Synthetic amyloid beta does not induce a robust transcriptional response in innate immune cell culture systems.

BACKGROUND: Alzheimer's disease (AD) is a progressive neurodegenerative disease that impacts nearly 400 million people worldwide. The accumulation of amyloid beta (Aß) in the brain has historically been associated with AD, and recent evidence suggests that neuroinflammation plays a central role in its origin and progression. These observations have given rise to the theory that Aß is the primary trigger of AD, and induces proinflammatory activation of immune brain cells (i.e., microglia), which culminates in neuronal damage and cognitive decline. To test this hypothesis, many in vitro systems have been established to study Aß-mediated activation of innate immune cells. Nevertheless, the transcriptional resemblance of these models to the microglia in the AD brain has never been comprehensively studied on a genome-wide scale. METHODS: We used bulk RNA-seq to assess the transcriptional differences between in vitro cell types used to model neuroinflammation in AD, including several established, primary and iPSC-derived immune cell lines (macrophages, microglia and astrocytes) and their similarities to primary cells in the AD brain. We then analyzed the transcriptional response of these innate immune cells to synthetic Aß or LPS and INFγ. RESULTS: We found that human induced pluripotent stem cell (hIPSC)-derived microglia (IMGL) are the in vitro cell model that best resembles primary microglia. Surprisingly, synthetic Aß does not trigger a robust transcriptional response in any of the cellular models analyzed, despite testing a wide variety of Aß formulations, concentrations, and treatment conditions. Finally, we found that bacterial LPS and INFγ activate microglia and induce transcriptional changes that resemble many, but not all, aspects of the transcriptomic profiles of disease associated microglia (DAM) present in the AD brain. CONCLUSIONS: These results suggest that synthetic Aß treatment of innate immune cell cultures does not recapitulate transcriptional profiles observed in microglia from AD brains. In contrast, treating IMGL with LPS and INFγ induces transcriptional changes similar to those observed in microglia detected in AD brains.

Denosumab is not associated with risk of malignancy: systematic review and meta-analysis of randomized controlled trials.

The immunomodulatory effects of denosumab have raised concerns for risk of malignancy. This meta-analysis of 25 randomized controlled trials (21,523 patients) shows similar risk of malignancy between denosumab (60 mg every 6 months, up to 48 months) and any comparator. Post-marketing surveillance may detect rare or late-occurring drug effects. Possible increased risk of malignancy in patients treated with denosumab has been concerned due to inhibition of the immune modulator receptor activator of nuclear factor κ-Β ligand (RANKL). We aimed to assess the risk of malignancy associated with denosumab treatment. PubMed and Cochrane Central Register of Controlled Trials were searched up to May 27, 2019 to include all randomized controlled trials of denosumab (60 mg every 6 months) versus any comparator. Trials using higher drug doses for prevention of skeletal-related events were excluded. Data were independently extracted by two reviewers and analyzed using a fixed-effect model to pool risk ratios (RRs) with 95% confidence intervals (CI). Twenty-five trials (21,523 patients) were included. The risk of malignancy was similar between denosumab and other comparators (absolute risk difference 0%, RR 1.08 [95% CI, 0.93-1.24], I2 = 0%). Sensitivity analysis based on adequate allocation concealment showed similar results. The risk of malignancy did not differ between groups in any of the subgroup analyses, including stratification by race, individual comparators, indications for treatment, and longer drug exposure (≥ 24 months, 9 studies). The risk ratio of malignancy-related death was similar between groups. Early concerns about a potential increased risk of malignancy resulting from an immunomodulatory effect of denosumab are not supported by evidence from this meta-analysis of 25 RCTs with drug exposure of up to 48 months. Since RCTs with longer observation for safety outcomes are not expected, post-marketing surveillance will be the main means for detection of rare or late-occurring events.

Denosumab-induced hypocalcemia in patients with osteoporosis: can you know who will get low?

