Spatial recovery of the murine gut microbiota after antibiotics perturbation.

Bacterial communities are highly complex, with interaction networks dictating ecosystem function. Bacterial interactions are constrained by the spatial organization of these microbial communities, yet studying the spatial organization of microbial communities at the single-cell level has been technically challenging. Here, we use the recently developed high-phylogenetic-resolution microbiota mapping by fluorescence in situ hybridization technology to image the gut microbiota at the species and single-cell level. We simultaneously image 63 different bacterial species to spatially characterize the perturbation and recovery of the gut microbiota to ampicillin and vancomycin in the cecum and distal colon of mice. To decipher the biology in this complex imaging data, we developed an analytical framework to characterize the spatial changes of the gut microbiota to a perturbation. The three-tiered analytical approach includes image-level diversity, pairwise colocalization analysis, and hypothesis-driven neighborhood analysis. Through this workflow, we identify biogeographic and antibiotic-based differences in the spatial organization of the gut microbiota. We demonstrate that the cecal microbiota has increased micrometer-scale diversity than the colon at baseline and recovers better from perturbation. Also, we identify potential foundation and keystone species that have high baseline neighborhood richness and that are associated with recovery from antibiotics. Through this workflow, we add a spatial layer to the characterization of bacterial communities and progress toward a better understanding of bacterial interactions leading to improved microbiome modulation strategies. IMPORTANCE: Antibiotics have broad off-target effects on the gut microbiome. When the microbial community is unable to recover from antibiotics, it can lead to increased susceptibility to gastrointestinal infections and increased risk of immunological and metabolic diseases. In this study, we work to better understand how the gut microbiota recovers from antibiotics by employing a recent technology to image the entire bacterial community at once. Through this approach, we characterize the spatial changes in the gut microbiota after treatment with model antibiotics in both the cecum and colon of mice. We find antibiotic- and biogeographic-dependent spatial changes between bacterial species and that many of these spatial colocalizations do not recover to baseline levels even 35 days after antibiotic administration.

Microstructure and mechanical properties of dissimilar NiTi and 304 stainless steel joints produced by ultrasonic welding.

Superelastic NiTi alloy and 304 stainless steel (304 SS) were joined with a Cu interlayer by ultrasonic spot welding (USW) using different welding energy inputs. The surface morphology, interfacial microstructure, mechanical properties, and fracture mechanisms of the dissimilar NiTi/304 SS USWed joints were studied. The results showed that the surface oxidation intensified with increasing ultrasonic welding energy due to mutual rubbing between tools and sheets. The weld interface microstructure exhibited voids or unbonded zones at low energy inputs, while an intimate contact was established at the joining interface when applying a higher energy input of 750 J. With increasing energy input to 750 J, the weld interface shows two interfaces due to the behavior of plastic flow of Cu interlayer. The lap-shear load of the joints first increased, achieving a maximum value of ∼690 N at an energy input of 750 J, and then decreased with further increase in welding energy. Interfacial failure was observed at NiTi/Cu interface at all energy inputs, and no intermetallic compounds were found on the fracture surfaces of both the NiTi/Cu and Cu/304 SS interfaces.

Acute Kidney Injury and Renal Replacement Therapy in COVID-19 Versus Other Respiratory Viruses: A Systematic Review and Meta-Analysis.

BACKGROUND: Acute kidney injury (AKI) is a potentially fatal complication of Coronavirus Disease-2019 (COVID-19). Binding of the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), the virus responsible for COVID-19, to its viral receptor, angiotensin converting enzyme 2 (ACE2), results in viral entry and may cause AKI. OBJECTIVES: We performed a systematic review and meta-analysis of the frequencies of AKI and renal replacement therapy (RRT) in critically ill COVID-19 patients and compared those frequencies with patients who were infected by respiratory viruses that bind or downregulate ACE2 (ACE2-associated viruses) and viruses that do not bind nor downregulate ACE2 (non-ACE2-associated viruses). DESIGN: Systematic review and meta-analysis. SETTING: Observational studies on COVID-19 and other respiratory viral infections reporting AKI and RRT were included. The exclusion criteria were non-English articles, non-peer-reviewed articles, review articles, studies that included patients under the age of 18, studies including fewer than 10 patients, and studies not reporting AKI and RRT rates. PATIENTS: Adult COVID-19, Severe Acute Respiratory Syndrome (SARS), Middle East Respiratory Syndrome (MERS), and influenza patients. MEASUREMENTS: We extracted the following data from the included studies: author, year, study location, age, sex, race, diabetes mellitus, hypertension, chronic kidney disease, shock, vasopressor use, mortality, intensive care unit (ICU) admission, ICU mortality, AKI, and RRT. METHODS: We systematically searched PubMed and EMBASE for articles reporting AKI or RRT. AKI was defined by authors of included studies. Critical illness was defined by ICU admission. We performed a random effects meta-analysis to calculate pooled estimates for the AKI and RRT rate within each virus group using a random intercept logistic regression model. RESULTS: Of 23 655 hospitalized, critically ill COVID-19 patients, AKI frequencies were not significantly different between COVID-19 patients (51%, 95% confidence interval [CI]: 44%-57%) and critically ill patients infected with ACE2-associated (56%, 95% CI: 37%-74%, P = .610) or non-ACE2-associated viruses (63%, 95% CI: 43%-79%, P = .255). Pooled RRT rates were also not significantly different between critically ill, hospitalized patients with COVID-19 (20%, 95% CI: 16%-24%) and ACE2-associated viruses (18%, 95% CI: 8%-33%, P = .747). RRT rates for both COVID-19 and ACE2-associated viruses were significantly different (P < .001 for both) from non-ACE2-associated viruses (49%, 95% CI: 44%-54%). After adjusting for shock or vasopressor use, AKI and RRT rates were not significantly different between groups. LIMITATIONS: Limitations of this study include the heterogeneity of definitions of AKI that were used across different virus studies. We could not match severity of infection or do propensity matching across studies. Most of the included studies were conducted in retrospective fashion. Last, we did not include non-English publications. CONCLUSIONS: Our findings suggest that viral ACE2 association does not significantly alter the rates of AKI and RRT among critically ill patients admitted to the ICU. However, the rate of RRT is lower in patients with COVID-19 or ACE2-associated viruses when compared with patients infected with non-ACE2-binding viruses, which might partly be due to the lower frequencies of shock and use of vasopressors in these two virus groups. Prospective studies are necessary to demonstrate whether modulation of the ACE2 axis with Renin-Angiotensin System inhibitors impacts the rates of AKI and whether they are beneficial or harmful in COVID-19 patients.

