Salmonella infection entails a cascade of attacks and defence measures. After breaching the intestinal epithelial barrier, Salmonella is phagocytosed by macrophages, where the bacteria encounter multiple stresses, to which it employs relevant countermeasures. Our study shows that, in Salmonella, the polyamine spermidine activates a stress response mechanism by regulating critical antioxidant genes. Salmonella Typhimurium mutants for spermidine transport and synthesis cannot mount an antioxidative response, resulting in high intracellular ROS levels. These mutants are also compromised in their ability to be phagocytosed by macrophages. Furthermore, it regulates a novel enzyme in Salmonella, Glutathionyl-spermidine synthetase (GspSA), which prevents the oxidation of proteins in E. coli. Moreover, the spermidine mutants and the GspSA mutant show significantly reduced survival in the presence of hydrogen peroxide in vitro and reduced organ burden in the mouse model of Salmonella infection. Conversely, in macrophages isolated from gp91phox-/- mice, we observed a rescue in the attenuated fold proliferation previously observed upon infection. We found that Salmonella upregulates polyamine biosynthesis in the host through its effectors from SPI-1 and SPI-2, which addresses the attenuated proliferation observed in spermidine transport mutants. Thus, inhibition of this pathway in the host abrogates the proliferation of Salmonella Typhimurium in macrophages. From a therapeutic perspective, inhibiting host polyamine biosynthesis using an FDA-approved chemopreventive drug, D, L-α-difluoromethylornithine (DFMO), reduces Salmonella colonisation and tissue damage in the mouse model of infection while enhancing the survival of infected mice. Therefore, our work provides a mechanistic insight into the critical role of spermidine in stress resistance of Salmonella. It also reveals a bacterial strategy in modulating host metabolism to promote their intracellular survival and shows the potential of DFMO to curb Salmonella infection.

BACKGROUND: Vitamin D deficiency is a worldwide public health concern, which can lead to severe diseases, such as rickets in children and osteomalacia in adults. Most studies have compared equimolar unit-to-unit doses of vitamin D2 and D3.
OBJECTIVE: The current study aimed to answer the research question: \"How effective is vitamin D2 (600,000 U/1.5 ml) compared to vitamin D3 (300,000 U/1 ml) parenteral supplementation for raising serum vitamin D levels in adult patients treated in a primary health care setting?\"
METHODS: Primary Health Care Corporation (PHCC) runs 28 health centers distributed throughout the State of Qatar and its capital city, Doha. Qatar is on the east coast of the Arabic peninsula, with very hot and sunny summers and a desert climate.
METHODS: This was a retrospective observational cohort study.
METHODS: A total of 15,716 participants were recruited following ethical approval. They were identified by electronic medical records (EMR) describing the clinical encounters of individuals aged 18 to 60-years-old who attended a health center operated by the PHCC during the 3.5-year study period from January 1, 2017 to June 30, 2020. The PHCC EMR system uses SNOMED codes (a systematically organized computer-processable collection of medical terms providing codes, names, synonyms, and definitions implemented for clinical documentation and reporting). Four study groups were created depending on the type of vitamin D injection and the oral form of replacement therapy. The analysis scheme used the serum vitamin D level within the preceding 4 weeks (pretreatment), followed by administration of the treatment dose. The post-treatment serum testing value should have been available within a maximum of 12 weeks. The Statistical Package for Social Sciences (IBMSPSS; IBM Corp., Armonk, NY, USA) version 23 software was used for the statistical analysis.
RESULTS: Four treatment options were compared, including a vitamin D2 injection, a vitamin D3 injection, combined use of a vitamin D2 injection + a D2 tablet, and combined use of a vitamin D3 injection + a D2 tablet. All four treatment groups were associated with a statistically significant increase in serum vitamin D within a maximum of 12 weeks of follow-up. The vitamin D2 injection alone was associated with the lowest increase in serum concentration by a mean of 3.2 ng/ml. In contrast, the vitamin D3 injection alone or with a D2 tablet increased serum vitamin D by 6.1 and 5.6 ng/ml, respectively. Using the combination of a vitamin D2 injection and a tablet only added a marginal increase of 2.3 ng/ml in serum vitamin D on top of the 3.2 ng/ml increase attained after administering the D2 injection alone.
CONCLUSIONS: Utilizing vitamin D3 in an injectable form is the best choice to restore severe vitamin D deficiency. Furthermore, it was superior to the injectable form of vitamin D2, even though vitamin D2 has double the molar units.

