Background Long COVID is a common complication of infection with severe acute respiratory syndrome coronavirus 2, but the prevalence and predictors of the condition remain poorly characterized.Methods We prospectively studied adults (>= 18 years) with acute coronavirus disease 2019 (COVID-19) presenting to an urban safety net hospital and associated clinics between July 2020 and December 2022. Logistic regression models were used to evaluate the association between baseline demographic, clinical, and laboratory characteristics with long COVID status, defined as symptoms persisting at least 9 months after acute disease. Among unrecovered participants, we describe the prevalence of individual symptoms.Results We enrolled 222 participants, 162 (73%) of whom had known recovery status by 9 months. Median age was 54 years, half (55%) were female, and the majority of participants (78%) had at least 1 comorbidity at the time of COVID-19 diagnosis. Based on acute illness characteristics, the adjusted odds ratio for long COVID was 3.0 (95% confidence interval [CI], 1.1-8.0) among those with detectable nucleocapsid antigen and 3.6 (95% CI, 1.2-11) for those who required supplemental oxygen. Of the 41% of participants with symptoms persisting at least 9 months, central nervous system and psychological symptoms were most commonly reported, with 57% reporting functional limitations due to their persistent symptoms.Conclusions The strong association with initial disease suggests a decreasing prevalence of long COVID as acute illnesses become milder. However, many contemporary patients still experience high viral burden with extended viral replication, even after vaccination. Our findings highlight the importance of properly characterizing long COVID as viral evolution shifts acute disease presentation.

Abstract Malaria, which results from infection with Plasmodium parasites, remains a major public health problem with over 200 million cases and nearly 500,000 deaths annually. Although long-lived, sterilizing immunity does not develop in humans following repeated exposure to Plasmodium parasites, protection against symptomatic disease correlates with the acquisition of humoral immunity. Despite the established role antibodies play in protection to malaria disease, excessive inflammation is thought to contribute to the ineffective immune response to Plasmodium infection. Plasmodium berghei ANKA (PbA) infection results in a fatal severe malaria disease in mice. We previously showed that treatment of mice with IL-15 complex (IL-15C; IL-15 bound to an IL-15Rα-Fc fusion protein) induces IL-10 expression in NK cells, which protects mice from PbA-induced death by dampening the fatal inflammatory response. Interestingly, IL-15C treatment promotes Tfh differentiation at 7 days post-PbA infection (dpi), and genetic deletion of NK cell-derived IL-10 or antibody blockade of IL-10R prevents IL-15C-induced Tfh differentiation. Additionally, IL-15C treatment enhances CD4 T cell-derived IL-27p28 production at 7 dpi and results in increased anti-PbA IgG antibody levels at 42 dpi. These data suggest that IL-15C treatment, via its induction of IL-10 from NK cells, modulates the inflammatory milieu to promote Tfh differentiation, IL-27 production, and PbA-specific antibody generation. These findings will facilitate improved control of malaria infection and protection from disease by informing therapeutic strategies and vaccine design. Supported by grants from NIH (K22 AI143969-01A1, K08 AI141761-01)

Background: Preclinical models of prostate cancer are challenging to develop and maintain, especially those that grow in a castrated setting while maintaining receptor and antigen expression. To this end, we have established and characterized a panel of XenoSTART patient-derived (XPDX) prostate models using both intact and castrated athymic nude mice. These models, designated ST1273, ST2347, ST4017, and ST4420, were characterized for receptor expression, genomic alterations, and in vivo drug sensitivity to relevant therapies. Methods: XPDX models representing prostate cancer were established from primary (ST1273) or metastatic (ST2347, ST4017, ST4420) biopsy samples implanted into intact athymic nude mice supplemented with exogenous testosterone. Resulting models were passaged and further developed in both intact and castrated athymic nudes until growth stabilization. Resulting models were characterized using genomic analysis, including WES and RNAseq, receptor expression, and in vivo drug sensitivity studies. Models found sensitive to enzalutamide were conditioned to resistance in vivo by chronic drug administration and resulting models (designated STxxxx/EZR) were characterized and compared with parent lines. For in vivo studies, activity of relevant treatments were benchmarked including enzalutamide administered once daily by oral gavage at 50 mg/kg and docetaxel administered by intravenous injection once weekly at 10 mg/kg. In vivo study endpoints included tumor volume and time from treatment initiation with %T/C values and tumor regression reported at study completion; a %T/C of ≤ 20 versus control was considered sensitive. Results: Each model developed in a castrate or conditioned setting retained similar receptor expression to the parent model including positive AR (2+/3+) and PSMA (2+/3+) staining. Genomic characterization identified a PIK3CA mutation in ST1273 models (PIK3CAE545A), AR mutations in ST2347 (ART878A) and ST4017 (ARH875Y), and a TMPRSS2:ERG fusion in ST4420. In vivo, the ST1273 parent model was found sensitive to enzalutamide (%T/C=11%) but insensitive in castrated mice (%T/C=76%) and the ST1273/EZR model was resistant to enzalutamide in intact (%T/C=56%) or castrated (%T/C=100%) mice. The ST2347 parent model was also found sensitive to enzalutamide (%T/C=19%) but insensitive in castrated mice (%T/C=50%). ST4017 and ST4420 studies in intact and castrated mice are currently underway. All models were sensitive to docetaxel. Conclusion: We have established and characterized a panel of prostate XPDX models using both intact and castrated athymic nude mice and conditioned resistance to enzalutamide by chronic drug administration. These models can be utilized as a valuable tool in better understanding castrate-resistant prostate cancer and in developing novel therapies for enzalutamide-resistant patients. Citation Format: Johnnie Flores, Alyssa Simonson, Dustin Kneifel, Alejandra Diaz, Morgan Harris, Kyriakos Papadopoulos, Amita Patnaik, Drew Rasco, Scott Ulmer, Michael J. Wick. Establishment and characterization of a panel of castrate-resistant prostate cancer XPDX models with differential enzalutamide response [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3109.