Hypocalcemia was reported at low rates (0.05-1.7%) in denosumab-treated postmenopausal women with osteoporosis. This real-life study shows a 7.4% rate of denosumab-induced hypocalcemia in community-dwelling osteoporotic men and women. Pretreatment serum calcium and creatinine levels are major predictors for this complication. Serum-calcium monitoring may help to identify and prevent severe hypocalcemia. PURPOSE: RCTs have reported a 0.05-1.7% rate of hypocalcemia in denosumab-treated postmenopausal women with osteoporosis, but long-term real-life data are lacking. We assessed the rate of hypocalcemia in osteoporotic community-dwelling patients treated with denosumab. METHODS: A retrospective analysis was conducted based on medical records (2010-2018) from a large HMO. An albumin-adjusted serum calcium concentration lower than 8.5 mg/dL was defined as hypocalcemia. RESULTS: We included 2005 patients (93% women, mean age 76 ± 9 years). Hypocalcemia developed during treatment in 149 patients (7.4%; 1% less than 8 mg/dL): in 66 after 0.5-1 years; 48 after 1-2 years; 35 after > 2 years. On comparison of the hypocalcemic and normocalcemic patients, the strongest predictors of hypocalcemia were pretreatment levels of albumin-adjusted serum calcium (9.1 ± 0.4 vs. 9.4 ± 0.5 mg/dL, respectively; p < 0.05) and creatinine (0.9 ± 0.5 vs. 0.8 ± 0.3 mg/dL, respectively; p < 0.05). The hypocalcemia rate increased in parallel to a decrease in eGFR (p = 0.032 for the difference between eGFR ranges). Baseline calcium level ≤ 9.31 mg/dL predicted hypocalcemia with a sensitivity of 77% and specificity of 56%. A model of (- 2)*calcium + creatinine predicted hypocalcemia (3.7% when lower and 17.1% when higher than - 17.4). Gender, age, 25-hydroxyvitamin-D, parathyroid hormone, alkaline phosphatase, and whether denosumab was given as first or advanced line of osteoporotic therapy had no predictive value. CONCLUSION: Real-life rates of denosumab-induced hypocalcemia are higher than previously reported. Hypocalcemia might develop after each dose of denosumab in ongoing treatment. Adequate calcium and vitamin D supplementation are needed. Serum calcium monitoring is advised in high-risk patients for early detection of severe hypocalcemia.

Interpretation of microbiota-based diagnostics by explaining individual classifier decisions.

BACKGROUND: The human microbiota is associated with various disease states and holds a great promise for non-invasive diagnostics. However, microbiota data is challenging for traditional diagnostic approaches: It is high-dimensional, sparse and comprises of high inter-personal variation. State of the art machine learning tools are therefore needed to achieve this goal. While these tools have the ability to learn from complex data and interpret patterns therein that cannot be identified by humans, they often operate as black boxes, offering no insight into their decision-making process. In most cases, it is difficult to represent the learning of a classifier in a comprehensible way, which makes them prone to be mistrusted, or even misused, in a clinical environment. In this study, we aim to elucidate microbiota-based classifier decisions in a biologically meaningful context to allow their interpretation. RESULTS: We applied a method for explanation of classifier decisions on two microbiota datasets of increasing complexity: gut versus skin microbiota samples, and inflammatory bowel disease versus healthy gut microbiota samples. The algorithm simulates bacterial species as being unknown to a pre-trained classifier, and measures its effect on the outcome. Consequently, each patient is assigned a unique quantitative estimation of which species in their microbiota defined the classification of their sample. The algorithm was able to explain the classifier decisions well, demonstrated by our validation method, and the explanations were biologically consistent with recent microbiota findings. CONCLUSIONS: Application of a method for explaining individual classifier decisions for complex microbiota analysis proved feasible and opens perspectives on personalized therapy. Providing an explanation to support a microbiota-based diagnosis could guide decisions of clinical microbiologists, and has the potential to increase their confidence in the outcome of such decision support systems. This may facilitate the development of new diagnostic applications.

Co-expression of fibulin-5 and VEGF165 increases long-term patency of synthetic vascular grafts seeded with autologous endothelial cells.

