The role of fetal hemoglobin in the artificial placenta: A premature ovine model.

INTRODUCTION: A radical paradigm shift in the treatment of premature infants failing conventional treatment is to recreate fetal physiology using an extracorporeal Artificial Placenta (AP). The aim of this study is to evaluate the effects of changing fetal hemoglobin percent (HbF%) on physiology and circuit function during AP support in an ovine model. METHODS: Extremely premature lambs (n = 5) were delivered by cesarean section at 117-121 d estimated gestational age (EGA) (term = 145d), weighing 2.5 ± 0.35 kg. Lambs were cannulated using 10-14Fr cannulae for drainage via the right jugular vein and reinfusion via the umbilical vein. Lambs were intubated and lungs were filled with perfluorodecalin to a meniscus with a pressure of 5-8 cm H2O. The first option for transfusion was fetal whole blood from twins followed by maternal red blood cells. Arterial blood gases were used to titrate AP support to maintain fetal blood gas values. RESULTS: The mean survival time on circuit was 119.6 ± 39.5 h. Hemodynamic parameters and lactate were stable throughout. As more adult blood transfusions were given to maintain hemoglobin at 10 mg/dL, the HbF% declined, reaching 40% by post operative day 7. The HbF% was inversely proportional to flow rates as higher flows were required to maintain adequate oxygen saturation and perfusion. CONCLUSIONS: Transfusion of adult blood led to decreased fetal hemoglobin concentration during AP support. The HbF% was inversely proportional to flow rates. Future directions include strategies to decrease the priming volume and establishing a fetal blood bank to have blood rich in HbF.

Bubble bilevel ventilation facilitates gas exchange in anesthetized rabbits.

BACKGROUND: Bubble continuous positive airway pressure is an established therapy for infants in respiratory distress. In resource-limited settings, few treatment options exist for infants requiring further respiratory support. A bubble bilevel device has been developed to provide nonelectric, time-cycled, pressure-limited respiratory support. We compared the efficacy of bubble bilevel ventilation with conventional mechanical ventilation in sedated rabbits. METHODS: Six adult rabbits under inhaled isoflurane general anesthesia were ventilated by alternating intervals of conventional and bubble bilevel ventilation for three 10-15-min periods. During each period, interval arterial blood gas (ABG) measurements were obtained after at least 10 min on the respective mode of ventilation. RESULTS: The bubble bilevel system was able to deliver the following pressures: 20/7, 15/5, 12/5, 8/5 cm H2O. The estimated differences in arterial blood gas values on bubble bilevel vs. ventilator were as follows (normalized values): pH 7.41 vs. 7.40, pCO2 37.7 vs. 40, pO2 97.6 vs. 80. In addition, the bubble bilevel ventilation delivered consistent pressure waveforms without interruption for over 60 min on two rabbits. CONCLUSION: This study demonstrates promising in vivo results on the efficacy of a novel bubble bilevel device, which may prove useful for infants in respiratory distress. IMPACT: Given the lack of personnel, funds or infrastructure to provide neonatal mechanical ventilation in resource-limited settings, additional low-cost, low-tech treatments are necessary to save infant lives. Bubble bilevel ventilation reliably delivers two levels of airway pressure to anesthetized rabbits resulting in normalization of blood gases comparable to those achieved on a traditional ventilator. If proven effective, simple technologies like this device have the potential to significantly impact neonatal mortality due to respiratory distress globally.

Developing a toll-like receptor biosensor for Gram-positive bacterial detection and its storage strategies.

The biorecognition ability of hybridized toll-like receptors (TLRs) 2 and 6 proteins on electrode surfaces has been studied. TLR biosensors have been designed to be non-specific to particular bacterial strains but rather to provide broad spectrum detection of cells and toxins containing relevant pathogen-associated molecular patterns (PAMPs). Our electrochemical TLR2/6 biosensors demonstrated selective detection towards Gram-positive bacterial whole-cells and a synthetic diacylated lipopeptide (Pam2CSK4), a PAMP. Responses towards Bacillus licheniformis (B. licheniformis) and Enterococcus hirae (E. hirae) were obtained. The biosensor was able to differentiate signals between B. licheniformis and a Gram-negative bacterial cell (control) as low as 100 CFU mL-1. One challenge in developing protein-based biosensors is to improve the shelf-life of the biosensor chips and preserve the detection activity of the protein molecules, therefore we did our first exploration into storage conditions. The activity of stored biosensors was found to be strongly dependent on storage medium, and that effective 'shelf-life' was obtained makes an important step towards creating robust sensors for real-life applications.

