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What made primary health care resilient against COVID-19? A mixed-methods positive deviance study in Nigeria. BMJ Glob Health 2023; 8:e012700. [PMID: 37984895 PMCID: PMC10660915 DOI: 10.1136/bmjgh-2023-012700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 10/01/2023] [Indexed: 11/22/2023] Open
Abstract
INTRODUCTION The SARS-CoV-2 (COVID-19) pandemic overwhelmed some primary health care (PHC) systems, while others adapted and recovered. In Nigeria, large, within-state variations existed in the ability to maintain PHC service volumes. Identifying characteristics of high-performing local government areas (LGAs) can improve understanding of subnational health systems resilience. METHODS Employing a sequential explanatory mixed-methods design, we quantitatively identified 'positive deviant' LGAs based on their speed of recovery of outpatient and antenatal care services to prepandemic levels using service volume data from Nigeria's health management information system and matched them to comparators with similar baseline characteristics and slower recoveries. 70 semistructured interviews were conducted with LGA officials, facility officers and community leaders in sampled LGAs to analyse comparisons based on Kruk's resilience framework. RESULTS A total of 57 LGAs were identified as positive deviants out of 490 eligible LGAs that experienced a temporary decrease in PHC-level outpatient and antenatal care service volumes. Positive deviants had an average of 8.6% higher outpatient service volume than expected, and comparators had 27.1% lower outpatient volume than expected after the initial disruption to services. Informants in 12 positive deviants described health systems that were more integrated, aware and self-regulating than comparator LGAs. Positive deviants were more likely to employ demand-side adaptations, whereas comparators primarily focused on supply-side adaptations. Barriers included long-standing financing and PHC workforce gaps. CONCLUSION Sufficient flexible financing, adequate PHC staffing and local leadership enabled health systems to recover service volumes during COVID-19. Resilient PHC requires simultaneous attention to bottom-up and top-down capabilities connected by strong leadership.
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Impacts of performance-based financing on health system performance: evidence from the Democratic Republic of Congo. BMC Med 2023; 21:381. [PMID: 37794389 PMCID: PMC10552286 DOI: 10.1186/s12916-023-03062-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Accepted: 09/04/2023] [Indexed: 10/06/2023] Open
Abstract
BACKGROUND Health systems' weakness remains one of the primary obstacles towards achieving universal access to quality healthcare in low-income settings. Performance-based financing (PBF) programs have been increasingly used to increase access to quality care in LMICs. However, evidence on the impacts of these programs remains fragmented and inconclusive. We analyze the health system impacts of the PBF program in the Democratic Republic of the Congo (DRC), one of the largest such programs introduced in LMICs to date. METHODS We used a health systems perspective to analyze the benefits of PBF relative to unconditional financing of health facilities. Fifty-eight health zones in six provinces were randomly assigned to either a control group (28 zones) in which facilities received unconditional transfers or to a PBF program (30 zones) that started at the end of 2016. Follow-up data collection took place in 2021-2022 and included health facility assessments, health worker interviews, direct observations of consultations and deliveries, patient exit interviews, and household surveys. Using multivariate regression models, we estimated the impact of the program on 55 outcomes in seven health system domains: structural quality, technical process quality, non-technical process quality, service fees, facility management, providers' satisfaction, and service coverage. We used random-effects meta-analysis to generate pooled average estimates within each domain. RESULTS The PBF program improved the structural quality of health facilities by 4 percentage points (ppts) (95% CI 0.01-0.08), technical process quality by 5 ppts (0.03-0.07), and non-technical process by 2 ppts (0-0.04). PBF also increased coverage of priority health services by 3 ppts (0.02-0.04). Improvements were also observed for facility management (9 ppts, 0.04-0.15), service fee policies, and users' satisfaction with service affordability (14 ppts, 0.07-0.20). Service fees and health workers' satisfaction were not affected by the program. CONCLUSIONS The results suggest that well-designed PBF programs can lead to improvements in most health systems domains relative to comparable unconditional financing. However, the large persisting gaps suggest that additional changes, such as allocating more resources to the health system and reforming the human resources for health management, will be necessary in DRC to achieve the ambitious global universal health coverage and mortality goals. TRIAL REGISTRATION American Economics Association Trial registry AEARCTR-0002880.
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Vaccination Utilization and Subnational Inequities during the COVID-19 Pandemic: An Interrupted Time-Series Analysis of Administrative Data across 12 Low- and Middle-Income Countries. Vaccines (Basel) 2023; 11:1415. [PMID: 37766092 PMCID: PMC10536121 DOI: 10.3390/vaccines11091415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 03/31/2023] [Accepted: 08/17/2023] [Indexed: 09/29/2023] Open
Abstract
BACKGROUND During and after the SARS-CoV-2 (COVID-19) pandemic, many countries experienced declines in immunization that have not fully recovered to pre-pandemic levels. This study uses routine health facility immunization data to estimate variability between and within countries in post-pandemic immunization service recovery for BCG, DPT1, and DPT3. METHODS After adjusting for data reporting completeness and outliers, interrupted time series regression was used to estimate the expected immunization service volume for each subnational unit, using an interruption point of March 2020. We assessed and compared the percent deviation of observed immunizations from the expected service volume for March 2020 between and within countries. RESULTS Six countries experienced significant service volume declines for at least one vaccine as of October 2022. The shortfall in BCG service volume was ~6% (95% CI -1.2%, -9.8%) in Guinea and ~19% (95% CI -16%, 22%) in Liberia. Significant cumulative shortfalls in DPT1 service volume are observed in Afghanistan (-4%, 95% CI -1%, -7%), Ghana (-3%, 95% CI -1%, -5%), Haiti (-7%, 95% CI -1%, -12%), and Kenya (-3%, 95% CI -1%, -4%). Afghanistan has the highest percentage of subnational units reporting a shortfall of 5% or higher in DPT1 service volume (85% in 2021 Q1 and 79% in 2020 Q4), followed by Bangladesh (2020 Q1, 83%), Haiti (80% in 2020 Q2), and Ghana (2022 Q2, 75%). All subnational units in Bangladesh experienced a 5% or higher shortfall in DPT3 service volume in the second quarter of 2020. In Haiti, 80% of the subnational units experienced a 5% or higher reduction in DPT3 service volume in the second quarter of 2020 and the third quarter of 2022. CONCLUSIONS At least one region in every country has a significantly lower-than-expected post-pandemic cumulative volume for at least one of the three vaccines. Subnational monitoring of immunization service volumes using disaggregated routine health facility information data should be conducted routinely to target the limited vaccination resources to subnational units with the highest inequities.