Small caliber synthetic vascular grafts are commonly used for bypass surgery and dialysis access sites but have high failure rates because of neointima formation and thrombosis. Seeding synthetic grafts with endothelial cells (ECs) provides a biocompatible surface that may prevent graft failure. However, EC detachment following exposure to blood flow still remains a major obstacle in the development of biosynthetic grafts. We tested the hypothesis that induced expression by the seeded EC, of vascular endothelial growth factor165 (VEGF165) and of fibulin-5, an extracellular matrix glycoprotein that has a crucial role in elastin fiber organization and increase EC adherence to surfaces, may improve long-term graft patency. Autologous ECs were isolated from venous segments, and were transduced with retroviral vectors expressing fibulin-5 and VEGF165. The modified cells were seeded on expanded polytetrafluoroethylene (ePTFE) grafts and implanted in a large animal model. Three months after transplantation, all grafts seeded with modified EC were patent on a selective angiography, whereas only a third of the control grafts were patent. Similar results were shown at 6 months. Thus, seeding ePTFE vascular grafts with genetically modified EC improved long-term small caliber graft patency. The biosynthetic grafts may provide a novel therapeutic modality for patients with peripheral vascular disease and patients requiring vascular access for hemodialysis.

The prospective evaluation of the TB strain typing service in England: a mixed methods study.

BACKGROUND: In response to rising TB notification rates in England, universal strain typing was introduced in 2010. We evaluated the acceptability, effectiveness and cost-effectiveness of the TB strain typing service (TB-STS). METHODS: We conducted a mixed-methods evaluation using routine laboratory, clinic and public health data. We estimated the effect of the TB-STS on detection of false positive Mycobacterium tuberculosis diagnoses (2010-2012); contact tracing yield (number of infections or active disease per pulmonary TB case); and diagnostic delay. We developed a deterministic age-structured compartmental model to explore the effectiveness of the TB-STS, which informed a cost-effectiveness analysis. RESULTS: Semi-structured interviews explored user experience. Strain typing identified 17 additional false positive diagnoses. The TB-STS had no significant effect on contact tracing yield or diagnostic delay. Mathematical modelling suggested increasing the proportion of infections detected would have little value in reducing TB incidence in the white UK-born population. However, in the non-white UK-born and non-UK-born populations, over 20 years, if detection of latent infection increases from 3% to 13% per year, then TB incidence would decrease by 11%; reducing diagnostic delay by one week could lead to 25% reduction in incidence. The current TB-STS was not predicted to be cost-effective over 20 years (£95 628/quality-adjusted life-years). Interviews found people had mixed experiences, but identified broader benefits, of the TB-STS. CONCLUSIONS: To reduce costs, improve efficiency and increase effectiveness, we recommend changes to the TB-STS, including discontinuing routine cluster investigations and focusing on reducing diagnostic delay across the TB programme. This evaluation of a complex intervention informs the future of strain typing in the era of rapidly advancing technologies.

Identifying workflow disruptions in the cardiovascular operating room.

The objectives of this study were to identify the frequency and nature of flow disruptions in the operating room with respect to three cardiac surgical team members: anaesthetists; circulating nurses; and perfusionists. Data collected from 15 cases and coded using a human factors taxonomy identified 878 disruptions. Significant differences were identified in frequency relative to discipline type. Circulating nurses experienced more coordination disruptions (χ(2) (2, N = 110) = 7.136, p < 0.028) and interruptions (χ(2) (2, N = 427) = 29.743, p = 0.001) than anaesthetists and perfusionists, whereas anaesthetists and perfusionists experienced more layout issues than circulating nurses (χ(2) (2, N = 153) = 48.558, p = 0.001). Time to resolve disruptions also varied among disciplines (λ (12, 878) = 5.186, p = 0.000). Although most investigations take a one-size fits all approach in addressing disruptions to flow, this study demonstrates that targeted interventions must focus on differences with respect to individual role.

MEDI4893* Promotes Survival and Extends the Antibiotic Treatment Window in a Staphylococcus aureus Immunocompromised Pneumonia Model.

Immunocompromised individuals are at increased risk of Staphylococcus aureus pneumonia. Neutralization of alpha-toxin (AT) with the monoclonal antibody (MAb) MEDI4893* protects normal mice from S. aureus pneumonia; however, the effects of the MAb in immunocompromised mice have not been reported. In this study, passive immunization with MEDI4893* increased survival rates and reduced bacterial numbers in the lungs in an immunocompromised murine S. aureus pneumonia model. Lungs from infected mice exhibited alveolar epithelial damage, protein leakage, and bacterial overgrowth, whereas lungs from mice passively immunized with MEDI4893* retained a healthy architecture, with an intact epithelial barrier. Adjunctive therapy or prophylaxis with a subtherapeutic MEDI4893* dose combined with subtherapeutic doses of vancomycin or linezolid improved survival rates, compared with the monotherapies. Furthermore, coadministration of MEDI4893* with vancomycin or linezolid extended the antibiotic treatment window. These data suggest that MAb-mediated neutralization of AT holds promise in strategies for prevention and adjunctive therapy among immunocompromised patients.