OBJECTIVE: The Novel Coronavirus (COVID-19) has infected over two hundred million worldwide and caused 4.4 million of deaths as of August 2021. Vaccines were quickly developed to address the pandemic. We sought to analyze the cost-effectiveness and budget impact of a non-specified vaccine for COVID-19.
METHODS: We constructed a Markov model of COVID-19 infections using a susceptible-exposed-infected-recovered structure over a 1-year time horizon from a U.S. healthcare sector perspective. The model consisted of two arms: do nothing and COVID-19 vaccine. Hospitalization and mortality rates were calibrated to U.S. COVID-19 reports as of November 2020. We performed economic calculations of costs in 2020 U.S. dollars and effectiveness in units of quality-adjusted life years (QALYs) to measure the budget impact and incremental cost-effectiveness at a $100,000/QALY threshold.
RESULTS: Vaccines have a high probability of reducing healthcare costs and increasing QALYs compared to doing nothing. Simulations showed reductions in hospital days and mortality by more than 50%. Even though this represents a major U.S. investment, the budget impacts of these technologies could save program costs by up to 60% or more if uptake is high.
CONCLUSIONS: The economic evaluation draws on the reported values of the clinical benefits of COVID-19 vaccines, although we do not currently have long-term conclusive data about COVID-19 vaccine efficacies.
CONCLUSIONS: Spending on vaccines to mitigate COVID-19 infections offer high-value potential that society should consider. Unusually high uptake in vaccines in a short amount of time could result in unprecedented budget impacts to government and commercial payers. Governments should focus on expanding health system infrastructure and subsidizing payer coverage to deliver these vaccines efficiently.

UNASSIGNED: This study was designed to describe health care resource utilization (HCRU) of patients with metastatic colorectal cancer (CRC) or gastric cancer to test the hypothesis that greater treatment variability would be associated with increased HCRU.
UNASSIGNED: A retrospective observational study using Marketscan claims data was conducted. Eligible patients had a first diagnosis of metastatic CRC or gastric cancer between 2004 and 2015 and must have received systemic anti-cancer therapy after diagnosis. Treatment variability was measured using the Herfindahl-Hirschman Index (HHI). HHI scores were stratified by quartile. HCRU variables were evaluated throughout the follow-up period and described by 6-month periods. Chi-square test was used for categorical variables and ANOVA for continuous variables.
UNASSIGNED: A total of 55,403 CRC and 9,073 gastric cancer patients were eligible. First-line HHI scores ranged from 0.1304-0.2778 for CRC and 0.0383-0.1778 for gastric cancer by state of residence. Statistically significant differences by HHI quartiles for HCRU in CRC included hospitalizations (p = 0.0003), ER visits (p < 0.0001), ER visits leading to hospitalization (p < 0.0001), and supportive care (all agents studied, p < 0.01). For gastric cancer, significant differences by HHI quartile were observed for ER visits (p = 0.002) and selected supportive care (G-CSF, erythropoiesis-stimulating agents, bisphosphonates, nutritional support, and antiemetics, each p < 0.05). No consistent increasing or decreasing trends were observed across the quartiles for either cohort.
UNASSIGNED: Large sample sizes could lead to statistical significance without being clinically meaningful. High treatment heterogeneity in the gastric cancer cohort and lack of a homogeneous quartile for comparisons limited the ability to evaluate HCRU by different levels of treatment variability.
UNASSIGNED: Statistically significant relationships were observed between treatment variability as measured by HHI and increased HCRU, but no consistent directional trends in HCRU variables were observed. Therefore, this study failed to reject the null hypothesis of equivalent HCRU by level of treatment variability.