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Availability and use of personal protective equipment in low- and middle-income countries during the COVID-19 pandemic. PLoS One 2023; 18:e0288465. [PMID: 37459298 PMCID: PMC10351736 DOI: 10.1371/journal.pone.0288465] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Accepted: 06/27/2023] [Indexed: 07/20/2023] Open
Abstract
BACKGROUND Availability and appropriate use of personal protective equipment (PPE) is of particular importance in Low and Middle-Income countries (LMICs) where disease outbreaks other than COVID-19 are frequent and health workers are scarce. This study assesses the availability of necessary PPE items during the COVID-19 pandemic at health facilities in seven LMICs. METHODS Data were collected using a rapid-cycle survey among 1554 health facilities in seven LMICs via phone-based surveys between August 2020 and December 2021. We gathered data on the availability of World Health Organization (WHO)-recommended PPE items and the use of items when examining patients suspected to be infected with COVID-19. We further investigated the implementation of service adaptation measures in a severe shortage of PPE. RESULTS There were major deficiencies in PPE availability at health facilities. Almost 3 out of 10 health facilities reported a stock-out of medical masks on the survey day. Forty-six percent of facilities did not have respirator masks, and 16% did not have any gloves. We show that only 43% of health facilities had sufficient PPE to comply with WHO guidelines. Even when all items were available, healthcare workers treating COVID-19 suspected patients were reported to wear all the recommended equipment in only 61% of health facilities. We did not find a statistically significant difference in implementing service adaptation measures between facilities experiencing a severe shortage or not. CONCLUSION After more than a year into the COVID-19 pandemic, the overall availability of PPE remained low in our sample of low and middle-income countries. Although essential, the availability of PPE did not guarantee the proper use of the equipment. The lack of PPE availability and improper use of available PPE enable preventable COVID-19 transmission in health facilities, leading to greater morbidity and mortality and risking the continuity of service delivery by healthcare workers.
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Vaccine hesitancy among healthcare workers in low- and middle-income countries during the COVID-19 pandemic: Results from facility surveys across six countries. PLoS One 2023; 18:e0288124. [PMID: 37418435 DOI: 10.1371/journal.pone.0288124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 06/20/2023] [Indexed: 07/09/2023] Open
Abstract
BACKGROUND Vaccine hesitancy remains a critical barrier in mitigating the effects of the ongoing COVID-19 pandemic. The willingness of health care workers (HCWs) to be vaccinated, and, in turn, recommend the COVID-19 vaccine for their patient population is an important strategy. This study aims to understand the uptake of COVID-19 vaccines and the reasoning for vaccine hesitancy among facility-based health care workers (HCWs) in LMICs. METHODS We conducted nationally representative phone-based rapid-cycle surveys across facilities in six LMICs to better understand COVID-19 vaccine hesitancy. We gathered data on vaccine uptake among facility managers, their perceptions of vaccine uptake and hesitancy among the HCWs operating in their facilities, and their perception of vaccine hesitancy among the patient population served by the facility. RESULTS 1,148 unique public health facilities participated in the study, with vaccines being almost universally offered to facility-based respondents across five out of six countries. Among facility respondents who have been offered the vaccine, more than 9 in 10 survey respondents had already been vaccinated at the time of data collection. Vaccine uptake among other HCWs at the facility was similarly high. Over 90% of facilities in Bangladesh, Liberia, Malawi, and Nigeria reported that all or most staff had already received the COVID-19 vaccine when the survey was conducted. Concerns about side effects predominantly drive vaccine hesitancy in both HCWs and the patient population. CONCLUSION Our findings indicate that the opportunity to get vaccinated in participating public facilities is almost universal. We find vaccine hesitancy among facility-based HCWs, as reported by respondents, to be very low. This suggests that a potentially effective effort to increase vaccine uptake equitably would be to channel promotional activities through health facilities and HCWs.However, reasons for hesitancy, even if limited, are far from uniform across countries, highlighting the need for audience-specific messaging.
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Resilience of front-line facilities during COVID-19: evidence from cross-sectional rapid surveys in eight low- and middle-income countries. Health Policy Plan 2023:7187082. [PMID: 37256762 DOI: 10.1093/heapol/czad032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 04/17/2023] [Accepted: 05/17/2023] [Indexed: 06/02/2023] Open
Abstract
Responsive primary health-care facilities are the foundation of resilient health systems, yet little is known about facility-level processes that contribute to the continuity of essential services during a crisis. This paper describes the aspects of primary health-care facility resilience to coronavirus disease 2019 (COVID-19) in eight countries. Rapid-cycle phone surveys were conducted with health facility managers in Bangladesh, Burkina Faso, Chad, Guatemala, Guinea, Liberia, Malawi and Nigeria between August 2020 and December 2021. Responses were mapped to a validated health facility resilience framework and coded as binary variables for whether a facility demonstrated capacity in eight areas: removing barriers to accessing services, infection control, workforce, surge capacity, financing, critical infrastructure, risk communications, and medical supplies and equipment. These self-reported capacities were summarized nationally and validated with the ministries of health. The analysis of service volume data determined the outcome: maintenance of essential health services. Of primary health-care facilities, 1,453 were surveyed. Facilities maintained between 84% and 97% of the expected outpatient services, except for Bangladesh, where 69% of the expected outpatient consultations were conducted between March 2020 and December 2021. For Burkina Faso, Chad, Guatemala, Guinea and Nigeria, critical infrastructure was the largest constraint in resilience capabilities (47%, 14%, 51%, 9% and 29% of facilities demonstrated capacity, respectively). Medical supplies and equipment were the largest constraints for Liberia and Malawi (15% and 48% of facilities demonstrating capacity, respectively). In Bangladesh, the largest constraint was workforce and staffing, where 44% of facilities experienced moderate to severe challenges with human resources during the pandemic. The largest constraints in facility resilience during COVID-19 were related to health systems building blocks. These challenges likely existed before the pandemic, suggesting the need for strategic investments and reforms in core capacities of comprehensive primary health-care systems to improve resilience to future shocks.