Antipsychotics activate the TGFß pathway effector SMAD3.

Although effective in treating an array of neurological disorders, antipsychotics are associated with deleterious metabolic side effects. Through high-throughput screening, we previously identified phenothiazine antipsychotics as modulators of the human insulin promoter. Here, we extended our initial finding to structurally diverse typical and atypical antipsychotics. We then identified the transforming growth factor beta (TGFß) pathway as being involved in the effect of antipsychotics on the insulin promoter, finding that antipsychotics activated SMAD3, a downstream effector of the TGFß pathway, through a receptor distinct from the TGFß receptor family and known neurotransmitter receptor targets of antipsychotics. Of note, antipsychotics that do not cause metabolic side effects did not activate SMAD3. In vivo relevance was demonstrated by reanalysis of gene expression data from human brains treated with antipsychotics, which showed altered expression of SMAD3 responsive genes. This work raises the possibility that antipsychotics could be designed that retain beneficial CNS activity while lacking deleterious metabolic side effects.

Geographical heterogeneity of multidrug-resistant tuberculosis in Georgia, January 2009 to June 2011.

In 2011, Georgia, in the Caucasus, reported that 11% of new and 32% of previously treated tuberculosis (TB) cases nationally had multidrug-resistant TB (MDR-TB). To help understand the mechanisms driving these high risks of drug-resistance and plan for targeted interventions, we identified geographical variability in the MDR-TB burden in Georgia and patient-level MDR-TB risk factors. We used routinely collected surveillance data on notified TB cases to estimate the MDR-TB incidence/100,000 people and the percentage of TB cases with MDR-TB for each of 65 districts and regression modelling to identify patient-level MDR-TB risk factors. 1,795 MDR-TB cases were reported (January 2009­June 2011); the nationwide notified MDR-TB incidence was 16.2/100,000 but far higher (837/100,000) in the penitentiary system. We found substantial geographical heterogeneity between districts in the average annual MDR-TB incidence/100,000 (range: 0.0­5.0 among new and 0.0­18.9 among previously treated TB cases) and the percentage of TB cases with MDR-TB (range: 0.0%­33.3% among new and 0.0%­75.0% among previously treated TB cases). Among treatment-naïve individuals, those in cities had greater MDR-TB risk than those in rural areas (increased odds: 43%; 95% confidence interval: 20%­72%). These results suggest that interventions for interrupting MDR-TB transmission are urgently needed in prisons and urban areas.

Treatment outcome of multi-drug resistant tuberculosis in the United Kingdom: retrospective-prospective cohort study from 2004 to 2007.

United Kingdom (UK) guidelines recommend at least 18 months treatment for patients with multidrug-resistant tuberculosis (MDR-TB). Prior to 2008, data on treatment outcome were only available at 12 months and therefore the proportion completing treatment was unknown. This retrospective-prospective cohort study reports on treatment outcomes for MDR-TB patients notified between 2004 and 2007 and examines factors associated with successful outcomes. 70.6% (144/204) completed treatment in 24 months or more, 6.9% (14) stopped treatment, 6.9% (14) died, 7.8% (16) were lost to follow up, 0.5% (1) relapsed and 4.4% (9) were transferred overseas. Following adjustment for age, being non-UK born, non-compliance and having co-morbidities, treatment with a fluoroquinolone (OR 3.09; 95% CI 1.21-7.88; p<0.05) or bacteriostatic drug (OR 4.23; 95% CI 1.60-11.18; p<0.05) were independently associated with successful treatment outcome. Treatment completion for MDR-TB cases remains below the World Health Organization (WHO) target. Our findings support current WHO guidelines for MDR-TB treatment. The UK should consider adopting individualised regimens based on WHO recommended drugs, taking into account drug sensitivities. Improving treatment completion rates will be key to tackling further drug resistance and transmission from untreated infectious cases.

Budget impact of next-generation sequencing for diagnosis of TB drug resistance in Moldova.