Intussusception Protocol Implementation: Single-Site Outcomes With Clinician and Family Satisfaction.

BACKGROUND: The objective of this study was to evaluate clinical outcomes, costs, and clinician and parent satisfaction after implementation of a protocol to discharge patients from the emergency department (ED) after successful reduction of uncomplicated ileocolic intussusception. MATERIALS AND METHODS: In March 2017, an intussusception management protocol was implemented for children presenting with ultrasound findings of ileocolic intussusception. Those meeting inclusion criteria were observed after successful radiological reduction in the ED and discharged after 6 h with resolution of symptoms. Retrospective chart review was completed for cases before and after protocol implementation for clinical outcomes and costs. Clinicians and parents were surveyed to assess overall satisfaction. RESULTS: Charts were reviewed before (42 encounters, 37 patients) and after (30 encounters, 23 patients) protocol implementation. After implementation, admission rates decreased from 95% (40/42) to 23% (7/30; P < 0.001) and antibiotic use was eliminated (91% to 0%, P < 0.001). There was no difference in recurrence rates (17% versus 23%, P = 0.44). Median total length of stay decreased from 18.87 to 9.52 h (P < 0.001), whereas median ED length of stay increased from 4.37 to 9.87 h (P < 0.001). In addition, there was an overall hospital cost saving of over $2000 ($9595 ± 3424 to $7465 ± 3723; P = 0.009) per encounter. Clinicians and parents were overall satisfied with the protocol and parents showed no changes in patient satisfaction with protocol implementation. CONCLUSIONS: An intussusception protocol can facilitate early discharge from the ED and improve patient care without increased risk of recurrence. Additional benefits include decreased hospital- and patient-related costs, elimination of antibiotic use, and parent as well as clinician satisfaction.

An Early Investigation into Possible Alternatives to Stapled Hysterotomy in Open Fetal Surgery.

PURPOSE: We hypothesized that surgical energy could be used to create hysterotomies in open fetal surgery. STUDY DESIGN: Initial studies compared the LigaSure Impact and Harmonic ACE + 7 Shears in the efficiency of hysterotomy and thermal damage. Pregnant ewes at an estimated gestational age (EGA) of 116 to 120 days (term = 145; n = 7) underwent hysterotomy using either device. Hysterotomy edges were resected, and thermal injury extent was determined by histopathological assessment. Upon determining a superior device, subsequent studies compared this to the AutoSuture Premium Poly CS*-57 Stapler in uterine healing. Pregnant ewes (n = 6) at an EGA of 87 to 93 days underwent 6-cm hysterotomy in each gravid horn with either the stapler (n = 5) or Harmonic (n = 5) followed by closure and animal recovery. After 37 to 42 days, uterine healing was assessed by evaluating tensile strength and histopathology. RESULTS: Thermal damage was more extensive with the LigaSure (n = 11 hysterotomies) than with the Harmonic (n = 11; 5.6 ± 1 vs. 3.1 ± 0.6 mm; p < 0.0001);therefore, the Harmonic was selected for healing studies. Gross scar appearance and tensile strength were the same between the Harmonic and stapler. The stapler caused more fibrosis (4/7 samples with "moderate" fibrosis vs. 0/8 with the Harmonic; p = 0.02). CONCLUSION: The Harmonic ACE + 7 caused less thermal injury than the LigaSure Impact and performed similar to the CS*-57 Stapler in uterine healing with continued gestation.

Acute kidney injury in necrotizing enterocolitis predicts mortality.

BACKGROUND: Morbidity and mortality with necrotizing enterocolitis (NEC) remains a significant challenge. Acute kidney injury (AKI) has been shown to worsen survival in critically ill neonates. To our knowledge, this study is the first to evaluate the prevalence of AKI and its impact on outcomes in neonatal NEC. METHODS: We carried out a single-center retrospective chart review of all neonates treated for NEC between 2003 and 2015 (N = 181). AKI is defined as a rise in serum creatinine (SCr) from a previous trough according to neonatal modified KDIGO criteria (stage 1 = SCr rise 0.3 mg/dL or SCr 150 < 200%, stage 2 = SCr rise 200 < 300%, stage 3 = SCr rise ≥300%, SCr 2.5 mg/dL or dialysis). Primary outcome was in-hospital mortality and secondary outcomes were hospital length of stay (LOS) and need for and type of surgery. RESULTS: Acute kidney injury occurred in 98 neonates (54%), with 39 stage 1 (22%), 31 stage 2 (18%), and 28 stage 3 (16%), including 5 requiring dialysis. Non-AKI and AKI groups were not statistically different in age, weight, Bell's NEC criteria, and medication exposure (vasopressors, vancomycin, gentamicin, or diuretic). Neonates with AKI had higher mortality (44% vs 25.6%, p = 0.008) and a higher chance of death (HR 2.4, CI 1.2-4.8, p = 0.009), but the effect on LOS on survivors did not reach statistical significance (79 days, interquartile range [IQR] 30-104 vs 54 days, IQR 30-92, p = 0.09). Overall, 48 (27.9%) patients required surgical intervention. CONCLUSIONS: This study shows that AKI not only occurs in over half of patients with NEC, but that it is also associated with more than a two-fold higher mortality, highlighting the importance of early recognition and potentially early intervention for AKI.