Background: First-line treatment for some cancer types includes platinum-based therapy. While the rate of initial response to treatment is high, most patients develop platinum-resistant disease. Current salvage therapy provides benefit to some patients, demonstrating the need for additional effective therapies. To assist in identifying new therapies, we have established XenoSTART patient-derived xenograft (XPDX) models representing breast, ovary, uterine, and lung cancers. Each model was characterized by DNA/RNA analysis, sensitivity to platinum treatment, and annotated with donor patient treatment status at the time of sample collection. Methods: 210 XPDX models were evaluated in this screen including 66 breast, 56 ovary, 36 uterine, and 52 lung xenografts. WES and RNAseq were performed on each model and patient treatment history and outcome annotated. For in vivo studies, models were implanted into female nudes and administered (IP; q7dx3) 3 m/k cisplatin or 60 m/k carboplatin. Study endpoints included tumor volume and time from treatment initiation with %T/C values and tumor regression reported at study completion; a %T/C of ≤ 20 versus control was considered sensitive. Results: Study results are summarized below in Table 1: Sequencing identified several variants in resistant, chemo-naïve models including point mutations in RAS/RAF/MET/PIK3CA genes and others, while sensitive models lacked common driver mutations. Conclusion: We have characterized 210 XPDX models. Uterine models were most often resistant to platinum, while almost 1/2 of ovary and 1/3 of breast models were sensitive, regardless of treatment status. Only 15% of lung models were sensitive to platinum; cancer driver variants were found in several models. Overall, we report differential platinum sensitivity in a panel of diverse models useful in understanding mechanisms of resistance and for development of effective therapies in platinum-resistant cancers. Table 1. Type Breast Ovary Uterine Lung Total 66 56 36 52 # Sensitive 25 25 9 8 % 38% 45% 25% 15% Naïve 11 16 8 5 % 44% 64% 89% 63% P-1st 6 6 1 2 % 24% 24% 11% 25% P-2nd+ 6 3 0 1 % 24% 12% 0% 13% # Insensitive 41 31 27 44 % 62% 55% 75% 85% Naïve 11 9 20 21 % 27% 29% 74% 48% P-1st 14 10 5 13 % 34% 32% 19% 30% P-2nd+ 16 12 2 10 % 39% 39% 7% 23% Naïve=No Prior Treatment; P-1st=Post 1st Line Therapy; P-2nd=Post 2nd+ Line Therapy Citation Format: Alyssa Simonson, Johnnie Flores, Lizette Firova, Christian Hernandez, Morgan Harris, Kyriakos Papadopoulos, Drew Rasco, Amita Patnaik, Allan White, Lon Smith, Ronald Drengler, Amy Lang, Murali Beeram, Michael J. Wick. Correlation of platinum sensitivity with donor patient treatment status in a panel of breast, ovary, uterine, and lung XPDX models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1092.

