Dose Range-Finding Toxicity Study in Rats With Recombinant Human Lactoferrin Produced in Komagataella phaffii.

The oral toxicity of recombinant human lactoferrin (rhLF, Helaina rhLF, Effera™) produced in Komagataella phaffii was investigated in adult Sprague Dawley rats by once daily oral gavage for 14 consecutive days. The study used groups of 3-6 rats/sex/dose. The vehicle control group received sodium citrate buffer, and the test groups received daily doses of 200, 1000, and 2000 mg of rhLF in sodium citrate buffer per kg body weight. Bovine LF at 2000 mg/kg body weight per day was used as a comparative control. Clinical observations, body weight, hematology, clinical chemistry, iron parameters, immunophenotyping, and gross examination at necropsy were used as criteria for detecting the effects of treatment in all groups and to help select dose levels for future toxicology studies. Quantitative LF levels were also analyzed as an indication of bioavailability. Overall, administration of Helaina rhLF by once daily oral gavage for 14 days was well tolerated in rats at levels up to 2000 mg/kg/day, or 57 × Helaina's intended commercial use in adults, and indicating that a high dose of 2000 mg/kg/day is appropriate for future definitive toxicology studies.

OGT prevents DNA demethylation and suppresses the expression of transposable elements in heterochromatin by restraining TET activity genome-wide.

The O- GlcNAc transferase OGT interacts robustly with all three mammalian TET methylcytosine dioxygenases. We show here that deletion of the Ogt gene in mouse embryonic stem cells (mESC) results in a widespread increase in the TET product 5-hydroxymethylcytosine (5hmC) in both euchromatic and heterochromatic compartments, with concomitant reduction of the TET substrate 5-methylcytosine (5mC) at the same genomic regions. mESC engineered to abolish the TET1-OGT interaction likewise displayed a genome-wide decrease of 5mC. DNA hypomethylation in OGT-deficient cells was accompanied by de-repression of transposable elements (TEs) predominantly located in heterochromatin, and this increase in TE expression was sometimes accompanied by increased cis -expression of genes and exons located 3' of the expressed TE. Thus, the TET-OGT interaction prevents DNA demethylation and TE expression in heterochromatin by restraining TET activity genome-wide. We suggest that OGT protects the genome against DNA hypomethylation and impaired heterochromatin integrity, preventing the aberrant increase in TE expression observed in cancer, autoimmune-inflammatory diseases, cellular senescence and ageing.

An in vitro model of human hematopoiesis identifies a regulatory role for the aryl hydrocarbon receptor.

In vitro models to study simultaneous development of different human immune cells and hematopoietic lineages are lacking. We identified and characterized, using single-cell methods, an in vitro stromal cell-free culture system of human hematopoietic stem and progenitor cell (HSPC) differentiation that allows concurrent development of multiple immune cell lineages. The aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor influencing many biological processes in diverse cell types. Using this in vitro model, we found that AHR activation by the highly specific AHR ligand, 2,3,7,8-tetrachlorodibenzo-p-dioxin, drives differentiation of human umbilical cord blood-derived CD34+ HSPCs toward monocytes and granulocytes with a significant decrease in lymphoid and megakaryocyte lineage specification that may lead to reduced immune competence. To our knowledge, we also discovered for the first time, using single-cell modalities, that AHR activation decreased the expression of BCL11A and IRF8 in progenitor cells, which are critical genes involved in hematopoietic lineage specification processes at both transcriptomic and protein levels. Our in vitro model of hematopoiesis, coupled with single-cell tools, therefore allows for a better understanding of the role played by AHR in modulating hematopoietic differentiation.

Establishing an Academic-Community Partnership to Explore the Potential of Barbers and Barbershops in the Southern United States to Address Racial Disparities in HIV Care Outcomes for Black Men Living With HIV.

