Flexible Usage and Interconnectivity of Diverse Cell Death Pathways Protect against Intracellular Infection.

Programmed cell death contributes to host defense against pathogens. To investigate the relative importance of pyroptosis, necroptosis, and apoptosis during Salmonella infection, we infected mice and macrophages deficient for diverse combinations of caspases-1, -11, -12, and -8 and receptor interacting serine/threonine kinase 3 (RIPK3). Loss of pyroptosis, caspase-8-driven apoptosis, or necroptosis had minor impact on Salmonella control. However, combined deficiency of these cell death pathways caused loss of bacterial control in mice and their macrophages, demonstrating that host defense can employ varying components of several cell death pathways to limit intracellular infections. This flexible use of distinct cell death pathways involved extensive cross-talk between initiators and effectors of pyroptosis and apoptosis, where initiator caspases-1 and -8 also functioned as executioners when all known effectors of cell death were absent. These findings uncover a highly coordinated and flexible cell death system with in-built fail-safe processes that protect the host from intracellular infections.

Rapid Tumor DNA Analysis of Cerebrospinal Fluid Accelerates Treatment of Central Nervous System Lymphoma.

Delays and risks associated with neurosurgical biopsies preclude timely diagnosis and treatment of central nervous system (CNS) lymphoma and other CNS neoplasms. We prospectively integrated targeted rapid genotyping of cerebrospinal fluid (CSF) into the evaluation of 70 patients with CNS lesions of unknown etiology. Participants underwent genotyping of CSF-derived DNA using a qPCR-based approach for parallel detection of single-nucleotide variants in the MYD88, TERT promoter, IDH1, IDH2, BRAF and H3F3A genes within 80 minutes of sample acquisition. Canonical mutations were detected in 42% of patients with neoplasms, including cases of primary and secondary CNS lymphoma, glioblastoma, IDH-mutant brainstem glioma and H3K27M-mutant diffuse midline glioma. Genotyping results eliminated the need for surgical biopsies in 7/33 (21.2%) cases of newly diagnosed neoplasms, resulting in significantly accelerated initiation of disease-directed treatment (median 3 vs 12 days; p = 0.027). This assay was then implemented in a Clinical Laboratory Improvement Amendments (CLIA) environment, with 2-day median turnaround for diagnosis of central nervous system lymphoma from 66 patients across 4 clinical sites. Our study prospectively demonstrates that targeted rapid CSF genotyping influences oncologic management for suspected CNS tumors.

Vaccine-induced inflammation and inflammatory monocytes promote CD4+ T cell-dependent immunity against murine salmonellosis.

Prior infection can generate protective immunity against subsequent infection, although the efficacy of such immunity can vary considerably. Live-attenuated vaccines (LAVs) are one of the most effective methods for mimicking this natural process, and analysis of their efficacy has proven instrumental in the identification of protective immune mechanisms. Here, we address the question of what makes a LAV efficacious by characterising immune responses to a LAV, termed TAS2010, which is highly protective (80-90%) against lethal murine salmonellosis, in comparison with a moderately protective (40-50%) LAV, BRD509. Mice vaccinated with TAS2010 developed immunity systemically and were protected against gut-associated virulent infection in a CD4+ T cell-dependent manner. TAS2010-vaccinated mice showed increased activation of Th1 responses compared with their BRD509-vaccinated counterparts, leading to increased Th1 memory populations in both lymphoid and non-lymphoid organs. The optimal development of Th1-driven immunity was closely correlated with the activation of CD11b+Ly6GnegLy6Chi inflammatory monocytes (IMs), the activation of which can be modulated proportionally by bacterial load in vivo. Upon vaccination with the LAV, IMs expressed T cell chemoattractant CXCL9 that attracted CD4+ T cells to the foci of infection, where IMs also served as a potent source of antigen presentation and Th1-promoting cytokine IL-12. The expression of MHC-II in IMs was rapidly upregulated following vaccination and then maintained at an elevated level in immune mice, suggesting IMs may have a role in sustained antigen stimulation. Our findings present a longitudinal analysis of CD4+ T cell development post-vaccination with an intracellular bacterial LAV, and highlight the benefit of inflammation in the development of Th1 immunity. Future studies focusing on the induction of IMs may reveal key strategies for improving vaccine-induced T cell immunity.

