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Reduced Spontaneous Neutrophil Migration Speed in Healthy Neonates
S156
Scientific Forum Abstracts
METHODS: Composite stooling and enema scores were analyzed for children with refractory constipation or incontinence undergoing SNS at our institution from November 2014 to November 2016 (n ¼ 14). Stooling diaries were used to calculate scores at baseline, after temporary electrode implantation (Stage I), after permanent device implantation (Stage II), and after device removal if applicable. Results were compared using paired t-tests, with p < 0.05 considered significant. RESULTS: Fourteen patients underwent Stage I implantation. Age ranged from 4.2 to 18.8 years. Nine patients had constipation and 5 had incontinence. Two patients underwent explant before Stage II due to lack of benefit, 1 patient suffered infection, and 11 patients went on to Stage II. Of these, 3 patients underwent device explant due to lack of benefit. In all patients who underwent explant due to lack of benefit, mean composite score was 17.4 7.9 before Stage I, and 15.8 7.0 after (p ¼ 0.20), with scores after Stage II of 17.7 8.1 (p ¼ 0.96). For patients who benefited, mean composite score was 17.8 10.9 before Stage I, and 12.0 6.1 after (p ¼ 0.05), with scores after Stage II of 8.2 4.6 (p ¼ 0.03) (Figure).
CONCLUSIONS: Composite stooling and enema scores after Stage I implantation predict benefit from SNS. Real-Time Application of a Computational Algorithm Using Trend Analysis of Abdominal Near-Infrared Spectroscopy Predicts the Onset of Necrotizing Enterocolitis in a Randomized Control Trial Stephanie M Cruz, MD, Patricio E Lau, MD, Barbara Stoll, PhD, Jason L Robinson, PhD, Ling Yu, PhD, Thomas Lu, Doug Burrin, PhD, Oluyinka O Olutoye, MD, PhD Baylor College of Medicine, Texas Children’s Hospital, Houston, TX INTRODUCTION: The purpose of this study was to prospectively validate, in real-time, a computational algorithm that detects variability trends of abdominal tissue saturation (aSt02) and indicates
J Am Coll Surg
the onset of necrotizing enterocolitis (NEC) prior to clinical symptoms in premature piglets. METHODS: Using the preterm piglet model, piglets were randomly assigned into 4 different treatment groups based on whether or not they received supplemental parental nutrition (PN) and/or oxygen. NIRS device (INVOS 5100C) was utilized to measure aStO2 and cerebral StO2 (cStO2) continuously. NEC was determined using a clinical assessment score and confirmed pathologically. Using LabVIEW and MATLAB, a computational algorithm was applied in real-time to detect and alert the onset of NEC. RESULTS: Of the 37 piglets, 22 (59%) developed NEC. The algorithm alarmed prior to clinical suspicion with a sensitivity of 93% and specificity of 82%. Alerts were issued at an average of 15.4 hours prior to onset of symptoms (range 5.75 to 26.27 hours, Figure). Two false alarms were present in piglets with generalized decreased global perfusion prior to death, not associated with NEC. Further analysis revealed that a ratio of cStO2:aStO2 greater than 0.6, at the time that characteristic changes in abdominal perfusion are detected distinguishes those premature piglets with NEC from those with circulatory compromise (area under the curve 0.80, sensitivity: 84%, specificity: 83%).
CONCLUSIONS: We have prospectively validated our computational algorithm that identifies NEC prior to the onset of clinical symptoms in piglets. The next phase of this study is to utilize the real-time alert to guide efficacy of treatment modalities and translate into clinical practice. Reduced Spontaneous Neutrophil Migration Speed in Healthy Neonates Steven L Raymond, MD, Tyler J Murphy, Felix Ellett, PhD, Julianne Jorgensen, Ricardo Ungaro, Lyle L Moldawer, PhD, Daniel Irimia, MD, PhD, Shawn D Larson, MBChB, FACS University of Florida, Gainesville, FL; Massachusetts General Hospital, Harvard University, Boston, MA INTRODUCTION: Neonates rely predominantly on the innate immune system to recognize and combat life-threatening bacterial infections. As such, neutrophils play a crucial role in neonatal
Vol. 225, No. 4S1, October 2017
survival. Previous studies have focused on neutrophil antimicrobial properties, but few have examined their ability to exit the bone marrow and reach the site of inflammation. To quantify the speed of migrating neutrophils, we utilized novel microfluidic approaches that require a single drop of blood. METHODS: Peripheral blood samples were collected from healthy, 1-day-old neonates and healthy, young adults. Neonates with prolonged rupture of membranes, chorioamnionitis, or evidence of infection were excluded. Microfluidic devices were employed, which circumvent the need for neutrophil purification. Ex vivo spontaneous neutrophil migration and neutrophil chemotaxis to N-formyl-methionyl-leucyl-phenylalanine were measured with time-lapse imaging for 10 hours. For each sample, at least 20 neutrophils were tracked to calculate average speed. RESULTS: Twenty-three neonatal and 18 adult samples were collected (Figure). The mean gestational time and birth weight for neonates were 38.9 weeks and 3,353 grams, respectively. Compared with adults, neonates had 45% decreased speed of spontaneously migrating neutrophils (15.1 vs 21.5 m/min, p < 0.05). However, the speed of neutrophil chemotaxis to fMLP was comparable between neonates and adults (11.6 vs 12.7 mm/min).
