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BACKGROUND: Sepsis-associated acute kidney injury (SA-AKI) is associated with significant morbidity and mortality. Immune dysregulation is a hallmark of sepsis, with important contributions to organ dysfunction including injury and repair mechanisms in AKI. Macrolide antibiotics, such as azithromycin, have previously demonstrated in pre-clinical models a myriad of immunomodulatory effects that may benefit critically ill patients with SA-AKI. The aim of this study was to determine if early receipt of azithromycin in SA-AKI is associated with a reduction in major adverse kidney events (MAKE) at hospital discharge. METHODS: This was a single center, retrospective cohort study of critically ill adult patients with SA-AKI. Early exposure to azithromycin was defined as receipt of one or more doses within 48 hours of a hospital admission with SA-AKI. The primary outcome of MAKE assessed at hospital discharge was the composite of death, requirement for kidney replacement therapy, or a decline in estimated glomerular filtration rate of 25% or more. Multivariable logistic regression was used to account for potential confounders in the assessment. RESULTS: Of 737 included patients with SA-AKI, 152 (20.6%) received azithromycin. Patients that received early azithromycin were less likely to experience MAKE at hospital discharge when compared to those patients not receiving azithromycin: 38.8% versus 48.4% (p=0.035). In multivariable logistic regression, receipt of azithromycin was independently associated with a decreased odds of MAKE at hospital discharge (aOR 0.62, 95% CI 0.41–0.93). CONCLUSIONS: Early exposure to azithromycin in SA-AKI is independently associated with lower odds of MAKE at hospital discharge.

The COVID-19 pandemic has resulted in changes in the way we teach at all levels of education globally. This chapter specifically focusses on the impact of COVID-19 pandemic on MS and PhD programs in pharmaceutical sciences in schools/colleges of pharmacy in the United States. Potential expectations to bring the pandemic in control by rolling out the vaccine gives us hope, but there is an unmet need of medicines to treat patients affected by the disease. The impact of the pandemic on pharmaceutical sciences education has been on the pedagogy of teaching, research, mentoring, writing, and enrollment. This has also affected the progression of students in their programs as well as their stress levels and well-being. The role of administrators and accreditation agencies is critical in supporting graduate education by providing leadership and directions for the successful outcomes of these programs. Challenges and opportunities for these graduate programs are discussed in this chapter.

Drug carriers to deliver macrolide antibiotics, such as azithromycin, show promise as antibacterial agents. Macrolide drug carriers have largely focused on improving the drug stability and pharmacokinetics, while reducing adverse reactions and improving antibacterial activity. Recently, macrolides have shown promise in treating inflammatory conditions by promoting a reparative effect and limiting detrimental pro-inflammatory responses, which shifts the immunologic setpoint from suppression to balance. While macrolide drug carriers have only recently been investigated for their ability to modulate immune responses, the previous strategies that deliver macrolides for antibacterial therapy provide a roadmap for repurposing the macrolide drug carriers for therapeutic interventions targeting inflammatory conditions. This review describes the antibacterial and immunomodulatory activity of macrolides, while assessing the past in vivo evaluation of drug carriers used to deliver macrolides with the intention of presenting a case for increased effort to translate macrolide drug carriers into the clinic.

Newborn mice are unable to clear Pneumocystis (PC) infection with the same efficiency as adults due, in part, to their inability to develop a robust immune response to infection until three weeks of age. It is known that infants tend develop a Th2 skewed response to antigen so we sought to determine whether a biased cytokine response altered the clearance of PC infection in neonatal mice. P. murina infection in neonatal mice resulted in increased IL-4 expression by CD4 T cells and myeloid cells, augmented IL-13 secretion within the airways and increased arginase activity in the airways, indicative of Th2-type responses. P. murina-infected IL-4Rα−/− neonates had a shift towards Th1 cytokine production and increased numbers of CD4 and CD8 T cells within the lung as well as elevated levels of P. murina-specific IgG. IFNγ−/− and IL-23 p19−/− mice had altered CD4-T cell-dependent cytokine and cell responses. Though we could alter the T helper cell environment in neonatal knockout mice, there was no loss in the ability of these pups to clear infection. It is possible that the Th2 phenotype normally seen in neonatal mice protects the developing lung from pro-inflammatory immune responses without compromising host defense against P. murina.

Azithromycin is effective at controlling exaggerated inflammation and slowing the long-term decline of lung function in patients with cystic fibrosis. We previously demonstrated that the drug shifts macrophage polarization toward an alternative, anti-inflammatory phenotype. In this study we investigated the immunomodulatory mechanism of azithromycin through its alteration of signaling via the NF-κB and STAT1 pathways. J774 murine macrophages were plated, polarized (with IFN-γ, IL-4/-13, or with azithromycin plus IFN-γ) and stimulated with LPS. The effect of azithromycin on NF-κB and STAT1 signaling mediators was assessed by Western blot, homogeneous time-resolved fluorescence assay, nuclear translocation assay, and immunofluorescence. The drug’s effect on gene and protein expression of arginase was evaluated as a marker of alternative macrophage activation. Azithromycin blocked NF-κB activation by decreasing p65 nuclear translocation, although blunting the degradation of IκBα was due, at least in part, to a decrease in IKKβ kinase activity. A direct correlation was observed between increasing azithromycin concentrations and increased IKKβ protein expression. Moreover, incubation with the IKKβ inhibitor IKK16 decreased arginase expression and activity in azithromycin-treated cells but not in cells treated with IL-4 and IL-13. Importantly, azithromycin treatment also decreased STAT1 phosphorylation in a concentration-dependent manner, an effect that was reversed with IKK16 treatment. We conclude that azithromycin anti-inflammatory mechanisms involve inhibition of the STAT1 and NF-κB signaling pathways through the drug’s effect on p65 nuclear translocation and IKKβ.