Black men comprise most new HIV infections in the Southern United States and have worse HIV outcomes than their non-Black counterparts. We developed an academic-community partnership in Nashville, Tennessee, to explore opportunities to improve HIV outcomes for Black men. We recruited barbers to an HIV training and focus group discussion about prevention and potential barber/barbershop-based strategies to address HIV-related needs for Black men. We assessed HIV knowledge and stigma with validated scales and conducted thematic analysis on discussion transcripts. HIV-related stigma was low (1.8 of 15 points [SD = 1.69]) among 13 participants of unknown HIV status (12 men and one woman). HIV knowledge increased among eight (67%) participants after receiving a brief HIV didactic. Participants described general health care barriers (e.g., the social norm that Black men do not go to the doctor until they are "damn near dead"), fears about unwanted HIV disclosure when seeking HIV testing or care, and community fears about negative stereotypes associated with HIV. Participants expressed enthusiasm about receiving more HIV-related training and utilizing communication skills and client/community relationships to serve as health educators and navigators. Barbers highlighted opportunities to disseminate HIV information in barbershops and combine HIV interventions with other health issues, such as COVID-19, and suggested that these interventions may help reduce HIV-related stigma. Our findings suggest that barbers and barbershops are an underutilized resource for disseminating HIV-related health information and engaging Black men in HIV and other important prevention and care activities such as COVID-19.

Prospective Placebo-Controlled Assessment of Spore-Based Probiotic Supplementation on Sebum Production, Skin Barrier Function, and Acne.

Probiotic supplementation has been shown to modulate the gut-skin axis. The goal of this study was to investigate whether oral spore-based probiotic ingestion modulates the gut microbiome, plasma short-chain fatty acids (SCFAs), and skin biophysical properties. This was a single-blinded, 8-week study (NCT03605108) in which 25 participants, 7 with noncystic acne, were assigned to take placebo capsules for the first 4 weeks, followed by 4 weeks of probiotic supplementation. Blood and stool collection, facial photography, sebum production, transepidermal water loss (TEWL), skin hydration measurements, and acne assessments were performed at baseline, 4, and 8 weeks. Probiotic supplementation resulted in a decreasing trend for the facial sebum excretion rate and increased TEWL overall. Subanalysis of the participants with acne showed improvement in total, noninflammatory, and inflammatory lesion counts, along with improvements in markers of gut permeability. The gut microbiome of the nonacne population had an increase in the relative abundance of Akkermansia, while the subpopulation of those with acne had an increase in the relative abundance of Lachnospiraceae and Ruminococcus gnavus. Probiotic supplementation augmented the circulating acetate/propionate ratio. There is preliminary evidence for the use of spore-based probiotic supplementation to shift the gut microbiome and augment short-chain fatty acids in those with and without acne. Further spore-based supplementation studies in those with noncystic acne are warranted.

Evaluation of the anti-inflammatory effects of selected cannabinoids and terpenes from Cannabis Sativa employing human primary leukocytes.

Cannabis is well established as possessing immune modulating activity. The objective of this study was to evaluate the anti-inflammatory properties of selected cannabis-derived terpenes and cannabinoids. Based on their activity in cannabis-chemovar studies, α-pinene, trans-nerolidol, D-limonene, linalool and phytol were the selected terpenes evaluated. The cannabinoid compounds evaluated included cannabidivarin, cannabidiol, cannabinol, cannabichromene, cannabigerol and delta-9-tetrahydrocannabinol. Human PBMC were pretreated with each compound, individually, at concentrations extending from 0.001 to 10 µM and then stimulated with CpG (plasmacytoid dendritic cell), LPS (monocytes), or anti-CD3/CD28 (T cells). Proliferation, activation marker expression, cytokine production and phagocytosis, were quantified. Of the 21 responses assayed for each compound, cannabinoids showed the greatest immune modulating activity compared to their vehicle control. Delta-9-tetrahydrocannabinol possessed the greatest activity affecting 11 immune parameters followed by cannabidivarin, cannabigerol, cannabichromene, cannabinol and cannabidiol. α-Pinene showed the greatest immune modulating activity from the selected group of terpenes, followed by linalool, phytol, trans-nerolidol. Limonene had no effect on any of the parameters tested. Overall, these studies suggest that selected cannabis-derived terpenes displayed minimal immunological activity, while cannabinoids exhibited a broader range of activity. Compounds possessing anti-inflammatory effects may be useful in decreasing inflammation associated with a range of disorders, including neurodegenerative disorders.