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Healthcare utilization and maternal and child mortality during the COVID-19 pandemic in 18 low- and middle-income countries: An interrupted time-series analysis with mathematical modeling of administrative data. PLoS Med 2022; 19:e1004070. [PMID: 36040910 PMCID: PMC9426906 DOI: 10.1371/journal.pmed.1004070] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Accepted: 07/06/2022] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND The Coronavirus Disease 2019 (COVID-19) pandemic has had wide-reaching direct and indirect impacts on population health. In low- and middle-income countries, these impacts can halt progress toward reducing maternal and child mortality. This study estimates changes in health services utilization during the pandemic and the associated consequences for maternal, neonatal, and child mortality. METHODS AND FINDINGS Data on service utilization from January 2018 to June 2021 were extracted from health management information systems of 18 low- and lower-middle-income countries (Afghanistan, Bangladesh, Cameroon, Democratic Republic of the Congo (DRC), Ethiopia, Ghana, Guinea, Haiti, Kenya, Liberia, Madagascar, Malawi, Mali, Nigeria, Senegal, Sierra Leone, Somalia, and Uganda). An interrupted time-series design was used to estimate the percent change in the volumes of outpatient consultations and maternal and child health services delivered during the pandemic compared to projected volumes based on prepandemic trends. The Lives Saved Tool mathematical model was used to project the impact of the service utilization disruptions on child and maternal mortality. In addition, the estimated monthly disruptions were also correlated to the monthly number of COVID-19 deaths officially reported, time since the start of the pandemic, and relative severity of mobility restrictions. Across the 18 countries, we estimate an average decline in OPD volume of 13.1% and average declines of 2.6% to 4.6% for maternal and child services. We projected that decreases in essential health service utilization between March 2020 and June 2021 were associated with 113,962 excess deaths (110,686 children under 5, and 3,276 mothers), representing 3.6% and 1.5% increases in child and maternal mortality, respectively. This excess mortality is associated with the decline in utilization of the essential health services included in the analysis, but the utilization shortfalls vary substantially between countries, health services, and over time. The largest disruptions, associated with 27.5% of the excess deaths, occurred during the second quarter of 2020, regardless of whether countries reported the highest rate of COVID-19-related mortality during the same months. There is a significant relationship between the magnitude of service disruptions and the stringency of mobility restrictions. The study is limited by the extent to which administrative data, which varies in quality across countries, can accurately capture the changes in service coverage in the population. CONCLUSIONS Declines in healthcare utilization during the COVID-19 pandemic amplified the pandemic's harmful impacts on health outcomes and threaten to reverse gains in reducing maternal and child mortality. As efforts and resource allocation toward prevention and treatment of COVID-19 continue, essential health services must be maintained, particularly in low- and middle-income countries.
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Competent and deficient provision of childbirth services: a descriptive observational study assessing the quality of intrapartum care in two provinces of the Democratic Republic of the Congo. BMC Health Serv Res 2022; 22:551. [PMID: 35468822 PMCID: PMC9040341 DOI: 10.1186/s12913-022-07737-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 02/25/2022] [Indexed: 11/28/2022] Open
Abstract
Background A majority of women in the Democratic Republic of the Congo (DRC) give birth in a health facility, but maternal and newborn mortality remains high. In rural areas, the quality of facility-based delivery care is often low. This study examines clinical quality of intrapartum care in two provinces of the DRC. Methods We observed process and input elements of delivery care provision at 29 facilities in Kwilu and Kwango provinces. Distinguishing non-performance attributable to provider behavior vs. input constraints, we compared both providers’ adherence to clinical standards (“competent care”) and non-adherence to processes for which required inputs were available (“deficient care”). Results Observing a total of 69 deliveries, care was most competent for partograph use (75% cases) and hemorrhage prevention (73%), but least for postpartum monitoring (4%). Competent care was significantly associated with higher case volumes (p = ·03), skilled birth attendance (p = ·05), and nulliparous women (p = ·02). Care was most deficient for infection prevention (62%) and timely care (49%) and associated with cases observed at hospitals and lower delivery volume. Conclusions Low quality was commonly not a result of missing equipment or supplies but related to providers’ non-adherence to standard protocols. Low case volumes and the absence of skilled attendants seemed to be main factors for sub-standard quality care. Birth assistance during labor stage 2 was the only intrapartum stage heavily affected by the unavailability of essential equipment. Future interventions should strengthen links between birth attendants’ practice to clinical protocols.
