Genome wide CRISPR screen for Pasteurella multocida toxin (PMT) binding proteins reveals LDL Receptor Related Protein 1 (LRP1) as crucial cellular receptor.

PMT is a protein toxin produced by Pasteurella multocida serotypes A and D. As causative agent of atrophic rhinitis in swine, it leads to rapid degradation of the nasal turbinate bone. The toxin acts as a deamidase to modify a crucial glutamine in heterotrimeric G proteins, which results in constitutive activation of the G proteins and permanent stimulation of numerous downstream signaling pathways. Using a lentiviral based genome wide CRISPR knockout screen in combination with a lethal toxin chimera, consisting of full length inactive PMT and the catalytic domain of diphtheria toxin, we identified the LRP1 gene encoding the Low-Density Lipoprotein Receptor-related protein 1 as a critical host factor for PMT function. Loss of LRP1 reduced PMT binding and abolished the cellular response and deamidation of heterotrimeric G proteins, confirming LRP1 to be crucial for PMT uptake. Expression of LRP1 or cluster 4 of LRP1 restored intoxication of the knockout cells. In summary our data demonstrate LRP1 as crucial host entry factor for PMT intoxication by acting as its primary cell surface receptor.

Comparison of Reverse-Transcription Polymerase Chain Reaction Cycle Threshold Values From Respiratory Specimens in Symptomatic and Asymptomatic Children With Severe Acute Respiratory Syndrome Coronavirus 2 Infection.

BACKGROUND: Understanding viral kinetics of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is important to assess risk of transmission, manage treatment, and determine the need for isolation and protective equipment. The impact of viral load in asymptomatic infected children is important to understand transmission potential. We sought to determine whether children deemed to be asymptomatic had a difference in the polymerase chain reaction (PCR) cycle threshold (Ct) value of respiratory samples from symptomatic children with SARS-CoV-2 infection. METHODS: This was a retrospective cross-sectional study to compare PCR Ct values of children who tested positive for SARS-CoV-2 by respiratory samples collected over a 4-month period at a large tertiary care children's hospital. RESULTS: We analyzed 728 children who tested positive for SARS-CoV-2 by reverse-transcription PCR (RT-PCR) from a respiratory sample over a 4-month period and for whom data were available in the electronic medical record. Overall, 71.2% of infected children were symptomatic. The mean Ct value for symptomatic patients (Ct mean, 19.9 [standard deviation, 6.3]) was significantly lower than for asymptomatic patients (Ct mean, 23.5 [standard deviation, 6.9]) (P < .001; 95% confidence interval, 2.6-4.6). The mean PCR Ct value was lowest in children <5 years of age. CONCLUSIONS: In this retrospective review of children who tested positive by RT-PCR for SARS-CoV-2, the mean Ct was significantly lower in symptomatic children and was lowest in children <5 years of age, indicating that symptomatic children and younger children infected with SARS-CoV-2 may have a higher viral load in the nasopharynx compared to asymptomatic children. Further studies are needed to assess the transmission potential from asymptomatic children.

Comparison of RT-PCR Cycle Threshold Values from Respiratory Specimens in Symptomatic and Asymptomatic Children with SARS-CoV-2 Infection.

BACKGROUND: Understanding viral kinetics of SARS-CoV-2 is important to assess risk of transmission, manage treatment, and determine the need for isolation and protective equipment. The impact of viral load in asymptomatic infected children is important to understand transmission potential. We sought to determine whether children deemed to be asymptomatic had a difference in the PCR cycle threshold (Ct) value of respiratory samples from symptomatic children with SARS-CoV-2 infection. METHODS: This was a retrospective cross-sectional study to compare PCR Ct values of children who tested positive for SARS-CoV-2 by respiratory samples collected over a 4-month period at a large tertiary care children's hospital. RESULTS: We analyzed 728 children who tested positive for SARS-CoV-2 by RT-PCR from a respiratory sample over a 4-month period and for whom data was available in the electronic medical record. Overall, 71.2% of infected children were symptomatic. The mean Ct value for symptomatic patients (Ct mean 19.9, SD 6.3) was significantly lower than asymptomatic patients (Ct mean 23.5, SD 6.5) (P value < 0.001, CI 95th 2.6 - 4.6). The mean PCR Ct value was lowest in children less than 5 years of age. CONCLUSIONS: In this retrospective review of children who tested positive by RT-PCR for SARS CoV-2, the mean Ct was significantly lower in symptomatic children and was lowest in children under 5 years of age, indicating that symptomatic children and younger children infected with SARS-CoV-2 may have a higher viral load in the nasopharynx compared to asymptomatic children. Further studies are needed to assess the transmission potential from asymptomatic children.

Applicability of the CT Radiomics of Skeletal Muscle and Machine Learning for the Detection of Sarcopenia and Prognostic Assessment of Disease Progression in Patients with Gastric and Esophageal Tumors.