Interprofessional education day - an evaluation of an introductory experience for first-year students.

Interprofessional health care teams have been shown to improve patient safety and reduce medical errors, among other benefits. Introducing interprofessional concepts to students in full day events is an established model that allows students to learn together. Our group developed an academic day for first-year students devoted to an introductory interprofessional education (IPE) experience, 'IPE Day'. In total, 438 students representing medicine, dentistry, pharmacy and optometry gathered together, along with 25 facilitators, for IPE Day. Following the day's program, students completed the evaluation consisting of the Interprofessional Collaborative Competencies Attainment Survey and open-ended questions. Narrative responses were analyzed for content and coded using the Canadian Interprofessional Health Collaborative competency domains. Three hundred and eight evaluations were completed. Students reported increased self-ratings of competency across all 20 items (p < 0.05). Their comments were organized into the six domains: interprofessional communication, collaborative leadership, role clarification, patient-centred care, conflict resolution, and team functioning. Based on these findings, we suggest that this IPE activity may be useful for improving learner perceptions about their interprofessional collaborative practice competence.

Geographic variation in the use of continuous outpatient inotrope infusion therapy and beta blockers.

BACKGROUND: Continuous outpatient inotrope infusion therapy (COIIT) can be used as palliative or interim treatment in patients with advanced heart failure (AHF). Despite widespread use, there is a relative lack of data informing best practices. This study aimed to examine whether patterns of COIIT use differed by region and to explore whether observed differences influenced clinical outcomes. METHODS: Retrospective study of AHF patients receiving COIIT from May 2009 through June 2016. The primary outcome was regional difference, the secondary outcome was persistence (duration) on therapy. Cox proportional hazards model was used to calculate hazard ratios for treatment regimens. RESULTS: There were 3,286 patients, mean (SD) age 61.9 (14.4) years and 74.0% (2,433) male. Inotrope selection and beta blocker use varied by region by chi square (χ2 (21) = 166.9, p < 0.001). Persistence was greater on milrinone compared to dobutamine (HR (for discontinuation) 0.54, CI 0.41-0.70, p < 0.001). Concurrent beta-blocker was associated with greater persistence for patients receiving milrinone (HR 0.13, CI 0.08-0.20, p < 0.001) and dobutamine (HR 0.36, CI 0.18-0.71, p < 0.001). CONCLUSIONS: Patterns of COIIT use varied by region, and variations in use were associated with differences in clinical outcomes.

Hepatic Function in Premature Lambs Supported by the Artificial Placenta and Total Parenteral Nutrition.

The artificial placenta (AP) promotes organ development and reduces organ injury in a lamb model of extreme prematurity. This study evaluates hepatic outcomes after AP support with total parenteral nutrition (TPN) administration. Premature lambs (116-121 days estimated gestational age; term = 145) were cannulated for 7 days of AP support. Lambs received TPN with SMOFlipid (n = 7) or Intralipid (n = 5). Liver function and injury were compared between the two groups biochemically and histologically. Groups were compared by ANOVA with Tukey's multiple comparisons or linear-mixed effects models. From baseline to day 7, total bilirubin (Intralipid 2.6 ± 2.3 to 7.9 ± 4.4 mg/dl; SMOFlipid 0.3 ± 0.1 to 5.5 ± 2.3 mg/dl), alanine aminotransferase, and gamma-glutamyl transferase increased in both groups ( p < 0.001 for all). Direct bilirubin (0.3 ± 0.2 to 1.8 ± 1.4 mg/dl; p = 0.006) and AST (27 ± 5 to 309 ± 242 mg/dl; p < 0.001) increased in SMOFlipid group (not measured in Intralipid group). On liver histology, Intralipid showed more cholestasis than SMOFlipid; both groups showed more than tissue controls. The Intralipid group alone showed hepatocyte injury and had more congestion than controls. Lambs supported by the AP with TPN administration maintain normal hepatic function and sustain minimal hepatic injury. SMOFlipid is associated with decreased cholestasis and hepatic injury versus Intralipid.