Dysregulation of stress erythropoiesis and enhanced susceptibility to Salmonella Typhimurium infection in AhR-deficient mice.

BACKGROUND: By acting as an environmental sensor, the ligand-induced transcription factor aryl hydrocarbon receptor (AhR) regulates acute innate and adaptive immune responses against pathogens. Here, we analyzed the function of AhR in a model for chronic systemic infection with attenuated Salmonella Typhimurium (STM). METHODS: WT and AhR-deficient mice were infected with the attenuated STM strain TAS2010 and analyzed for bacterial burden, host defense functions and inflammatory stress erythropoiesis. RESULTS: AhR-deficient mice were highly susceptible to TAS2010 infection compared with WT mice demonstrated by reduced bacterial clearance and increased mortality. STM infection resulted in macrocytic anemia and enhanced splenomegaly along with destruction of the splenic architecture in AhR-deficient mice. In addition, AhR-deficient mice displayed a major expansion of splenic immature red blood cells, indicative of infection-induced stress erythropoiesis. Elevated serum levels of erythropoietin and interleukin-6 upon infection as well as increased numbers of splenic stress erythroid progenitors already in steady state probably drive this effect and might cause the alterations in splenic immune cell compartments, thereby preventing an effective host defense against STM in AhR-deficient mice. CONCLUSIONS: AhR-deficient mice fail to clear chronic TAS2010 infection due to enhanced stress erythropoiesis in the spleen and accompanying destruction of the splenic architecture.

Problems with Using Polygenic Scores to Select Embryos.

Companies have recently begun to sell a new service to patients considering in vitro fertilization: embryo selection based on polygenic scores (ESPS). These scores represent individualized predictions of health and other outcomes derived from genomewide association studies in adults to partially predict these outcomes. This article includes a discussion of many factors that lower the predictive power of polygenic scores in the context of embryo selection and quantifies these effects for a variety of clinical and nonclinical traits. Also discussed are potential unintended consequences of ESPS (including selecting for adverse traits, altering population demographics, exacerbating inequalities in society, and devaluing certain traits). Recommendations for the responsible communication about ESPS by practitioners are provided, and a call for a society-wide conversation about this technology is made. (Funded by the National Institute on Aging and others.).

Therapeutic Role of Tamoxifen for Triple-Negative Breast Cancer: Leveraging the Interaction Between ERß and Mutant p53.

The absence of effective therapeutic targets and aggressive nature of triple-negative breast cancer (TNBC) renders this disease subset difficult to treat. Although estrogen receptor beta (ERß) is expressed in TNBC, studies on its functional role have yielded inconsistent results. However, recently, our preclinical studies, along with other observations, have shown the potential therapeutic utility of ERß in the context of mutant p53 expression. The current case study examines the efficacy of the selective estrogen receptor modulator tamoxifen in p53-mutant TNBC with brain metastases. Significant increase in ERß protein expression and anti-proliferative interaction between mutant p53 and ERß were observed after cessation of tamoxifen therapy, with significant regression of brain metastases. This case study provides supporting evidence for the use of tamoxifen in p53-mutant, ERß+TNBC, especially in the setting of brain metastasis.

CD4+ T cell immunity to Salmonella is transient in the circulation.

