Outcomes of a multicomponent safe surgery intervention in Tanzania's Lake Zone: a prospective, longitudinal study.

BACKGROUND: Evidence-based strategies for improving surgical quality and patient outcomes in low-resource settings are a priority. OBJECTIVE: To evaluate the impact of a multicomponent safe surgery intervention (Safe Surgery 2020) on (1) adherence to safety practices, teamwork and communication, and documentation in patient files, and (2) incidence of maternal sepsis, postoperative sepsis, and surgical site infection. METHODS: We conducted a prospective, longitudinal study in 10 intervention and 10 control facilities in Tanzania's Lake Zone, across a 3-month pre-intervention period in 2018 and 3-month post-intervention period in 2019. SS2020 is a multicomponent intervention to support four surgical quality areas: (i) leadership and teamwork, (ii) evidence-based surgery, anesthesia and equipment sterilization practices, (iii) data completeness and (iv) infrastructure. Surgical team members received training and mentorship, and each facility received up to a $10 000 infrastructure grant. Inpatients undergoing major surgery and postpartum women were followed during their stay up to 30 days. We assessed adherence to 14 safety and teamwork and communication measures through direct observation in the operating room. We identified maternal sepsis (vaginal or cesarean delivery), postoperative sepsis and SSIs prospectively through daily surveillance and assessed medical record completeness retrospectively through chart review. We compared changes in surgical quality outcomes between intervention and control facilities using difference-in-differences analyses to determine areas of impact. RESULTS: Safety practices improved significantly by an additional 20.5% (95% confidence interval (CI), 7.2-33.7%; P = 0.003) and teamwork and communication conversations by 33.3% (95% CI, 5.7-60.8%; P = 0.02) in intervention facilities compared to control facilities. Maternal sepsis rates reduced significantly by 1% (95% CI, 0.1-1.9%; P = 0.02). Documentation completeness improved by 41.8% (95% CI, 27.4-56.1%; P < 0.001) for sepsis and 22.3% (95% CI, 4.7-39.8%; P = 0.01) for SSIs. CONCLUSION: Our findings demonstrate the benefit of the SS2020 approach. Improvement was observed in adherence to safety practices, teamwork and communication, and data quality, and there was a reduction in maternal sepsis rates. Our results support the emerging evidence that improving surgical quality in a low-resource setting requires a focus on the surgical system and culture. Investigation in diverse contexts is necessary to confirm and generalize our results and to understand how to adapt the intervention for different settings. Further work is also necessary to assess the long-term effect and sustainability of such interventions.

Surgical referrals in Northern Tanzania: a prospective assessment of rates, preventability, reasons and patterns.

BACKGROUND: An effective referral system is essential for a high-quality health system that provides safe surgical care while optimizing patient outcomes and ensuring efficiency. The role of referral systems in countries with under-resourced health systems is poorly understood. The aim of this study was to examine the rates, preventability, reasons and patterns of outward referrals of surgical patients across three levels of the healthcare system in Northern Tanzania. METHODS: Referrals from surgical and obstetric wards were assessed at 20 health facilities in five rural regions prospectively over 3 months. Trained physician data collectors used data collection forms to capture referral details daily from hospital referral letters and through discussions with clinicians and nurses. Referrals were deemed preventable if the presenting condition was one that should be managed at the referring facility level per the national surgical, obstetric and anaesthesia plan but was referred. RESULTS: Seven hundred forty-three total outward referrals were recorded during the study period. The referral rate was highest at regional hospitals (2.9%), followed by district hospitals (1.9%) and health centers (1.5%). About 35% of all referrals were preventable, with the highest rate from regional hospitals (70%). The most common reasons for referrals were staff-related (76%), followed by equipment (55%) and drugs or supplies (21%). Patient preference accounted for 1% of referrals. Three quarters of referrals (77%) were to the zonal hospital, followed by the regional hospitals (17%) and district hospitals (12%). The most common reason for referral to zonal (84%) and regional level (66%) hospitals was need for specialist care while the most common reason for referral to district level hospitals was non-functional imaging diagnostic equipment (28%). CONCLUSIONS: Improving the referral system in Tanzania, in order to improve quality and efficiency of patient care, will require significant investments in human resources and equipment to meet the recommended standards at each level of care. Specifically, improving access to specialists at regional referral and district hospitals is likely to reduce the number of preventable referrals to higher level hospitals, thereby reducing overcrowding at higher-level hospitals and improving the efficiency of the health system.