BACKGROUND Diagnosing drug resistance is critical for choosing effective TB treatment regimens. Next-generation sequencing (NGS) represents an alternative approach to conventional phenotypic drug susceptibility testing (pDST) for diagnosing TB drug resistance.METHODS We undertook a budget impact analysis estimating the costs of introduction and routine use of NGS in the Moldovan National TB Programme. We conducted an empirical costing study and collated price and operating characteristics for NGS platforms. We examined multiple NGS scenarios in comparison to the current approach (pDST) for pre-treatment drug resistance testing over 2021-2025.RESULTS Annual testing volume ranged from 912 to 1,926 patients. For the pDST scenario, we estimated total costs of US$362,000 (2021 USD) over the 5-year study period. Total costs for NGS scenarios ranged from US$475,000 to US$1,486,000. Lowest cost NGS options involved targeted sequencing as a replacement for pDST, and excluded individuals diagnosed as RIF-susceptible on Xpert® MTB/RIF. For all NGS scenarios, the majority (55-80%) of costs were devoted to reagent kits. Start-up costs of NGS were small relative to routine costs borne each year.CONCLUSION NGS adoption will require expanded resources compared to conventional pDST. Further work is required to better understand the feasibility of NGS in settings such as Moldova.

Current intraoperative storage and handling practices of autologous bypass conduit: A survey of the royal australasian college of surgeons.

During bypass surgery for peripheral arterial occlusive disease and ischaemic heart disease, autologous graft conduit including great saphenous veins and radial arteries are frequently stored in solution. Endothelial damage adversely affects the performance and patency of autologous bypass grafts, and intraoperative graft storage solutions have been shown to influence this process. The distribution of storage solutions currently used amongst Cardiothoracic and Vascular Surgeons from Australia and New Zealand is not well defined in the literature. The aim of this study was to determine current practices regarding autologous graft storage and handling amongst this cohort of surgeons, and discuss their potential relevance in the context of early graft failure. From this survey, the most frequently used storage solutions were heparinized saline for great saphenous veins, and pH-buffered solutions for radial arteries. Duration of storage was 30-45 min for almost half of respondents, although responses to this question were limited. Further research is required to investigate whether ischaemic endothelial injury generates a prothrombotic state, whether different storage media can alter this state, and whether this is directly associated with clinical outcomes of interest such as early graft failure.

Incidence of lung cancer following pneumonia in smokers: a population-based study.

BACKGROUND: Pneumonia is more common in smokers compared with non-smokers. A high 1-year prevalence of lung cancer following hospitalization for pneumonia was demonstrated in heavy smokers. AIM: To assess the association between hospitalization for pneumonia among ever-smokers and subsequent lung cancer risk. DESIGN: Retrospective analysis. METHODS: The study cohort included all ever-smokers aged 55-80 hospitalized for pneumonia between the years 2010-15 covered by a large medical insurer in Israel. Controls were matched to cases by age in a 4:1 ratio. The primary outcome was the association between hospitalization for pneumonia and subsequent 1-year incidence of lung cancer, adjusted for gender, smoking status (past/current) and pack years. Pre-specified sensitivity analyses excluded heavy smokers (smoking history of more than 30 pack years) and patients diagnosed with lung cancer within 30 days of hospitalization, as they probably had clinical or radiological findings suggestive of lung cancer, making them ineligible for screening. RESULTS: Lung cancer was identified in 275 of 12 807 (2.1%) patients following hospitalization for pneumonia and in 44 of 51 228 (0.1%) controls (adjusted odds ratio 22.46, 95% CI 16.29-30.96, P < 0.001). Among patients hospitalized for pneumonia, 1-year lung cancer incidence remained high after excluding heavy smokers and patients diagnosed within 30 days of the index date (1.3% and 1.4%, respectively). CONCLUSIONS: Hospitalization for pneumonia is associated with high 1-year incidence of lung cancer in ever-smokers, supporting the important role of the widely used practice of performing follow up imaging post-pneumonia to exclude occult malignancy.

Assessing spatiotemporal patterns of multidrug-resistant and drug-sensitive tuberculosis in a South American setting.

