Hepatitis B transmission/reactivation associated with Hepatitis B core antibody and Hepatitis C nucleic acid testing positive organs: A report from the Organ Procurement and Transplantation Network Disease Transmission Advisory Committee.

BACKGROUND: Better access to direct-acting antiviral (DAA) therapy has broadened the utilization of hepatitis C virus (HCV) nucleic acid testing (NAT) positive organs with excellent outcomes. However, DAA therapy has been associated with hepatitis B virus (HBV) reactivation. AIM: To determine the risk of HBV transmission or reactivation with utilization of HBV core antibody positive (HBcAb+) and HCV NAT positive (HCV+) organs, which presumably required DAA therapy. METHODS: The number of HBcAb+ donors with delineated HCV NAT status was obtained from the Organ Procurement and Transplantation Network (OPTN) database. The number of unexpected HBV infections from transplanted organs adjudicated as "proven" or "probable" transmission was obtained from the OPTN Ad Hoc Disease Transmission Advisory Committee database. A chart review of the donors of "proven" or "probable" cases was conducted. RESULTS: From January 1, 2016, to December 31, 2021, 7735 organs were procured from 3767 HBcAb+ donors and transplanted into 7469 recipients; 545 (14.5%) donors were also HCV+. HBV transmission or reactivation occurred in seven recipients. The rate is not significantly different between recipients of HCV+ (0.18%, 2/1115) and the HCV NAT negative (HCV-) organs (0.08%, 5/6354) (p = 0.28) or between recipients of HCV+ and HCV- livers as well as non-liver organs. HBV transmission or reactivation occurred within a median of 319 (range, 41-1117) days post-transplant in the setting of missing, inadequate, or truncated prophylaxis. CONCLUSION: HBV reactivation associated with DAA therapy for HBcAb+ HCV+ organs is less frequent than reported in the non-transplant population, possibly due to the common use of HBV prophylaxis in the at-risk transplant population.

Deceased Donors With HIV in the Era of the HOPE Act: Referrals and Procurement.

Background: The HIV Organ Policy Equity Act legalizes organ procurement from donors with HIV (HIV D+). A prior survey of Organ Procurement Organizations (OPOs) estimated >2000 HIV D+ referrals/year; however, only 30-35 HIV D+/year have had organs procured. Given this gap, we sought to understand HIV D+ referrals and procurements in practice. Methods: We prospectively collected data on all OPO-reported HIV D+ referrals, including reasons for nonprocurement. We evaluated trends and compared HIV D+ characteristics by procurement status using regression, chi-squared tests, and Wilcoxon rank-sum tests. Results: From December 23, 2015 to May 31, 2021, there were 710 HIV D+ referrals from 49 OPOs, of which 171 (24%) had organs procured. HIV D+ referrals increased from 7 to 15 per month (P < 0.001), and the procurement rate increased from 10% to 39% (P < 0.001). Compared with HIV D+ without procurement, HIV D+ with procurement were younger (median age 36 versus 50 y), more commonly White (46% versus 36%), and more often had trauma-related deaths (29% versus 8%) (all P < 0.001). Nonprocurement was attributed to medical reasons in 63% of cases, of which 36% were AIDS-defining infections and 64% were HIV-unrelated, commonly due to organ failure (36%), high neurologic function (31%), and cancer (14%). Nonprocurement was attributed to nonmedical reasons in 26% of cases, commonly due to no authorization (42%), no waitlist candidates (21%), or no transplant center interest (20%). Conclusions: In the early years of the HIV Organ Policy Equity Act, actual HIV D+ referrals were much lower than prior estimates; however, the numbers and procurement rates increased over time. Nonprocurement was attributed to both medical and nonmedical issues, and addressing these issues could increase organ availability.

Neighbourhood factors and tuberculosis incidence in Cape Town: A negative binomial regression and spatial analysis.