While Salmonella enterica is seen as an archetypal facultative intracellular bacterial pathogen where protection is mediated by CD4+ T cells, identifying circulating protective cells has proved very difficult, inhibiting steps to identify key antigen specificities. Exploiting a mouse model of vaccination, we show that the spleens of C57BL/6 mice vaccinated with live-attenuated Salmonella serovar Typhimurium (S. Typhimurium) strains carried a pool of IFN-γ+ CD4+ T cells that could adoptively transfer protection, but only transiently. Circulating Salmonella-reactive CD4+ T cells expressed the liver-homing chemokine receptor CXCR6, accumulated over time in the liver and assumed phenotypic characteristics associated with tissue-associated T cells. Liver memory CD4+ T cells showed TCR selection bias and their accumulation in the liver could be inhibited by blocking CXCL16. These data showed that the circulation of CD4+ T cells mediating immunity to Salmonella is limited to a brief window after which Salmonella-specific CD4+ T cells migrate to peripheral tissues. Our observations highlight the importance of triggering tissue-specific immunity against systemic infections.

Disparities in COVID-19 testing and outcomes among Asian American and Pacific Islanders: an observational study in a large health care system.

BACKGROUND: The COVID-19 pandemic has disproportionately impacted racial and ethnic minorities in the United States, including Asian Americans, Native Hawaiians and Pacific Islanders (Asian Americans and NH/PIs). However, few studies have highlighted nor disaggregated these disparities by Asian Americans and NH/PIs ethnic subgroups. METHODS: This retrospective, cross-sectional observational study aimed to assess variation of Asian Americans and NH/PIs COVID-19 testing and outcomes compared to non-Hispanic Whites (NHW). The study utilized data from the electronic health records (EHR) and the COVID-19 Universal Registry for Vital Evaluations (CURVE) from all patients tested for SARS-CoV-2 (n = 556,690) at a large, health system in Northern and Central California between February 20, 2020 and March 31, 2021. Chi-square tests were used for testing differences in the severity of COVID-19 (hospitalization, ICU admission, death) and patient demographic and clinical characteristics across the Asian Americans and NH/PIs subgroups and NHW. Unadjusted and adjusted Odds Ratios (ORs) were estimated for measuring effect of race ethnicity on severity of COVID-19 using multivariable logistic regression. RESULTS: Of the entire tested population, 70,564/556,690 (12.7%) tested positive for SARS-CoV-2. SARS-CoV-2 positivity of Asian subgroups varied from 4% in the Chinese and Korean populations, to 11.2%, 13.5%, and 12.5% for Asian Indian, Filipino, and "other Asian" populations respectively. Pacific Islanders had the greatest subgroup test positivity at 20.1%. Among Asian Americans and NH/PIs patients with COVID-19 disease, Vietnamese (OR = 2.06, 95% CI = 1.30-3.25), "Other Asian" (OR = 2.13, 95% CI = 1.79-2.54), Filipino (OR = 1.78, 95% CI = 1.34-2.23), Japanese (OR = 1.78, 95% CI = 1.10-2.88), and Chinese (OR = 1.73, 95% CI = 1.34-2.23) subgroups had almost double the odds of hospitalization compared to NHW. Pacific Islander (OR = 1.58, 95% CI = 1.19-2.10) and mixed race subgroups (OR = 1.55, 95% CI = 1.10-2.20) had more than one and a half times odds of hospitalization compared to NHW. Adjusted odds of ICU admission or death among hospitalized patients by different Asian subgroups varied but were not statistically significant. CONCLUSIONS: Variation of COVID-19 testing and hospitalization by Asian subgroups was striking in our study. A focus on the Asian Americans and NH/PIs population with disaggregation of subgroups is crucial to understand nuances of health access, utilization, and outcomes among subgroups to create health equity for these underrepresented populations.

Biofilm colonization of stone materials from an Australian outdoor sculpture: Importance of geometry and exposure.

