Capnography access and use in Kenya and Ethiopia.

PURPOSE: Lack of access to safe and affordable anesthesia and monitoring equipment may contribute to higher rates of morbidity and mortality in low- and middle-income countries (LMICs). While capnography is standard in high-income countries, use in LMICs is not well studied. We evaluated the association of capnography use with patient and procedure-related characteristics, as well as the association of capnography use and mortality in a cohort of patients from Kenya and Ethiopia. METHODS: For this retrospective observational study, we used historical cohort data from Kenya and Ethiopia from 2014 to 2020. Logistic regression was used to study the association of capnography use (primary outcome) with patient/procedure factors, and the adjusted association of intraoperative, 24-hr, and seven-day mortality (secondary outcomes) with capnography use. RESULTS: A total of 61,792 anesthetic cases were included in this study. Tertiary or secondary hospital type (compared with primary) was strongly associated with use of capnography (odds ratio [OR], 6.27; 95% confidence interval [CI], 5.67 to 6.93 and OR, 6.88; 95% CI, 6.40 to 7.40, respectively), as was general (vs regional) anesthesia (OR, 4.83; 95% CI, 4.41 to 5.28). Capnography use was significantly associated with lower odds of intraoperative mortality in patients who underwent general anesthesia (OR, 0.31; 95% CI, 0.17 to 0.48). Nevertheless, fully-adjusted models for 24-hr and seven-day mortality showed no evidence of association with capnography. CONCLUSION: Capnography use in LMICs is substantially lower compared with other standard anesthesia monitors. Capnography was used at higher rates in tertiary centres and with patients undergoing general anesthesia. While this study revealed decreased odds of intraoperative mortality with capnography use, further studies need to confirm these findings.

RéSUMé: OBJECTIF: Le manque d'accès à des équipements d'anesthésie et de monitorage sécuritaires et abordables peut contribuer à des taux plus élevés de morbidité et de mortalité dans les pays à revenu faible et intermédiaire (PRFI). Alors que la capnographie est une modalité standard dans les pays à revenu élevé, son utilisation dans les PRFI n'est pas bien étudiée. Nous avons évalué l'association de l'utilisation de la capnographie avec les caractéristiques des patient·es et des interventions, ainsi que l'association de l'utilisation de la capnographie et de la mortalité dans une cohorte de patient·es du Kenya et d'Éthiopie. MéTHODE: Pour cette étude observationnelle rétrospective, nous avons utilisé des données de cohortes historiques du Kenya et de l'Éthiopie de 2014 à 2020. Une régression logistique a été utilisée pour étudier l'association entre l'utilisation de la capnographie (critère d'évaluation principal) et les facteurs patient·es/interventions, ainsi que pour étudier l'association ajustée entre la mortalité peropératoire, à 24 h et à sept jours (critères d'évaluation secondaires) et l'utilisation de la capnographie. RéSULTATS: Au total, 61 792 cas d'anesthésie ont été inclus dans cette étude. Le type d'hôpital tertiaire ou secondaire (par rapport à un établissement primaire) était fortement associé à l'utilisation de la capnographie (rapport de cotes [RC], 6,27; intervalle de confiance [IC] à 95 %, 5,67 à 6,93 et RC, 6,88; IC 95 %, 6,40 à 7,40, respectivement), tout comme l'était l'anesthésie générale (vs régionale) (RC, 4,83; IC 95 %, 4,41 à 5,28). L'utilisation de la capnographie était significativement associée à une probabilité plus faible de mortalité peropératoire chez les patient·es ayant reçu une anesthésie générale (RC, 0,31; IC 95 %, 0,17 à 0,48). Néanmoins, les modèles entièrement ajustés pour la mortalité à 24 heures et à sept jours n'ont montré aucune donnée probante d'association avec la capnographie. CONCLUSION: L'utilisation de la capnographie dans les PRFI est considérablement moins répandue que celle d'autres moniteurs d'anesthésie standard. La capnographie a été utilisée à des taux plus élevés dans les centres tertiaires et chez des patient·es sous anesthésie générale. Bien que cette étude ait révélé une diminution de la probabilité de mortalité peropératoire avec l'utilisation de la capnographie, d'autres études doivent confirmer ces résultats.