OBJECTIVES: Although the link between poverty and tuberculosis (TB) is widely recognised, limited studies have investigated the association between neighbourhood factors and TB incidence. Since the factors influencing different episodes of TB might be different, this study focused on the first episode of TB disease (first-episode TB). METHODS: All first episodes in previously linked and geocoded TB notification data from 2007 to 2015 in Cape Town, South Africa, were aggregated at the neighbourhood level and merged with the 2011 census data. We conducted an ecological study to assess the association between neighbourhood incidence of first-episode TB and neighbourhood factors (total TB burden [all episodes] in the previous year, socioeconomic index, mean household size, mean age, and percentage males) using a negative binomial regression. We also examined the presence of hotspots in neighbourhood TB incidence with the Global Moran's I statistic and assessed spatial dependency in the association between neighbourhood factors and TB incidence using a spatial lag model. RESULTS: The study included 684 neighbourhoods with a median first-episode TB incidence rate of 114 (IQR: 0-345) per 100,000 people. We found lower neighbourhood socioeconomic index (SEI), higher neighbourhood total TB burden, lower neighbourhood mean household size, and lower neighbourhood mean age were associated with increased neighbourhood first-episode TB incidence. Our findings revealed a hotspot of first-episode TB incidence in Cape Town and evidence of spatial dependency in the association between neighbourhood factors and TB incidence. CONCLUSION: Neighbourhood TB burden and SEI were associated with first-episode TB incidence, and there was spatial dependency in this association. Our findings can inform targeted interventions to reduce TB in high-risk neighbourhoods, thereby reducing health disparities and promoting health equity.

Determination of clopidogrel effect in cats using point-of-care Plateletworks ADP and shipped samples for PFA-200 analysis in a clinical practice setting.

OBJECTIVES: Clopidogrel is the recommended first-line antithrombotic in cats for a variety of conditions; however, it is ineffective in 15-20% of cats. The determination of clopidogrel effectiveness with platelet function assays has historically been limited to specialty centers; however, recent work has suggested that in-hospital or shipped analyses of samples may be feasible. The aim of the present study was to investigate the utility of an in-house analysis and shipping of blood samples collected in primary practices for the determination of clopidogrel effectiveness. METHODS: Citrated blood samples were collected from cats receiving clopidogrel therapy by veterinarians in clinical practices across Canada, a median of 304.4 km from the reference laboratory (range 8-4425). Samples were analyzed in-house using Plateletworks ADP and shipped for remote analysis using PFA-200 P2Y and COL/ADP cartridges. RESULTS: A total of 30 samples were collected from 25 cats. Of these, the percentage of samples analyzable for the presence or absence of the clopidogrel effect was 86% for Plateletworks ADP, 90% for PFA-200 P2Y and 87% for PFA-200 COL/ADP. There was no significant difference in the number of samples unable to be analyzed by each modality (P = 0.689) due to flow obstruction or other sample characteristics. The prevalence of absence of clopidogrel effectiveness on platelet function assays was 8% with the PFA-200 COL/ADP assay, 25% with the PFA-200 P2Y assay and 30% with the Plateletworks ADP assay. CONCLUSIONS AND RELEVANCE: The results of this study confirm that samples of feline blood can be collected in clinical practices and shipped to a reference laboratory for PFA-200 analysis with a high rate of success, comparable to point-of-care analysis.

Donor Electrocardiogram Associations With Cardiac Dysfunction, Heart Transplant Use, and Survival: The Donor Heart Study.

BACKGROUND: Potential organ donors often exhibit abnormalities on electrocardiograms (ECGs) after brain death, but the physiological and prognostic significance of such abnormalities is unknown. OBJECTIVES: This study sought to characterize the prevalence of ECG abnormalities in a nationwide cohort of potential cardiac donors and their associations with cardiac dysfunction, use for heart transplantation (HT), and recipient outcomes. METHODS: The Donor Heart Study enrolled 4,333 potential cardiac organ donors at 8 organ procurement organizations across the United States from 2015 to 2020. A blinded expert reviewer interpreted all ECGs, which were obtained once hemodynamic stability was achieved after brain death and were repeated 24 ± 6 hours later. ECG findings were summarized, and their associations with other cardiac diagnostic findings, use for HT, and graft survival were assessed using univariable and multivariable regression. RESULTS: Initial ECGs were interpretable for 4,136 potential donors. Overall, 64% of ECGs were deemed clinically abnormal, most commonly as a result of a nonspecific St-T-wave abnormality (39%), T-wave inversion (19%), and/or QTc interval >500 ms (17%). Conduction abnormalities, ectopy, pathologic Q waves, and ST-segment elevations were less common (each present in ≤5% of donors) and resolved on repeat ECGs in most cases. Only pathological Q waves were significant predictors of donor heart nonuse (adjusted OR: 0.39; 95% CI: 0.29-0.53), and none were associated with graft survival at 1 year post-HT. CONCLUSIONS: ECG abnormalities are common in potential heart donors but often resolve on serial testing. Pathologic Q waves are associated with a lower likelihood of use for HT, but they do not portend worse graft survival.