Conditional Deletion of the L-Type Calcium Channel Cav1.2 in NG2-Positive Cells Impairs Remyelination in Mice.

Exploring the molecular mechanisms that drive the maturation of oligodendrocyte progenitor cells (OPCs) during the remyelination process is essential to developing new therapeutic tools to intervene in demyelinating diseases such as multiple sclerosis. To determine whether L-type voltage-gated calcium channels (L-VGCCs) are required for OPC development during remyelination, we generated an inducible conditional knock-out mouse in which the L-VGCC isoform Cav1.2 was deleted in NG2-positive OPCs (Cav1.2KO). Using the cuprizone (CPZ) model of demyelination and mice of either sex, we establish that Cav1.2 deletion in OPCs leads to less efficient remyelination of the adult brain. Specifically, Cav1.2KO OPCs mature slower and produce less myelin than control oligodendrocytes during the recovery period after CPZ intoxication. This reduced remyelination was accompanied by an important decline in the number of myelinating oligodendrocytes and in the rate of OPC proliferation. Furthermore, during the remyelination phase of the CPZ model, the corpus callosum of Cav1.2KO animals presented a significant decrease in the percentage of myelinated axons and a substantial increase in the mean g-ratio of myelinated axons compared with controls. In addition, in a mouse line in which the Cav1.2KO OPCs were identified by a Cre reporter, we establish that Cav1.2KO OPCs display a reduced maturational rate through the entire remyelination process. These results suggest that Ca2+ influx mediated by L-VGCCs in oligodendroglial cells is necessary for normal remyelination and is an essential Ca2+ channel for OPC maturation during the remyelination of the adult brain.SIGNIFICANCE STATEMENT Ion channels implicated in oligodendrocyte differentiation and maturation may induce positive signals for myelin recovery. Voltage-gated Ca2+ channels (VGCCs) are important for normal myelination by acting at several critical steps during oligodendrocyte progenitor cell (OPC) development. To determine whether voltage Ca2+ entry is involved in oligodendrocyte differentiation and remyelination, we used a conditional knockout mouse for VGCCs in OPCs. Our results indicate that VGCCs can modulate oligodendrocyte maturation in the demyelinated brain and suggest that voltage-gated Ca2+ influx in OPCs is critical for remyelination. These findings could lead to novel approaches for obtaining a better understanding of the factors that control OPC maturation in order to stimulate this pool of progenitors to replace myelin in demyelinating diseases.

Enhanced oligodendrocyte maturation and myelination in a mouse model of Timothy syndrome.

To study the role of L-type voltage-gated Ca++ channels in oligodendrocyte development, we used a mouse model of Timothy syndrome (TS) in which a gain-of-function mutation in the α1 subunit of the L-type Ca++ channel Cav1.2 gives rise to an autism spectrum disorder (ASD). Oligodendrocyte progenitor cells (OPCs) isolated from the cortex of TS mice showed greater L-type Ca++ influx and displayed characteristics suggestive of advanced maturation compared to control OPCs, including a more complex morphology and higher levels of myelin protein expression. Consistent with this, expression of Cav1.2 channels bearing the TS mutation in wild-type OPCs triggered process formation and promoted oligodendrocyte-neuron interaction via the activation of Ca++ /calmodulin-dependent protein kinase II. To ascertain whether accelerated OPC maturation correlated with functional enhancements, we examined myelination in the TS brain at different postnatal time points. The expression of myelin proteins was significantly higher in the corpus callosum, cortex and striatum of TS animals, and immunohistochemical analysis for oligodendrocyte stage-specific markers revealed an increase in the density of myelinating oligodendrocytes in several areas of the TS brain. Along the same line, electron microscopy studies in the corpus callosum of TS animals showed significant increases both in the percentage of myelinated axons and in the thickness of myelin sheaths. In summary, these data indicate that OPC development and oligodendrocyte myelination is enhanced in the brain of TS mice, and suggest that this mouse model of a syndromic ASD is a useful tool to explore the role of L-type Ca++ channels in myelination.