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THE INTERGENERATIONAL MORTALITY TRADE-OFF OF COVID-19 LOCKDOWN POLICIES. INTERNATIONAL ECONOMIC REVIEW 2022; 63:IERE12574. [PMID: 35600320 PMCID: PMC9111371 DOI: 10.1111/iere.12574] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 01/28/2022] [Indexed: 05/21/2023]
Abstract
In lower-income countries, the economic contractions that accompany lockdowns to contain COVID-19 transmission can increase child mortality, counteracting the mortality reductions achieved by the lockdown. To formalize and quantify this effect, we build a macrosusceptible-infected-recovered model that features heterogeneous agents and a country-group-specific relationship between economic downturns and child mortality and calibrate it to data for 85 countries across all income levels. We find that in some low-income countries, a lockdown can produce net increases in mortality. The optimal lockdown that maximizes the present value of aggregate social welfare is shorter and milder in poorer countries than in rich ones.
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Financially incentivized knowledge assessments to improve provider compliance with treatment guidelines: a cluster-randomized controlled trial. Trials 2022; 23:227. [PMID: 35313932 PMCID: PMC8935753 DOI: 10.1186/s13063-022-06129-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Accepted: 02/24/2022] [Indexed: 11/10/2022] Open
Abstract
Background Despite increasing access to health care, under-5 mortality remains high in many parts of Sub-Saharan Africa. Interventions to improve quality of care have mostly focused on additional training for medical staff, but generally shown little impact. We will assess the impact of financially incentivized quarterly provider knowledge assessment on compliance with Integrated Management of Childhood Illness (IMCI) protocols in Congo, DRC. Methods Out of a total of 1738 facilities currently receiving results-based financing under an ongoing health financing program, 110 facilities were chosen for this study. All health care workers providing outpatient services to children under age 5 in these facilities will be included in the study. Facilities were randomized with equal probability to control and treatment. Treatment facilities will receive quarterly medical staff knowledge assessments using interactive vignettes. Performance on these vignettes will be rewarded through financial bonus payments to facilities. A baseline survey of health worker knowledge was conducted in 2018. An endline assessment is scheduled to start in the second half of 2021. The primary outcome of interest is health worker compliance with Integrated Management of Childhood Illness (IMCI) guidelines. Compliance will be verified through direct observation of medical staff-patient interactions. Discussion This is to our knowledge the first trial assessing whether linking health financing to health care worker performance on knowledge assessments can increase compliance with under-5 case management protocols. Trial registration ClinicalTrials.gov NCT04634019. Registered on November 18, 2020.
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Continuous monitoring of advanced hemodynamic parameters shows early cardiovascular changes in a cohort of 492 COVID-19 hospitalized patients. Eur Heart J 2021. [DOI: 10.1093/eurheartj/ehab724.3090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Background
COVID-19 exerts deleterious cardiopulmonary effects, leading to worse prognosis in the most effected.
Purpose
The aim of this retrospective multi-center observational cohort study was to analyze the trajectories of key advanced hemodynamic parameters amongst hospitalized COVID-19 patients according to different risk populations using a chest-patch wearable providing continuous remote patient monitoring.
Methods
The study was conducted in five COVID-19 isolation units. Patients admitted to the units were connected to a photoplethysmography based noninvasive remote advanced hemodynamic monitor after completing a basic risk factor survey. Physiological parameters were measured every 15 minutes during the hospitalization, including cardiac output (CO), cardiac index (CI), systemic vascular resistance (SVR), heart rate, blood pressure (BP), respiratory rate, blood oxygen saturation (SpO2), and body temperature.
Results
492 COVID-19 patients (179 females, average age 58.7 years) were included in the final analysis, with more than 3 million measurements collected during an average of 75.3 hours. Overall, within the first five days of hospitalizations we found a significant increase in SVR, and a significant decrease in SpO2, DBP, CO and CI (p<0.01 for all). The changes were more prominent in high risk populations- males, older age and obesity and had a temporal correspondence to changes in respiratory parameters.
Conclusions
This is the first comprehensive continuous advanced hemodynamic profiling of COVID-19 patients. Worse hemodynamic status was prominent in high risk populations.
Funding Acknowledgement
Type of funding sources: None.
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How many infants may have died in low-income and middle-income countries in 2020 due to the economic contraction accompanying the COVID-19 pandemic? Mortality projections based on forecasted declines in economic growth. BMJ Open 2021; 11:e050551. [PMID: 34429282 PMCID: PMC8413467 DOI: 10.1136/bmjopen-2021-050551] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVES While COVID-19 has a relatively small direct impact on infant mortality, the pandemic is expected to indirectly increase mortality of this vulnerable group in low-income and middle-income countries through its effects on the economy and health system performance. Previous studies projected indirect mortality by modelling how hypothesised disruptions in health services will affect health outcomes. We provide alternative projections, relying on modelling the relationship between aggregate income shocks and mortality. DESIGN We construct a sample of 5.2 million births by pooling retrospective birth histories reported by women in Demographic and Health Surveys conducted in 83 low-income and middle-income countries between 1985 and 2018. We employ regression models with country-specific fixed-effects and flexible time trends to estimate the impact of gross domestic product per capita on infant mortality rate. We then use growth projections by the International Monetary Fund to predict the effect of the economic downturn in 2020 on infant mortality. RESULTS We estimate 267 208 (95% CI 112 000 to 422 415) excess infant deaths in 128 countries, corresponding to a 6.8% (95% CI 2.8% to 10.7%) increase in the total number of infant deaths expected in 2020. CONCLUSIONS The findings underscore the vulnerability of infants to the negative income shocks such as those imposed by the COVID-19 pandemic. While efforts towards prevention and treatment of COVID-19 remain paramount, the global community should also strengthen social safety nets and assure continuity of essential health services.