Implementation of the WHO core components of an infection prevention and control programme in two sub-saharan African acute health-care facilities: a mixed methods study.

BACKGROUND: The coronavirus pandemic again highlighted the need for robust health care facility infection prevention and control (IPC) programmes. WHO guidelines on the core components (CCs) of IPC programmes provides guidance for facilities, but their implementation can be difficult to achieve in resource-limited settings. We aimed to gather evidence on an initial WHO IPC implementation experience using a mixed methods approach. METHODS: A five-day training on the WHO IPC CCs was conducted at two reference acute health care facilities in the Democratic Republic of Congo and Burkina Faso. This was accompanied by a three-part mixed-methods evaluation consisting of a: (1) baseline and follow-up survey of participants' knowledge, attitudes and practices (KAP), (2) qualitative assessment of plenary discussion transcripts and (3) deployment of the WHO IPC assessment framework (IPCAF) tool. Results were analysed descriptively and with a qualitative inductive thematic approach. RESULTS: Twenty-two and twenty-four participants were trained at each facility, respectively. Baseline and follow-up KAP results suggested increases in knowledge related to the necessity of a dedicated IPC focal person and annual evaluations of IPC training although lack of recognition on the importance of including hospital leadership in IPC training and hand hygiene monitoring recommendations remained. Most participants reported rarely attending IPC meetings or participating in IPC action planning although attitudes shifted towards stronger agreement with the feeling of IPC responsibility and importance of an IPC team. A reocurring theme in plenary discussions was related to limited resources as a barrier to IPC implementation, namely lack of reliable water access. However, participants recognised the importance of IPC improvement efforts such as practical IPC training methods or the use of data to improve quality of care. The facilities' IPCAF scores reflected a 'basic/intermediate' IPC implementation level. CONCLUSIONS: The training and mixed methods evaluation revealed initial IPC implementation experiences that could be used to inform stepwise approaches to facility IPC improvement in resource-limited settings. Implementation strategies should consider both global standards such as the WHO IPC CCs and specific local contexts. The early involvement of all relevant stakeholders and parallel efforts to advocate for sufficient resources and health system infrastructure are critical.

Parenteral support and micronutrient deficiencies in children with short bowel syndrome: A comprehensive retrospective study.

BACKGROUND & AIMS: Short bowel syndrome (SBS) is the leading cause of chronic intestinal failure. The duration of parenteral support (PS) and the long-term micronutrient needs in children with SBS vary, based on their clinical and anatomical characteristics. Our study aimed to review the clinical course and identify high risk patient groups for prolonged PS and long-term micronutrient supplementation. METHODS: A retrospective review was conducted on electronic medical records of children with SBS and chronic intestinal failure who were enrolled in the multidisciplinary intestinal rehabilitation program at Manchester Children's Hospital, UK. Children were included in the review if they required PN for more than 60 days out of 74 consecutive days and had at least 3 years of follow-up. Statistical analysis was performed using IBM SPSS Statistics 24.0. RESULTS: 40 children with SBS achieved enteral autonomy (EA) and 14 remained dependent on PS after 36 months of follow up. Necrotizing enterocolitis was the most common cause for intestinal resection (38.9%) followed by gastroschisis (22.2%), malrotation with volvulus (20.4%), segmental volvulus (9.3%) and long segment Hirschsprung disease (1.9%). Those who achieved EA had significantly longer intestinal length 27.5% (15.0-39.3) than those who remained on PS 6.0% (1.5-12.5) (p < 0.001). Type I SBS was only found in the PS cohort. Median PN dependence was 10.82 months [IQR 5.73-20.78]. Congenital diagnosis was associated with longer PN dependence (21.0 ± 20.0) than acquired (8.7 ± 7.8 months), (p = 0.02). The need for micronutrient supplementation was assessed after the transition to EA; 87.5% children had at least one micronutrient depletion, most commonly Vitamin D (64.1%), followed by iron (48.7%), Vitamin B12 (34.2%), and vitamin E (28.6%). Iron deficiency and vitamin A depletion were correlated with longer PS after multivariate analysis (OR: 1.103, 1.006-1.210, p = 0.037 and OR: 1.048, 0.998-1.102, p = 0.062 respectively). CONCLUSION: In our cohort, small bowel length was the main predictor for EA. Children on longer PS, had more often a congenital cause of resection and were at risk for micronutrient deficiencies in EA.