Conditional Deletion of the L-Type Calcium Channel Cav1.2 in Oligodendrocyte Progenitor Cells Affects Postnatal Myelination in Mice.

To determine whether L-type voltage-operated Ca2+ channels (L-VOCCs) are required for oligodendrocyte progenitor cell (OPC) development, we generated an inducible conditional knock-out mouse in which the L-VOCC isoform Cav1.2 was postnatally deleted in NG2-positive OPCs. A significant hypomyelination was found in the brains of the Cav1.2 conditional knock-out (Cav1.2KO) mice specifically when the Cav1.2 deletion was induced in OPCs during the first 2 postnatal weeks. A decrease in myelin proteins expression was visible in several brain structures, including the corpus callosum, cortex, and striatum, and the corpus callosum of Cav1.2KO animals showed an important decrease in the percentage of myelinated axons and a substantial increase in the mean g-ratio of myelinated axons. The reduced myelination was accompanied by an important decline in the number of myelinating oligodendrocytes and in the rate of OPC proliferation. Furthermore, using a triple transgenic mouse in which all of the Cav1.2KO OPCs were tracked by a Cre reporter, we found that Cav1.2KO OPCs produce less mature oligodendrocytes than control cells. Finally, live-cell imaging in early postnatal brain slices revealed that the migration and proliferation of subventricular zone OPCs is decreased in the Cav1.2KO mice. These results indicate that the L-VOCC isoform Cav1.2 modulates oligodendrocyte development and suggest that Ca2+ influx mediated by L-VOCCs in OPCs is necessary for normal myelination. SIGNIFICANCE STATEMENT: Overall, it is clear that cells in the oligodendrocyte lineage exhibit remarkable plasticity with regard to the expression of Ca2+ channels and that perturbation of Ca2+ homeostasis likely plays an important role in the pathogenesis underlying demyelinating diseases. To determine whether voltage-gated Ca2+ entry is involved in oligodendrocyte maturation and myelination, we used a conditional knock-out mouse for voltage-operated Ca2+ channels in oligodendrocyte progenitor cells. Our results indicate that voltage-operated Ca2+ channels can modulate oligodendrocyte development in the postnatal brain and suggest that voltage-gated Ca2+ influx in oligodendroglial cells is critical for normal myelination. These findings could lead to novel approaches to intervene in neurodegenerative diseases in which myelin is lost or damaged.

Retinoic acid expands the evolutionarily reduced dentition of zebrafish.

Zebrafish lost anterior teeth during evolution but retain a posterior pharyngeal dentition that requires retinoic acid (RA) cell-cell signaling for its development. The purposes of this study were to test the sufficiency of RA to induce tooth development and to assess its role in evolution. We found that exposure of embryos to exogenous RA induces a dramatic anterior expansion of the number of pharyngeal teeth that later form and shifts anteriorly the expression patterns of genes normally expressed in the posterior tooth-forming region, such as pitx2 and dlx2b. After RA exposure, we also observed a correlation between cartilage malformations and ectopic tooth induction, as well as abnormal cranial neural crest marker gene expression. Additionally, we observed that the RA-induced zebrafish anterior teeth resemble in pattern and number the dentition of fish species that retain anterior pharyngeal teeth such as medaka but that medaka do not express the aldh1a2 RA-synthesizing enzyme in tooth-forming regions. We conclude that RA is sufficient to induce anterior ectopic tooth development in zebrafish where teeth were lost in evolution, potentially by altering neural crest cell development, and that changes in the location of RA synthesis correlate with evolutionary changes in vertebrate dentitions.

Improving surgical quality in low-income and middle-income countries: why do some health facilities perform better than others?