Time to defervescence evaluation for extended- vs. standard-infusion cefepime in patients with acute leukemia and febrile neutropenia.

BACKGROUND/OBJECTIVES: Febrile neutropenia (FN) occurs in up to 80% of patients with hematologic malignancies. Evidence suggests using extended infusions (EI) of beta-lactams can improve outcomes in some populations, but there is limited clinical literature comparing cefepime standard infusion (SI) versus EI for FN. The FDA-approved regimen for FN was used at a large community teaching hospital for patients with FN until a hospital-wide EI beta-lactam protocol was introduced that allowed for EI cefepime in FN at the physicians' discretion. We sought to compare outcomes between patients with FN who received SI and EI cefepime. METHODS: Patients with acute myeloid or lymphocytic leukemia who developed FN between April 2014 and January 2021 were included in this single-center, retrospective study. The primary outcome was to compare mean time to defervescence after the initiation of cefepime SI or EI regimens. SI regimens consisted of IV cefepime 2G q8h/0.5 h, and EI regimens as IV cefepime 1G q8h/4 h. Secondary outcomes included 30-day all-cause mortality, hospital length of stay (LOS), duration of cefepime, and need to escalate therapy. RESULTS: Overall, 193 patients were included. Baseline characteristics were similar between groups. Time to defervescence was significantly shorter with EI compared with the SI group (median 48 h [48-100.5] vs. 70 h [48-113], p = 0.005). Cefepime duration of therapy was significantly shorter in the EI compared with the SI group (median 6.0 days vs. 8.0 days, p = 0.002). There was no difference between other secondary outcomes including LOS, mortality, and antibiotic escalation. CONCLUSION: Despite reduced total daily dose of cefepime, EI cefepime administered as a 1G/0.5 h LD followed 2 h later by 1G q8h/4 h for FN acutely achieves more rapid defervescence than the FDA-approved SI regimen and ultimately attains comparable patient outcomes.

Role of Programmed Cell Death Protein-1 and Lymphocyte Specific Protein Tyrosine Kinase in the Aryl Hydrocarbon Receptor- Mediated Impairment of the IgM Response in Human CD5+ Innate-Like B Cells.

Innate-like B cells (ILBs) are a heterogeneous population B cells which participate in innate and adaptive immune responses. This diverse subset of B cells is characterized by the expression of CD5 and has been shown to secrete high levels of immunoglobulin M (IgM) in the absence of infection or vaccination. Further, CD5+ ILBs have been shown to express high basal levels of lymphocyte specific protein tyrosine kinase (LCK) and programmed cell death protein-1 (PD-1), which are particularly sensitive to stimulation by interferon gamma (IFNγ). Previous studies have demonstrated that activation of the aryl hydrocarbon receptor (AHR), a cytosolic ligand-activated transcription factor, results in suppressed IgM responses and is dependent on LCK. A recent study showed that CD5+ ILBs are particularly sensitive to AHR activation as evidenced by a significant suppression of the IgM response compared to CD5- B cells, which were refractory. Therefore, the objective of this study was to further investigate the role of LCK and PD-1 signaling in AHR-mediated suppression of CD5+ ILBs. In addition, studies were conducted to establish whether IFNγ alters the levels of LCK and PD-1 in CD5+ ILBs. We found that AHR activation led to a significant upregulation of total LCK and PD-1 proteins in CD5+ ILBs, which correlated with suppression of IgM. Interestingly, treatment with recombinant IFNγ reduced LCK protein levels and reversed AHR-mediated IgM suppression in CD5+ ILBs in a similar manner as LCK inhibitors. Collectively, these results support a critical role for LCK and PD-1 in AHR-mediated suppression of the IgM response in human CD5+ ILBs.

Cytosolic aspartate aminotransferase moonlights as a ribosome-binding modulator of Gcn2 activity during oxidative stress.

