Nucleotide metabolism is linked to cysteine availability.

The small molecule erastin inhibits the cystine-glutamate antiporter, system xc-, which leads to intracellular cysteine and glutathione depletion. This can cause ferroptosis, which is an oxidative cell death process characterized by uncontrolled lipid peroxidation. Erastin and other ferroptosis inducers have been shown to affect metabolism but the metabolic effects of these drugs have not been systematically studied. To this end, we investigated how erastin impacts global metabolism in cultured cells and compared this metabolic profile to that caused by the ferroptosis inducer RAS-selective lethal 3 or in vivo cysteine deprivation. Common among the metabolic profiles were alterations in nucleotide and central carbon metabolism. Supplementing nucleosides to cysteine-deprived cells rescued cell proliferation in certain contexts, showing that these alterations to nucleotide metabolism can affect cellular fitness. While inhibition of the glutathione peroxidase GPX4 caused a similar metabolic profile as cysteine deprivation, nucleoside treatment did not rescue cell viability or proliferation under RAS-selective lethal 3 treatment, suggesting that these metabolic changes have varying importance in different scenarios of ferroptosis. Together, our study shows how global metabolism is affected during ferroptosis and points to nucleotide metabolism as an important target of cysteine deprivation.

Achieving Universal Health Coverage (UHC): Dominance analysis across 183 countries highlights importance of strengthening health workforce.

BACKGROUND: Despite increasing political will to achieve Universal Health Coverage (UHC), there is a paucity of empiric data describing what health system indicators are useful surrogates of country-level progress towards UHC. We sought to determine what public health interventions were useful tracers of country-level UHC progress. METHODS: Across 183 countries we evaluated the extent to which 16 service delivery indicators explained variability in the UHC Service Coverage Index, (UHC SCI) a WHO-validated indicator of country-level health coverage. Dominance analyses, stratifying countries by World Bank income criteria, were used to determine which indicators were most important in in predicting UHC SCI scores. FINDINGS: Health workforce density ranked first overall, provision of basic sanitation and access to clean water ranked second, and provision of basic antenatal services ranked third. In analysis stratified by World Bank income criteria, health workforce density ranked first in Lower Middle Income-Countries (LMICs) (n = 45) and third in Upper Middle Income-Countries (UMICs) (n = 51). CONCLUSIONS: While each country will have a different approach to achieving UHC, strengthening the health workforce will need to be a key priority if they are to be successful in achieving UHC.

Patient/service user involvement in medical education: A best evidence medical education (BEME) systematic review: BEME Guide No. 58.

Background: The extent to which patients and service users are involved in medical education varies widely. There is a need for an up to date systematic review of the literature that examines what involvement (description), the potential outcome of such involvement (justification) and 'why' such involvement impacts students (clarification).Methods: Systematic searches of four databases were undertaken. Citations were screened and consensus reached for inclusion/exclusion of studies. Quality of study design and interventional presentation were assessed.Results: Of the 39 studies included in the review, 4 studies were encounter based, 17 sharing experiences, 16 with patients involved in teaching, 2 studies describing consumers as tutors, and none with involvement at the institutional level. Outcomes in terms of benefits to learners included increased empathy and understanding of illness as experienced by patients, improved communication with patients and a greater understanding of patient-center care. Educational quality assessment showed specific weaknesses in theoretical underpinning, curriculum outcomes, content or pedagogy.Conclusions: Patients can enrich medical education by allowing learners to explore patient-centered perspectives in holistic care. For educators this review highlights the lack of an underpinning conceptual basis for which to translate theory into practice.

Improving the cascade of global tuberculosis care: moving from the "what" to the "how" of quality improvement.

Tuberculosis is preventable, treatable, and curable, yet it has the highest mortality rate of infectious diseases worldwide. Over the past decade, services to prevent, screen, diagnose, and treat tuberculosis have been developed and scaled up globally, but progress to end the disease as a public health threat has been slow, particularly in low-income and middle-income countries. In these settings, low-quality tuberculosis prevention, diagnostic, and treatment services frustrate efforts to translate use of existing tools, approaches, and treatment regimens into improved individual and public health outcomes. Increasingly sophisticated methods have been used to identify gaps in quality of tuberculosis care, but inadequate work has been done to apply these findings to activities that generate population-level improvements. In this Personal View, we contend that shifting the focus from the "what" to the "how" of quality improvement will require National Tuberculosis Programmes to change the way they organise, use data, implement, and respond to the needs and preferences of people with tuberculosis and at-risk communities.