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Disruptions in maternal and child health service utilization during COVID-19: analysis from eight sub-Saharan African countries. Health Policy Plan 2021; 36:1140-1151. [PMID: 34146394 PMCID: PMC8344431 DOI: 10.1093/heapol/czab064] [Citation(s) in RCA: 95] [Impact Index Per Article: 31.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 04/01/2021] [Accepted: 05/27/2021] [Indexed: 12/31/2022] Open
Abstract
The coronavirus-19 pandemic and its secondary effects threaten the continuity of essential health services delivery, which may lead to worsened population health and a protracted public health crisis. We quantify such disruptions, focusing on maternal and child health, in eight sub-Saharan countries. Service volumes are extracted from administrative systems for 63 954 facilities in eight countries: Cameroon, Democratic Republic of Congo, Liberia, Malawi, Mali, Nigeria, Sierra Leone and Somalia. Using an interrupted time series design and an ordinary least squares regression model with facility-level fixed effects, we analyze data from January 2018 to February 2020 to predict what service utilization levels would have been in March-July 2020 in the absence of the pandemic, accounting for both secular trends and seasonality. Estimates of disruption are derived by comparing the predicted and observed service utilization levels during the pandemic period. All countries experienced service disruptions for at least 1 month, but the magnitude and duration of the disruptions vary. Outpatient consultations and child vaccinations were the most commonly affected services and fell by the largest margins. We estimate a cumulative shortfall of 5 149 491 outpatient consultations and 328 961 third-dose pentavalent vaccinations during the 5 months in these eight countries. Decreases in maternal health service utilization are less generalized, although significant declines in institutional deliveries, antenatal care and postnatal care were detected in some countries. There is a need to better understand the factors determining the magnitude and duration of such disruptions in order to design interventions that would respond to the shortfall in care. Service delivery modifications need to be both highly contextualized and integrated as a core component of future epidemic response and planning.
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Quality of clinical assessment and child mortality: a three-country cross-sectional study. Health Policy Plan 2021; 35:878-887. [PMID: 32577749 DOI: 10.1093/heapol/czaa048] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/21/2020] [Indexed: 11/14/2022] Open
Abstract
This analysis describes specific gaps in the quality of health care in Central Africa and assesses the association between quality of clinical care and mortality at age 2-59 months. Regionally representative facility and household surveys for the Democratic Republic of the Congo, Cameroon and Central African Republic were collected between 2012 and 2016. These data are novel in linking facilities with households in their catchment area. Compliance with diagnostic and danger sign protocols during sick-child visits was observed by trained assessors. We computed facility- and district-level compliance indicators for patients aged 2-59 months and used multivariate multi-level logistic regression models to estimate the association between clinical assessment quality and mortality at age 2-59 months in the catchment areas of the observed facilities. A total of 13 618 live births were analysed and 1818 sick-child visits were directly observed and used to rate 643 facilities. Eight percent of observed visits complied with 80% of basic diagnostic protocols, and 13% of visits fully adhered to select general danger sign protocols. A 10% greater compliance with diagnostic protocols was associated with a 14.1% (adjusted odds ratio (aOR) 95% CI: 0.025-0.244) reduction in the odds of mortality at age 2-59 months; a 10% greater compliance with select general danger sign protocols was associated with a 15.3% (aOR 95% CI: 0.058-0.237) reduction in the same odds. The results of this article suggest that compliance with recommended clinical protocols remains poor in many settings and improvements in mortality at age 2-59 months could be possible if compliance were improved.
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Quality of care for children with severe disease in the Democratic Republic of the Congo. BMC Public Health 2019; 19:1608. [PMID: 31791291 PMCID: PMC6889659 DOI: 10.1186/s12889-019-7853-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Accepted: 10/28/2019] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Despite the almost universal adoption of Integrated Management of Childhood Illness (IMCI) guidelines for the diagnosis and treatment of sick children under the age of five in low- and middle-income countries, child mortality remains high in many settings. One possible explanation of the continued high mortality burden is lack of compliance with diagnostic and treatment protocols. We test this hypothesis in a sample of children with severe illness in the Democratic Republic of the Congo (DRC). METHODS One thousand one hundred eighty under-five clinical visits were observed across a regionally representative sample of 321 facilities in the DRC. Based on a detailed list of disease symptoms observed, patients with severe febrile disease (including malaria), severe pneumonia, and severe dehydration were identified. For all three disease categories, treatments were then compared to recommended case management following IMCI guidelines. RESULTS Out of 1180 under-five consultations observed, 332 patients (28%) had signs of severe febrile disease, 189 patients (16%) had signs of severe pneumonia, and 19 patients (2%) had signs of severe dehydration. Overall, providers gave the IMCI-recommended treatment in 42% of cases of these three severe diseases. Less than 15% of children with severe disease were recommended to receive in-patient care either in the facility they visited or in a higher-level facility. CONCLUSIONS These results suggest that adherence to IMCI protocols for severe disease remains remarkably low in the DRC. There is a critical need to identify and implement effective approaches for improving the quality of care for severely ill children in settings with high child mortality.
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Going beyond incentivizing formal health providers: Evidence from the Rwanda Community Performance-Based Financing program. HEALTH ECONOMICS 2018; 27:2087-2106. [PMID: 30159944 DOI: 10.1002/hec.3822] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Revised: 07/16/2018] [Accepted: 08/02/2018] [Indexed: 06/08/2023]
Abstract
Pay-for-performance programs are introduced in an increasing number of low- and middle-income countries with the goal of reducing maternal and child mortality and morbidity through increased health service utilization and quality. Although most programs incentivize formal health providers, some constraints to utilization might be better alleviated by incentivizing other actors in the health care system. This paper presents results from a randomized controlled trial set to evaluate the effects of two incentive schemes that were introduced on top of Rwanda's national Performance-Based Financing program at the health facility level. One scheme rewarded community health worker cooperatives for the utilization of five services by their communities. The second scheme provided in-kind transfers to users of three services. The analysis finds no impact of the cooperative performance payments on coverage of the targeted services, behaviors of community health workers, or outcomes at the cooperative level. Although health centers experienced frequent stock outs of the gifts, the demand-side intervention significantly increased timely antenatal care by 9.3 percentage points and timely postnatal care by 8.6 percentage points. This study shows that demand-side incentives can increase service utilization also when provided in addition to a supply-side pay-for-performance scheme.