Effects of Atorvastatin and Rosuvastatin on Blood Lipids in Quaker Parrots (Myiopsitta monachus).

Statin drugs are the most effective class of hypolipidemic and antiatherosclerotic drugs, with atorvastatin and rosuvastatin being the most effective. While the use of statins would be a tremendous asset in the treatment of dyslipidemia and lipid-accumulation disorders in birds, there are only limited data available regarding their use and effectiveness in psittacine species. Two consecutive randomized crossover trials on Quaker parrots (Myiopsitta monachus) were performed to study the effect of atorvastatin and rosuvastatin. Ten birds were used in an initial balanced crossover experiment with 5 oral treatments (control; atorvastatin 10 mg/kg q12h and q24h; rosuvastatin 10 mg/kg q12h and q24h) for 2 weeks each. Plasma lipidomics and lipoprotein profiling were performed after each treatment. Twelve birds were used in a second experiment consisting of 2 parallel crossover studies, each with 6 birds either fed their regular diet or a 0.3% cholesterol diet. In the 2 parallel crossover studies, the treatment group was administered atorvastatin 20 mg/kg orally q12h and the control group a placebo suspension orally q12h. Plasma lipidomics, lipoprotein profiles, and 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase activity were subsequently measured. Results were analyzed with serial linear mixed models and trends were assessed graphically. No statistically significant effect of any statin treatment was detected on plasma lipids, lipoproteins, creatinine kinase, or HMG-CoA reductase activity. In the first trial, all the rosuvastatin treatments led to some nonsignificant decreases in several triacylglycerol species, while in the second trial this was only observed in the birds on atorvastatin 20 mg/kg q12h being fed their regular diet. Quaker parrots may require much higher doses of statin drugs to show significant and clinically useful lipid-lowering effects.

Investigation of Platelet Function Analyzer 200 platelet function measurements in healthy cats and cats receiving clopidogrel.

The Platelet Function Analyzer 200 (PFA-200; Siemens) is an in vitro substitute for in vivo bleeding time that is designed to investigate platelet function in a more physiologic manner than traditional aggregometry. The analyzer reports a closure time (CT) as a marker of platelet function, and may also report the calculated platelet function measurement primary hemostasis components, PHC1 and PHC2. These incorporate the measured total volume (TV) of blood aspirated and the initial flow rate (IF). We determined, for the COL/ADP and P2Y cartridges, the median total volume (TVmedian), and RIs for CT, IF, TV, PHC1, and PHC2, and investigated the sensitivity and specificity of those parameters at the determined interpretation thresholds in determination of the clopidogrel effect. Healthy client-owned cats were recruited prospectively to determine RIs for CT, IF, TV, PHC1, and PHC2. Healthy blood-donor cats and cats on clopidogrel therapy were included retrospectively to determine test performance. In 20 healthy cats, RIs for COL/ADP were CT (19.5-87.2 s), IF (199-278 µL/min), TV (199-332 µL), PHC1 (94-106%), and PHC2 (52-148%); and for P2Y, CT (4.2-94.3 s), IF (112-208 µL/min), TV (151-294 µL), PHC1 (35-178%), and PHC2 (90-109%). CVs were calculated for all of these values. Specificity for detection of the clopidogrel effect was calculated from a group of healthy blood donors, and sensitivity for detection of the clopidogrel effect from a group of cats with known clopidogrel effect. Sensitivity and specificity were, for COL/ADP: CT (83.3%, 66.6%), IF (41.4%, 83.3%), TV (83.3%, 100%), PHC1 (100%, 100%) and PHC2 (100%, 83.3%); and for P2Y: CT (100%, 94.4%), IF (30%, 44.4%), TV (100%, 94.4%), PHC1 (100%, 100%), and PHC2 (100%, 97.7%). These PFA-200 values may be beneficial in the determination of platelet function in cats.