PURPOSE: Sarcopenia is considered a negative prognostic factor in patients with malignant tumors. Among other diagnostic options, computed tomography (CT), which is repeatedly performed on tumor patients, can be of further benefit. The present study aims to establish a framework for classifying the impact of sarcopenia on the prognosis of patients diagnosed with esophageal or gastric cancer. Additionally, it explores the significance of CT radiomics in both diagnostic and prognostic methodologies. MATERIALS AND METHODS: CT scans of 83 patients with esophageal or gastric cancer taken at the time of diagnosis and during a follow-up period of one year were evaluated retrospectively. A total of 330 CT scans were analyzed. Seventy three of these patients received operative tumor resection after neoadjuvant chemotherapy, and 74% of the patients were male. The mean age was 64 years (31-83 years). Three time points (t) were defined as a basis for the statistical analysis in order to structure the course of the disease: t1 = initial diagnosis, t2 = following (neoadjuvant) chemotherapy and t3 = end of the first year after surgery in the "surgery" group or end of the first year after chemotherapy. Sarcopenia was determined using the psoas muscle index (PMI). The additional analysis included the analysis of selected radiomic features of the psoas major, quadratus lumborum, and erector spinae muscles at the L3 level. Disease progression was monitored according to the response evaluation criteria in solid tumors (RECIST 1.1). CT scans and radiomics were used to assess the likelihood of tumor progression and their correlation to sarcopenia. For machine learning, the established algorithms decision tree (DT), K-nearest neighbor (KNN), and random forest (RF) were applied. To evaluate the performance of each model, a 10-fold cross-validation as well as a calculation of Accuracy and Area Under the Curve (AUC) was used. RESULTS: During the observation period of the study, there was a significant decrease in PMI. This was most evident in patients with surgical therapy in the comparison between diagnosis and after both neoadjuvant therapy and surgery (each p < 0.001). Tumor progression (PD) was not observed significantly more often in the patients with sarcopenia compared to those without sarcopenia at any time point (p = 0.277 to p = 0.465). On average, PD occurred after 271.69 ± 104.20 days. The time from initial diagnosis to PD in patients "with sarcopenia" was not significantly shorter than in patients "without sarcopenia" at any of the time points (p = 0.521 to p = 0.817). The CT radiomics of skeletal muscle could predict both sarcopenia and tumor progression, with the best results for the psoas major muscle using the RF algorithm. For the detection of sarcopenia, the Accuracy was 0.90 ± 0.03 and AUC was 0.96 ± 0.02. For the prediction of PD, the Accuracy was 0.88 ± 0.04 and the AUC was 0.93 ± 0.04. CONCLUSIONS: In the present study, the CT radiomics of skeletal muscle together with machine learning correlated with the presence of sarcopenia, and this can additionally assist in predicting disease progression. These features can be classified as promising alternatives to conventional methods, with great potential for further research and future clinical application. However, when sarcopenia was diagnosed with PMI, no significant correlation between sarcopenia and PD could be observed.

Assessing pediatric trauma specimen integrity.

OBJECTIVE: This study investigated the quality of trauma specimens by comparing line draws to venipuncture. DESIGN: The draw type (line or venipuncture); container type (Vacutainer or Microtainer); and suitability for processing (processed/hemolyzed/clotted) of routinely collected trauma specimens was analyzed. SETTING: The clinical laboratory of a Level I Pediatric Trauma Center. MAIN OUTCOME MEASURE: Hemolyzed trauma specimens were analyzed according to method of collection, collector, and type of container to identify issues resulting in unusable samples. RESULTS: The data shows that for 13% of all draws, portions of the results were affected by hemolysis. Sixteen percent of line draws and 6% of venipunctures were hemolyzed (p = 0.04). There was no statistical association with who collected the sample (p = 0.07) or type of container (p = 1.00). CONCLUSION: Based on this sample of data, the laboratory recommends that, whenever possible, venipunctures be performed for laboratory testing of blood specimens to improve trauma specimen integrity.

Pediatric transplantation: the Hamburg experience.

BACKGROUND: Since starting our program in 1989, 455 pediatric orthotopic liver transplantations have been performed using all techniques. In April 2001, we experienced our last in-hospital death of a pediatric liver-transplant recipient. Since then, all our liver-transplant children (n=170) were able to be discharged from the hospital. The aim of this study is to analyze the actual status of pediatric liver transplantation at the University of Hamburg and to find future perspectives to improve the results after pediatric liver transplantation. METHODS: From May 4, 2001 until September 8, 2004, 22 (13%) whole organs, 18 (11%) reduced-size organs, 79 (47%) split organs, and 51 (30%) organs from living donors were transplanted into 142 patients. One hundred forty-one were primary liver transplants, 25 retransplants, 3 third, and 1 fourth liver transplants. Of the 170 orthotopic liver transplantations (OLT), 31 (18%) were highly urgent (United Network of Organ Sharing [UNOS] I). RESULTS: After 170 consecutive pediatric liver transplants, no patients died during the hospital course (100% patient survival<3 months), but overall, 5 (2.9%) recipients died during further follow-up. The 3-month and actual graft survival rates are 93% and 85%, respectively. Twenty (11.8%) children had to undergo retransplantation. However, patient survival was not sustained by longer graft survival. Analyzing our series, we see that graft survival after reduced-size liver transplantation showed a significantly lower rate versus living-donor liver transplantation. CONCLUSION: The learning curve in pediatric liver transplantation has reached a turning point where immediate patient survival is considered the rule. The challenge is to increase graft survival to the same level. The long-term management of the transplant patients, with the aim of avoiding late graft loss and achieving excellent quality of life, will become the center of the debate.