Regulation of translation is a fundamental facet of the cellular response to rapidly changing external conditions. Specific RNA-binding proteins (RBPs) co-ordinate the translational regulation of distinct mRNA cohorts during stress. To identify RBPs with previously under-appreciated roles in translational control, we used polysome profiling and mass spectrometry to identify and quantify proteins associated with translating ribosomes in unstressed yeast cells and during oxidative stress and amino acid starvation, which both induce the integrated stress response (ISR). Over 800 proteins were identified across polysome gradient fractions, including ribosomal proteins, translation factors, and many others without previously described translation-related roles, including numerous metabolic enzymes. We identified variations in patterns of PE in both unstressed and stressed cells and identified proteins enriched in heavy polysomes during stress. Genetic screening of polysome-enriched RBPs identified the cytosolic aspartate aminotransferase, Aat2, as a ribosome-associated protein whose deletion conferred growth sensitivity to oxidative stress. Loss of Aat2 caused aberrantly high activation of the ISR via enhanced eIF2α phosphorylation and GCN4 activation. Importantly, non-catalytic AAT2 mutants retained polysome association and did not show heightened stress sensitivity. Aat2 therefore has a separate ribosome-associated translational regulatory or 'moonlighting' function that modulates the ISR independent of its aspartate aminotransferase activity.

Beta adrenergic receptor antagonist can modify Pseudomonas aeruginosa biofilm formation in vitro: Implications for chronic wounds.

Non-healing wounds are a major medical challenge, affecting over 6.5 million people in the US alone, with associated healthcare costs of about $16 billion annually. They can result in prolonged hospitalizations, work loss, disability, poor quality of life, and in diabetic patients with foot ulcers, amputation of the affected limb in 25% of patients. Though chronic ulcers may arise from different underlying diseases, the unifying feature is chronic infection, driving persistent inflammation that prolongs the healing process. One of the most frequently cultured or genetically identified pathogens in skin wounds is Pseudomonas aeruginosa. This species avidly forms biofilms in the wound that impede bacterial eradication by the host's immune mechanisms and limit efficacy of systemic antibiotics. Thus, non-antibiotic approaches to limit the growth and biofilm formation of this wound pathogen would be an advance in the treatment of chronic wounds. Prior work has demonstrated that the growth of other microbial species can be modulated by catecholamine agonists and antagonists of the adrenergic receptors (ARs). Here, we demonstrate that not only can the growth of this common wound pathogen be modulated by catecholamines, but also that the beta-AR antagonists can significantly decrease their growth, and importantly, limit their ability to form biofilms. These findings suggest that beta adrenergic antagonists may have a therapeutic role in the treatment of chronic skin wounds.

Resource Over-Utilization in Hospitalized Patients With Uncomplicated Skin and Soft Tissue Infections.

BACKGROUND: Inpatient management of SSTIs utilizes considerable healthcare resources. The CREST+SEWS score categorizes patients with SSTIs into 4 severity classes. Hospitalizations can be avoided in Class I as they are treated as outpatients with oral antibiotics, whereas Class IV require hospitalization for intravenous antibiotics. OBJECTIVE: The purpose of this study was to perform a budget impact analysis on CREST+SEWS Class 1 patients, to compare the medical costs of current treatment, in the inpatient setting with intravenous antibiotics, with a proposed alternative of using oral antibiotics in the outpatient setting. Further, resource utilization in Class I was evaluated. METHODS: This was a retrospective study of adult patients hospitalized in 2015 for SSTIs who received >24 hours of antimicrobials. The CREST+SEWS scoring system was used to stratify patients into Class I to IV. Pharmacy and medical costs and resources associated with inpatient management of Class I SSTIs were derived from the itemized discharge records. RESULTS: Of the 252 patients who met the inclusion criteria, 61 (24%) were classified as Class I. The total cost of treating Class I SSTI patients in the inpatient setting was $281,816 (cost per patient: $4,619) in 2015 USD. In the hypothetical situation of treatment with oral antibiotics in the outpatient setting, the cost savings were estimated to be $4,398 per patient. Fifty-three percent of patients had blood cultures, and on average, each patient received 2 radiographic tests. CONCLUSIONS: Identifying outpatient candidates, and avoiding tests with low diagnostic can reduce the economic burden of SSTIs.