It was hypothesized that the catalyst nanoceria can increase inflammation/oxidative stress from the basal and reduce it from the elevated state. Macrophages clear nanoceria. To test the hypothesis, M0 (non-polarized), M1- (classically activated, pro-inflammatory), and M2-like (alternatively activated, regulatory phenotype) RAW 264.7 macrophages were nanoceria exposed. Inflammatory responses were quantified by IL-1β level, arginase activity, and RT-qPCR and metabolic changes and oxidative stress by the mito and glycolysis stress tests (MST and GST). Morphology was determined by light microscopy, macrophage phenotype marker expression, and a novel three-dimensional immunohistochemical method. Nanoceria blocked IL-1β and arginase effects, increased M0 cell OCR and GST toward the M2 phenotype and altered multiple M1- and M2-like cell endpoints toward the M0 level. M1-like cells had greater volume and less circularity/roundness. M2-like cells had greater volume than M0 macrophages. The results are overall consistent with the hypothesis.

A growing body of evidence shows that altering the inflammatory response by alternative macrophage polarization is protective against complications related to acute myocardial infarction (MI). We have previously shown that oral azithromycin (AZM), initiated prior to MI, reduces inflammation and its negative sequelae on the myocardium. Here, we investigated the immunomodulatory role of a liposomal AZM formulation (L-AZM) in a clinically relevant model to enhance its therapeutic potency and avoid off-target effects. L-AZM (40 or 10 mg/kg, IV) was administered immediately post-MI and compared to free AZM (F-AZM). L-AZM reduced cardiac toxicity and associated mortality by 50% in mice. We observed a significant shift favoring reparatory/anti-inflammatory macrophages with L-AZM formulation. L-AZM use resulted in a remarkable decrease in cardiac inflammatory neutrophils and the infiltration of inflammatory monocytes. Immune cell modulation was associated with the downregulation of pro-inflammatory genes and the upregulation of anti-inflammatory genes. The immunomodulatory effects of L-AZM were associated with a reduction in cardiac cell death and scar size as well as enhanced angiogenesis. Overall, L-AZM use enhanced cardiac recovery and survival after MI. Importantly, L-AZM was protective from F-AZM cardiac off-target effects. We demonstrate that the liposomal formulation of AZM enhances the drug's efficacy and safety in an animal model of acute myocardial injury. This is the first study to establish the immunomodulatory properties of liposomal AZM formulations. Our findings strongly support clinical trials using L-AZM as a novel and clinically relevant therapeutic target to improve cardiac recovery and reduce heart failure post-MI in humans.

The rapid advancement of the COVID-19 pandemic has prompted an accelerated pursuit to identify effective therapeutics. Stages of the disease course have been defined by viral burden, lung pathology, and progression through phases of the immune response. Immunological factors including inflammatory cell infiltration and cytokine storm have been associated with severe disease and death. Many immunomodulatory therapies for COVID-19 are currently being investigated, and preliminary results support the premise of targeting the immune response. However, because suppressing immune mechanisms could also impact the clearance of the virus in the early stages of infection, therapeutic success is likely to depend on timing with respect to the disease course. Azithromycin is an immunomodulatory drug that has been shown to have antiviral effects and potential benefit in patients with COVID-19. Multiple immunomodulatory effects have been defined for azithromycin which could provide efficacy during the late stages of the disease, including inhibition of pro-inflammatory cytokine production, inhibition of neutrophil influx, induction of regulatory functions of macrophages, and alterations in autophagy. Here we review the published evidence of these mechanisms along with the current clinical use of azithromycin as an immunomodulatory therapeutic. We then discuss the potential impact of azithromycin on the immune response to COVID-19, as well as caution against immunosuppressive and off-target effects including cardiotoxicity in these patients. While azithromycin has the potential to contribute efficacy, its impact on the COVID-19 immune response requires additional characterization so as to better define its role in individualized therapy.

A growing body of evidence shows that altering the inflammatory response by alternative macrophage polarization is protective against complications related to acute myocardial infarction (MI). We have previously shown that oral azithromycin (AZM), initiated prior to MI, reduces inflammation and its negative sequelae on the myocardium. Here, we investigated the immunomodulatory role of a liposomal AZM formulation (L-AZM) in a clinically relevant model to enhance its therapeutic potency and avoid off-target effects. L-AZM (40 or 10 mg/kg, IV) was administered immediately post-MI and compared to free AZM (F-AZM). L-AZM reduced cardiac toxicity and associated mortality by 50% in mice. We observed a significant shift favoring reparatory/anti-inflammatory macrophages with L-AZM formulation. L-AZM use resulted in a remarkable decrease in cardiac inflammatory neutrophils and the infiltration of inflammatory monocytes. Immune cell modulation was associated with the downregulation of pro-inflammatory genes and the upregulation of anti-inflammatory genes. The immunomodulatory effects of L-AZM were associated with a reduction in cardiac cell death and scar size as well as enhanced angiogenesis. Overall, L-AZM use enhanced cardiac recovery and survival after MI. Importantly, L-AZM was protective from F-AZM cardiac off-target effects. We demonstrate that the liposomal formulation of AZM enhances the drug’s efficacy and safety in an animal model of acute myocardial injury. This is the first study to establish the immunomodulatory properties of liposomal AZM formulations. Our findings strongly support clinical trials using L-AZM as a novel and clinically relevant therapeutic target to improve cardiac recovery and reduce heart failure post-MI in humans.

The appropriateness of term limits for administrative appointments is a subject of much discussion, not just within pharmacy programs, but in organizations of all types. The prospect of term limits for involves a wide variety of important organizational issues, including succession planning, institutional memory, strategic decision-making, and concepts regarding leadership styles overall. This paper examines both sides of the debate regarding the appropriateness of term limits for administrative appointments. Arguments supporting term limits include the ability for strategic changes in the diversity of leaders as well as a more focused effort on continuous quality improvement. The arguments against term limits focus around the need for stability and the time involved in the development of effective leaders.