Platelet function analyzer-200 closure curve analysis and assessment of flow-obstructed samples.

BACKGROUND: The Platelet function analyzer-200 can determine the effect of clopidogrel in cats. Flow obstruction is an error that causes uninterpretable results. Closure curves and parameters initial flow rate (IF) and total volume (TV) are displayed by the PFA-200 and may allow interpretation of results in cases of flow obstruction. The primary hemostasis components (PHC) are calculated values that normalize these parameters. OBJECTIVES: To determine if closure curves and research parameters allow detecting the effect of clopidogrel in cases of flow obstruction. METHODS: A review of closure curves identified those with flow obstruction and paired analysis that did not. Non-flow-obstructed curves were used to categorize curves with respect to clopidogrel effects. IF, TV, PHC(1), and PHC(2) were evaluated to determine if these could be used to categorize if a sample exhibited the effects of clopidogrel. Curves were visually analyzed, and characteristics identified that were more common with or without the effect of clopidogrel. Visual analysis of curves was performed by blinded observers to determine if a visual analysis was able to predict the effect of clopidogrel. RESULTS: Analysis of parameters was able to predict closure or non-closure in flow-obstructed curves. TV, PHC(1), and PHC(2) had area under the curve of the receiver operating characteristics of 0.79, 0.79, and 0.87. Visual curve analysis was unable to predict closure, with an average accuracy of only 55%, among three reviewers. Agreement between reviewers was poor (Fleiss' Kappa 0.06). CONCLUSIONS: Visual curve analysis was unable to determine the effect of clopidogrel in flow-obstructed samples. Numerical parameters were able to detect the effect of clopidogrel with a high degree of accuracy in flow-obstructed samples.

Left Ventricular Dysfunction Associated With Brain Death: Results From the Donor Heart Study.

BACKGROUND: Left ventricular dysfunction in potential donors meeting brain death criteria often results in nonuse of donor hearts for transplantation, yet little is known about its incidence or pathophysiology. Resolving these unknowns was a primary aim of the DHS (Donor Heart Study), a multisite prospective cohort study. METHODS: The DHS enrolled potential donors by neurologic determination of death (n=4333) at 8 organ procurement organizations across the United States between February 2015 and May 2020. Data included medications administered, serial diagnostic tests, and transthoracic echocardiograms (TTEs) performed: (1) within 48 hours after brain death was formally diagnosed; and (2) 24±6 hours later if left ventricular (LV) dysfunction was initially present. LV dysfunction was defined as an LV ejection fraction <50% and was considered reversible if LV ejection fraction was >50% on the second TTE. TTEs were also examined for presence of LV regional wall motion abnormalities and their reversibility. We assessed associations between LV dysfunction, donor heart acceptance for transplantation, and recipient 1-year survival. RESULTS: An initial TTE was interpreted for 3794 of the 4333 potential donors by neurologic determination of death. A total of 493 (13%) of these TTEs showed LV dysfunction. Among those donors with an initial TTE, LV dysfunction was associated with younger age, underweight, and higher NT-proBNP (N-terminal pro-B-type natriuretic peptide) and troponin levels. A second TTE was performed within 24±6 hours for a subset of donors (n=224) with initial LV dysfunction; within this subset, 130 (58%) demonstrated reversibility. Sixty percent of donor hearts with normal LV function were accepted for transplant compared with 56% of hearts with reversible LV dysfunction and 24% of hearts with nonreversible LV dysfunction. Donor LV dysfunction, whether reversible or not, was not associated with recipient 1-year survival. CONCLUSIONS: LV dysfunction associated with brain death occurs in many potential heart donors and is sometimes reversible. These findings can inform decisions made during donor evaluation and help guide donor heart acceptance for transplantation.

