Early national trends of lung allograft use during donation after circulatory death heart procurement in the United States

Objective

Innovative technology such as normothermic regional perfusion and the Organ Care System has expanded donation after circulatory death heart transplantation. We wanted to investigate the impact of donation after circulatory death heart procurement in concurrent lung donation and implantation at a national level.

Methods

We reviewed the United Network for Organ Sharing database for heart donation between December 2019 and March 2022. Donation after circulatory death donors were separated from donation after brain death donors and further categorized based on concomitant organ procurement of lung and heart, or heart only.

Results

A total of 8802 heart procurements consisted of 332 donation after circulatory death donors and 8470 donation after brain death donors. Concomitant lung procurement was lower among donation after circulatory death donors (19.3%) than in donation after brain death donors (38.0%, P < .001). The transplant rate of lungs in the setting of concomitant procurement is 13.6% in donation after circulatory death, whereas it is 38% in donation after brain death (P < .001). Of the 121 lungs from 64 donation after circulatory death donors, 22 lungs were retrieved but discarded (32.2%). Normothermic regional perfusion was performed in 37.3% of donation after circulatory death donors, and there was no difference in lung use between normothermic regional perfusion versus direct procurement and perfusion (20.2% and 18.8%). There was also no difference in 1-year survival between normothermic regional perfusion and direct procurement and perfusion.

Conclusions

Although national use of donation after circulatory death hearts has increased, donation after circulatory death lungs has remained at a steady state. The implantation of lungs after concurrent procurement with the heart remains low, whereas transplantation of donation after circulatory death hearts is greater than 90%. The use of normothermic regional perfusion lungs has been controversial, and we report comparable 1-year outcomes to standard donation after circulatory death lungs. Further studies are warranted to investigate the underlying mechanisms of normothermic regional perfusion on lung function.

Incidence of post-transplant cytomegalovirus viremia in patients receiving lungs after ex vivo lung perfusion

Objectives

Cytomegalovirus infection after lung transplant is associated with increased morbidity and mortality. Inflammation, infection, and longer ischemic times are important risk factors for cytomegalovirus infection. Ex vivo lung perfusion has helped to successfully increase the use of high-risk donors over the last decade. However, the impact of ex vivo lung perfusion on post-transplant cytomegalovirus infection is unknown.

Methods

We performed a retrospective analysis of all adult lung transplant recipients from 2010 to 2020. The primary end point was comparison of cytomegalovirus viremia between patients who received ex vivo lung perfusion donor lungs and patients who received non-ex vivo lung perfusion donor lungs. Cytomegalovirus viremia was defined as cytomegalovirus viral load greater than 1000 IU/mL within 2 years post-transplant. Secondary end points were the time from lung transplant to cytomegalovirus viremia, peak cytomegalovirus viral load, and survival. Outcomes were also compared between the different donor recipient cytomegalovirus serostatus matching groups.

Results

Included were 902 recipients of non-ex vivo lung perfusion lungs and 403 recipients of ex vivo lung perfusion lungs. There was no significant difference in the distribution of the cytomegalovirus serostatus matching groups. A total of 34.6% of patients in the non-ex vivo lung perfusion group developed cytomegalovirus viremia, as did 30.8% in the ex vivo lung perfusion group (P = .17). There was no difference in time to viremia, peak viral loads, or survival when comparing both groups. Likewise, all outcomes were comparable in the non-ex vivo lung perfusion and ex vivo lung perfusion groups within each serostatus matching group.

Conclusions

The practice of using more injured donor organs via ex vivo lung perfusion has not affected cytomegalovirus viremia rates and severity in lung transplant recipients in our center.

Haem Iron Intake Is Associated with Increased Major Adverse Cardiovascular Events, All-Cause Mortality, Congestive Cardiac Failure, and Coronary Revascularisation in Older Men: The Concord Health and Ageing in Men Project

BACKGROUND

Nutritional intake can influence major adverse cardiovascular events (MACE). Dietary iron is found in two forms: haem-iron (HI) only found in animal sources and non-haem iron (NHI) present mostly in plant sources.

OBJECTIVE

We evaluated the associations between dietary iron intakes with MACE and iron status biomarkers.

DESIGN

Prospective cohort study.

SETTING

The Concord Health and Ageing in Men Project, Sydney, Australia.

PARTICIPANTS

539 community-dwelling older Australian men aged 75 years and older.

METHODS

Men underwent nutritional assessment using a validated diet history questionnaire. Entries were converted to food groups and nutrients. The dietary calculation was used to derive HI and NHI intakes from total iron intakes. Analyses of iron intakes with iron status biomarkers were conducted using linear regression, and with MACE and individual endpoints were conducted using Cox regression. Five-point MACE comprised of all-cause mortality, myocardial infarction (MI), congestive cardiac failure (CCF), coronary revascularisation, and/or ischaemic stroke. Four-point MACE included the four endpoints of MI, CCF, coronary revascularisation, and/or ischaemic stroke, and excluded all-cause mortality.