Many external drivers may be influencing a paradigm shift in graduate education. Workforce dynamics are driving a re-examination of what is instructed in graduate programs as well as how curricula are delivered. Most graduate programs have made incremental changes in their philosophical approaches, but new and more dramatic paradigms may be needed to sufficiently address the future needs of employers and students alike.

Regulatory properties of macrophages associated with alternative activation serve to limit the exaggerated inflammatory response during pneumonia caused by Pseudomonas aeruginosa infection. Arginase-1 is an important effector of these macrophages believed to play an essential role in decreasing injury and promoting repair. We investigated the role of arginase-1 in the control of inflammatory immune responses to P. aeruginosa pneumonia in mice that exhibit different immunologic phenotypes. C57BL/6 mice with conditional knockout of the arginase-1 (Arg1) gene from myeloid cells (Arg1(ΔM)) or BALB/c mice treated with small molecule inhibitors of arginase were infected intratracheally with P. aeruginosa. Weight loss, mortality, bacterial clearance, and lung injury were assessed and compared, as were the characterization of immune cell populations over time post-infection. Myeloid arginase-1 deletion resulted in greater morbidity along with more severe inflammatory responses compared to littermate control mice. Arg1(ΔM) mice had greater numbers of neutrophils, macrophages, and lymphocytes in their airways and lymph nodes compared to littermate controls. Additionally, Arg1(ΔM) mice recovered from inflammatory lung injury at a significantly slower rate. Conversely, treatment of BALB/c mice with the arginase inhibitor S-(2-boronoethyl)-L-cysteine hydrochloride (BEC) did not change morbidity as defined by weight loss, but mice at day 10 post-infection treated with BEC had gained significantly more weight back than controls. Neutrophil and macrophage infiltration were similar between groups in the lung parenchyma, and neutrophil migration into the airways was reduced by BEC treatment. Differences seem to lie in the impact on T cell subset disposition. Arg1(ΔM) mice had increased total CD4+ T cell expansion in the lymph nodes, and increased T cell activation, IFNγ production, and IL-17 production in the lymph nodes, lung interstitium, and airways, while treatment with BEC had no impact on T cell activation or IL-17 production, but reduced the number of T cells producing IFNγ in the lungs. Lung injury scores were increased in the Arg1(ΔM) mice, but no differences were observed in the mice treated with pharmacologic arginase inhibitors. Overall, myeloid arginase production was demonstrated to be essential for control of damaging inflammatory responses associated with P. aeruginosa pneumonia in C57BL/6 mice, in contrast to a protective effect in the Th2-dominant BALB/c mice when arginase activity is globally inhibited.

Introduction Acute myocardial infarction (MI) is a primary cause of worldwide morbidity and mortality. Macrophages are fundamental components of post-MI inflammation. Pro-inflammatory macrophages can lead to adverse cardiac remodeling and heart failure while anti-inflammatory/reparative macrophages enhance tissue healing. Shifting the balance between pro-inflammatory and reparative macrophages post-MI is a novel therapeutic strategy. Azithromycin (AZM), a commonly used macrolide antibiotic, polarizes macrophages towards the anti-inflammatory phenotype, as shown in animal and human studies. We hypothesized that AZM modulates post-MI inflammation and improves cardiac recovery. Methods and results Male WT mice (C57BL/6, 6–8 weeks old) were treated with either oral AZM (160 mg/kg/day) or vehicle (control) starting 3 days prior to MI and continued to day 7 post-MI. We observed a significant reduction in mortality with AZM therapy. AZM-treated mice showed a significant decrease in pro-inflammatory (CD45+/Ly6G-/F4-80+/CD86+) and increase in anti-inflammatory (CD45+/Ly6G-/F4-80+/CD206+) macrophages, decreasing the pro-inflammatory/anti-inflammatory macrophage ratio in the heart and peripheral blood as assessed by flow cytometry and immunohistochemistry. Macrophage changes were associated with a significant decline in pro- and increase in anti-inflammatory cytokines. Mechanistic studies confirmed the ability of AZM to shift macrophage response towards an anti-inflammatory state under hypoxia/reperfusion stress. Additionally, AZM treatment was associated with a distinct decrease in neutrophil count due to apoptosis, a known signal for shifting macrophages towards the anti-inflammatory phenotype. Finally, AZM treatment improved cardiac recovery, scar size, and angiogenesis. Conclusion Azithromycin plays a cardioprotective role in the early phase post-MI through attenuating inflammation and enhancing cardiac recovery. Post-MI treatment and human translational studies are warranted to examine the therapeutic applications of AZM.

RSV is the most significant cause of serious lower respiratory tract infection in infants and young children worldwide. There is currently no vaccine for the virus, and antiviral therapy (e.g., ribavirin) has shown no efficacy against the disease. We reported that alternatively activated macrophages (AAMs) mediate resolution of RSV-induced pathology. AAM differentiation requires macrophage-derived IL-4 and -13, autocrine/paracrine signaling through the type I IL-4 receptor, and STAT6 activation. Based on these findings, we reasoned that it would be possible to intervene therapeutically in RSV disease by increasing AAM differentiation, thereby decreasing lung pathology. Mice treated with the IL-4/anti-IL-4 immune complexes, shown previously to sustain levels of circulating IL-4, increased the RSV-induced AAM markers arginase-1 and mannose receptor and decreased the lung pathology. Induction of PPARγ, shown to play a role in AAM development, by the PPARγ agonist rosiglitazone or treatment of mice with the macrolide antibiotic AZM, also reported to skew macrophage differentiation to an AAM phenotype, increased the AAM markers and mitigated RSV-induced lung pathology. Collectively, our data suggest that therapeutic manipulation of macrophage differentiation to enhance the AAM phenotype is a viable approach for ameliorating RSV-induced disease.