Telemanagement of heart failure: a diuretic treatment algorithm for advanced practice nurses.

Thirty-three percent of patients with heart failure (HF) are readmitted to the hospital with worsening disease within 90 days of discharge. Acute decompensation accounts for nearly 50% of these admissions because of nonadherence with diet guidelines, medication regimens, or both. One way to promote adherence is through a disease management approach that can prevent HF decompensation by providing aggressive follow-up care. Within such an approach, advanced practice nurses can use a decision algorithm to implement pharmacologic and nonpharmacologic interventions. This article presents a diuretic treatment algorithm for advanced practice nurses as part of a telemanagement program. Preliminary data from the implementation of such an algorithm within an established HF program shows a decrease in hospitalizations rates and cost of care. In addition, the algorithm helps define the scope of advanced practice nursing and promotes consistency across health care sites.

Remote titration of carvedilol for heart failure patients by advanced practice nurses.

BACKGROUND: beta-blockers (BB) in the treatment of heart failure (HF) are frequently underprescribed and underdosed, perhaps because of recommendations for office visits at each dose change. In previous work, we demonstrated the feasibility of remote telephonically assisted BB titration and found favorable effects on morbidity, time to target dose, and low withdrawal rates. In the current expanded evaluation, we reasoned that a structured remote telephonic titration protocol would achieve outcomes comparable to US Carvedilol Trials in regard to optimal dose, titration time, and morbidity. METHODS: Seventy HF patients were initiated on BB therapy (carvedilol). Before therapy, patients were instructed on BB side effects, pulse taking, and weight monitoring. Patients reported weights, vital signs, and symptoms 3 times per week by phone. Advanced practice nurses counseled, educated, and reminded patients to increase their dose every 2 weeks until target doses were reached. RESULTS: A total of 96% reached a therapeutic dose (6.25 mg twice daily). Moreover, 71% of patients reached target doses of 25 mg twice weekly in approximately 8 weeks. No HF hospitalizations occurred during remote titration. CONCLUSIONS: The use of advanced practice nurses, titration protocols, and telemanagement technologies may improve the number of HF patients initiated and treated with appropriate doses of BB.

One hundred thirty-two consecutive pediatric liver transplants without hospital mortality: lessons learned and outlook for the future.

OBJECTIVE: Orthotopic liver transplantation (OLT) has become an established procedure for the treatment of pediatric patients with end-stage liver disease. Since starting our program in 1989, 422 pediatric OLTs have been performed using all techniques presently available. Analyzing our series, we have concluded that the year of transplantation is the most important prognostic factor in patient and graft survival in a multivariate analysis. METHODS: From April 2001 to December 1, 2003, 18 whole organs (14%), 17 reduced-size organs (13%), 53 split organs (42%; 46 ex situ, 7 in situ), and 44 organs from living donors (33%) were transplanted into 115 patients (62 male and 53 female). One hundred twelve were primary liver transplants, 18 were retransplants, one third and one fourth liver transplants. Of the 132 OLTs, 26 were highly urgent (19.7%). The outcome of these 132 OLTs was retrospectively analyzed. RESULTS: Of 132 consecutive pediatric liver transplants, no patients died within the 6 months posttransplantation. Overall, 3 recipients (2%) died during further follow-up, 1 child because of severe pneumonia 13 months after transplantation and the second recipient with unknown cause 7 months postoperatively, both with good functioning grafts after uneventful transplantation. The third had a recurrence of an unknown liver disease 9 months after transplantation. The 3-month and actual graft survival rates are 92% and 86%, respectively. Sixteen children (12%) had to undergo retransplantation, the causes of which were chronic rejection (3.8%), primary nonfunction (3.8%), primary poor function (PPF; 1.5%), and arterial thrombosis (3%). The biliary complication rate was 6%; arterial complications occurred in 8.3%; intestinal perforation was observed in 3%; and in 5%, postoperative bleeding required reoperation. The portal vein complication rate was 2%. CONCLUSIONS: Progress during the past 15 years has enabled us to perform pediatric liver transplantation with near perfect patient survival. Advances in posttransplant care of the recipients, technical refinements, standardization of surgery and monitoring, and adequate choice of the donor organ and transplantation technique enable these results, which mark a turning point at which immediate survival after transplantation will be considered the norm. The long-term treatment of the transplanted patient, with the aim of avoiding late graft loss and achieving optimal quality of life, will become the center of debate.