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The influence of long term water immersion on shear bond strength of amalgam repaired by resin composite and mediated by adhesives or resin modified glass ionomers. J Dent 2012; 40:594-602. [PMID: 22504527 DOI: 10.1016/j.jdent.2012.04.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2011] [Revised: 04/01/2012] [Accepted: 04/02/2012] [Indexed: 11/17/2022] Open
Abstract
OBJECTIVE To assess the shear bond strength between amalgam and resin composite mediated by either multipurpose adhesive systems or RMGI when subjected to long term immersion in saline. METHODS Part I: Cylindrical specimens (6 mm × 6 mm) composed of equal parts of sandblasted set amalgam (Oralloy) and composite (Z-100), with a thin layer of either Scotchbond Multipurpose, All Bond 2, Amalgam Bond Plus, High Q Bond Plus or Vitrebond in between were fabricated (n = 100 × 5). Each group was divided into 3 subgroups, immersed in saline at 37 °C for either 48 h, 3 or 6 months, followed by thermocycling (5000; 5/55 °C) and shear bond strength testing (SBS). Part II: Identical specimens were fabricated with intermediary of either Ketac Cem, Fuji Lining LC, Rely X Luting, Fuji Plus or Meron Plus (n = 100 × 5). Immersion periods, followed by thermocycling and SBS testing as in Part I. Two representative specimens from each subgroup were sectioned and inspected under SEM. RESULTS The two classes of intermediary agents yielded SBS which differed mainly in the 6 months incubation period. While multipurpose adhesives provided SBS values of ~9-10 MPa RMGI provided higher SBS of ~16 MPa. All Bond 2 and Amalgam Bond Plus exhibited deterioration of SBS during the 6 month period as well as Rely X Luting. Gap sizes between 0.5 and 3 μm exist between all intermediaries and the amalgam; on the other hand all intermediaries exhibit gap-free interfaces between the adhesives/RMGI and the composite. CONCLUSIONS Vitrebond in particular and RMGIs in general can serve as an excellent coupler of resin composite to amalgam, providing a durable bond.
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Use of hormone replacement therapy by menopausal women in six family-practice teaching clinics in Israel. Climacteric 2009. [DOI: 10.1080/cmt.6.1.75.80] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Gas flow during bronchoscopic ablation therapy causes gas emboli to the heart: a comparative animal study. Chest 2008; 133:892-6. [PMID: 18198247 DOI: 10.1378/chest.07-2266] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Thermal ablation is one of the most commonly used modalities to treat central airway obstruction. Both laser and argon plasma coagulation (APC) have been reported to cause gas emboli and cardiac arrest. We sought to determine whether bronchoscopic ablation therapy can result in systemic gas emboli, correlate their presence with the rate of gas flow, and establish whether a zero-flow (ZF) modality would result in the significant reduction or elimination of emboli. METHODS CO(2) laser delivered through a photonic bandgap fiber (PBF) and APC were applied in the trachea and mainstem bronchi of six anesthetized sheep at varying dosages and gas flow rates. Direct epicardial echocardiography was used to obtain a four-chamber view and detect gas emboli. RESULTS The presence of gas flow accompanying APC and the CO(2) laser with forward flow correlated significantly with the appearance of gas bubbles in the atria. A definite dose response was observed between the gas flow rate and the number of bubbles seen. When the CO(2) laser was delivered through a PBF with ZF to the trachea or bronchi, no bubbles were observed. CONCLUSION Bronchoscopic thermal ablation therapy using gas flow is associated with gas emboli in a dose-dependent fashion. The use of the flexible PBF with ZF is not associated with the development of gas emboli. Further study is required to determine whether a clinically safe threshold of gas emboli exists, and the relationships among the pathologic depth of tissue destruction, gas flow, pulse duration, and the development of gas emboli.
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DETECTION OF GAS EMBOLI IN BRONCHOSCOPIC ABLATION THERAPY PERFORMED UNDER ZERO FLOW AND LOW FLOW CONDITIONS: A QUALITATIVE COMPARATIVE ANIMAL STUDY. Chest 2007. [DOI: 10.1378/chest.132.4_meetingabstracts.425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
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Abstract
OBJECTIVE This study tested a newly developed flexible fiber for CO(2) laser surgery. BACKGROUND DATA The lack of a flexible delivery system with the current CO(2) laser has limited its surgical application. We conducted in vitro and in vivo studies by using the skin tissue model of animals to test a new laser fiber system. METHODS In an in vitro study, the acute thermal effect of laser surgery using this new fiber was tested and compared on fresh porcine skin at 3.0-5.0-W laser power and at 0.3-0.5-mm spot size. In the in vivo experiments, the healing process of the skin incisions and wounds was followed microscopically in 16 rats, at post-operative days 2, 6, 12, and 21 after the laser surgery with 3.0-W power and 0.5-mm spot size. RESULTS The results from the in vitro tissue showed limited thermal damage to neighboring tissue. In the in vivo study, there was rapid postoperative healing. CONCLUSION Our findings indicate that this fiber system, at least with the laser parameters used in this study, appears to be an effective and feasible alternative for CO(2) laser surgery. It has great potential for development of office-based surgery under local anesthesia.