BackgroundAzithromycin treatment improves clinical parameters in patients with CF, and alters macrophage activation from a pro-inflammatory (M1) phenotype to a pro-fibrotic, alternatively activated (M2) phenotype. The transcriptional profile of cells from patients receiving azithromycin is unknown.MethodsGene expression in association with macrophage polarization, inflammation, and tissue remodeling was assessed from sputum samples collected from patients with CF. Transcriptional profiles and clinical characteristics, including azithromycin therapy, were compared.ResultsExpression of NOS2 and TNFα was decreased in subjects receiving azithromycin, whereas expression of M2-associated genes was unaffected. Principal component analysis revealed gene expression profiles consistent with M1- (MMP9, NOS2, and TLR4) or M2-polarization (CCL18, fibronectin, and MR1) in select subject groups. These expression signatures did not significantly correlate with clinical characteristics.ConclusionsPro-inflammatory gene expression was low in subjects receiving AZM. Genes were stratified into groupings characteristic of M1- or M2-polarization, suggesting that overall polarization status is distinct among patient groups.

Effect of the meropenem MIC on the killing activity of meropenem and polymyxin B in combination against KPC-producing Klebsiella pneumoniae

Purpose The use of a continuous infusion of a β-lactam antibiotic in combination with high-dose, extended-interval amino-glycoside therapy for eradication of Pseudomonas aeruginosa in an adult patient with cystic fibrosis (CF) is reported. Summary Testing of an expectorated sputum sample taken during routine evaluation of a 32-year-old woman with CF isolated P. aeruginosa; the patient’s medical record indicated no prior episodes of P. aeruginosa colonization. In an initial attempt to eradicate the organism, the woman received outpatient therapy with oral ciprofloxacin twice daily combined with an aminoglycoside (tobramycin solution) by nebulization twice daily. After a culture four weeks later again isolated P. aeruginosa, the patient was hospitalized, and i.v. antimicrobial therapy was initiated. The inpatient treatment regimen consisted of continuous-infusion cefepime 6 g (100 mg/kg/24 hr) and i.v. tobramycin 700 mg (12 mg/kg/24 hr), with both drugs administered via a peripherally inserted central catheter, for two weeks. A bronchoalveolar lavage fluid culture performed two months after completion of the i.v. antimicrobial regimen, as well as several sputum cultures obtained during the subsequent three years, tested negative for P. aeruginosa. Conclusion The administration of continuous-infusion cefepime and high-dose, extended-interval tobramycin led to the successful eradication of P. aeruginosa in an adult patient with CF.

Allergic bronchopulmonary aspergillosis (ABPA) is a complex hypersensitivity reaction to Aspergillus fumigatus that occur frequently in patients with cystic fibrosis (CF). Recurrent episodes of bronchial obstruction, inflammation, and mucoid impaction occur in ABPA and results in bronchiectasis, fibrosis, and respiratory failure. The treatment of ABPA includes corticosteroids to reduce the acute inflammation and intraconazole to reduce the fungal colonization load in order to reduce lung injury. This case discusses the successful use of aerosolized amphotericin B for the treatment of ABPA in a 14-year-old patient with CF listed for lung transplant. The patient required fewer hospitalizations, and both oral corticosteroids and anti-fungal therapy were eventually stopped. Pediatr Pulmonol. 2010;45:1145–1148. © 2010 Wiley-Liss, Inc.

Background Chronic airway inflammation characterizes patients with cystic fibrosis (CF). The role of alternative macrophage activation in this disease course is unknown. Objective We evaluated markers of alternative and classical macrophage activation in the lungs of patients with CF and evaluated these characteristics in the context of Pseudomonas aeruginosa ( PA ) infection, immunomodulatory drug therapy and pulmonary function. Methods Bronchoalveolar lavage or spontaneously expectorated sputum samples were collected from 48 CF patients. Clinical data were related to macrophage surface expression of mannose receptor (MR) (up-regulated in alternatively activated macrophages) and TLR4 (up-regulated in classically activated macrophages). Also, the activity of the alternatively activated macrophage effector molecule arginase was compared among patient groups, and pro- and anti-inflammatory cytokines produced by alternatively and classically activated macrophages were measured. Results There were significant differences between PA -infected and -uninfected patients in several clinical measurements. PA -infected patients exhibited increased use of azithromycin, up-regulation of MR on CD11b+ cells and increased arginase activity in their lung samples, and had a strong inverse relationship between MR and arginase activity to FEV 1 . Upon further analysis, PA -infected patients who were treated with azithromycin had the highest arginase activity and the highest number of macrophages that were MR+TLR4−, and both of these markers were inversely related to the FEV 1 . Conclusions Our findings suggest an increase in both MR and arginase expression as pulmonary function declines in PA -infected patients with CF. These markers of an alternatively activated macrophage phenotype give cause for future study to define the function of macrophage activation states in the CF lung.