From HIV prevention to non-communicable disease health promotion efforts in sub-Saharan Africa: A Narrative Review.

OBJECTIVE: To synthesize published literature on noncommunicable disease (NCD) behavior change communication (BCC) interventions in sub-Saharan Africa (SSA) among persons living with HIV (PLHIV) and in the general population to inform efforts to adopt similar HIV and NCD BCC intervention activities. METHODS: We conducted a literature review of NCD BCC interventions and included 20 SSA-based studies. Inclusion criteria entailed describing a BCC intervention targeting any four priority NCDs (cardiovascular disease, type 2 diabetes, cervical cancer, and depression) or both HIV and any of the NCDs. The RE-AIM (Reach, Effectiveness, Adoption, Implementation, and Maintenance) framework was used to assess potential public health impact of these studies. We also solicited expert opinions from 10 key informants on the topic of HIV/NCD health promotion in five SSA countries. RESULTS: The BCC interventions reviewed targeted multiple parts of the HIV and NCD continuum at both individual and community levels. Various strategies (i.e. health education, social marketing, motivational interviewing, mobile health, and peer support) were employed. However, few studies addressed more than one dimension of the RE-AIM framework. Opinions solicited from the key informants supported the feasibility of integrating HIV and NCD BCC interventions in SSA potentially improving access, service provision and service demand, especially for marginalized and vulnerable populations. CONCLUSION: Although HIV/NCD integration can improve effectiveness of preventive services at individual and community levels, potential public health impact of such approaches remain unknown as reach, adoptability, and sustainability of both integrated and nonintegrated NCD BCC approaches published to date have not been well characterized.

Serine Availability Influences Mitochondrial Dynamics and Function through Lipid Metabolism.

Cell proliferation can be dependent on the non-essential amino acid serine, and dietary restriction of serine inhibits tumor growth, but the underlying mechanisms remain incompletely understood. Using a metabolomics approach, we found that serine deprivation most predominantly impacts cellular acylcarnitine levels, a signature of altered mitochondrial function. Fuel utilization from fatty acid, glucose, and glutamine is affected by serine deprivation, as are mitochondrial morphological dynamics leading to increased fragmentation. Interestingly, these changes can occur independently of nucleotide and redox metabolism, two known major functions of serine. A lipidomics analysis revealed an overall decrease in ceramide levels. Importantly, supplementation of the lipid component of bovine serum or C16:0-ceramide could partially restore defects in cell proliferation and mitochondrial fragmentation induced by serine deprivation. Together, these data define a role for serine in supporting mitochondrial function and cell proliferation through ceramide metabolism.

Decompressing rescue personnel during Australian submarine rescue operations.

INTRODUCTION: Personnel rescuing survivors from a pressurized, distressed Royal Australian Navy (RAN) submarine may themselves accumulate a decompression obligation, which may exceed the bottom time limits of the Defense and Civil Institute of Environmental Medicine (DCIEM) Air and In-Water Oxygen Decompression tables (DCIEM Table 1 and 2) presently used by the RAN. This study compared DCIEM Table 2 with alternative decompression tables with longer bottom times: United States Navy XVALSS_DISSUB 7, VVAL-18M and Royal Navy 14 Modified tables. METHODS: Estimated probability of decompression sickness (PDCS), the units pulmonary oxygen toxicity dose (UPTD), the volume of oxygen required and the total decompression time were calculated for hypothetical single and repetitive exposures to 253 kPa air pressure for various bottom times and prescribed decompression schedules. RESULTS: Compared to DCIEM Table 2, XVALSS_DISSUB 7 single and repetitive schedules had lower estimated PDCS, which came at the cost of longer oxygen decompressions. For single exposures, DCIEM schedules had PDCS estimates ranging from 1.8% to 6.4% with 0 to 101 UPTD and XVALSS_DISSUB 7 schedules had PDCS of less than 3.1%, with 36 to 350 UPTD. CONCLUSIONS: The XVALSS_DISSUB 7 table was specifically designed for submarine rescue and, unlike DCIEM Table 2, has schedules for the estimated maximum required bottom times at 253 kPa. Adopting these tables may negate the requirement for saturation decompression of rescue personnel exceeding DCIEM limits.