The safeguarding of Australian outdoor stone heritage is currently limited by a lack of information concerning mechanisms responsible for the degradation of the built heritage. In this study, the bacterial community colonizing the stone surface of an outdoor sculpture located at the Church of St. John the Evangelist in Melbourne was analysed, providing an overview of the patterns of microbial composition associated with stone in an anthropogenic context. Illumina MiSeq 16S rRNA gene sequencing together with confocal laser microscope investigations highlighted the bacterial community was composed of both phototrophic and chemotrophic microorganisms characteristic of stone and soil, and typical of arid, salty and urban environments. Cardinal exposure, position and surface geometry were the most important factors in determining the structure of the microbial community. The North-West exposed areas on the top of the sculpture with high light exposure gave back the highest number of sequences and were dominated by Cyanobacteria. The South and West facing in middle and lower parts of the sculpture received significantly lower levels of radiation and were dominated by Actinobacteria. Proteobacteria were observed as widespread on the sculpture. This pioneer research provided an in-depth investigation of the microbial community structure on a deteriorated artistic stone in the Australian continent and provides information for the identification of deterioration-associated microorganisms and/or bacteria beneficial for stone preservation.

Nonparametric estimation of the survival distribution under covariate-induced dependent truncation.

There is often delayed entry into observational studies, which results in left truncation. In the estimation of the distribution of time-to-event from left-truncated data, standard survival analysis methods require quasi-independence between the truncation time and event time. Incorrectly assuming quasi-independence may lead to biased estimation. We address the problem of estimation of the survival distribution when dependence between the event time and its left truncation time is induced by shared covariates. We introduce propensity scores for truncated data and propose two inverse probability weighting methods that adjust for both truncation and dependence, if all of the shared covariates are measured. The proposed methods additionally allow for right censoring. We evaluate the proposed methods in simulations, conduct sensitivity analyses, and provide guidelines for use in practice. We illustrate our approach in application to data from a central nervous system lymphoma study. The proposed methods are implemented in the R package, depLT.

Ethnic differences on long term outcomes of polypoidal choroidal vasculopathy after predominantly bevacizumab monotherapy.

BACKGROUND: A 3-year single-centre, retrospective, comparative, non-randomized cohort study to describe the long-term outcomes of treatment-naïve, Caucasian and non-Caucasian eyes with polypoidal choroidal vasculopathy (PCV) after treatment with predominantly Bevacizumab monotherapy or in combination with rescue photodynamic therapy (PDT). METHODS: Demographics, visual outcomes, optical coherence tomography (OCT) and treatment data were collected up to 3 years after the first visit. Stratified analysis according to ethnicity and baseline vision was performed to identify factors predictive of long-term visual improvement and maintenance. RESULTS: A total of 89 eyes with PCV were identified, of which 14 received rescue verteporfin PDT. There was an equal distribution between Caucasian and non-Caucasian individuals. Non-Caucasians present at a younger age (67.3 vs. 76.0 years, p = 0.002), have a higher proportion of foveal involvement (80.9%, vs.54.2% p = 0.007), choroidal hyperpermeability (50% vs 25.8%, p = 0.013) and lower baseline visual acuity (53.1 vs. 63.3 letters, p = 0.008). Mean visual acuity (VA) gain was + 8.9 letters and + 5.0 letters at 1 and 3 years of follow-up, respectively. Non-Caucasian individuals had a lower mean final visual acuity (VA) (54.7 vs. 70.5, respectively; P < 0.001) and net gain in VA (+ 2.0 vs. + 7.6 letters, p = 0.581) compared to Caucasian individuals. The mean total number of injections given over 3 years was 14. CONCLUSIONS: Most patients treated with predominantly Bevacizumab anti-vascular endothelial growth factor (VEGF) monotherapy achieved sustained visual acuity gains out to 3 years. Due to ethnic-specific differences in presenting PCV phenotypes, non-Caucasians presented with lower baseline VA and had poorer long-term visual outcomes.

Understanding the bigger picture: syndemic interactions of the immigrant and refugee context with the lived experience of diabetes and obesity.