Automated Image Analysis Pipeline Development to Monitor Disease Progression in Muscular Dystrophy Using Cell Profiler.

Muscular dystrophies are inherited disorders that are characterized by progressive muscle degeneration. These disorders are caused by mutations in the genes encoding structural elements within the muscle, which leads to increased vulnerability to mechanical stress and sarcolemma damage. Although myofibers have the capacity to regenerate, the newly formed myofibers still harbor genetic mutation, which induces continuous cycles of muscle fiber death and regeneration. This repeated cycling is accompanied by an inflammatory response which eventually provokes excessive fibrotic deposition. The histopathological changes in skeletal muscle tissue are central to the disease pathogenesis. Analysis of muscle histopathology is the gold standard for monitoring muscle health and disease progression. However, manual, or semi-manual quantification methods, are not only immensely tedious but can be subjective. Here, we present four image analysis pipelines built in CellProfiler which enable users without a background in computer vision or programming to quantitatively analyze biological images. These image analysis pipelines are designed to quantify skeletal muscle histopathological staining for membrane damage, the abundance and size distribution of regenerating muscle fibers, inflammation via quantification of CD68+ M1 macrophages, and collagen deposition. Additionally, we discuss methods to address common errors associated with the quantification of microscopy images. These automated tools can not only improve workflow efficiency but can provide a better understanding of the histopathological progression of muscular dystrophy.

Tacrolimus induces fibroblast-to-myofibroblast transition via a TGF-ß-dependent mechanism to contribute to renal fibrosis.

Use of immunosuppressant calcineurin inhibitors (CNIs) is limited by irreversible kidney damage, hallmarked by renal fibrosis. CNIs directly damage many renal cell types. Given the diverse renal cell populations, additional targeted cell types and signaling mechanisms warrant further investigation. We hypothesized that fibroblasts contribute to CNI-induced renal fibrosis and propagate profibrotic effects via the transforming growth factor-ß (TGF-ß)/Smad signaling axis. To test this, kidney damage-resistant mice (C57BL/6) received tacrolimus (10 mg/kg) or vehicle for 21 days. Renal damage markers and signaling mediators were assessed. To investigate their role in renal damage, mouse renal fibroblasts were exposed to tacrolimus (1 nM) or vehicle for 24 h. Morphological and functional changes in addition to downstream signaling events were assessed. Tacrolimus-treated kidneys displayed evidence of renal fibrosis. Moreover, α-smooth muscle actin expression was significantly increased, suggesting the presence of fibroblast activation. TGF-ß receptor activation and downstream Smad2/3 signaling were also upregulated. Consistent with in vivo findings, tacrolimus-treated renal fibroblasts displayed a phenotypic switch known as fibroblast-to-myofibroblast transition (FMT), as α-smooth muscle actin, actin stress fibers, cell motility, and collagen type IV expression were significantly increased. These findings were accompanied by concomitant induction of TGF-ß signaling. Pharmacological inhibition of the downstream TGF-ß effector Smad3 attenuated tacrolimus-induced phenotypic changes. Collectively, these findings suggest that 1) tacrolimus inhibits the calcineurin/nuclear factor of activated T cells axis while inducing TGF-ß1 ligand secretion and receptor activation in renal fibroblasts; 2) aberrant TGF-ß receptor activation stimulates Smad-mediated production of myofibroblast markers, notable features of FMT; and 3) FMT contributes to extracellular matrix expansion in tacrolimus-induced renal fibrosis. These results incorporate renal fibroblasts into the growing list of CNI-targeted cell types and identify renal FMT as a process mediated via a TGF-ß-dependent mechanism.NEW & NOTEWORTHY Renal fibrosis, a detrimental feature of irreversible kidney damage, remains a sinister consequence of long-term calcineurin inhibitor (CNI) immunosuppressive therapy. Our study not only incorporates renal fibroblasts into the growing list of cell types negatively impacted by CNIs but also identifies renal fibroblast-to-myofibroblast transition as a process mediated via a TGF-ß-dependent mechanism. This insight will direct future studies investigating the feasibility of inhibiting TGF-ß signaling to maintain CNI-mediated immunosuppression while ultimately preserving kidney health.

Lipin1 plays complementary roles in myofibre stability and regeneration in dystrophic muscles.