Decompressing recompression chamber attendants during Australian submarine rescue operations.

INTRODUCTION: Inside chamber attendants rescuing survivors from a pressurised, distressed submarine may themselves accumulate a decompression obligation which may exceed the limits of Defense and Civil Institute of Environmental Medicine tables presently used by the Royal Australian Navy. This study assessed the probability of decompression sickness (PDCS) for medical attendants supervising survivors undergoing oxygen-accelerated saturation decompression according to the National Oceanic and Atmospheric Administration (NOAA) 17.11 table. METHODS: Estimated probability of decompression sickness (PDCS), the units pulmonary oxygen toxicity dose (UPTD) and the volume of oxygen required were calculated for attendants breathing air during the NOAA table compared with the introduction of various periods of oxygen breathing. RESULTS: The PDCS in medical attendants breathing air whilst supervising survivors receiving NOAA decompression is up to 4.5%. For the longest predicted profile (830 minutes at 253 kPa) oxygen breathing at 30, 60 and 90 minutes at 132 kPa partial pressure of oxygen reduced the air-breathing-associated PDCS to less than 3.1 %, 2.1% and 1.4% respectively. CONCLUSIONS: The probability of at least one incident of DCS among attendants, with consequent strain on resources, is high if attendants breathe air throughout their exposure. The introduction of 90 minutes of oxygen breathing greatly reduces the probability of this interruption to rescue operations.

Redox interventions to increase exercise performance.

Skeletal muscle continually produces reactive oxygen species (ROS) and nitric oxide (NO) derivatives. Both oxidant cascades have complex effects on muscle contraction, metabolic function and tissue perfusion. Strenuous exercise increases oxidant production by muscle, limiting performance during endurance exercise tasks. Conversely, redox interventions that modulate ROS or NO activity have the potential to improve performance. Antioxidants have long been known to buffer ROS activity and lessen oxidative perturbations during exercise. The capacity to enhance human performance varies among antioxidant categories. Vitamins, provitamins and nutriceuticals often blunt oxidative changes at the biochemical level but do not enhance performance. In contrast, reduced thiol donors have been shown to delay fatigue or increase endurance under a variety of experimental conditions. Dietary nitrate supplementation has recently emerged as a second redox strategy for increasing endurance. Purified nitrate salts and nitrate-rich foods, notably beetroot and beetroot juice, are reported to lessen the oxygen cost of exercise, increase efficiency, and enhance performance during endurance tasks. These findings are exciting but enigmatic since nitrate per se has little bioactivity and cannot be converted to NO by mammalian cells. Overall, the available data suggest exercise endurance can be augmented by redox-active supplements, either reduced thiol donors or dietary nitrates. These findings have clear implications for athletes seeking a competitive edge. More importantly, interventions that increase endurance may benefit individuals whose physical activity is limited by illness, ageing, or frailty.

Leveraging HIV Programming to Enhance Access to Noncommunicable Disease Care in Southern Botswana.

OBJECTIVE: The objective of this study was to assess whether HIV programming in southern Botswana could be leveraged to provide care for patients with noncommunicable diseases (NCDs). METHODS: A retrospective analysis was performed to determine the spectrum and complexity of NCDs seen by HIV-focused outreach programming delivered between July 2011 and December 2013, to 9 facilities in southern Botswana. The association of HIV status and specific International Classification of Disease codes was examined using bivariate analysis. RESULTS: Outreach HIV physicians recorded 926 outpatient consults involving 835 patients during the studied period. While 25% (n=209) of patients seen were HIV infected, most patients were either HIV negative (49%, n=410) or had an unknown HIV status (26%, n=216). Noncommunicable disease referrals were as common at primary- and district-level facilities (90% [n=459] versus 93% [n=301]; P=.22). CONCLUSION: This study demonstrates how HIV programming in Botswana can be leveraged to improve access to specialist medical services for patients with NCDs.