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FLEXIBLE DELIVERY OF CARBON DIOXIDE LASERS THROUGH THE OMNIGUIDE PHOTONIC BANDGAP FIBER FOR TREATMENT OF AIRWAY OBSTRUCTION: SAFETY AND FEASIBILITY STUDY. Chest 2005. [DOI: 10.1378/chest.128.4_meetingabstracts.497s] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
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Abstract
OBJECTIVES/HYPOTHESIS The objective was to investigate the functional and histological properties of surgical procedures using a new carbon dioxide (CO2) laser fiber. STUDY DESIGN In vitro and in vivo animal models. METHODS In vitro experiments using porcine true vocal cord and arytenoid cartilage were designed to study the histological effects of using a photonic band-gap fiber assembly for CO2 laser energy delivery. Continuous and pulsed-wave settings at different wattages were tested. In vivo endoscopic surgery on canine larynges and buccal mucosa were performed to examine functional and short-term healing when performing photonic band-gap fiber assembly-assisted laser surgery. RESULTS In vitro experiments showed consistent cutting with the photonic band-gap fiber assembly using either straight or 90 degrees bent-tip fibers. The surrounding tissue in these experiments showed little collateral thermal damage with the average range of thermal width from 14.1 to 18.8 microm in vocal cords and from 5.2 to 10.5 microm in cartilage. Similarly, thermal depth ranged from 28.0 to 350.0 microm in vocal cords and from 269.7 to 739.6 microm in cartilage. In vivo experiments demonstrated ease in maneuvering and flexibility for cutting. There was minimal blood loss, smoke plume, or carbonaceous debris. There were no postprocedural complications. Normal oral intake was noted on postprocedural day 1. There was no evidence of stridor or respiratory distress. Seven days after the procedure, re-epithelialization was complete in the buccal incisions and nearly completed in the laryngeal incisions. CONCLUSION The photonic band-gap fiber assembly produced reliable results in cutting with functional characteristics representing an improvement over current technology. The device shows promise as an effective tool for minimally invasive procedures that are amenable to use of the CO2 laser.
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A virtual reality dental simulator predicts performance in an operative dentistry manikin course. EUROPEAN JOURNAL OF DENTAL EDUCATION : OFFICIAL JOURNAL OF THE ASSOCIATION FOR DENTAL EDUCATION IN EUROPE 2003; 7:160-163. [PMID: 14753761 DOI: 10.1034/j.1600-0579.2003.00299.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
This study was designed to test the ability of a virtual reality dental simulator to predict the performance of students in a traditional operative dentistry manikin course. Twenty-six dental students were pre-tested on the simulator, prior to the course. They were briefly instructed and asked to prepare 12 class I cavities which were automatically graded by the simulator. The instructors in the manikin course that followed were unaware of the students' performances in the simulator pre-test. The scores achieved by each student in the last six simulator cavities were compared to their final comprehensive grades in the manikin course. Class standing of the students in the simulator pre-test positively correlated with their achievements in the manikin course with a correlation coefficient of 0.49 (P = 0.012). Eighty-nine percent of the students in the lower third of the class in the pre-test remained in the low performing half of the class in the manikin course. These results indicate that testing students in a dental simulator, prior to a manikin course, may be an efficient way to allow early identification of those who are likely to perform poorly. This in turn could enable early allocation of personal tutors to these students in order to improve their chances of success.
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Use of hormone replacement therapy by menopausal women in six family-practice teaching clinics in Israel. Climacteric 2003; 6:75-80. [PMID: 12725667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Abstract
BACKGROUND The necessity of hormone replacement therapy (HRT) remains a controversial subject, but guidelines suggest that the subject be discussed with all menopausal women. AIM To determine the rate of HRT use among women cared for in family-practice, university-affiliated teaching clinics. METHODS Physicians from six family-practice teaching clinics enrolled all menopausal patients, aged between 50 and 70 years, registered in their practice. A detailed questionnaire was completed regarding demographic and health variables, gynecological history and the nature of HRT use. RESULTS In total, 682 women were invited to participate in the study; 587 (86%) participated. Some 74% of the women were married, 64% were secular and 43% stated that they performed regular exercise. Current HRT use was reported by 156 women (26.6%). Most women (83%) had been treated for over 1 year. Common indications for starting treatment were hot flushes (75%), and routine recommendation by their physician (68%). Eighty-three (14%) women were past HRT users. It was stated by 45% of never-users that HRT had never been offered to them. Current users of HRT were found to be younger than non-users (mean age 58.2 years vs. 61.5 years, p < 0.0001), more secular than traditional or religious (p < 0.0001) with more years of formal education (p < 0.0001), and more likely to be of Western or European ("Ashkenazi") origin (p < 0.0001). Current HRT users reported fewer chronic illnesses than did non-users (p = 0.001); they were more likely to report being engaged in regular exercise (p < 0.002) and were less likely to be obese (p < 0.005). In a multiple regression model, HRT use was associated with more years of formal education and a secular identity. CONCLUSION Our study found a higher proportion of women using HRT than in other Israeli studies. HRT use was more prevalent among women with improved health status and higher socioeconomic status. The most common reason given for not using HRT was that a physician had not raised the subject, indicating that physician-related factors might contribute to using HRT. Thus, comparing HRT prescribing rates in non-teaching clinics should clarify this factor.
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Urinary incontinence in women: prevalence, characteristics and effect on quality of life. A primary care clinic study. THE ISRAEL MEDICAL ASSOCIATION JOURNAL : IMAJ 2001; 3:663-6. [PMID: 11574982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
BACKGROUND Urinary incontinence in older women is common. Its characteristics and impact on quality of life is not well established since these women are usually reluctant to tell their healthcare providers about the problem. OBJECTIVE To determine the characteristics of urinary incontinence in women and the manner in which it affects patients' quality of life. METHODS Twenty family physicians were requested to distribute a questionnaire to the first 25 consecutive women aged 30 to 75 years who visited their clinic for any reason. The questionnaire covered general health issues, symptoms of urinary incontinence, and quality of life. RESULTS A total of 418 women, mean age 50.0 +/- 11.8 years, completed the questionnaire (84% response rate). Of these, 148 (36%) reported having episodes of urinary incontinence. Urinary incontinence was found to be associated with older age, menopause, obesity and coexisting chronic disorders. Sixty percent of the women with urinary incontinence found it to be a disturbing symptom, and 44% reported that it had a detrimental effect on their quality of life. Only 32% of the affected women had sought medical advice, half of them from their family physician. Treatment was recommended to 66% of those who sought help, and in about two-thirds of these it brought some measure of relief. CONCLUSIONS Urinary incontinence is a common complaint among women attending primary care clinics, but it does not receive appropriate attention. Though it often adversely affects quality of life, only a small proportion of women seek medical advice. Family physicians should raise the issue as a part of the routine general health check-up.
