 1 week, 2.1-log reduction of CLR-R after 4 weeks, and 2.17-log reduction in MAC/mL blood. Treatment of MAC 101 CLR-S strain had comparable results.