Behavioral inhibition (BI) is a temperament characteristic in which an individual tends to avoid unfamiliar situations or environments. Individuals with high BI are more vulnerable to developing an anxiety disorder, such as Post‐Traumatic Stress Disorder (PTSD), when placed under stressful conditions (Gladstone and Parker, 2005). Behaviorally inhibited organisms learn faster and are slower to extinguish the response to a stimulus (Sheynin et al., 2013; Servatius et al.,, 2008). Our lab over the past several years has been investigating the relationship between a respiratory stress response to CO2 and BI. In this study, participants played a computer game used previously by Sheynin et al., 2013, to evaluate avoidance acquisition and extinction. BI and non‐BI individuals were separated based on Adult Measure of Behavioral Inhibition (AMBI) and Retrospective Measure of Behavioral Inhibition (RMBI). Gas volumes of 4.5% and 7.0% CO2 were applied as different doses of a respiratory stimulant to further the understanding of any physiological differences in breathing between those with BI compared to those without. We hypothesize that individuals with high BI exhibit differences in all parameters of breathing compared to non‐BI individuals during both levels of CO2, and therefore predict that individuals with high BI respond more robustly to CO2. The 4.5% and 7.0% CO2 were obtained by mixing room air with pure CO2 in a Tissot Spirometer and validated using an Oxygraph O2 and CO2 analyzer. The mixed gas was then delivered from a 100 liter gas bag attached to a breathing tube attached to a Hans Rudolph two‐way non‐rebreathing valve. The subjects placed a two‐way valve attached to a mouthpiece into their mouths and then had a nose clip placed over their noses to create a tight seal between the breathing gas bags and themselves. Respiratory data were collected using a BioPac computer data collection system. Our sample sizes are for 4.5% CO2 – Air BI (n=8) and for non‐BI (n=7), and for 7.0% CO2 – Air BI (n=5) and for non‐BI (n=7). When the data were analyzed there were no apparent differences for VT, VI, Fbr between BI and non‐BI individuals exposed to 7.0% CO2, however, in the 4.5% CO2 breathing parameters there was a marked increased both in absolute value and in percent change for Fbr for BI individuals when compared to non‐BI individuals. Given the small sample sizes of the groups, we conclude that increasing the sample sizes is necessary before any more substantive conclusions can be drawn. In addition, our future studies will include measurements of heart rate, blood pressure, salivary cortisol and salivary amylase.Support or Funding InformationNASA Training Grant #NNX15Aj12H, Wisconsin Space Grant Consortium Infrastructure Grant, RIP‐17 #30116‐03This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Behavioral inhibition (BI) is a temperament in which an individual tends to avoid unfamiliar situations or environments. Individuals with high BI are more vulnerable to developing an anxiety disorder, such as Post‐Traumatic Stress Disorder (PTSD), when placed under stressful conditions. Behaviorally inhibited individuals learn faster and are slower to stop the response to a stimulus (Sheynin, 2005; Servatius, 2008). Our lab over the past several years has been investigating the relationship between a respiratory stress response to 4.5% CO2 and BI. BI is characterized by avoidance behavior, which is an active response aimed to reduce fear of a certain stimulus. In this study, a computer game was used as an aversive stimulus to detect BI. 4.5% CO2 was applied as a mild respiratory stimulant to detect any differences in those with BI compared to those without. One indication of PTSD is avoidance behaviors. 4.5% CO2 decreases the pH of the blood, hence causing an increase in frequency of breathing (fbr), tidal volume (VT), and inspired minute ventilation (VI). We hypothesize that individuals with high BI will exhibit greater increases in all parameters of breathing compared to individuals with low BI. The 4.5% CO2 was obtained by mixing room air with pure CO2 in a Tissot Spirometer and was validated using an Oxygraph O2 and CO2 analyzer. The mixed gas was then delivered from a 100 liter gas bag attached to a breathing tube attached to a Hans Rudolph two‐way nonrebreathing valve. The subjects placed the two‐way valve attached to a mouthpiece into their mouths and then had a nose clip placed over their noses to created a tight seal between the breathing gas bags and the participants. BI and non‐BI individuals were separated based on Adult Measure of Behavioral Inhibition (AMBI) and Retrospective Measure of Behavioral Inhibition (RMBI). Heart rate and respiratory data were collected using a BioPac computer data collection system while breathing room air and 4.5% CO2. In BI individuals, we observed a 35.9% (+/−33.3) increase in minute ventilation and a 32.4% (+/−32.1) increase in breathing frequency (n=4). In non‐BI individuals, we observed a −6.4% (+/−18.3) decrease in minute ventilation and a −15.1% (+/−2.9) decrease in breathing frequency (n=2). We observed no difference in tidal volume or heart rate for either group. In conclusion, individuals who scored high on the BI test have a greater response to a respiratory stimuli. Our future studies will include cortisol measurements by analyzing saliva samples taken before and after the test. Support or Funding Information Carthage College Research and Development Grants

The method of parabiosis has been called into use by a number of workers in efforts to determine whether resistance to transplanted tumors is conditional on the presence of circulating antibodies in the host. In 1909 Rous (13) united tumor-bearing rats with those of another strain which were resistant to the growth of the tumor, but this procedure did not produce any observable effect on the growth of the tumors. Lambert (8), however, asserted that mouse sarcoma grew better and for a longer time in rats joined parabiotically with mice than in intact rats. According to Albrecht and Hecht (1), the parabiotic relation in itself led to a resistance against the transplanted tumors; mouse carcinoma grafted into either member of a pair of mice grew much more slowly than in controls. Similar results were reported in rats by Kross (7), who preferred to base an explanation on possible ill health of the animals. The illuminating researches of Morpurgo (11) tended to confirm the earlier conclusions of Rous. Morpurgo found that if susceptible and resistant rats were united and the tumor concerned placed in the peritoneal cavity common to the two animals, growth of the implanted cells occurred 0nly in the tissues of the susceptible animal. Recently Furth, Barnes, and Brower (5) have used the parabiotic technic to investigate whether susceptibility or resistance to leukemia in mice is transferable. In varied series, involving the union of susceptible with resistant mice, no evidence was found that either of these hereditary qualities could be modified by parabiosis. In all the investigations mentioned above the animals termed resistant had either acquired resistance prior to operation or possessed this condition as a hereditary trait. It is of additional interest to study the development of resistance in animals already in parabiotic connection, and in particular, the influence of regression of a tumor in one parabiont on the later inoculation of the same tumor in the opposite para-