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Structure and Colonization Dynamics of Epiphytic Bacterial Communities and of Selected Component Strains on Tomato (Lycopersicon esculentum) Leaves. MICROBIAL ECOLOGY 2000; 40:300-308. [PMID: 12035088 DOI: 10.1007/s002480000023] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/1999] [Accepted: 01/06/2000] [Indexed: 05/23/2023]
Abstract
The sizes and compositions of bacterial populations found on leaves of greenhouse and field grown tomato plants were studied by dilution plating, fatty acid methyl ester analysis (FAME), and BIOLOG plates of isolates in pure cultures. In the greenhouse, overhead-irrigated plants sustained higher microbial populations (up to 105 cfu g-1) than soil-irrigated plants (103 cfu g-1). Strains isolated from overhead-irrigated plants grown in a vegetable garden (n = 216) and from greenhouse-grown plants (n = 114) were subjected to FAME analysis. Similarly, strains from soil-irrigated field-grown plants (n = 83) were identified using BIOLOG plates. In each case, populations were dominated by a few genera. When concentrated phyllosphere washes (CPW) were sprayed on greenhouse-grown, soil-irrigated plants, leaf bacterial populations of more than 105 CFU g-1 were sustained for 4 days; sterile buffer-sprayed leaves sustained less than 104 CFU g-1. No significant enrichment of any strain isolated from the sprayed leaves could be detected by FAME identification of randomly selected colonies. However, when recurring leaf saprophytic species (both Gram-positive and Gram-negative) isolated from these experiments and from plants grown outdoors were tested for epiphytic colonization under stressful conditions, all could still be detected at various levels up to 4 days after inoculation, indicating differential epiphytic fitness. The non-epiphytic bacteria Escherichia coli and Azospirillum brasilense disappeared from the leaf surface within the same experimental period.
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Severe weight loss, renal failure, and metabolic alkalosis due to duodenal adenomyoma. Am J Gastroenterol 1993; 88:472-3. [PMID: 8438873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Abstract
Human myelin basic protein (MBP), a long-lived brain protein, undergoes gradual racemization of its amino acids, primarily aspartic acid and serine. Purified protein was treated at neutral pH with trypsin to yield peptides that were separated by HPLC using a C18 column. Twenty-nine peptides were isolated and analyzed for amino acid composition and aspartate racemization. Each aspartate and asparagine in the protein was racemized to a different extent, ranging from 2.2 to 17.1% D isomer. When the racemization was examined in terms of the beta-structure model of MBP, a correlation was observed in which six aspartate/asparagine residues assumed to be associated with myelin membrane lipids showed little racemization (2.2-4.9% D isomer), whereas five other aspartate residues were more highly racemized (9.9-17.1% D isomer). Although the observed aspartate racemization may be related to steric hindrance by neighboring residues and/or the protein secondary structure, interaction of aspartates with membrane lipids may also be a major factor. The data are compatible with a model in which each MBP molecule interacts with adjacent cytoplasmic layers of myelin membrane through a beta-sheet on one surface and loops and helices on the other surface, thereby stabilizing the myelin multilamellar structure.
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Novel use of synthetic oligonucleotide insertion mutants for the study of homologous recombination in mammalian cells. Proc Natl Acad Sci U S A 1983; 80:4827-31. [PMID: 6576360 PMCID: PMC384138 DOI: 10.1073/pnas.80.15.4827] [Citation(s) in RCA: 72] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Thymidine kinase-deficient mouse L cells have been transformed with plasmid DNAs carrying 8-base-pair Xho I linker insertion mutations in the coding region of the herpes simplex virus type 1 thymidine kinase gene. When the mutant plasmids are introduced individually into LTK- cells, transformation efficiencies are greatly reduced relative to the wild type. However, when two mutant plasmids are cotransferred into the same LTK- recipients, significantly higher frequencies of transformation are observed (30-300 times). Here we demonstrate the usefulness of linker insertions for the study of homologous recombination in detecting the existence of normal thymidine kinase gene sequences (i.e., sequences lacking the insertions after recombination are substantiated by DNA . DNA hybridization). In addition, the frequencies of recombination in the various "crosses" are consistent with the known positions of the mutations.
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An improved and easy technique for polyamine determination in biological samples. Application to cell-free system from hypertrophied rat heart. JOURNAL OF CHROMATOGRAPHY 1979; 162:547-59. [PMID: 160916 DOI: 10.1016/s0378-4347(00)81834-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
An accurate, improved cation-exchange chromatographic method using o-phthalaldehyde and ultraviolet detection at 280 nm for the determination of free polyamines (putrescine, spermidine, spermine) has been developed. Different samples, such as the 105,000 g supernatant of reticulocyte or heart muscle, and KCl ribosomal wash containing initiation factors, can be analysed. The minor modification of reagents results in a good precision and sensitivity, which is demonstrated by a relative standard deviation of 5--9% and recoveries of 98%. This technique is of particular interest because it allows polyamine determination in biological samples with high concentrations of salt.
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A Proposed Test for Mobility-Training Readiness. JOURNAL OF VISUAL IMPAIRMENT & BLINDNESS 1967. [DOI: 10.1177/0145482x6706100201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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