Mycobacterium tuberculosis cell wall is intricate and impermeable to many agents. A D, D-carboxypeptidase (DacB1) is one of the enzymes involved in the biosynthesis of cell wall peptidoglycan and catalyzes the terminal D-alanine cleavage from pentapeptide precursors. Catalytic activity and mechanism by which DacB1 functions is poorly understood. Herein, we investigated the acylation mechanism of DacB1 by β-lactams using a 6-membered ring transition state model that involves a catalytic water molecule in the reaction pathway. The full transition states (TS) optimization plus frequency were achieved using the ONIOM (B3LYP/6-31 + G(d): AMBER) method. Subsequently, the activation free energies were computed via single-point calculations on fully optimized structures using B3LYP/6-311++(d,p): AMBER and M06-2X/6-311++(d,p): AMBER with an electronic embedding scheme. The 6-membered ring transition state is an effective model to examine the inactivation of DacB1 via acylation by β-lactams antibiotics (imipenem, meropenem, and faropenem) in the presence of the catalytic water. The ΔG# values obtained suggest that the nucleophilic attack on the carbonyl carbon is the rate-limiting step with 13.62, 19.60 and 30.29 kcal mol-1 for Imi-DacB1, Mero-DacB1 and Faro-DacB1, respectively. The electrostatic potential (ESP) and natural bond orbital (NBO) analysis provided significant electronic details of the electron-rich region and charge delocalization, respectively, based on the concerted 6-membered ring transition state. The stabilization energies of charge transfer within the catalytic reaction pathway concurred with the obtained activation free energies. The outcomes of this study provide important molecular insight into the inactivation of D, D-carboxypeptidase by β-lactams.

The aims of our study were to determine for the first time differentially expressed genes (DEGs) and enriched molecular pathways involving the PARK7 interactome in PBMCs donated from tuberculosis patients.
Data on a previously reconstructed PARK7 interactome (Vavougios et al., 2017) from datasets GDS4966 (Case-Control) and GDS4781 (Treatment Series) were retrieved from the Gene Expression Omnibus (GEO) repository. Gene Enrichment analysis was performed via the STRING algorithm and the GeneTrail2 software.
17 and 22 PARK7 interactores were determined as DEGs in the active TB vs HD and Treatment Series subset analyses, correspondingly, associated with significantly enriched pathways (FDR <0.05) involving p53 and PTEN mediated, stress responsive apoptosis regulation pathways. The treatment subset was characterized by the emergence of an additional layer of transcriptional regulation mediated by polycomb proteins among others, as well as TLR-mediated and cytokine survival signaling. Finally, the enrichment of a Parkinson\'s disease signature including PARK7 interactors was determined by its differential regulation both in the exploratory analyses (FDR = 0.024), as well as the confirmatory analyses (FDR = 1.81e-243).
Our in silico analysis revealed for the first time the role of PARK7\'s interactome in regulating the epigenetics of the PBMC lifecycle and Mtb symbiosis.

OBJECTIVE: D-negative patients are at risk of developing an alloantibody to D (anti-D) if exposed to D during transfusion. The presence of anti-D can lead to haemolytic transfusion reactions and haemolytic disease of the newborn. Anti-D alloimmunization can also complicate allogeneic haematopoietic stem cell transplantation (HSCT) with haemolysis and increased transfusion requirements. The goal of this study was to determine whether cancer centres have transfusion practices intended to prevent anti-D alloimmunization with special attention in patients considered for HSCT.
METHODS: To understand transfusion practices regarding D-positive platelets in D-negative patients with large transfusion needs, we surveyed the 28 cancer centres that are members of the National Comprehensive Cancer Network® (NCCN® ).
RESULTS: Nineteen centres responded (68%). Most centres (79%) avoid transfusing D-positive platelets to RhD-negative patients when possible. Four centres (21%) avoid D-positive platelets only in D-negative women of childbearing age. If a D-negative patient receives a D-positive platelet transfusion, 53% of centres would consider treating with Rh immune globulin (RhIg) to prevent alloimmunization in women of childbearing age. Only one centre also gives RhIg to all D-negative patients who are HSCT candidates including adult men and women of no childbearing age.
CONCLUSIONS: There is wide variation in platelet transfusion practices for supporting D-negative patients. The majority of centres do not have D-positive platelet transfusion policies focused on preventing anti-D alloimmunization specifically in patients undergoing HSCT. Multicentre, longitudinal studies are needed to understand the clinical implications of anti-D alloimmunization in HSCT patients.