Validation of storage and shipping of feline blood samples for analysis on the Platelet Function Analyzer-200 for determining the effect of clopidogrel.

BACKGROUND: The Platelet function analyzer-200 (PFA-200) can determine the effect of clopidogrel in cats, but analysis traditionally must be performed at point-of-care (POC). The ability to ship samples of blood to a laboratory would allow widespread access. OBJECTIVES: We aimed to validate the shipping of blood samples for PFA-200 analysis in cats to determine the effect of clopidogrel. METHODS: Twenty healthy cats and 10 cats receiving clopidogrel were recruited. Blood was collected from cats and aliquoted into two samples, one was analyzed at POC within 2 hours using the PFA-200, and the other was packaged and transported to a location 4 km away, stored, and transported back to the lab for analysis the following day. RESULTS: Median closure times (CTs) with the collagen/adenosine diphosphate (COL/ADP) cartridge in healthy cats were 51.5 seconds (POC) and 78.8 seconds (shipped), which were significantly different (P < 0.001), and for cats on clopidogrel, median CTs were 147.5 seconds (POC) and 190 seconds (shipped), which were not significantly different (P = 0.131). Median CTs with the P2Y cartridge in healthy cats were 50.5 seconds (POC) and 64.9 seconds (shipped), which were significantly different (P = 0.03), and in cats receiving clopidogrel, median CTs were 300 seconds (POC) and 300 seconds (shipped) which were not significantly different (P = 1.000). Reference intervals for CTs differed for COL/ADP at POC (19.8-89.7 seconds) and shipped (50.9-161.6 seconds) and for P2Y at POC (35.5-118.8 seconds) and shipped (35.1-108.9 seconds). Receiver operating characteristics showed similar areas under the curve (AUCROCs) regarding the effect of clopidogrel for COL/ADP at POC (0.994 seconds) and shipped (0.932) and for P2Y at POC (0.904 seconds) and shipped (0.975 seconds). When classifying for the presence of clopidogrel effects, Cohen's Kappa was 0.62 for COL/ADP and 1.00 for P2Y. CONCLUSIONS: Shipping blood samples for PFA analysis are feasible with similar performance to POC analyses for determining the effect of clopidogrel in cats.

Extended sample storage for platelet function testing in healthy dogs.

BACKGROUND: Platelet function testing is important for monitoring the effects of antiplatelet therapy but is not readily used due to time constraints for testing and the need for specialized equipment. OBJECTIVES: This study evaluated the effects of various storage methods on selected platelet function tests to determine if delayed platelet function testing is feasible in canine blood samples. Our hypotheses were that platelet function would not decline during storage and, thus, no differences in test results would be found over time. METHODS: Thirteen healthy dogs were studied. Citrated blood samples were tested with a Platelet Function Analyzer-200 (PFA), which mimics high-shear conditions, using P2Y and CADP cartridges, after being held at room temperature for 2 h and refrigerated for 24 and 48 h. Plateletworks (PW), which measures aggregation based on platelet counting, was performed on an optical hematology analyzer using 10-min-old native samples, citrated samples held at room temperature for 3-4 h and refrigerated for 24 and 48 h, and samples stored in the preservative solution, AGGFix, up to 7 days. RESULTS: PFA closure times increased with storage, especially with the P2Y cartridge. Median aggregation with fresh PW was 94%, and this was maintained at all time points (range of median values 88%-94%). Most samples showed decreased, yet still robust (>70%), aggregation with longer storage. Spontaneous aggregation in citrate was noted in most dogs. AGGFix stabilized platelet aggregates to allow for delayed testing. CONCLUSIONS: Delayed platelet function testing is feasible, but ranges of expected values may differ from tests using fresh samples.

Validation of Plateletworks ADP for the ProCyte Dx analyzer.