RESULTS

At a median of 5.3 (4.6 - 6.3) years follow-up, the incidences were: 31.2% (n = 168) five-point MACE, 17.8% (n = 96) four-point MACE excluding all-cause mortality, 20.1% (n = 111) all-cause mortality, 11.3% (n = 61) CCF, and 3.1% (n = 15) coronary revascularisation. In adjusted analyses, higher HI intake (per 1mg increment) was associated with increased five-point MACE (HR: 1.45 [95% CI: 1.16, 1.80, P = .001]), four-point MACE excluding all-cause mortality (HR: 1.64 [95% CI: 1.26, 2.15, P <.001]), all-cause mortality (HR: 1.51 [95% CI: 1.15, 1.99, P = .003]), CCF (HR: 2.08 [95% CI: 1.45, 2.98, P <.001]), and coronary revascularisation (HR: 1.89 [95% CI: 1.15, 3.10, P = .012]). Compared with the bottom tertile of NHI intake, the middle tertile of NHI intake was associated with reduced risk of all-cause mortality (HR: 0.56 [95% CI: 0.33, 0.96, P = .035]). Total iron intake was not associated with MACE and individual endpoints. Dietary iron intakes were not associated with serum iron and haemoglobin.

CONCLUSION

Higher haem iron intake was independently associated with increased risks of five-point MACE, four-point MACE excluding all-cause mortality, all-cause mortality, CCF, and coronary revascularisation in older men over 5 years.

Plant-Based Dietary Patterns, Body Composition, Muscle Strength and Function in Middle and Older Age: A Systematic Review

BACKGROUND

Sarcopenia is prevalent in middle-aged and older adults. A plant-based diet may be linked to changes in body composition and musculoskeletal health.

OBJECTIVE

This systematic review aimed to investigate the effects of plant-based dietary patterns on the body composition, muscle strength and function in middle-aged and older adults. PRISMA guidelines were followed.

METHOD

A systematic search was completed on databases including MEDLINE, Embase, Global Health, PREMEDLINE, Cochrane library, CINAHL and Scopus on articles published until 1st March 2019. Search terms included 'middle-aged', 'older adult', 'plant-based diet' and 'muscle strength'. Title and abstract screening were conducted on 1,868 publications after deduplication. Sample size, subject characteristics, recruitment, inclusion and exclusion criteria, dietary measures, health outcome measures, statistical results and confounders were sorted by author, study type, year and country. The quality of evidence of extracted data was assessed using the Scottish Intercollegiate Guidelines Network (SIGN) and the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) tools.

RESULTS/CONCLUSIONS

17 papers were included from 31 articles selected for full review. The majority of the studies were cross-sectional studies (n = 9) and RCTs (n = 6).The remaining studies were cohort studies. Positive associations were found between plant-based dietary patterns; negative association with body composition; and inconclusive association with muscle function. However, further studies are needed to improve the understanding.

SUMCOR: Cascade summing correction for volumetric sources applying MCNP6

The main features of code SUMCOR developed for cascade summing correction for volumetric sources are described. MCNP6 is used to track histories starting from individual points inside the volumetric source, for each set of cascade transitions from the radionuclide. Total and FEP efficiencies are calculated for all gamma-rays and X-rays involved in the cascade. Cascade summing correction is based on the matrix formalism developed by Semkow et al. (1990). Results are presented applying the experimental data sent to the participants of two intercomparisons organized by the ICRM-GSWG and coordinated by Dr. Marie-Cristine Lépy from the Laboratoire National Henri Becquerel (LNE-LNHB), CEA, in 2008 and 2010, respectively and compared to the other participants in the intercomparisons.

Cyclic electron flow, NPQ and photorespiration are crucial for the establishment of young plants of Ricinus communis and Jatropha curcas exposed to drought

Although plant physiological responses to drought have been widely studied, the interaction between photoprotection, photorespiration and antioxidant metabolism in water-stressed plants is scarcely addressed. This study aimed to evaluate the physiological adjustments preserving photosynthesis and growth in two plant species with different tolerance to drought: Jatropha curcas and Ricinus communis. We measured stress indicators, gas exchange, photochemistry of PSII and PSI, antioxidant enzymes, cyclic electron flow and photorespiration. Physiological stress indicators associated with reduction in growth confirmed R. communis as sensitive and J. curcas as tolerant to drought. Drought induced loss of photosynthesis in R. communis, whereas J. curcas maintained higher leaf gas exchange and photochemistry under drought. In addition, J. curcas showed higher dissipation of excess energy and presented higher cyclic electron flow when exposed to drought. Although none of these mechanisms have been triggered in R. communis, this species showed increases in photorespiration. R. communis displayed loss of Rubisco content while the Rubisco relative abundance did not change in J. curcas under drought. Accordingly, the in vivo maximum Rubisco carboxylation rate (V_cmax ) and the maximum photosynthetic electron transport rate driving RuBP regeneration (J_max ) were less affected in J. curcas. Both species displayed an efficient antioxidant mechanism by increasing activities of ascorbate peroxidase (APX) and superoxide dismutase (SOD). Overall, we suggest that the modulation of different photoprotective mechanisms is crucial to mitigate the effects caused by excess energy, maintaining photosynthetic apparatus efficiency and promoting the establishment of young plants of these two species under drought.