N-Heterocyclic carbenes meet toll-like receptors.

Combining the stability of the N-heterocyclic carbenes (NHCs) and broad-spectrum recognition of toll-like receptor (TLR) proteins, we report new electrochemical biosensors for bacteria detection. Instead of traditional thiol-gold chemistry, newly synthesized NHCs are employed as the linker molecules to immobilize TLR bio-recognition elements on gold electrodes. Our proof-of-concept methodology includes testing the fidelity of TLR-based electrochemical sensors with NHC linkers. The performance of the biosensors is demonstrated using whole-cell bacterial cultures.

Realizing new designs of multiplexed electrode chips by 3-D printed masks.

Creating small and portable analytical methods is a fast-growing field of research. Devices capable of performing bio-analytical detection are especially desirable with the onset of the global pandemic. Lab-on-a-chip (LOC) technologies, including rapid point-of-care (POC) devices such as glucose sensors, are attractive for applications in resource-poor settings. There are many challenges in creating such devices, from sensitive molecular designs to stable conditions for storing the sensor chips. In this study we have explored using three-dimensional (3D) printing to create shadow masks as a low-cost method to produce multiplexed electrodes by physical vapour deposition. Although the dimensional resolution of the electrodes produced by using 3D printed masks is inferior to those made through photolithography-based techniques, their dimensions can be readily tailored ranging from 1 mm to 3 mm. Multiple mask materials were tested, such as polylactic acid and polyethylene terephthalate glycol, with acrylonitrile butadiene styrene shown to be the best. Simple strategies in making chip holders by 3D printing and controlling working electrode surface area with epoxy glue were also investigated. The prepared chips were tested by performing surface chemistry with thiol-containing molecules and monitoring the signals electrochemically.

Acute pulmonary pressure change after transition to sacubitril/valsartan in patients with heart failure reduced ejection fraction.

AIMS: Sacubitril/valsartan combines renin-angiotensin-aldosterone system inhibition with amplification of natriuretic peptides. In addition to well-described effects, natriuretic peptides exert direct effects on pulmonary vasculature. The effect of sacubitril/valsartan on pulmonary artery pressure (PAP) has not been fully defined. METHODS AND RESULTS: This was a retrospective case-series of PAP changes following transition from angiotensin-converting enzyme inhibitor (ACEI) or angiotensin receptor blocker (ARB) to sacubitril/valsartan in patients with heart failure reduced ejection fraction and a previously implanted CardioMEMS™ sensor. Pre-sacubitril/valsartan and post-sacubitril/valsartan PAPs were compared for each patient by examining averaged consecutive daily pressure readings from 1 to 5 days before and after sacubitril/valsartan exposure. PAP changes were also compared between patients based on elevated trans-pulmonary gradients (trans-pulmonary gradient ≥ 12 mmHg) at time of CardioMEMS™ sensor implantation. The cohort included 18 patients, 72% male, mean age 60.1 ± 13.6 years. There was a significant decrease in PAPs associated with transition from ACEI/ARB to sacubitril/valsartan. The median (interquartile range) pre-treatment and post-treatment change in mean, systolic and diastolic PAPs were -3.6 (-9.8, -0.7) mmHg (P < 0.001), -6.5 (-15.0, -2.0) mmHg (P = 0.001), and -2.5 (-5.7, -0.7) (P = 0.001), respectively. The decrease in PAPs was independent of trans-pulmonary gradient (F(1,16) = 0.49, P = 0.49). CONCLUSIONS: In this retrospective case series, transition from ACEI/ARB to sacubitril/valsartan was associated with an early and significant decrease in PAPs.

Application of adenosine triphosphate-driven bioluminescence for quantification of plaque bacteria and assessment of oral hygiene in children.