Physical inactivity and muscle weakness in the critically ill.

Patients in the intensive care unit commonly develop muscle weakness. In part, this reflects loss of mechanical loading due to physical inactivity, bed rest, or immobilization. Mechanical unloading stimulates a complex adaptive response that results in muscle atrophy and loss of specific force. One element of this response is slowing of protein synthesis, which is regulated by signaling pathways downstream of mammalian target of rapamycin and insulin-like growth factor-1. In parallel, protein degradation is accelerated via three coordinate processes: calcium-dependent proteolysis, adenosine triphosphate-dependent proteolysis, and lysosomal proteolysis. Finally, unloading stimulates apoptosis of a subset of myonuclei within multinucleated muscle fibers. This helps to stabilize the relationship between nuclear number and cell volume during atrophy. Each of these responses is promoted by concurrent development of oxidative stress caused by increased production of reactive oxygen species in unloaded muscle fibers. Countermeasures that lessen the effects of unloading include physical activity, nutritional supplements, hormone therapy, and antioxidant administration. Targeted research is needed to define the role of mechanical unloading in intensive care unit-associated weakness and develop countermeasures to preserve muscle function, lessen illness, and hasten the recovery of critically ill patients.

Genes associated with opening and senescence of Mirabilis jalapa flowers.

A modest ethylene climacteric accompanies flower senescence in Mirabilis jalapa L., and exogenous ethylene accelerates the process. However, inhibitors of ethylene action and synthesis have little effect on the life-span of these ephemeral flowers. Treatment with alpha-amanitin, an inhibitor of DNA-dependent RNA synthesis, substantially delays the onset of senescence. This effect falls linearly between 7 h and 8 h after the start of flower opening. Subtractive hybridization was used to isolate transcripts that were up- and down-regulated during this critical period. Eighty-two up-regulated and 65 down-regulated transcripts were isolated. The genes identified encode homologues of a range of transcription factors, and of proteins involved in protein turnover and degradation. Real-time quantitative RT-PCR was used to examine expression patterns of these genes during flower opening and senescence. Genes that were identified as being down-regulated during senescence showed a common pattern of very high expression during floral opening. These genes included a homologue of CCA1, a 'clock' gene identified in Arabidopsis thaliana and an aspartyl protease. Up-regulated genes commonly showed a pattern of increase during the critical period (4-9 h after opening), and some showed very strong up-regulation. For example, the abundance of transcripts encoding a RING zinc finger protein increased >40 000 fold during the critical period.

Chalcone synthase as a reporter in virus-induced gene silencing studies of flower senescence.

Agrobacterium-mediated infection of petunia (Petunia hybrida) plants with tobacco rattle virus (TRV) bearing fragments of Petunia genes resulted in systemic infection and virus-induced gene silencing (VIGS) of the homologous host genes. Infection with TRV containing a phytoene desaturase (PDS) fragment resulted in reduced abundance of PDS transcripts and typical photobleaching of photosynthetic tissues. Infection with TRV containing a chalcone synthase (CHS) fragment resulted in silencing of anthocyanin production in infected flowers. The silencing phenotype ranged from scattered white spots on the normal purple background to entirely white flowers. Symptoms in the V26 cultivar were a diffuse mosaic, but infection of some purple-flowered commercial cultivars resulted in large white sectors and even entirely white flowers. Abundance of CHS transcripts in the white flowers was less than 4% of that in purple flowers on the same plant. Infection with TRV containing a tandem construct of PDS and CHS resulted in leaf photobleaching and white patterns on the flowers. Transcripts of CHS and PDS were reduced both in leaves and in flowers confirming simultaneous silencing of both genes by the tandem construct. We tested the effects of infection with TRV containing CHS and a fragment of a petunia gene encoding for 1-aminocyclopropane-1-carboxylate oxidase (ACO4) Abundance of transcripts encoding ACO4 and ACO1 were reduced (by 5% and 20%, respectively) in infected flowers. Whether the flowers were treated with ACC or pollinated, the white (silenced) flowers or flower sectors produced less ethylene and senesced later than purple (non-silenced) tissues. These results indicate the value of VIGS with tandem constructs containing CHS as reporter and a target gene as a tool for examining the function of floral-associated genes.