Cannabidiol selectively modulates interleukin (IL)-1ß and IL-6 production in toll-like receptor activated human peripheral blood monocytes.

Cannabidiol (CBD) is a major non-euphoric cannabis-derived compound that has become popular in its over-the-counter use. CBD possesses low affinity for cannabinoid receptors, while the primary molecular target(s) by which it mediates biological activity remain poorly defined. Individuals commonly self-medicate using CBD products with little knowledge of its specific immunopharmacological effects on the human immune system; however, research has established primarily in rodent models that CBD possesses immune modulating properties. The objective of this study was to evaluate whether CBD modulates the innate immune response by human primary monocytes activated through toll-like receptors (TLR) 1-9. Monocytes were activated through each TLR and treated with CBD (0.5-10 µM) for 22 h. Monocyte secretion profiles for 13 immune mediators were quantified including: IL-4, IL-2, IP-10, IL-1ß, TNFα, MCP-1, IL-17a, IL-6, IL-10, IFNγ, IL-12p70, IL-8, and TGF-ß1. CBD treatment significantly suppressed secretion of proinflammatory cytokine IL-1ß by monocytes activated through most TLRs, apart from TLRs 3 and 8. Additionally, CBD treatment induced significant modulation of IL-6 production by monocytes activated through most TLRs, except for TLRs 1 and 3. Most other monocyte-derived factors assayed were refractory to CBD modulation. Overall, CBD selectively altered monocyte-derived IL-1ß and IL-6 when activated through most TLRs. This study is of particular importance as it provides a direct and comprehensive assessment of the effects of CBD on TLR-activated primary human monocytes at a time when CBD containing products are being widely used by the public.

Transrectal intracolon cooling prevents paraplegia and mortality in a rat model of aortic occlusion-induced spinal cord ischemia.

OBJECTIVE: Spinal cord ischemia-reperfusion injury (SC-IRI) occurs in many medical conditions such as aneurysm surgical repair but no treatment of SC-IRI is available in clinical practice. The objective of the present study was to develop a novel medical device for the treatment of SC-IRI. METHODS: A rat model of SC-IRI was used. A novel transrectal intracolon (TRIC) temperature management device was developed to maintain an intracolon wall temperature at either 37°C (TRIC37°C) or 12°C (TRIC12°C). The upper body temperature was maintained as close as possible to 37°C in both groups. A 2F Fogarty balloon catheter was inserted via the left common carotid artery to block the distal aortic blood flow to the spinal cord. The proximal blood pressure was controlled by the withdrawal and infusion of blood via the jugular vein catheter, such that the distal tail artery blood pressure was maintained at ∼10 mmHg for 13 and 20 minutes, respectively. Next, the balloon was deflated, and TRIC temperature management was continued for an additional 30 minutes to maintain the colon wall temperature at either 37°C or 12°C during the reperfusion period. RESULTS: All the rats subjected to 13 minutes of spinal cord ischemia in the TRIC37°C group had developed paraplegia during the postischemic phase. In striking contrast, TRIC at 12°C completely prevented the paraplegia, dramatically improved the arterial blood gas parameters, and avoided the histopathologic injuries to the spinal cord in rats subjected to 13 minutes of spinal cord ischemia. Furthermore, TRIC12°C allowed for the extension of the ischemia duration from 13 minutes to 20 minutes, with significantly reduced functional deficits. CONCLUSIONS: Directly cooling the intestine focally with the TRIC device offered an exceptional survival rate and functional improvement after aortic occlusion-induced spinal cord ischemia.

Long-term core outcomes in cauda equina syndrome.