PURPOSE: Dentistry has undergone a shift in caries management toward prevention and improved oral hygiene and diagnosis. Caries prevention now represents one of the most important aspects of modern dental practice. The purpose of this cross-sectional study was to demonstrate the use of adenosine triphosphate- (ATP-) driven bioluminescence as an innovative tool for the rapid chairside enumeration of oral bacteria (including plague streptococci) and assessment of oral hygiene and caries risk. METHODS: Thirty-three pediatric patients (7- to 12-year-old males and females) were examined, and plague specimens, in addition to stimulated saliva, were collected from representative teeth within each quadrant. Oral specimens (n=150 specimens) were assessed by plating on enriched and selective agars, to enumerate total bacteria and streptococci, and subjected to adenosine triphosphate- (ATP-) driven bioluminescence determinations using a luciferase-based assay system. RESULTS: Statistical correlations, linking ATP values to numbers of total bacteria, oral streptococci and mutans streptococci, yielded highly significant r values of 0.854, 0.840, and 0.796, respectively CONCLUSIONS: Our clinical data is consistent with the hypothesis that ATP measurements have a strong statistical association with bacterial number in plague and saliva specimens, including numbers for oral streptococci, and may be used as a potential assessment tool for oral hygiene and caries risk in children.

Circumstances surrounding gun violence with youths in an urban setting.

BACKGROUND: Our pediatric trauma center has noted an increase in the occurrence of gunshot wounds in children. We aimed to understand the circumstances surrounding these injuries in order to provide targeted injury prevention methodologies. METHODS: A retrospective review was performed on patients who presented with a gunshot wound to our Level I Pediatric Trauma Center and two neighboring Adult Trauma Centers between 2013 and 2017. RESULTS: Three hundred twenty-six patients (6 months to 18 years) were treated for gunshot wounds. Patients were African American (86%), Caucasian (9%), and other races (5%). Eight zip-codes were identified as high-risk, accounting for 52% of patients. Most injuries (86%) were from powder firearms. Known circumstances (n = 275) included drive-by shootings (47%), unlocked guns (19%), crime related (13%), altercation between adolescents (7%), cross-fire from adult altercation (6%), home invasion (6%), and suicide attempts (2%). There was a progressive increase of 50% over the last 4 years. The increase in incidence was predominantly from an increase in drive-by shootings; however, the incidence of injuries from unlocked guns has remained relatively constant per year. Mortality was 6%. CONCLUSION: Identifying high-risk zones for drive-by shootings and other crimes is critical for developing system-focused interventions. Zip-code data stratified by age and circumstances, will allow for targeted community outreach on gun safety education, in an effort to reduce the incidence of injuries from unlocked guns. LEVEL OF EVIDENCE: Prognostic and Epidemiologic study, Level III.

Acute hemorrhagic rectal ulcer: Experience in 11 patients at an urban acute care center in the USA: A case series.

INTRODUCTION: Acute hemorrhagic rectal ulcer (AHRU) is a rare entity which has most frequently been described in Japan and Taiwan literature. This study characterizes 11 AHRUs identified and managed at an urban acute care hospital in the United States of America (USA). METHODS: A total of 2253 inpatients underwent colonoscopy. In 1172 patients (52%), colonoscopy was performed for evaluation of lower gastrointestinal (LGI) bleeding. Eleven (0.9%) of the 1172 patients with LGI bleeding had AHRU. RESULTS: AHRU is characterized by a sudden onset of painless and massive lower rectal bleeding in elderly, bedridden patients (pts) with major underlying diseases. The endoscopic findings were classified into 4 types. All 11 ulcers were located in the distal rectum within 10 cm of the dentate line. All 11 patients required blood transfusion (mean = 3.7 units; range 2-9 units). Seven patients responded to blood, plasma, and platelet transfusions. The other 4 patients required endoscopic hemostasis.Three patients died within a month of colonoscopy from comorbidities. None had bleeding as a cause of death. Eight surviving patients did not have recurrent bleeding. CONCLUSION: AHRU does exist in the USA and should be considered as an important cause of acute lower GI bleeding in elderly, critically ill, and bedridden patients. AHRU should be recognized and managed correctly.

Comparing mortality risk models in VLBW and preterm infants: systematic review and meta-analysis.

OBJECTIVE: To compare the prognostic accuracy of six neonatal illness severity scores (CRIB, CRIB II, SNAP, SNAP II, SNAP-PE, and SNAP-PE II), birthweight (BW), and gestational age (GA) for predicting pre-discharge mortality among very low birth weight (VLBW) infants (<1500 g) and very preterm infants (<32 weeks' gestational age). STUDY DESIGN: PubMed, EMBASE, and Scopus were the data sources searched for studies published before January 2019. Data were extracted, pooled, and analyzed using random-effects models and reported as AUC with 95% confidence intervals (CI). RESULTS: Of 1659 screened studies, 24 met inclusion criteria. CRIB was the most discriminate for predicting pre-discharge mortality [AUC 0.88 (0.86-0.90)]. GA was the least discriminate [AUC 0.76 (0.72-0.80)]. CONCLUSIONS: Although the original CRIB score was the most accurate predictor of pre-discharge mortality, significant heterogeneity between studies lowers confidence in this pooled estimate. A more precise illness severity score to predict pre-discharge mortality is still needed.