BACKGROUND: Providing contextually appropriate care and interventions for people with diabetes and/or obesity in vulnerable situations within ethnocultural newcomer communities presents significant challenges. Because of the added complexities of the refugee and immigrant context, a deep understanding of their realities is needed. Syndemic theory sheds light on the synergistic nature of stressors, chronic diseases and environmental impact on immigrant and refugee populations living in vulnerable conditions. We used a syndemic perspective to examine how the migrant ethnocultural context impacts the experience of living with obesity and/or diabetes, to identify challenges in their experience with healthcare. METHODS: This qualitative participatory research collaborated with community health workers from the Multicultural Health Brokers Cooperative of Edmonton, Alberta. Study participants were people living with diabetes and/or obesity from diverse ethnocultural communities in Edmonton and the brokers who work with these communities. We conducted 3 focus groups (two groups of 8 and one of 13 participants) and 22 individual interviews (13 community members and 9 brokers). The majority of participants had type 2 diabetes and 4 had obesity. We conducted a thematic analysis to explore the interactions of people's living conditions with experiences of: 1) diabetes and obesity; and 2) healthcare and resources for well-being. RESULTS: The synergistic effects of pre- and post-immigration stressors, including lack of social network cultural distance, and poverty present an added burden to migrants' lived experience of diabetes/obesity. People need to first navigate the challenges of immigration and settling into a new environment in order to have capacity to manage their chronic diseases. Diabetes and obesity care is enhanced by the supportive role of the brokers, and healthcare providers who have an awareness of and consideration for the contextual influences on patients' health. CONCLUSIONS: The syndemic effects of the socio-cultural context of migrants creates an additional burden for managing the complexities of diabetes and obesity that can result in inadequate healthcare and worsened health outcomes. Consequently, care for people with diabetes and/or obesity from vulnerable immigrant and refugee situations should include a holistic approach where there is an awareness of and consideration for their context.

One-year real-world outcomes of bevacizumab for the treatment of macular oedema secondary to retinal vein occlusion.

BACKGROUND: Bevacizumab is the only agent that many people can afford, yet there are only limited data on whether it improves macular oedema (MO) secondary to retinal vein occlusion (RVO) in real-world clinical practice. Here we studied 12-month real-world treatment outcomes of bevacizumab for RVO-related MO. METHODS: This was a multicentre, observational study analysing 12-month data from the Fight Retinal Blindness! (FRB) database. We studied treatment-naïve eyes with MO secondary to RVO commencing bevacizumab therapy between June 2009 and June 2019. Visual acuity (VA) and central subfield thickness (CST) were measured at baseline, 6 and 12 months. The primary outcome was a change in VA from baseline to 12 months. RESULTS: Two hundred and twenty treatment naive eyes were analyzed. The baseline VA for BRVO was better than CRVO (55.8 vs. 42.6 LogMAR letters) and this gap widened over the 12-month period, with a 12-month VA change of +14.0 (95% CI 11.1, 16.8) letters for BRVO and + 11.9 (95% CI 6.4, 17.4) for CRVO. The mean CST at baseline was 511 µm for BRVO and 627 µm for CRVO, falling at 12 months by -155 µm (-190, -121) in BRVO and -198 µm (-252, -145) in CRVO. The median number of injections for BRVO and CRVO completers was 7 (5, 9). CONCLUSIONS: Bevacizumab can be an effective treatment of RVO-MO in a real-world setting with outcomes approaching those reported by the seminal clinical trials. The functional and anatomical outcomes of intravitreal therapy were better for BRVO than CRVO.

Optimal preparation of SARS-CoV-2 viral transport medium for culture.