Duchenne muscular dystrophy (DMD) is a severe muscle wasting disorder caused by dystrophin mutations, leading to the loss of sarcolemmal integrity, and resulting in progressive myofibre necrosis and impaired muscle function. Our previous studies suggest that lipin1 is important for skeletal muscle regeneration and myofibre integrity. Additionally, we discovered that mRNA expression levels of lipin1 were significantly reduced in skeletal muscle of DMD patients and the mdx mouse model. To understand the role of lipin1 in dystrophic muscle, we generated dystrophin/lipin1 double knockout (DKO) mice, and compared the limb muscle pathology and function of wild-type B10, muscle-specific lipin1 deficient (lipin1Myf5cKO ), mdx and DKO mice. We found that further knockout of lipin1 in dystrophic muscle exhibited a more severe phenotype characterized by increased necroptosis, fibrosis and exacerbated membrane damage in DKO compared to mdx mice. In barium chloride-induced muscle injury, both lipin1Myf5cKO and DKO showed prolonged regeneration at day 14 post-injection, suggesting that lipin1 is critical for muscle regeneration. In situ contractile function assays showed that lipin1 deficiency in dystrophic muscle led to reduced specific force production. Using a cell culture system, we found that lipin1 deficiency led to elevated expression levels of necroptotic markers and medium creatine kinase, which could be a result of sarcolemmal damage. Most importantly, restoration of lipin1 inhibited the elevation of necroptotic markers in differentiated primary lipin1-deficient myoblasts. Overall, our data suggests that lipin1 plays complementary roles in myofibre stability and muscle function in dystrophic muscles, and overexpression of lipin1 may serve as a potential therapeutic strategy for dystrophic muscles. KEY POINTS: We identified that lipin1 mRNA expression levels are significantly reduced in skeletal muscles of Duchenne muscular dystrophy patients and mdx mice. We found that further depletion of lipin1 in skeletal muscles of mdx mice induces more severe dystrophic phenotypes, including enhanced myofibre sarcolemma damage, muscle necroptosis, inflammation, fibrosis and reduced specific force production. Lipin1 deficiency leads to elevated expression levels of necroptotic markers, whereas restoration of lipin1 inhibits their expression. Our results suggest that lipin1 is functionally complementary to dystrophin in muscle membrane integrity and muscle regeneration.

Pediatric Perioperative Mortality in Kenya: A Prospective Cohort Study from 24 Hospitals.

BACKGROUND: The global surgery access imbalance will have a dramatic impact on the growing population of the world's children. In regions of the world with pediatric surgery and anesthesia manpower deficits and pediatric surgery-specific infrastructure and supply chain gaps, this expanding population will present new challenges. Perioperative mortality rate is an established indicator of the quality and safety of surgical care. To establish a baseline pediatric perioperative mortality rate and factors associated with mortality in Kenya, the authors designed a prospective cohort study and measured 24-h, 48-h, and 7-day perioperative mortality. METHODS: The authors trained anesthesia providers to electronically collect 132 data elements for pediatric surgical cases in 24 government and nongovernment facilities at primary, secondary, and tertiary hospitals from January 2014 to December 2016. Data assistants tracked all patients to 7 days postoperative, even if they had been discharged. Adjusted analyses were performed to compare mortality among different hospital levels after adjusting for prespecified risk factors. RESULTS: Of 6,005 cases analyzed, there were 46 (0.8%) 24-h, 62 (1.1%) 48-h, and 77 (1.7%) 7-day cumulative mortalities reported. In the adjusted analysis, factors associated with a statistically significant increase in 7-day mortality were American Society of Anesthesiologists Physical Status of III or more, night or weekend surgery, and not having the Safe Surgery Checklist performed. The 7-day perioperative mortality rate is less in the secondary (1.4%) and tertiary (2.4%) hospitals when compared with the primary (3.7%) hospitals. CONCLUSIONS: The authors have established a baseline pediatric perioperative mortality rate that is greater than 100 times higher than in high-income countries. The authors have identified factors associated with an increased mortality, such as not using the Safe Surgery Checklist. This analysis may be helpful in establishing pediatric surgical care systems in low-middle income countries and develop research pathways addressing interventions that will assist in decreasing mortality rate.