Figure. Comparison of average speed of neutrophils from young adults and neonates.
CONCLUSIONS: Decreased spontaneous neutrophil migration in neonates may limit their sentinel activities and reduce their transit from bone marrow, but not affect their recruitment to sites of infection. How this affects host immunity is currently under investigation. Serotonin Reuptake Transporter Knockout Mice Exhibit Increased Enterocyte Mass and Intestinal Glucose Absorption Chasen J Greig, MD, Lucy Zhang, Robert A Cowles, MD, FACS Yale School of Medicine, New Haven, CT INTRODUCTION: Enteric serotonin is an integral neurotransmitter participating in a wide range of intestinal functions. Enhanced serotonin signaling occurs after genetic knockout of the serotonin reuptake transporter (SERT), which manifests in the intestine as increased crypt cell proliferation, neuroplasticity, and substantial anatomic increases in mucosal surface area. However, it remains unknown whether the above changes result in increased function. We hypothesized that serotonin-mediated mucosal growth would result in increases in enterocyte mass and absorptive function.
Scientific Forum Abstracts
S157
METHODS: After institutional approval, 10- to 12-week-old SERT-knockout (SERTKO) and wild-type (WT) C57Bl/6 mice were used for experiments. Plasma citrulline, a putative marker of enterocyte mass, was measured colorimetrically. Glucose absorption rate in perfused, isolated segments of proximal, middle, and distal small bowel was calculated using a previously described method involving instillation of glucose and a nonabsorbable substrate into the lumen for 15 minutes, with subsequent quantification of glucose remaining in aspirated contents after correction for fluid shifts. RESULTS: Plasma citrulline levels in SERTKO mice were significantly increased when compared to WT levels (Table). Glucose absorption in WT mice varied throughout the small intestine, with the highest rate in the proximal bowel. Compared with WT, SERTKO mice demonstrated increased glucose absorption in all regions of the bowel, with statistically significant increases in the middle and distal bowel (Table). Table. Mean SEM Values for Citrulline and Glucose Absorption Variable
Plasma citrulline (mM) Glucose absorption (mg/min) Proximal small bowel Middle small bowel Distal small bowel
Wild type
652 98
SERTKO
1,067 69
p Value
0.0059
5.01 0.50 6.11 0.03 0.0922 4.03 0.15 5.67 0.36 0.0135 2.82 0.57 5.82 0.17 0.0071
CONCLUSIONS: Enhanced serotonin signaling results in increased enterocyte mass and intestinal absorptive function. Taken together with previously demonstrated serotonin-mediated mucosal growth, these data further advance the concept that the serotonin system is an attractive therapeutic target for increasing functional intestinal mucosa. The Artificial Placenta Rescues Premature Lambs from Ventilatory Failure Joseph T Church, MD, Jennifer S McLeod, MD, Elena M Perkins, Robert H Bartlett, MD, George B Mychaliska, MD, FACS University of Michigan, Ann Arbor, MI INTRODUCTION: An artificial placenta (AP) utilizing extracorporeal life support (ECLS) would revolutionize the care of extremely premature neonates. In clinical application, neonates would likely undergo a trial of mechanical ventilation (MV) prior to AP support. We investigated the AP’s ability to rescue extremely premature lambs from failed MV. METHODS: Institutional Animal Care and Use Committee approval was obtained (protocol 00007211). Preterm fetal lambs at estimated gestational age (EGA) 116 to 121 days (term ¼ 145, n ¼ 3) were delivered via laparotomy and hysterotomy. The jugular vein and umbilical vein were cannulated and cannulas were clamped. Lambs were intubated, MV was initiated, and umbilical lines were placed. Surfactant was administered. Ventilation was continued for up to 1 hour, with failure defined as inability to
Scientific Forum Abstracts
METHODS: Composite stooling and enema scores were analyzed for children with refractory constipation or incontinence undergoing SNS at our institution from November 2014 to November 2016 (n ¼ 14). Stooling diaries were used to calculate scores at baseline, after temporary electrode implantation (Stage I), after permanent device implantation (Stage II), and after device removal if applicable. Results were compared using paired t-tests, with p < 0.05 considered significant. RESULTS: Fourteen patients underwent Stage I implantation. Age ranged from 4.2 to 18.8 years. Nine patients had constipation and 5 had incontinence. Two patients underwent explant before Stage II due to lack of benefit, 1 patient suffered infection, and 11 patients went on to Stage II. Of these, 3 patients underwent device explant due to lack of benefit. In all patients who underwent explant due to lack of benefit, mean composite score was 17.4 7.9 before Stage I, and 15.8 7.0 after (p ¼ 0.20), with scores after Stage II of 17.7 8.1 (p ¼ 0.96). For patients who benefited, mean composite score was 17.8 10.9 before Stage I, and 12.0 6.1 after (p ¼ 0.05), with scores after Stage II of 8.2 4.6 (p ¼ 0.03) (Figure).