BACKGROUND: Evidence on heterogeneity in outcomes of surgical quality interventions in low-income and middle-income countries is limited. We explored factors driving performance in the Safe Surgery 2020 intervention in Tanzania's Lake Zone to distil implementation lessons for low-resource settings. METHODS: We identified higher (n=3) and lower (n=3) performers from quantitative data on improvement from 14 safety and teamwork and communication indicators at 0 and 12 months from 10 intervention facilities, using a positive deviance framework. From 72 key informant interviews with surgical providers across facilities at 1, 6 and 12 months, we used a grounded theory approach to identify practices of higher and lower performers. RESULTS: Performance experiences of higher and lower performers differed on the following themes: (1) preintervention context, (2) engagement with Safe Surgery 2020 interventions, (3) teamwork and communication orientation, (4) collective learning orientation, (5) role of leadership, and (6) perceived impact of Safe Surgery 2020 and beyond. Higher performers had a culture of teamwork which helped them capitalise on Safe Surgery 2020 to improve surgical ecosystems holistically on safety practices, teamwork and communication. Lower performers prioritised overhauling safety practices and began considering organisational cultural changes much later. Thus, while also improving, lower performers prioritised different goals and trailed higher performers on the change continuum. CONCLUSION: Future interventions should be tailored to facility context and invest in strengthening teamwork, communication and collective learning and facilitate leadership engagement to build a receptive climate for successful implementation of safe surgery interventions.

Small molecule-based binding environments: combinatorial construction of microarrays for multiplexed affinity screening.

This paper describes the construction of a combinatorial artificial receptor array (CARA) and the application of the array to differentiation of proteins based on their binding patterns. Microarrays displaying 5035 unique binding environments were prepared using a library of 19 small molecule building blocks. Each building block was equipped with a carboxylic acid handle, allowing mixtures of the building blocks to be spotted onto the surface of an amine functionalized glass slide for covalent immobilization as subunits of the binding environments. This strategy employs the microarray surface as the receptor synthesis platform, which allows for flexibility in array preparation and agility in application. An advantage of the CARA strategy is the enormous flexibility it enables in the construction of alternate microarray configurations, which facilitates rapid access to the breadth and depth of binding space. Four fluorescently labeled proteins, ubiquitin, myoglobin, alpha-1-acid glycoprotein and lysozyme, were incubated with the arrays to demonstrate the reproducibility of binding and the level of differentiation that can be achieved. The binding environments are stable, scalable, and adaptable to other formats.

Inhaled nitric oxide prevents systemic and pulmonary vasoconstriction due to hemoglobin-based oxygen carrier infusion: A case report.

Hemoglobin-based oxygen carriers (HBOCs) are used in extreme circumstances to increase hemoglobin concentration and improve oxygen delivery when allogenic red blood cell transfusions are contraindicated or not immediately available. However, HBOC-induced severe pulmonary and systemic vasoconstriction due to peripheral nitric oxide (NO) scavenging has stalled its implementation in clinical practice. We present a case of an 87 year-old patient with acute life-threatening anemia who received HBOC while breathing NO gas. This case shows that inhaled NO allows for the safe use of HBOC infusion by preventing HBOC-induced pulmonary and systemic vasoconstriction.

Effectiveness of a multicomponent safe surgery intervention on improving surgical quality in Tanzania's Lake Zone: protocol for a quasi-experimental study.