BACKGROUND: Platelet function testing in cats allows determination of clopidogrel effect. Plateletworks assesses aggregation based on decreasing platelet counts on hematology analyzers in response to agonists. It has not been validated for the IDEXX ProCyte Dx analyzer. Ideal time to perform analysis and the utility of other platelet parameters have not been fully assessed. OBJECTIVES: To validate Plateletworks ADP on the ProCyte Dx, to investigate the utility of various platelet parameters using Plateletworks ADP, and determine the ideal time to perform analysis. ANIMALS: Twenty healthy cats recruited from the general population used for transference of reference intervals to a new analyzer, and 10 cats receiving clopidogrel to determine clopidogrel effect. METHODS: Plateletworks ADP using the ProCyte Dx and ADVIA 2120i analyzer was run simultaneously in both healthy cats and cats receiving clopidogrel, and CBC results at different timepoints were compared between analyzers. RESULTS: Aggregation was significantly different (P < .001) between analyzers. Cohen's kappa showed almost perfect agreement for determination of clopidogrel effect, and the area under the curve of the receiver operating characteristic was 1.0. Lower limits of the aggregation reference interval in healthy cats were 28.8% on the ProCyte Dx and 12.5% on the ADVIA 2120i. Coefficients of variation for platelet parameters were not different between analyzers. No significant changes in mean platelet volume, plateletcrit, large platelets, and mean platelet component were identified. No significant change in aggregation was observed within the first hour after phlebotomy. CONCLUSIONS AND CLINICAL IMPORTANCE: Our study validated the Plateletworks ADP system on the ProCyte Dx analyzer. Samples may be analyzed up to 1 h after collection.

Spring and latch dynamics can act as control pathways in ultrafast systems.

Ultrafast movements propelled by springs and released by latches are thought limited to energetic adjustments prior to movement, and seemingly cannot adjust once movement begins. Even so, across the tree of life, ultrafast organisms navigate dynamic environments and generate a range of movements, suggesting unrecognized capabilities for control. We develop a framework of control pathways leveraging the non-linear dynamics of spring-propelled, latch-released systems. We analytically model spring dynamics and develop reduced-parameter models of latch dynamics to quantify how they can be tuned internally or through changing external environments. Using Lagrangian mechanics, we test feedforward and feedback control implementation via spring and latch dynamics. We establish through empirically-informed modeling that ultrafast movement can be controllably varied during latch release and spring propulsion. A deeper understanding of the interconnection between multiple control pathways, and the tunability of each control pathway, in ultrafast biomechanical systems presented here has the potential to expand the capabilities of synthetic ultra-fast systems and provides a new framework to understand the behaviors of fast organisms subject to perturbations and environmental non-idealities.

Transplant of organs from donors with positive SARS-CoV-2 nucleic acid testing: A report from the organ procurement and transplantation network ad hoc disease transmission advisory committee.

BACKGROUND: Decisions to transplant organs from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleic acid test-positive (NAT+) donors must balance risk of donor-derived transmission events (DDTE) with the scarcity of available organs. METHODS: Organ Procurement and Transplantation Network (OPTN) data were used to compare organ utilization and recipient outcomes between SARS-CoV-2 NAT+ and NAT- donors. NAT+ was defined by either a positive upper or lower respiratory tract (LRT) sample within 21 days of procurement. Potential DDTE were adjudicated by OPTN Disease Transmission Advisory Committee. RESULTS: From May 27, 2021 (date of OTPN policy for required LRT testing of lung donors) to January 31, 2022, organs were recovered from 617 NAT+ donors from all OPTN regions and 53 of 57 (93%) organ procurement organizations. NAT+ donors were younger and had higher organ quality scores for kidney and liver. Organ utilization was lower for NAT+ donors compared to NAT- donors. A total of 1241 organs (776 kidneys, 316 livers, 106 hearts, 22 lungs, and 21 other) were transplanted from 514 NAT+ donors compared to 21 946 organs from 8853 NAT- donors. Medical urgency was lower for recipients of NAT+ liver and heart transplants. The median waitlist time was longer for liver recipients of NAT+ donors. The match run sequence number for final acceptor was higher for NAT+ donors for all organ types. Outcomes for hospital length of stay, 30-day mortality, and 30-day graft loss were similar for all organ types. No SARS-CoV-2 DDTE occurred in this interval. CONCLUSIONS: Transplantation of SARS-CoV-2 NAT+ donor organs appears safe for short-term outcomes of death and graft loss and ameliorates the organ shortage. Further study is required to assure comparable longer term outcomes.