Background Macrophages persist indefinitely at sites of spinal cord injury (SCI) and contribute to both pathological and reparative processes. While the alternative, anti-inflammatory (M2) phenotype is believed to promote cell protection, regeneration, and plasticity, pro-inflammatory (M1) macrophages persist after SCI and contribute to protracted cell and tissue loss. Thus, identifying non-invasive, clinically viable, pharmacological therapies for altering macrophage phenotype is a challenging, yet promising, approach for treating SCI. Azithromycin (AZM), a commonly used macrolide antibiotic, drives anti-inflammatory macrophage activation in rodent models of inflammation and in humans with cystic fibrosis. Methods We hypothesized that AZM treatment can alter the macrophage response to SCI and reduce progressive tissue pathology. To test this hypothesis, mice (C57BL/6J, 3-month-old) received daily doses of AZM (160 mg/kg) or vehicle treatment via oral gavage for 3 days prior and up to 7 days after a moderate-severe thoracic contusion SCI (75-kdyn force injury). Fluorescent-activated cell sorting was used in combination with real-time PCR (rtPCR) to evaluate the disposition and activation status of microglia, monocytes, and neutrophils, as well as macrophage phenotype in response to AZM treatment. An open-field locomotor rating scale (Basso Mouse Scale) and gridwalk task were used to determine the effects of AZM treatment on SCI recovery. Bone marrow-derived macrophages (BMDMs) were used to determine the effect of AZM treatment on macrophage phenotype in vitro. Results In accordance with our hypothesis, SCI mice exhibited significantly increased anti-inflammatory and decreased pro-inflammatory macrophage activation in response to AZM treatment. In addition, AZM treatment led to improved tissue sparing and recovery of gross and coordinated locomotor function. Furthermore, AZM treatment altered macrophage phenotype in vitro and lowered the neurotoxic potential of pro-inflammatory, M1 macrophages. Conclusions Taken together, these data suggest that pharmacologically intervening with AZM can alter SCI macrophage polarization toward a beneficial phenotype that, in turn, may potentially limit secondary injury processes. Given that pro-inflammatory macrophage activation is a hallmark of many neurological pathologies and that AZM is non-invasive and clinically viable, these data highlight a novel approach for treating SCI and other maladaptive neuroinflammatory conditions. Electronic supplementary material The online version of this article (doi:10.1186/s12974-015-0440-3) contains supplementary material, which is available to authorized users.

B cells play a critical role in the clearance of Pneumocystis. In addition to production of Pneumocystis-specific Abs, B cells are required during the priming phase for CD4+ T cells to expand normally and generate memory. Clearance of Pneumocystis was found to be dependent on Ag specific B cells and on the ability of B cells to secrete Pneumocystis-specific Ab, as mice with B cells defective in these functions or with a restricted BCR were unable to control Pneumocystis infection. Because Pneumocystis-specific antiserum was only able to partially protect B cell–deficient mice from infection, we hypothesized that optimal T cell priming requires fully functional B cells. Using adoptive transfer and B cell depletion strategies, we determined that optimal priming of CD4+ T cells requires B cells during the first 2–3 d of infection and that this was independent of the production of Ab. T cells that were removed from Pneumocystis-infected mice during the priming phase were fully functional and able to clear Pneumocystis infection upon adoptive transfer into Rag1−/− hosts, but this effect was ablated in mice that lacked fully functional B cells. Our results indicate that T cell priming requires a complete environment of Ag presentation and activation signals to become fully functional in this model of Pneumocystis infection.

Sulfamethoxazole-trimethoprim and zidovudine (AZT), drugs used often in combination in patients infected with HIV, were investigated for their effects on B cell development in a mouse model. BALB/c mice were randomized to receive oral doses of AZT, sulfamethoxazole-trimethoprim, or the combination via oral gavage for up to 28 days. Immune cell populations in the spleen, lung, and peripheral blood were examined, and toxicity to B lineage subtypes in the bone marrow was investigated by phenotypic analysis via flow cytometry. Pre-pro-B, pro-B, early pre-B, and late pre-B cells were assayed for apoptosis and analyzed for cell cycle profile. Total as well as B cell splenic and bone marrow cellularities were significantly decreased by using the drugs concomitantly, while B cell populations in the lungs and percentage in the peripheral blood were not affected. Combination therapy caused significant increases in apoptosis in B cells and granulocytes in the bone marrow, with the late pre-B cell population being the most depleted. The proliferative expansion and differentiation of early pre-B cells (B220+/CD43+/BP-1+/HSA+) to the late pre-B cell (B220+/CD43-/IgM-) stage was blocked, with early pre-B cells accumulating in the proliferative phases of the cell cycle. This apoptosis increase is likely due to elevated blood sulfamethoxazole concentrations that were observed in mice also receiving AZT. Concurrent sub-chronic administration of AZT and sulfamethoxazole-trimethoprim adversely affected B lymphocyte development in mouse bone marrow.

Influenza infection predisposes patients to secondary bacterial pneumonia that contributes significantly to morbidity and mortality. Although this association is well documented, the mechanisms that govern this synergism are poorly understood. A window of hyporesponsiveness following influenza infection has been associated with a substantial increase in local and systemic IFN-γ concentrations. Recent data suggest that the oxazolidinone antibiotic linezolid decreases IFN-γ and TNF-α production in vitro from stimulated PBMCs. We therefore sought to determine whether linezolid would reverse immune hyporesponsiveness after influenza infection in mice through its effects on IFN-γ. In vivo dose-response studies demonstrated that oral linezolid administration sufficiently decreased bronchoalveolar lavage fluid levels of IFN-γ at day 7 postinfluenza infection in a dose-dependent manner. The drug also decreased morbidity as measured by weight loss compared with vehicle-treated controls. When mice were challenged intranasally with Streptococcus pneumoniae 7 d postinfection with influenza, linezolid pretreatment led to decreased IFN-γ and TNF-α production, decreased weight loss, and lower bacterial burdens at 24 h postbacterial infection in comparison with vehicle-treated controls. To determine whether these effects were due to suppression of IFN-γ, linezolid-treated animals were given intranasal instillations of rIFN-γ before challenge with S. pneumoniae. This partially reversed the protective effects observed in the linezolid-treated mice, suggesting that the modulatory effects of linezolid are mediated partially by its ability to blunt IFN-γ production. These results suggest that IFN-γ, and potentially TNF-α, may be useful drug targets for prophylaxis against secondary bacterial pneumonia following influenza infection.