CONCLUSIONS: Composite stooling and enema scores after Stage I implantation predict benefit from SNS. Real-Time Application of a Computational Algorithm Using Trend Analysis of Abdominal Near-Infrared Spectroscopy Predicts the Onset of Necrotizing Enterocolitis in a Randomized Control Trial Stephanie M Cruz, MD, Patricio E Lau, MD, Barbara Stoll, PhD, Jason L Robinson, PhD, Ling Yu, PhD, Thomas Lu, Doug Burrin, PhD, Oluyinka O Olutoye, MD, PhD Baylor College of Medicine, Texas Children’s Hospital, Houston, TX INTRODUCTION: The purpose of this study was to prospectively validate, in real-time, a computational algorithm that detects variability trends of abdominal tissue saturation (aSt02) and indicates
J Am Coll Surg
the onset of necrotizing enterocolitis (NEC) prior to clinical symptoms in premature piglets. METHODS: Using the preterm piglet model, piglets were randomly assigned into 4 different treatment groups based on whether or not they received supplemental parental nutrition (PN) and/or oxygen. NIRS device (INVOS 5100C) was utilized to measure aStO2 and cerebral StO2 (cStO2) continuously. NEC was determined using a clinical assessment score and confirmed pathologically. Using LabVIEW and MATLAB, a computational algorithm was applied in real-time to detect and alert the onset of NEC. RESULTS: Of the 37 piglets, 22 (59%) developed NEC. The algorithm alarmed prior to clinical suspicion with a sensitivity of 93% and specificity of 82%. Alerts were issued at an average of 15.4 hours prior to onset of symptoms (range 5.75 to 26.27 hours, Figure). Two false alarms were present in piglets with generalized decreased global perfusion prior to death, not associated with NEC. Further analysis revealed that a ratio of cStO2:aStO2 greater than 0.6, at the time that characteristic changes in abdominal perfusion are detected distinguishes those premature piglets with NEC from those with circulatory compromise (area under the curve 0.80, sensitivity: 84%, specificity: 83%).
CONCLUSIONS: We have prospectively validated our computational algorithm that identifies NEC prior to the onset of clinical symptoms in piglets. The next phase of this study is to utilize the real-time alert to guide efficacy of treatment modalities and translate into clinical practice. Reduced Spontaneous Neutrophil Migration Speed in Healthy Neonates Steven L Raymond, MD, Tyler J Murphy, Felix Ellett, PhD, Julianne Jorgensen, Ricardo Ungaro, Lyle L Moldawer, PhD, Daniel Irimia, MD, PhD, Shawn D Larson, MBChB, FACS University of Florida, Gainesville, FL; Massachusetts General Hospital, Harvard University, Boston, MA INTRODUCTION: Neonates rely predominantly on the innate immune system to recognize and combat life-threatening bacterial infections. As such, neutrophils play a crucial role in neonatal
Vol. 225, No. 4S1, October 2017
survival. Previous studies have focused on neutrophil antimicrobial properties, but few have examined their ability to exit the bone marrow and reach the site of inflammation. To quantify the speed of migrating neutrophils, we utilized novel microfluidic approaches that require a single drop of blood. METHODS: Peripheral blood samples were collected from healthy, 1-day-old neonates and healthy, young adults. Neonates with prolonged rupture of membranes, chorioamnionitis, or evidence of infection were excluded. Microfluidic devices were employed, which circumvent the need for neutrophil purification. Ex vivo spontaneous neutrophil migration and neutrophil chemotaxis to N-formyl-methionyl-leucyl-phenylalanine were measured with time-lapse imaging for 10 hours. For each sample, at least 20 neutrophils were tracked to calculate average speed. RESULTS: Twenty-three neonatal and 18 adult samples were collected (Figure). The mean gestational time and birth weight for neonates were 38.9 weeks and 3,353 grams, respectively. Compared with adults, neonates had 45% decreased speed of spontaneously migrating neutrophils (15.1 vs 21.5 m/min, p < 0.05). However, the speed of neutrophil chemotaxis to fMLP was comparable between neonates and adults (11.6 vs 12.7 mm/min).