AIMS: Cauda equina syndrome (CES) can be associated with chronic severe lower back pain and long-term autonomic dysfunction. This study assesses the recently defined core outcome set for CES in a cohort of patients using validated questionnaires. METHODS: Between January 2005 and December 2019, 82 patients underwent surgical decompression for acute CES secondary to massive lumbar disc prolapse at our hospital. After review of their records, patients were included if they presented with the clinical and radiological features of CES, then classified as CES incomplete (CESI) or with painless urinary retention (CESR) in accordance with guidelines published by the British Association of Spinal Surgeons. Patients provided written consent and completed a series of questionnaires. RESULTS: In total, 61 of 82 patients returned a completed survey. Their mean age at presentation was 43 years (20 to 77; SD 12.7), and the mean duration of follow-up 58.2 months (11 to 182; SD 45.3). Autonomic dysfunction was frequent: 33% of patients reported bladder dysfunction, and 10% required a urinary catheter. There was a 38% and 53% incidence of bowel and sexual dysfunction, respectively: 47% of patients reported genital numbness. A total of 67% reported significant back pain: 44% required further investigation and 10% further intervention for the management of lower back pain. Quality of life was lower than expected when corrected for age and sex. Half the patients reported moderate or worse depression, and 40% of patients of working age could no longer work due to problems attributable to CES. Urinary and faecal incontinence, catheter use, sexual dysfunction, and genital numbness were significantly more common in patients with CESR. CONCLUSION: This study reports the long-term outcome of patients with CES and is the first to use validated patient-reported outcome measures to assess the CES Core Outcome Set. Persistent severe back pain and on-going autonomic dysfunction were frequently reported at a mean follow-up of five years. Cite this article: Bone Joint J 2021;103-B(9):1464-1471.

MicroRNA-based host response to toxicant exposure is influenced by the presence of gut microbial populations.

Segmented filamentous bacteria (SFB) and Bacteroides fragilis are known to interact with the host immune response through the aryl hydrocarbon receptor (Ahr). 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD), an environmental toxicant and a high-affinity Ahr ligand has the potential to modify the effect of SFB and B. fragilis. MicroRNAs (miRNA) with their role in regulating gene expression post-transcriptionally, may potentially be used to observe such interactions between SFB, B. fragilis, and TCDD. However, little is known regarding the impact of gut microbial members on miRNA expression or its modulation in the presence of an environmental toxicant. This information is important in understanding toxicant-mediated dysbiosis in gut microbiome and the resulting human health impacts. In this study, C57BL/6 germ-free (GF) mice were colonized with SFB and B. fragilis and administered 30 µg/kg TCDD every 4 d for 28 d and miRNA were measured. Compared to GF mice, colonization with SFB resulted in an increase in up- and down-regulated Ileal miRNAs. TCDD treatment of this group decreased the number of upregulated miRNA and increased the number of down-regulated miRNAs. Association with SFB and B. fragilis together had a similar but less pronounced effect in response to TCDD treatment. TCDD treatment of GF mice had no miRNA expression response. Immune and inflammatory responses and T-cell differentiation were the key functions impacted by these miRNAs. Overall, these results reveal that the host response to toxicants may also depend on the presence of specific gut microbial populations.

Overlapping regions of Caf20 mediate its interactions with the mRNA-5'cap-binding protein eIF4E and with ribosomes.

By interacting with the mRNA 5' cap, the translation initiation factor eIF4E plays a critical role in selecting mRNAs for protein synthesis in eukaryotic cells. Caf20 is a member of the family of proteins found across eukaryotes termed 4E-BPs, which compete with eIF4G for interaction with eIF4E. Caf20 independently interacts with ribosomes. Thus, Caf20 modulates the mRNA selection process via poorly understood mechanisms. Here we performed unbiased mutagenesis across Caf20 to characterise which regions of Caf20 are important for interaction with eIF4E and with ribosomes. Caf20 binding to eIF4E is entirely dependent on a canonical motif shared with other 4E-BPs. However, binding to ribosomes is weakened by mutations throughout the protein, suggesting an extended binding interface that partially overlaps with the eIF4E-interaction region. By using chemical crosslinking, we identify a potential ribosome interaction region on the ribosome surface that spans both small and large subunits and is close to a known interaction site of eIF3. The function of ribosome binding by Caf20 remains unclear.

Identification of a Sensitive Human Immunological Target of Aryl Hydrocarbon Receptor Activation: CD5+ Innate-Like B Cells.