We examined the spatiotemporal distribution of laboratory-confirmed multidrug-resistant tuberculosis (MDR TB) cases and that of other TB cases in Lima, Peru with the aim of identifying mechanisms responsible for the rise of MDR TB in an urban setting. All incident cases of TB in two districts of Lima, Peru during 2005-2007 were included. The spatiotemporal distributions of MDR cases and other TB cases were compared with Ripley's K statistic. Of 11,711 notified cases, 1187 received drug susceptibility testing and 376 were found to be MDR. Spatial aggregation of patients with confirmed MDR disease appeared similar to that of other patients in 2005 and 2006; however, in 2007, cases with confirmed MDR disease were found to be more tightly grouped. Subgroup analysis suggests the appearance of resistance may be driven by increased transmission. Interventions should aim to reduce the infectious duration for those with drug-resistant disease and improve infection control.

Mitochondrial gene expression in single cells shape pancreatic beta cells' sub-populations and explain variation in insulin pathway.

Mitochondrial gene expression is pivotal to cell metabolism. Nevertheless, it is unknown whether it diverges within a given cell type. Here, we analysed single-cell RNA-seq experiments from human pancreatic alpha (N = 3471) and beta cells (N = 1989), as well as mouse beta cells (N = 1094). Cluster analysis revealed two distinct human beta cells populations, which diverged by mitochondrial (mtDNA) and nuclear DNA (nDNA)-encoded oxidative phosphorylation (OXPHOS) gene expression in healthy and diabetic individuals, and in newborn but not in adult mice. Insulin gene expression was elevated in beta cells with higher mtDNA gene expression in humans and in young mice. Such human beta cell populations also diverged in mitochondrial RNA mutational repertoire, and in their selective signature, thus implying the existence of two previously overlooked distinct and conserved beta cell populations. While applying our approach to human alpha cells, two sub-populations of cells were identified which diverged in mtDNA gene expression, yet these cellular populations did not consistently diverge in nDNA OXPHOS genes expression, nor did they correlate with the expression of glucagon, the hallmark of alpha cells. Thus, pancreatic beta cells within an individual are divided into distinct groups with unique metabolic-mitochondrial signature.

The impact of COVID-19 on TB: a review of the data.

Early in the COVID-19 pandemic, models predicted hundreds of thousands of additional TB deaths as a result of health service disruption. To date, empirical evidence on the effects of COVID-19 on TB outcomes has been limited. Here we summarise the evidence available at a country level, identifying broad mechanisms by which COVID-19 may modify TB burden and mitigation efforts. From the data, it is clear that there have been substantial disruptions to TB health services and an increase in vulnerability to TB. Evidence for changes in Mycobacterium tuberculosis transmission is limited, and it remains unclear how the resources required and available for the TB response have changed. To advocate for additional funding to mitigate the impact of COVID-19 on the global TB burden, and to efficiently allocate resources for the TB response, requires a significant improvement in the TB data available.

From Bite to Byte: Dental Structures Resolved at a Single-Cell Resolution.

The systematic classification of the cells that compose a tissue or an organ is key to understanding how these cells cooperate and interact as a functional unit. Our capacity to detect features that define cell identity has evolved from morphological and chemical analyses, through the use of predefined genetic markers, to unbiased transcriptomic and epigenetic profiling. The innovative technology of single-cell RNA sequencing (scRNA-seq) enables transcriptional profiling of thousands of individual cells. Since its development, scRNA-seq has been extensively applied to numerous organs and tissues in a wide range of animal models and human samples, thereby providing a plethora of fundamental biological insights into their development, homeostasis, and pathology. In this review, we present the findings of 3 recent studies that employed scRNA-seq to unravel the complexity of cellular composition in mammalian teeth. These findings offer an unprecedented catalogue of cell types in the mouse incisor, which is a convenient model system for studying continuous tooth growth. These studies identified novel cell types in the tooth epithelium and mesenchyme, as well as new markers for known cell types. Computational analyses of the data also uncovered the lineage and dynamics of cell states during ameloblast and odontoblast differentiation during both normal homeostasis and injury repair. The transcriptional differences between the mouse incisor and mouse and human molars uncover species-specific as well as shared features in tooth cell composition. Here, we highlight these findings and discuss important similarities and differences between these studies. We also discuss potential future applications of scRNA-seq in dental research and dentistry. Together, these studies demonstrate how the rapidly evolving technology of scRNA-seq can advance the study of tooth development and function and provide putative targets for regenerative approaches.