MISE EN CONTEXTE: L'insuffisance rénale aiguë (IRA) est une complication potentiellement mortelle de la maladie à coronavirus-2019 (COVID-19). Obligatoire du Coronavirus 2 du Syndrome Respiratoire Aigu Sévère (SARS-CoV-2), le virus responsable du COVID-19, à son récepteur, l'enzyme de conversion de l'angiotensine 2 (ACE2), entraîne une entrée virale et peut provoquer une IRA. OBJECTIFS DE L'ÉTUDE: Nous avons effectué une revue systématique et une méta-analyse des fréquences de l'IRA et de la thérapie de remplacement renal (RRT) chez les patients COVID-19 gravement malades et a comparé ces fréquences avec les patients qui ont été infectés par des voies respiratoires virus qui lient ou régulent négativement l'ACE2 (virus associés à l'ACE2) et les virus qui ne régulent pas négativement ni ne lient l'ACE2 (virus non associés à l'ACE2). CADRE ET TYPE D'ÉTUDE: Revue systématique et méta-analyse. Des études d'observation sur le COVID-19 et d'autres infections virales respiratoires signalant une AKI et une RRT ont été incluses. Les critères d'exclusion étaient des articles non anglophones, des articles non évalués par des pairs, des articles de revue, des études incluant des patients moins de 18 ans, les études incluant moins de 10 patients et les études ne rapportant pas les taux d'IRA et de RRT. PATIENTS: Adultes COVID-19, syndrome respiratoire aigu sévère (SRAS), syndrome respiratoire du Moyen-Orient (MERS) et malades de la grippe. MESURES: Nous avons extrait les données suivantes des études incluses : auteur, année, lieu de l'étude, âge, sexe, race, diabète sucré, hypertension, maladie rénale chronique, état de choc, utilisation de vasopresseurs, mortalité, admission en unité de soins intensifs (USI), Mortalité en soins intensifs, AKI et RRT. MÉTHODOLOGIE: Nous avons systématiquement recherché dans PubMed et EMBASE les articles rapportant AKI ou RRT. AKI a été défini par les auteurs des études incluses. La maladie grave a été définie par l'admission aux soins intensifs. Nous avons effectué une méta-analyse à effets aléatoires pour calculer estimations regroupées pour le taux d'IRA et de RRT au sein de chaque groupe de virus à l'aide d'un modèle de régression logistique d'interception aléatoire. RÉSULTATS: Sur 23 655 patients hospitalisés et gravement malades COVID-19, les fréquences AKI n'étaient pas significativement différentes entre patients COVID-19 (51 %, intervalle de confiance à 95 % [IC] : 44 %-57 %) et patients gravement malades infectés par l'ACE2 associé (56 %, IC à 95 % : 37 % à 74 %, P = 0,610) ou des virus non associés à l'ACE2 (63 %, IC à 95 % : 43 % à 79 %, P = 0,255). Tarifs RRT groupés n'étaient pas non plus significativement différents entre les patients hospitalisés gravement malades atteints de COVID-19 (20 %, IC à 95 % : 16 % à 24 %) et virus associés à l'ACE2 (18 %, IC à 95 % : 8 % à 33 %, P = 0,747). Taux de RRT pour les virus associés au COVID-19 et à l'ACE2 étaient significativement différents (P < 0,001 pour les deux) des virus non associés à l'ACE2 (49 %, IC à 95 % : 44 % à 54 %). Après ajustement pour le choc ou l'utilisation de vasopresseurs, les taux d'IRA et de RRT n'étaient pas significativement différents entre les groupes. LIMITES DE L'ÉTUDE: Les limites de cette étude incluent l'hétérogénéité des définitions de l'IRA qui ont été utilisées pour différents virus études. Nous n'avons pas pu faire correspondre la gravité de l'infection ou faire une correspondance de propension entre les études. La plupart des études incluses ont été menées de manière rétrospective. Enfin, nous n'avons pas inclus les publications non anglophones. CONCLUSIONS: Nos résultats suggèrent que l'association virale ACE2 ne modifie pas de manière significative les taux d'IRA et de RRT parmi les patients gravement malades admis aux soins intensifs. Cependant, le taux de RRT est plus faible chez les patients atteints de COVID-19 ou associés à l'ACE2 virus par rapport aux patients infectés par des virus ne se liant pas à l'ACE2, ce qui pourrait être dû en partie à la plus faible fréquences de choc et utilisation de vasopresseurs dans ces deux groupes de virus. Des études prospectives sont nécessaires pour démontrer si la modulation de l'axe ACE2 avec les inhibiteurs du système rénine-angiotensine a un impact sur les taux d'IRA et si ells sont bénéfiques ou nocifs chez les patients COVID-19.