INTRODUCTION: The sudden arrival of the COVID-19 pandemic placed significant stresses on supply chains including viral transport medium (VTM). The VTM that was urgently required needed to support viral replication, as well as other routine diagnostic approaches. We describe the preparation and validation testing of VTM for rapidly expanding diagnostic testing, where the capacity of the VTM to preserve viral integrity, for culture, isolation and full sequence analysis, was maintained. METHODS: VTM was prepared using different methods of sterilization then 'spiked' with virus. The VTM was investigated using viral culture in Vero cells, and for nucleic acid detection by quantitative PCR. RESULTS: The best results were obtained by filter and autoclave-based sterilization. The VTM proved robust for culture-based analyses provided the inoculated VTM was stored at 4 °C, and tested within 48 h. The filtered VTM also supported PCR-based diagnosis for at least 5 days when the mock inoculated VTM was held at room temperature. DISCUSSION: The manual handling of VTM production, including filling and sterilization, was optimized. SARS-CoV-2 was spiked into VTM to assess different sterilization methods and measure the effects of storage time and temperature upon VTM performance. While most diagnostic protocols will not require replication competent virus, the use of high quality VTM will allow for the next phase of laboratory analysis in the COVID-19 pandemic, including drug and antibody susceptibility analysis of re-isolated SARS-CoV-2, and for the testing of vaccine escape mutants.

Orally Fast Disintegrating Cyclodextrin/Prednisolone Inclusion-Complex Nanofibrous Webs for Potential Steroid Medications.

Prednisolone is a widely used immunosuppressive and anti-inflammatory drug type that suffers from low aqueous solubility and bioavailability. Due to the inclusion complexation with cyclodextrins (CDs), prednisolone's drawbacks that hinder its potential during the administration can be eliminated effectively. Here, we have early shown the electrospinning of free-standing nanofibrous webs of CD/prednisolone inclusion complexes (ICs) in the absence of a polymer matrix. In this study, hydroxypropyl-beta-CD (HPßCD) has been used to form ICs with prednisolone and generate nanofibrous webs with a drug loading capacity of ∼10% (w/w). Pullulan/prednisolone nanofibrous webs have been also fabricated as a control sample having the same drug loading (∼10%, w/w). It has been demonstrated that prednisolone has been found in an amorphous state in the HPßCD/prednisolone nanofibrous web due to inclusion complexation, while it has retained its crystal structure in the pullulan/prednisolone nanofibrous web. Therefore, the HPßCD/prednisolone IC nanofibrous web has shown a faster and enhanced release profile and superior disintegration feature in artificial saliva than the pullulan/prednisolone nanofibrous web. The complexation energy calculated using ab initio modeling displayed a more favorable interaction between HPßCD and prednisolone in the case of a molar ratio of 2:1 than 1:1 (CD: drug). Here, the HPßCD/prednisolone IC nanofibrous web has been developed without using a toxic component or solvent to dissolve drug molecules and boost drug loading in amorphous nature. The investigation of IC nanofibrous webs has been conducted to formulate a promising alternative to the orally disintegrating tablet formulation of prednisolone in the market. The nanofibrous structure and the improved physicochemical properties of prednisolone arising with the complexation might ensure a faster disintegration and onset of action against commercially available and orally disintegrating delivery systems during the desired treatment.

Salmonella Effectors SseK1 and SseK3 Target Death Domain Proteins in the TNF and TRAIL Signaling Pathways.

Strains of Salmonella utilize two distinct type three secretion systems to deliver effector proteins directly into host cells. The Salmonella effectors SseK1 and SseK3 are arginine glycosyltransferases that modify mammalian death domain containing proteins with N-acetyl glucosamine (GlcNAc) when overexpressed ectopically or as recombinant protein fusions. Here, we combined Arg-GlcNAc glycopeptide immunoprecipitation and mass spectrometry to identify host proteins GlcNAcylated by endogenous levels of SseK1 and SseK3 during Salmonella infection. We observed that SseK1 modified the mammalian signaling protein TRADD, but not FADD as previously reported. Overexpression of SseK1 greatly broadened substrate specificity, whereas ectopic co-expression of SseK1 and TRADD increased the range of modified arginine residues within the death domain of TRADD. In contrast, endogenous levels of SseK3 resulted in modification of the death domains of receptors of the mammalian TNF superfamily, TNFR1 and TRAILR, at residues Arg376 and Arg293 respectively. Structural studies on SseK3 showed that the enzyme displays a classic GT-A glycosyltransferase fold and binds UDP-GlcNAc in a narrow and deep cleft with the GlcNAc facing the surface. Together our data suggest that salmonellae carrying sseK1 and sseK3 employ the glycosyltransferase effectors to antagonise different components of death receptor signaling.