Figure. Comparison of average speed of neutrophils from young adults and neonates.
CONCLUSIONS: Decreased spontaneous neutrophil migration in neonates may limit their sentinel activities and reduce their transit from bone marrow, but not affect their recruitment to sites of infection. How this affects host immunity is currently under investigation. Serotonin Reuptake Transporter Knockout Mice Exhibit Increased Enterocyte Mass and Intestinal Glucose Absorption Chasen J Greig, MD, Lucy Zhang, Robert A Cowles, MD, FACS Yale School of Medicine, New Haven, CT INTRODUCTION: Enteric serotonin is an integral neurotransmitter participating in a wide range of intestinal functions. Enhanced serotonin signaling occurs after genetic knockout of the serotonin reuptake transporter (SERT), which manifests in the intestine as increased crypt cell proliferation, neuroplasticity, and substantial anatomic increases in mucosal surface area. However, it remains unknown whether the above changes result in increased function. We hypothesized that serotonin-mediated mucosal growth would result in increases in enterocyte mass and absorptive function.
Scientific Forum Abstracts
S157
METHODS: After institutional approval, 10- to 12-week-old SERT-knockout (SERTKO) and wild-type (WT) C57Bl/6 mice were used for experiments. Plasma citrulline, a putative marker of enterocyte mass, was measured colorimetrically. Glucose absorption rate in perfused, isolated segments of proximal, middle, and distal small bowel was calculated using a previously described method involving instillation of glucose and a nonabsorbable substrate into the lumen for 15 minutes, with subsequent quantification of glucose remaining in aspirated contents after correction for fluid shifts. RESULTS: Plasma citrulline levels in SERTKO mice were significantly increased when compared to WT levels (Table). Glucose absorption in WT mice varied throughout the small intestine, with the highest rate in the proximal bowel. Compared with WT, SERTKO mice demonstrated increased glucose absorption in all regions of the bowel, with statistically significant increases in the middle and distal bowel (Table). Table. Mean SEM Values for Citrulline and Glucose Absorption Variable
Plasma citrulline (mM) Glucose absorption (mg/min) Proximal small bowel Middle small bowel Distal small bowel
Wild type
652 98
SERTKO
1,067 69
p Value
0.0059
5.01 0.50 6.11 0.03 0.0922 4.03 0.15 5.67 0.36 0.0135 2.82 0.57 5.82 0.17 0.0071
CONCLUSIONS: Enhanced serotonin signaling results in increased enterocyte mass and intestinal absorptive function. Taken together with previously demonstrated serotonin-mediated mucosal growth, these data further advance the concept that the serotonin system is an attractive therapeutic target for increasing functional intestinal mucosa. The Artificial Placenta Rescues Premature Lambs from Ventilatory Failure Joseph T Church, MD, Jennifer S McLeod, MD, Elena M Perkins, Robert H Bartlett, MD, George B Mychaliska, MD, FACS University of Michigan, Ann Arbor, MI INTRODUCTION: An artificial placenta (AP) utilizing extracorporeal life support (ECLS) would revolutionize the care of extremely premature neonates. In clinical application, neonates would likely undergo a trial of mechanical ventilation (MV) prior to AP support. We investigated the AP’s ability to rescue extremely premature lambs from failed MV. METHODS: Institutional Animal Care and Use Committee approval was obtained (protocol 00007211). Preterm fetal lambs at estimated gestational age (EGA) 116 to 121 days (term ¼ 145, n ¼ 3) were delivered via laparotomy and hysterotomy. The jugular vein and umbilical vein were cannulated and cannulas were clamped. Lambs were intubated, MV was initiated, and umbilical lines were placed. Surfactant was administered. Ventilation was continued for up to 1 hour, with failure defined as inability to