Pregnancy and COVID-19: pharmacologic considerations.

In this review, we summarize evidence regarding the use of routine and investigational pharmacologic interventions for pregnant and lactating patients with coronavirus disease 2019 (COVID-19). Antenatal corticosteroids may be used routinely for fetal lung maturation between 24 and 34 weeks' gestation, but decisions in those with critical illness and those < 24 or > 34 weeks' gestation should be made on a case-by-case basis. Magnesium sulfate may be used for seizure prophylaxis and fetal neuroprotection, albeit cautiously in those with hypoxia and renal compromise. There are no contraindications to using low-dose aspirin to prevent placenta-mediated pregnancy complications when indicated. An algorithm for thromboprophylaxis in pregnant patients with COVID-19 is presented, which considers disease severity, timing of delivery in relation to disease onset, inpatient vs outpatient status, underlying comorbidities and contraindications to the use of anticoagulation. Nitrous oxide may be administered for labor analgesia while using appropriate personal protective equipment. Intravenous remifentanil patient-controlled analgesia should be used with caution in patients with respiratory depression. Liberal use of neuraxial labor analgesia may reduce the need for emergency general anesthesia which results in aerosolization. Short courses of non-steroidal anti-inflammatory drugs can be administered for postpartum analgesia, but opioids should be used with caution due to the risk of respiratory depression. For mechanically ventilated pregnant patients, neuromuscular blockade should be used for the shortest duration possible and reversal agents should be available on hand if delivery is imminent. To date, dexamethasone is the only proven and recommended experimental treatment for pregnant patients with COVID-19 who are mechanically ventilated or who require supplemental oxygen. Although hydroxycholoroquine, lopinavir/ritonavir and remdesivir may be used during pregnancy and lactation within the context of clinical trials, data from non-pregnant populations have not shown benefit. The role of monoclonal antibodies (tocilizumab), immunomodulators (tacrolimus), interferon, inhaled nitric oxide and convalescent plasma in pregnancy and lactation needs further evaluation. © 2020 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

[Clinical application of intraoperative CT in management of maxillofacial fracture].

Nine patients with maxillofacial fracture that received intraoperative CT examination in Lanzhou General Hospital of Lanzhou Military Command from January 2017 to March 2017 were retrospectively studied. The procedure of intraoperative CT was introduced. The value of this technique was preliminarily discussed in order to provide a new method for the accurate implementation of maxillofacial fracture surgery.

Chest radiography for active tuberculosis case finding in the homeless: a systematic review and meta-analysis.

SETTING: In low-incidence regions, tuberculosis (TB) often affects vulnerable populations. Guidelines recommend active case finding (ACF) in homeless populations, but there is no consensus on a preferred screening method. OBJECTIVE: We performed a systematic review and meta-analysis to evaluate the use of chest X-ray (CXR) screening in ACF for TB in homeless populations. DESIGN: Articles were identified through EMBASE, Medline and the Cochrane Library. Studies using symptom screens, CXRs, sputum sweeps, tuberculin skin tests and/or interferon-gamma release assays to detect active TB in homeless populations were sought. Data were extracted using a standardised method by two reviewers and validated with an objective tool. RESULTS: Sixteen studies addressing CXR screening of homeless populations for active TB in low-incidence regions were analysed. The pooled prevalence of active TB in the 16 study cohorts was 931 per 100 000 population screened (95%CI 565-1534) and 782/100 000 CXR performed (95%CI 566-1079). Six of seven longitudinal screening programs reported a reduction in regional TB incidence after implementation of the CXR-based ACF programme. CONCLUSION: Our data suggest that CXR screening is a good tool for ACF in homeless populations in low-incidence regions.