Chronic azithromycin therapy has been associated with improved clinical outcomes in patients with cystic fibrosis (CF) who are chronically infected with Pseudomonas aeruginosa. We have previously demonstrated that azithromycin polarizes macrophages towards an alternatively activated phenotype, thereby blunting inflammation associated with infection. Because this phenotype is pro-fibrotic, it is important to evaluate azithromycin's consequential effects upon fibroblast function and extracellular matrix (ECM) protein production.We co-cultured macrophages and fibroblasts together and stimulated them by adding P. aeruginosa or lipopolysaccharide to assess the ability of azithromycin to alter the macrophage phenotype, along with the impact exerted upon the production of fibronectin and other effectors that govern tissue remodelling, including transforming growth factor β (TGFβ), matrix metalloproteinase-9 (MMP-9) and arginase. We supported these studies by evaluating the impact of azithromycin treatment on these proteins in a mouse model of P. aeruginosa infection.Azithromycin increased arginase expression in vitro, as well as the activation of latent TGFβ, consistent with polarization to the alternative macrophage phenotype. While the drug increased fibronectin concentrations after stimulation in vitro, secretion of the ECM-degrading enzyme MMP-9 was also increased. Neutralization of active TGFβ resulted in the ablation of azithromycin's ability to increase fibronectin concentrations, but did not alter its ability to increase MMP-9 expression. In P. aeruginosa-infected mice, azithromycin significantly decreased MMP-9 and fibronectin concentrations in the alveolar space compared with non-treated, infected controls.Our results suggest that azithromycin's effect on MMP-9 is regulated independently of TGFβ activity. Additionally, the beneficial effects of azithromycin may be partially due to effects on homeostasis in which ECM-degrading mediators like MMP-9 are up-regulated early after infection. This may impact the damaging effects of inflammation that lead to fibrosis in this patient population.

Platelet activation results in the release and upregulation of mediators responsible for immune cell activation and recruitment, suggesting that platelets play an active role in immunity. Animal models and retrospective data have demonstrated benefit of antiplatelet therapy on inflammatory mediator expression and clinical outcomes. This study sought to characterize effects of clopidogrel on the incidence and severity of community-acquired pneumonia (CAP). A retrospective cohort study was conducted of Kentucky Medicaid patients (2001–2005). The exposed cohort consisted of patients receiving at least six consecutive clopidogrel prescriptions; the non-exposed cohort was comprised of patients not prescribed clopidogrel. Primary endpoints included incidence of CAP and inpatient treatment. Secondary severity endpoints included mortality, intensive care unit admission, mechanical ventilation, sepsis, and acute respiratory distress syndrome/acute lung injury. CAP incidence was significantly greater in the exposed cohort (OR 3.39, 95 % CI 3.27–3.51, p

Recurrent acute pancreatitis associated with metronidazole developed in a 49-year-old woman who was taking the drug as treatment for vaginal trichomoniasis. The lack of alternative effective therapies for trichomoniasis governed the decision to rechallenge the patient with metronidazole despite a vague history of this reaction on a previous occasion. Six reports of this reaction are found in the literature. The patient was admitted to the hospital 12 hours after taking a single dose of metronidazole. Severe epigastric pain and elevated amylase and lipase concentrations led to the diagnosis of acute pancreatitis, although results of an abdominal ultrasound were unremarkable. The patient made a full recovery. Although this reaction occurs infrequently, this case report illustrates the need to develop additional therapies for treatment of trichomoniasis.

Bronchopulmonary dysplasia (BPD) results from prematurity and surfactant deficiency with contributing factors from barotrauma, volutrauma, and oxygen toxicity from supportive mechanical ventilation care and infection. These factors result in chronic inflammation with recurring cycles of lung damage and repair that impair alveolarisation and vascularisation in developing infant lungs. With advancement in the understanding of its pathophysiology and resulting therapy, BPD has evolved into a different disorder which has been coined the 'new' BPD. As these patients age, primary care physicians need to understand the impact on pulmonary function. This discussion reviews the pulmonary function outcomes resulting from BPD through later childhood and young adulthood.

Allergic bronchopulmonary aspergillosis (ABPA) is a complex hypersensitivity reaction to Aspergillus fumigatus that occur frequently in patients with cystic fibrosis (CF). Recurrent episodes of bronchial obstruction, inflammation, and mucoid impaction occur in ABPA and results in bronchiectasis, fibrosis, and respiratory failure. The treatment of ABPA includes corticosteroids to reduce the acute inflammation and intraconazole to reduce the fungal colonization load in order to reduce lung injury. This case discusses the successful use of aerosolized amphotericin B for the treatment of ABPA in a 14-year-old patient with CF listed for lung transplant. The patient required fewer hospitalizations, and both oral corticosteroids and anti-fungal therapy were eventually stopped.

Infection with mucoid strains of Pseudomonas aeruginosa in chronic inflammatory diseases of the airway is difficult to eradicate and can cause excessive inflammation. The roles of alternatively activated and regulatory subsets of macrophages in this pathophysiological process are not well characterized. We previously demonstrated that azithromycin induces an alternatively activated macrophage-like phenotype in vitro . In the present study, we tested whether azithromycin affects the macrophage activation status and migration in the lungs of P. aeruginosa -infected mice. C57BL/6 mice received daily doses of oral azithromycin and were infected intratracheally with a mucoid strain of P. aeruginosa . The properties of macrophage activation, immune cell infiltration, and markers of pulmonary inflammation in the lung interstitial and alveolar compartments were evaluated postinfection. Markers of alternative macrophage activation were induced by azithromycin treatment, including the surface expression of the mannose receptor, the upregulation of arginase 1, and a decrease in the production of proinflammatory cytokines. Additionally, azithromycin increased the number of CD11b + monocytes and CD4 + T cells that infiltrated the alveolar compartment. A predominant subset of CD11b + cells was Gr-1 positive (Gr-1 + ), indicative of a subset of cells that has been shown to be immunoregulatory. These differences corresponded to decreases in neutrophil influx into the lung parenchyma and alteration of the characteristics of peribronchiolar inflammation without any change in the clearance of the organism. These results suggest that the immunomodulatory effects of azithromycin are associated with the induction of alternative and regulatory macrophage activation characteristics and alteration of cellular compartmentalization during infection.