DlCO is a widely used pulmonary function test in clinical practice and a particularly useful measure for assessing patients with chronic obstructive pulmonary disease (COPD). We hypothesized that elucidating genetic determinants of DlCO could lead to better understanding of the genetic architecture of COPD. We estimated the heritability of DlCO using common genetic variants and performed genome-wide association analyses in four cohorts enriched for subjects with COPD (COPDGene [Genetic Epidemiology of COPD], NETT [National Emphysema Treatment Trial], GenKOLS [Genetics of Chronic Obstructive Lung Disease study], and TESRA [Treatment of Emphysema With a Gamma-Selective Retinoid Agonist study]) using a combined European ancestry white dataset and a COPDGene African American dataset. We assessed our genome-wide significant and suggestive associations for DlCO in previously reported genome-wide association studies of COPD and related traits. We also characterized associations of known COPD-associated variants and DlCO. We estimated the SNP-based heritability of DlCO in the European ancestry white population to be 22% (P = 0.0004). We identified three genome-wide significant associations with DlCO: variants near TGFB2, CHRNA3, and PDE11A loci (P < 5 × 10-8). In addition, 12 loci were suggestively associated with DlCO in European ancestry white (P < 1 × 10-5 in the combined analysis and P < 0.05 in both COPDGene and GenKOLS), including variants near NEGR1, CADM2, PCDH7, RETREG1, DACT2, NRG1, ANKRD18A, KRT86, NTN4, ARHGAP28, INSR, and PCBP3. Some DlCO-associated variants were also associated with COPD, emphysema, and/or spirometric values. Among 25 previously reported COPD loci, TGFB2, CHRNA3/CHRNA5, FAM13A, DSP, and CYP2A6 were associated with DlCO (P < 0.001). We identified several genetic loci that were significantly associated with DlCO and characterized effects of known COPD-associated loci on DlCO. These results could lead to better understanding of the heterogeneous nature of COPD.

While wastewater treatment plant (WWTP) effluents have become increasingly recognized as a stressor for receiving rivers, their effects on river microbial communities remain elusive. Moreover, global change is increasing the frequency and duration of desiccation events in river networks, and we ignore how desiccation might influence the response of microbial communities to WWTP effluents. In this study, we evaluated the interaction between desiccation events and WWTP effluents under different dilution capacities. Specifically, we used artificial streams in a replicated regressional design, exposing first a section of the streams to a 7-day desiccation period and then the full stream to different levels of a realistic WWTP effluent dilution, from 0% to 100% of WWTP effluent proportion of the total stream flow. The microbial community response was assessed by means of high-throughput sequencing of 16S rRNA gene amplicons and quantitative PCR targeting ecologically-relevant microbial groups. Threshold Indicator Taxa Analysis (TITAN) was used, together with model fitting, to determine community thresholds and potential indicator taxa. Results show significant interactions between WWTP effluents and desiccation, particularly when sediment type is considered. Indicator taxa included members of Proteobacteria, Actinobacteria and Cyanobacteria, with abrupt changes in community structure at WWTP effluent proportion of the total flow above 50%, which is related to nutrient levels ranging 4.6-5.2 mg N-NO3-L-1, 0.21-0.32 mg P-PO43-L-1 and 7.09-9.00 mg DOC L-1. Our work indicates that situations where WWTP effluents account for >50% of the total river flow might risk of dramatic microbial community structure changes and should be avoided.