Xenobiotic-mediated activation of the aryl hydrocarbon receptor (AHR) is immunotoxic in a number of immune cell types, with the B cell being a well-established sensitive target. Recent advances have provided evidence that the B cell repertoire is a heterogeneous population, with subpopulations exhibiting vastly different cellular and functional phenotypes. Recent work from our laboratory identified the T cell specific kinase lck as being differentially regulated by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), which is a potent activator of AHR. While LCK is primarily expressed in T cells, a subset of CD5+ B cells also express LCK. CD5 positivity describes a broad class of B lymphocytes termed innate-like B cells (ILBs) that are critical mediators of innate immunity through constitutive secretion of polyvalent natural immunoglobulin M (IgM). We hypothesized that CD5+ ILBs may be sensitive to AHR-mediated immunotoxicity. Indeed, when CD5+ B cells were isolated from the CD19+ pool and treated with TCDD, they showed increased suppression of the CD40 ligand-induced IgM response compared to CD5- B cells. Further, characterization of the CD5+ population indicated increased basal expression of AHR, AHR repressor (AHRR), and cytochrome p450 family 1 member a1 (CYP1A1). Indeed the levels of AHR-mediated suppression of the IgM response from individual donors strongly correlated with the percentage of the B cell pool that was CD5+, suggesting that CD5+ B cells are more sensitive to AHR-mediated impairment. Together these data highlight the sensitive nature of CD5+ ILBs to AHR activation and provide insight into mechanisms associated with AHR activation in human B cells.

A global metagenomic map of urban microbiomes and antimicrobial resistance.

We present a global atlas of 4,728 metagenomic samples from mass-transit systems in 60 cities over 3 years, representing the first systematic, worldwide catalog of the urban microbial ecosystem. This atlas provides an annotated, geospatial profile of microbial strains, functional characteristics, antimicrobial resistance (AMR) markers, and genetic elements, including 10,928 viruses, 1,302 bacteria, 2 archaea, and 838,532 CRISPR arrays not found in reference databases. We identified 4,246 known species of urban microorganisms and a consistent set of 31 species found in 97% of samples that were distinct from human commensal organisms. Profiles of AMR genes varied widely in type and density across cities. Cities showed distinct microbial taxonomic signatures that were driven by climate and geographic differences. These results constitute a high-resolution global metagenomic atlas that enables discovery of organisms and genes, highlights potential public health and forensic applications, and provides a culture-independent view of AMR burden in cities.

Directly Cooling Gut Prevents Mortality in the Rat Model of Reboa Management of Lethal Hemorrhage.

BACKGROUND: Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a lifesaving technique for the management of lethal torso hemorrhage. Its benefit, however, must be weighed against the lethal distal organ ischemia-reperfusion injury (IRI). This study uses a novel direct gut cooling technique to manage the distal organ IRI. METHODS: A rat lethal hemorrhage model was established by bleeding of 50% of the estimated total blood volume via inferior vena cava. A novel TransRectal Intra-Colon (TRIC) temperature management device was positioned in the descending colon either to maintain intra-colon temperature at 37°C or 12°C. The upper body temperature was maintained at as close to 37°C as possible in both groups. A 2F Fogarty balloon catheter was inserted via the femoral artery into the descending thoracic aorta for the implementation of REBOA. After REBOA, the balloon was deflated, and the shed blood was returned. The temperature managements were continued for additional 180 to 270 min during the post-REBOA period. RESULTS: All rats subjected to REBOA management of lethal hemorrhage at 37°C had severe histopathological gut and abdominal organ IRI, severe functional deficits, and died within 24 h with 100% mortality. By contrast, directly cooling the colon to 10°C to 12°C with the novel TRIC device abolished mortality, and dramatically improved ABG parameters, prevented the abdominal organ injury, and reduced the functional deficits during the 7-day post-REBOA period. CONCLUSIONS: Direct trans-rectal colon cooling during REBOA management of lethal hemorrhage offers extraordinary functional improvement and amazing tissue protection, and abolishes mortality.