Phytosterol supplements lower low-density lipoprotein (LDL) cholesterol, but accumulate in vascular lesions of patients and limit the anti-atherosclerotic effects of LDL lowering in apolipoprotein E (Apo E)-deficient mice, suggesting that the cholesterol-lowering benefit of phytosterol supplementation may not be fully realized. Individual phytosterols have cell-type specific effects that may be either beneficial or deleterious with respect to atherosclerosis, but little is known concerning their effects on macrophage function. The effects of phytosterols on ABCA1 and ABCG1 abundance, cholesterol efflux and inflammatory cytokine secretion were determined in cultured macrophage foam cells. Among the commonly consumed phytosterols, stigmasterol increased expression of ABCA1 and ABCG1 and increased efflux of cholesterol to apolipoprotein (Apo) AI and high-density lipoprotein (HDL). Campesterol and sitosterol had no effect on ABCA1 or ABCG1 levels. Sitosterol had no effect on cholesterol efflux to Apo AI or HDL, whereas campesterol had a modest but significant reduction in cholesterol efflux to HDL in THP-1 macrophages. Whereas stigmasterol blunted aggregated LDL (agLDL) induced increases in tumor necrosis factor (TNF)-α, interleukin (IL)-6 and IL-1β secretion, sitosterol exacerbated these effects. The presence of campesterol had no effect on agLDL-induced inflammatory cytokine secretion from THP-1 macrophages. In conclusion, the presence of stigmasterol in modified lipoproteins promoted cholesterol efflux and suppressed inflammatory cytokine secretion in response to lipid loading in macrophage foam cells. While campesterol was largely inert, the presence of sitosterol increased the proinflammatory cytokine secretion.

Lung transplantation is the only life-prolonging therapy available for cystic fibrosis (CF) patients with end-stage lung disease. The presence of pathogens in the airways of CF patients prior to transplantation is the major risk factor for infection in the post-transplantation period, with methicillin-resistant Staphylococcus aureus (MRSA) having a growing impact. Aerosolized vancomycin has been used successfully in the treatment of MRSA in the CF population but its use after lung transplantation has not been previously reported. We report the case of a lung transplant recipient who was successfully treated for MRSA infection with aerosolized vancomycin.

Inquilinus limosus is a alpha-proteobacterium that has been recently isolate in the airways of cystic fibrosis (CF) patients. We report the isolation of a mucoid strain of I. limosus from the sputum of a 20-year-old male patient with CF over 1 year that was associated with the clinical, spirometric, and radiographic decline in a previously healthy patient.

Study Objective. To determine if exposure to trimethoprim-sulfamethoxazole (TMP-SMX) causes a defect in peripheral B-cell function among patients with the human immunodeficiency virus (HIV) who are receiving zidovudine antiretroviral therapy. Design. Prospective, single-center, single-group, case-crossover design with a 4-week exposure period. Setting. University-affiliated infectious diseases outpatient clinic. Patients. Fourteen HIV-infected adult men receiving zidovudine, who had CD4+ cell counts above 350 cells/mm3 and undetectable viral loads. Intervention. Patients were administered a 28-day course of TMP 160 mg-SMX 800 mg/day (one double-strength tablet/day). Peripheral blood mononuclear cells (PBMCs) were obtained and isolated before and after exposure to TMP-SMX. Cells were cultured ex vivo with three mitogens of differing immunologic properties: pokeweed mitogen ([PWM] T-cell-dependent B-cell mitogen), Staphylococcus aureus Cowan ([SAC] T-cell-independent B-cell mitogen), and phytohemagglutinin A ([PHA] T-cell mitogen). Functionality of the B and T lymphocytes was then assessed. Measurements and Main Results. Proliferative capacity, cytokine secretion, and antibody production were measured and compared before and after TMP-SMX exposure. Reduced proliferative capacities of both PBMC and B cells stimulated with mitogens were observed at the 3-day culture time point in response to PWM, PHA, and SAC (p=0.029, 0.028, and 0.026, respectively). Proliferative capacity at day 7 of culture was not significantly different for any condition examined. Cytokine production was not altered by combination drug exposure after 10 days of culture when cells were stimulated with either PWM or PHA. Although antibody responses to PWM and PHA were similar, total immunoglobulin G concentration was lower in cells stimulated with SAC in samples obtained after TMP-SMX regimen completion compared with those obtained before exposure (p=0.005). Conclusion. Although these data were affected by limitations in power and study design, they suggest that peripheral B-lymphocyte function is altered as a result of TMP-SMX exposure in HIV-infected patients concurrently receiving zidovudine. Further study of this effect is warranted.

Bronchopulmonary dysplasia (BPD) refers to a heterogeneous group of lung disorders in infants that is commonly associated with prematurity and surfactant deficiency. BPD results from the complex interplay between impairments in the premature lung such as surfactant deficiency, perinatal insults such as infection, and damage resulting from supportive care of the infant due to barotrauma or volutrauma from mechanical ventilation and oxygen toxicity from supplemental oxygen administration. These factors result in chronic inflammation in the infant lung with recurring cycles of lung damage and repair that may impair alveolarization and vascularization in the developing lungs. As our insight in how to treat BPD improves along with the ability to do so with developing technology and therapies, the underlying pathogenesis will also change. The term ‘new’ BPD is now commonly used, to describe the changes seen in the post-surfactant era. This discussion reviews the pathogenesis of BPD according to the current medical literature.