Incidence and antimicrobial resistance of enteropathogens isolated from an integrated aquaculture system

AIMS

To evaluate an integrated aquaculture system, microbiological analyses of water used in this system were carried out and the incidence and antimicrobial resistance of enteropathogens were determined in the related ecosystem.

METHODS AND RESULTS

Microbiological analysis was undertaken for Salmonella sp., Shigella sp., Vibrio sp. and Aeromonas sp. The disc-diffusion method was performed according to the Clinical and Laboratory Standards Institute. Water samples tested had 32.9% of faecal coliform rates (≤1600 per 100 ml) in accordance with WHO for pisciculture in wastewater. Salmonella spp. were detected in 14.5% of the samples. From a total of 33 strains, 15.1% were resistant to one or two antimicrobial drugs tested and multidrug resistance was not observed. Aeromonas spp. were identified in 91.6% of the samples. From a total of 416 strains, resistance to one antimicrobial class was observed in 66.3% and multidrug resistance in 37.7%.

CONCLUSIONS

This system reflects the community profile, drawing attention to the circulation of pathogens, because the genes coding for resistance to classical antibiotics and broad spectrum are a public health problem.

SIGNIFICANCE AND IMPACT OF THE STUDY

The reuse of water resources requires continuous monitoring as the system is subject to treatment failure, which can result in the spread of bacterial pathogens.

Functional groups of forest succession as dissipative structures: an applied study

This study tested the hypothesis that dissipative efficiency of tropical tree species could be an ecological advantage in the forest succession process. Daily leaf gas exchanges of a pioneer species (Guazuma ulmifolia) and a late successional species (Cariniana legalis) were evaluated under well-irrigated conditions and by withholding irrigation. Analyses of network connectance (Cg) and plant autonomy (At) were carried out in order to assess metabolic network changes in response to environmental perturbation. As a global estimation of latent heat dissipation, the capacity to both maintain and cool leaf temperature in response to air temperature changes (deltaT = T degrees Cair - T degrees Cleaf) was evaluated. The changes observed in both the systemic parameters (Cg and At) and the physiological ones brought about by water deficit, associated with discrepant growth rates between both species, suggested that the initial formation of gap canopies composed by pioneer species could simply be a result of the higher photosynthetic rates of these species, and not necessarily because late successional species cannot cope with such a heterogeneous environment as that of a gap. Our results indicate that, in the absence of water constraints, the highest CO2 assimilation rates of pioneer species are supported by the efficiency of the whole dissipative structure, involving both degradation and dissipative processes. As a practical result, our study suggests the deltaT analysis in order to evaluate the efficiency of dissipative structures and as a aid in characterizing functional groups.

Analysis of some factors involved in the virulence mechanism of Vibrio cholerae non-01

A study was carried out to evaluate the potential intestinal toxicity of 188 samples of Vibrio cholerae non-01 isolated from seawater found along the beaches of Rio de Janeiro city. Three different assays were carried out involving: (a) detection of vascular permeability factor (PF) in guinea pigs (together with assessment of two culture media for production of the toxin); (b) intestinal fluid accumulation (FA) in suckling mice; and (c) detection of haemolysin. The results demonstrated that both culture media gave a similar level of performance. In the animal assays, 43% of the samples induced PF in guinea pigs, 28.7% caused intestinal fluid accumulation in suckling mice, and 63.28% contained haemolysin. Only 4.25% of the samples gave positive results in all three tests.

Evaluation of virulence factors in environmental isolates of Vibrio species

Strains of Vibrio parahaemolyticus, Vibrio fluvialis and Vibrio mimicus isolated from seafood and seawater were examined for characteristics related to infectivity, such as enzymatic activity and animal assays. All strains hydrolysed DNA, starch, gelatin and chitin. Variable results were obtained with the haemolysin, chondroitin, collagen, elastin and lecithin tests. Production of thermostable direct haemolysin by V. parahaemolyticus was detected in 7.1% strains derived from seafood and 2% from seawater. In the animal assays, strains of V. fluvialis showed positive results at skin PF (75%), mouse lethality (100%), but no fluid accumulation in the suckling mice model was noted. Concerning V. mimicus, results showed skin PF (100%), mouse lethality (100%) and fluid accumulation in suckling mice (66.6%).

Analysis of some virulence factors of Vibrio vulnificus isolated from Rio de Janeiro, Brazil

Twenty strains of V. vulnificus isolated from the environment were investigated for characteristics related to their infectivity such as colonial morphology, enzymatic activity and animal assays. The presence of DNase, chitinase, amylase, lecithinase and gelatinase was observed in 100% of the strains, haemolytic activity was absent, and variable results were obtained in elastase, collagenase and chondroitinase. In the animal assays, 70% of the strains were lethal to adult mice, while 45% caused fluid accumulation in suckling mice. Although all strains had opaque colonies, only 3 of the 20 had the three enzymes elastase, collagenase and gelatinase, and only one of these was virulent in animal assays.