INTRODUCTION: Effective, scalable strategies for improving surgical quality are urgently needed in low-income and middle-income countries; however, there is a dearth of evidence about what strategies are most effective. This study aims to evaluate the effectiveness of Safe Surgery 2020, a multicomponent intervention focused on strengthening five areas: leadership and teamwork, safe surgical and anaesthesia practices, sterilisation, data quality and infrastructure to improve surgical quality in Tanzania. We hypothesise that Safe Surgery 2020 will (1) increase adherence to surgical quality processes around safety, teamwork and communication and data quality in the short term and (2) reduce complications from surgical site infections, postoperative sepsis and maternal sepsis in the medium term. METHODS AND ANALYSIS: Our design is a prospective, longitudinal, quasi-experimental study with 10 intervention and 10 control facilities in Tanzania's Lake Zone. Participants will be surgical providers, surgical patients and postnatal inpatients at study facilities. Trained Tanzanian medical data collectors will collect data over a 3-month preintervention and postintervention period. Adherence to safety as well as teamwork and communication processes will be measured through direct observation in the operating room. Surgical site infections, postoperative sepsis and maternal sepsis will be identified prospectively through daily surveillance and completeness of their patient files, retrospectively, through the chart review. We will use difference-in-differences to analyse the impact of the Safe Surgery 2020 intervention on surgical quality processes and complications. We will use interviews with leadership and surgical team members in intervention facilities to illuminate the factors that facilitate higher performance. ETHICS AND DISSEMINATION: The study has received ethical approval from Harvard Medical School and Tanzania's National Institute for Medical Research. We will report results in peer-reviewed publications and conference presentations. If effective, the Safe Surgery 2020 intervention could be a promising approach to improve surgical quality in Tanzania's Lake Zone region and other similar contexts.

Protocol of a randomised controlled trial in cardiac surgical patients with endothelial dysfunction aimed to prevent postoperative acute kidney injury by administering nitric oxide gas.

INTRODUCTION: Postoperative acute kidney injury (AKI) is a common complication in cardiac surgery. Levels of intravascular haemolysis are strongly associated with postoperative AKI and with prolonged (>90 min) use of cardiopulmonary bypass (CPB). Ferrous plasma haemoglobin released into the circulation acts as a scavenger of nitric oxide (NO) produced by endothelial cells. Consequently, the vascular bioavailability of NO is reduced, leading to vasoconstriction and impaired renal function. In patients with cardiovascular risk factors, the endothelium is dysfunctional and cannot replenish the NO deficit. A previous clinical study in young cardiac surgical patients with rheumatic fever, without evidence of endothelial dysfunction, showed that supplementation of NO gas decreases AKI by converting ferrous plasma haemoglobin to ferric methaemoglobin, thus preserving vascular NO. In this current trial, we hypothesised that 24 hours administration of NO gas will reduce AKI following CPB in patients with endothelial dysfunction. METHODS: This is a single-centre, randomised (1:1) controlled, parallel-arm superiority trial that includes patients with endothelial dysfunction, stable kidney function and who are undergoing cardiac surgery procedures with an expected CPB duration >90 min. After randomisation, 80 parts per million (ppm) NO (intervention group) or 80 ppm nitrogen (N2, control group) are added to the gas mixture. Test gases (N2 or NO) are delivered during CPB and for 24 hours after surgery. The primary study outcome is the occurrence of AKI among study groups. Key secondary outcomes include AKI severity, occurrence of renal replacement therapy, major adverse kidney events at 6 weeks after surgery and mortality. We are recruiting 250 patients, allowing detection of a 35% AKI relative risk reduction, assuming a two-sided error of 0.05. ETHICS AND DISSEMINATION: The Partners Human Research Committee approved this trial. Recruitment began in February 2017. Dissemination plans include presentations at scientific conferences, scientific publications and advertising flyers and posters at Massachusetts General Hospital. TRIAL REGISTRATION NUMBER: NCT02836899.

Global kinomic and phospho-proteomic analyses of the human malaria parasite Plasmodium falciparum.

The role of protein phosphorylation in the life cycle of malaria parasites is slowly emerging. Here we combine global phospho-proteomic analysis with kinome-wide reverse genetics to assess the importance of protein phosphorylation in Plasmodium falciparum asexual proliferation. We identify 1177 phosphorylation sites on 650 parasite proteins that are involved in a wide range of general cellular activities such as DNA synthesis, transcription and metabolism as well as key parasite processes such as invasion and cyto-adherence. Several parasite protein kinases are themselves phosphorylated on putative regulatory residues, including tyrosines in the activation loop of PfGSK3 and PfCLK3; we show that phosphorylation of PfCLK3 Y526 is essential for full kinase activity. A kinome-wide reverse genetics strategy identified 36 parasite kinases as likely essential for erythrocytic schizogony. These studies not only reveal processes that are regulated by protein phosphorylation, but also define potential anti-malarial drug targets within the parasite kinome.