Opportunities for Supporting Latino Immigrants in Emergency and Ambulatory Care Settings.

Toughened immigration policies exacerbate barriers to public benefits and health care for immigrants. The objective of this study is to examine the impact of the immigration climate on the utilization of pediatric emergency and ambulatory care services and elucidate ways to best support Latino immigrant families. This is a cross-sectional study involving surveys and interviews with Latino parents (≥ 18 years) in the pediatric emergency department. Forty-five parents completed surveys and 40 were interviewed. We identified two themes on health care utilization: fear of detention and deportation in health care settings, and barriers to pediatric primary care; and two themes on how pediatric providers can best support Latinos: information and guidance on immigration policies, and reassurance and safety during visits. Despite immigration fears, Latino parents continue to seek health care for their children. This highlights the unique access that pediatric providers have to this vulnerable population to address immigration fears and establish trust in the health care system. Health care providers are also perceived as trusted figures from whom Latino families want more information on the latest immigration policies, immigration resources, and education on legal rights during medical visits.

Optimal protection against Salmonella infection requires noncirculating memory.

While CD4 Th1 cells are required for resistance to intramacrophage infections, adoptive transfer of Th1 cells is insufficient to protect against Salmonella infection. Using an epitope-tagged vaccine strain of Salmonella, we found that effective protection correlated with expanded Salmonella-specific memory CD4 T cells in circulation and nonlymphoid tissues. However, naive mice that previously shared a blood supply with vaccinated partners lacked T cell memory with characteristics of tissue residence and did not acquire robust protective immunity. Using a YFP-IFN-γ reporter system, we identified Th1 cells in the liver of immunized mice that displayed markers of tissue residence, including P2X7, ARTC2, LFA-1, and CD101. Adoptive transfer of liver memory cells after ARTC2 blockade increased protection against highly virulent bacteria. Taken together, these data demonstrate that noncirculating memory Th1 cells are a vital component of immunity to Salmonella infection and should be the focus of vaccine strategies.

Neurologic complications of melanoma.

Neurologic complications are common in patients with melanoma and are often associated with a poor prognosis. In an era with new, effective treatments, patients are living longer, and this has resulted in an increase in complications of both the disease and the therapy. A multidisciplinary approach to neurologic complications in patients with melanoma, with involvement from medical oncology, neuro-oncology, radiation oncology, and often neurosurgery, is necessary. In this review, neurologic complications of melanoma, including clinical implications and treatment strategies, are described.

The multifunctional enzyme S-adenosylhomocysteine/methylthioadenosine nucleosidase is a key metabolic enzyme in the virulence of Salmonella enterica var Typhimurium.

Key physiological differences between bacterial and mammalian metabolism provide opportunities for the development of novel antimicrobials. We examined the role of the multifunctional enzyme S-adenosylhomocysteine/Methylthioadenosine (SAH/MTA) nucleosidase (Pfs) in the virulence of S. enterica var Typhimurium (S. Typhimurium) in mice, using a defined Pfs deletion mutant (i.e. Δpfs). Pfs was essential for growth of S. Typhimurium in M9 minimal medium, in tissue cultured cells, and in mice. Studies to resolve which of the three known functions of Pfs were key to murine virulence suggested that downstream production of autoinducer-2, spermidine and methylthioribose were non-essential for Salmonella virulence in a highly sensitive murine model. Mass spectrometry revealed the accumulation of SAH in S. Typhimurium Δpfs and complementation of the Pfs mutant with the specific SAH hydrolase from Legionella pneumophila reduced SAH levels, fully restored growth ex vivo and the virulence of S. Typhimurium Δpfs for mice. The data suggest that Pfs may be a legitimate target for antimicrobial development, and that the key role of Pfs in bacterial virulence may be in reducing the toxic accumulation of SAH which, in turn, suppresses an undefined methyltransferase.