To investigate the in vitro effects of azithromycin on macrophage phenotype. Utilizing a mouse macrophage cell line (J774), we examined the effect of azithromycin on the properties that define classical macrophage activation (M1) and alternative macrophage activation (M2).J774 cells were cultured in the presence of azithromycin and stimulated with classical activation [interferon-gamma (IFNgamma)] and alternative activation [interleukin (IL)-4 and IL-13] cytokines along with lipopolysaccharide (LPS). Macrophages were analysed for inflammatory cytokine production, surface receptor expression, inducible nitric oxide synthase (iNOS) protein expression and arginase activity.Azithromycin altered the overall macrophage phenotype. Azithromycin-treated J774 macrophages demonstrated a significantly reduced production of the pro-inflammatory cytokines IL-12 and IL-6, increased production of the anti-inflammatory cytokine IL-10 and decreased the ratio of IL-12 to IL-10 by 60%. Receptor expression indicative of the M2 phenotype (mannose receptor and CD23) was increased, and receptor expression typically up-regulated in M1 cells (CCR7) was inhibited. The presence of azithromycin increased arginase (M2 effector molecule) activity 10-fold in cells stimulated with IFNgamma and LPS, and iNOS protein (M1 effector molecule) concentrations were attenuated by the drug.These data provide evidence that azithromycin affects the inflammatory process at the level of the macrophage and shifts macrophage polarization towards the alternatively activated phenotype. This recently defined M2 phenotype has been described in conditions in which pulmonary inflammation and fibrosis are major determinants of clinical outcome, but the concept of antibiotics altering macrophage phenotype has not yet been critically evaluated.

Study Objectives. To determine as proof of principle the effect of combination exposure to zidovudine plus trimethoprim-sulfamethoxazole (TMP-SMX) on humoral immune responses to influenza vaccination in patients with human immunodeficiency virus (HIV). Design. Prospective, open-label trial. Setting. University-affiliated infectious diseases outpatient clinic. Patients. Twenty-three HIV-infected adults receiving antiretroviral therapy, with CD4+ cell counts greater than 350 cells/mm3 and undetectable viral loads. Intervention. Patients were assigned to one of four treatment groups: zidovudine (6 patients), TMP-SMX (7), zidovudine plus TMP-SMX (5), or neither drug (5); TMP-SMX was given as a 28-day course. Patients were subsequently immunized with the yearly influenza vaccine, and humoral responses were compared among groups 20–24 days after vaccination. Measurements and Main Results. Antibody responses to influenza A and B were measured, and total and activated T and B cell percentages in the peripheral blood were determined. Mean influenza B—specific serum immunoglobulin (Ig)G titers were significantly lower in patients receiving TMP-SMX alone (0.98 ± 0.60 reference value, p=0.010) or the combination of zidovudine plus TMP-SMX (0.73 ± 0.29 reference value, p=0.003) compared with those receiving neither drug (1.95 ± 0.38 reference value). This corresponded to a significantly lower percentage of patients in the combination group that achieved immunoprotective titers to influenza B compared with the group who received neither drug (control group; 20% vs 100%, p=0.048). In addition, the relationship between serum IgG titer and CD4+ cell count was statistically significantly different for patients exposed to zidovudine plus TMP-SMX versus control patients for both influenza A and B (F statistics 8.72 and 11.70, respectively, compared with critical F value 7.26 for p

Drug therapy for human immunodeficiency virus (HIV) is highly effective in suppressing viral replication and restoring immune function in patients with HIV. However, this same treatment can also be associated with immunotoxicity. For example, zidovudine and various other antiretroviral agents are capable of causing bone marrow suppression. Agents used to treat opportunistic infections in these individuals, including ganciclovir, foscarnet, and sulfamethoxazole-trimethoprim, can cause additional hematotoxicity. Drug-drug interactions must also be considered and managed in order to control iatrogenic causes of immunotoxicity. In this review, we examine the normal immune response to HIV, and the benefits of antiretroviral therapy in prolonging immune function. We then discuss immune-related adverse effects of drugs used to treat HIV and the opportunistic infections that are common among these patients. Finally, we address in vitro, animal, and clinical evidence of toxicity associated with various combination use of these agents.

BACKGROUND:Polymyxin B sulfate and colistin, also known as colistimethate, have not been used for many years because less toxic antimicrobials are available. Gram-negative bacteria that are resistant to the aminoglycosides, β-lactams, and fluoroquinolones are becoming more common. These bacteria are often susceptible to the polymyxins.OBJECTIVE:To present a review of the chemistry, antibacterial spectrum, dosing, pharmacokinetics, toxicity, and indications for polymyxin B sulfate and colistin.DATA SOURCE:A MEDLINE search (1966–1998) of the English-language literature was performed to identify primary literature on the polymyxins. Older citations (1949–1965) were identified through the bibliographies of these articles.STUDY SELECTION:All available reports of in vitro antibacterial activity, animal and clinical trials, and case reports were reviewed.DATA SYNTHESIS:The polymyxins are amphipathic molecules that interact with lipopolysaccharide in the bacterial outer membrane. They have potent antiendotoxic properties and antibacterial activity against Pseudomonas aeruginosa and many of the Enterobacteriaceae. Polymyxin B and colistin are usually given at a dose of 1.5–2.5 and 5 mg/kg/d, respectively, in two divided doses. Dosing must be altered in renal failure since the kidney is the primary route of elimination. Distribution into pleural fluid, joints, and cerebrospinal fluid is poor. Toxic effects involve the kidney and central nervous system. The polymyxins are recommended for serious systemic infections caused by gram-negative bacteria that are resistant to other agents.CONCLUSIONS:Polymyxin B sulfate and colistin have a role in the therapy of multidrug-resistant gram-negative bacterial infections.