Treatment of myeloid neoplasia with doxorubicin and cytarabine in 11 dogs.

Myelodysplastic syndrome (MDS) and acute myeloid leukaemia (AML) are primary myeloid neoplasms in dogs generally considered to have a poor outcome. In this study, we assessed toxicity, efficacy and outcome of concurrent administration of doxorubicin and cytarabine in 11 dogs with myeloid neoplasia. Bone marrow specimens were reviewed by three pathologists and classified as either MDS (n = 2), high grade MDS/early AML (MDS/AML; n = 4) or AML (n = 5). The median number of treatment cycles was 5 (range 1-9) and resolution of cytopenia was reported in 7 of 11 dogs including 2 dogs with MDS, 2 dogs with MDS/AML, and 3 dogs with AML. The median duration of remission in the seven responders was 344 days (range 109-1428) and the median overall survival for all dogs was 369 days. Adverse events consisted of predominantly low-grade gastrointestinal illness and myelosuppression. Three dogs developed grade V toxicity manifesting with heart failure (n = 2) at 369 and 1170 days after diagnosis and acute gastrointestinal side effects (n =1). Despite a limited sample size, these results suggest that a doxorubicin and cytarabine protocol may be considered as a therapeutic option in dogs with myeloid neoplasia. Protocol safety, in particular regarding myocardial toxicity, and efficacy should be further investigated.

Statewide survey of medically important ticks on white-tailed deer, Odocoileus virginianus Zimmerman, in Alabama, U.S.A.

A statewide survey of the tick fauna found on deer, using harvested deer heads as the sample unit, was conducted during the Alabama hunting seasons of 2019-2020 and 2020-2021. Four species of ticks: Ixodes scapularis (n= 936, % of catch 69.1%), Amblyomma americanum (315, 23.2%), Dermacentor albipictus (97, 7.1%), and Amblyomma maculatum (6, 0.4%) were taken from 151 deer heads harvested from 21 deer processing centers (n = 4-17 heads/processor). A total of 87.7% (prevalence) of deer heads had one or more ticks. We used two standard numerical descriptors of tick numbers, abundance, and relative abundance. No significant stepwise regressions (p > 0.05) were found between tick abundance (all ticks, I. scapularis, A. americanum) and the predictor variables of latitude, deer density, season, and year. In addition, the correlation between the abundance of I. scapularis and A. americanum was not significant (p > 0.5). In contrast, the relative abundance of both I. scapularis and A. americanum showed a significant (P < 0.05) relationship with latitude, with the relative abundance of I. scapularis increasing on deer with increased latitude and A. americanum showing the opposite pattern.

Outcomes of a High-Volume Organ Procurement Organization in the Era of Increasing Donation After Circulatory Death.

Introduction: Donation after circulatory death (DCD) is rapidly increasing in the United States. Detailed data outlining the process from referral to organ transplantation is lacking. Project Aims: We sought to quantify differences at each stage along the referral to donation pathway by donor type. Additionally, we examined factors associated with successful DCD organ utilization. Design: This program evaluation analyzed data from a single organ procurement organization in 2018 to assess demographic and clinical predictors of progression through the donation process, including the role of first-person authorization in DCD. Descriptive statistics were examined by donation stage for demographic characteristics using chi-square; univariate and multivariate logistic regression was used to model predictors of utilization and authorization by organ type, respectively. Results: There were 2466 organ donation referrals during 2018, including 575 donations after brainstem death (DBD), 1890 controlled DCD referrals, and 1 uncontrolled DCD referral. Univariate and multivariate logistic regression models highlighted differences in authorization rates by donor type (DCD vs DBD) and by age, race, and ethnicity. Next-of-kin authorization was declined in 23% of first-person authorized potential DCD, highlighting issues related to the role of donor registration in DCD. Pre-mortem heparin administration was predictive of DCD organ utilization; donor age and warm ischemia time of less than 30 min was statistically significantly associated with DCD extra-renal organ utilization. Conclusion: These results provided insight into strategies for increasing authorization and transplantation of organs from DCD donors and identified areas of improvement for process standardization and policy development.