A Model of Pediatric End-Stage Lung Failure in Small Lambs <20 kg.

One in five children with end-stage lung failure (ESLF) die while awaiting lung transplant. No suitable animal model of ESLF exists for the development of artificial lung devices for bridging to transplant. Small lambs weighing 15.7 ± 3.1 kg (n = 5) underwent ligation of the left anterior pulmonary artery (PA) branch, and gradual occlusion of the right main PA over 48 hours. All animals remained hemodynamically stable. Over seven days of disease model conditions, they developed pulmonary hypertension (mean PA pressure 20 ± 5 vs. 33 ± 4 mm Hg), decreased perfusion (SvO2 66 ± 3 vs. 55 ± 8%) with supplemental oxygen requirement, and severe tachypneic response (45 ± 9 vs. 82 ± 23 breaths/min) (all p < 0.05). Severe right heart dysfunction developed (tricuspid annular plane systolic excursion 13 ± 3 vs. 7 ± 2 mm, fractional area change 36 ± 6 vs. 22 ± 10 mm, ejection fraction 51 ± 9 vs. 27 ± 17%, all p < 0.05) with severe tricuspid regurgitation and balloon-shaped dilation of the right ventricle. This model of pediatric ESLF reliably produces pulmonary hypertension, right heart strain, and impaired gas exchange, and will be used to develop a pediatric artificial lung.

Ex Vivo Heart Perfusion for 72 Hours Using Plasma Cross Circulation.

Preservation of a donor heart for transplantation is limited to 6-8 hours. Based on our demonstration of 12 hour perfusion with plasma cross circulation, this study aimed to evaluate ex vivo heart perfusion (EVHP) for up to 72 hours using cross plasma circulation (XC-plasma) from a live, awake paracorporeal sheep (PCS). Six ovine hearts were perfused for 72 hours using plasma cross circulation at a rate of 1 L/min with a live, awake PCS. Controls were seven perfused hearts without cross circulation. Experiments were electively ended at 72 hours, and epinephrine (0.1 mg) was delivered to demonstrate hormonal responsiveness. All controls failed at 6-10 hours. All six hearts perfused for 72 hours maintained normal heart function, metabolism, and responsiveness to epinephrine. Blood gases, electrolytes, and lactate levels were normal and stable throughout the study. All hearts appeared suitable for transplantation. We have demonstrated successful normothermic EVHP for 72 hours.

Plaque retention by self-ligating vs elastomeric orthodontic brackets: quantitative comparison of oral bacteria and detection with adenosine triphosphate-driven bioluminescence.

INTRODUCTION: Enamel decalcification is a common problem in orthodontics. The objectives of this randomized clinical study were to enumerate and compare plaque bacteria surrounding 2 bracket types, self-ligating (SL) vs elastomeric ligating (E), and to determine whether adenosine triphosphate (ATP)-driven bioluminescence could be used for rapid assessment of bacterial load in plaque. METHODS: Patients (ages, 11-17 years) were bonded with SL and E brackets in 14 maxillary and 12 mandibular arches by using a split-mouth design. Recall visits were at 1 and 5 weeks after bonding. Plaque specimens were assayed for oral bacteria and subjected to ATP-driven bioluminescence determinations with a luciferin-based assay. RESULTS: In most patients, teeth bonded with SL attachments had fewer bacteria in plaque than did teeth bonded with E brackets. At 1 and 5 weeks after bonding, the means for SL vs E brackets were statistically lower for total bacteria and oral streptococci (P <0.05). ATP bioluminescence values were statistically correlated to the total oral bacteria and oral streptococci, with correlation coefficients of 0.895 and 0.843, respectively. CONCLUSIONS: SL appliances promote reduced retention of oral bacteria, and ATP bioluminescence might be a useful tool in the rapid quantification of bacterial load and the assessment of oral hygiene during orthodontic treatment.

Splenic development and injury in premature lambs supported by the artificial placenta.

INTRODUCTION: The purpose of this study is to evaluate splenic effects during artificial placenta (AP) support. METHODS: AP lambs (118-121 d, n = 14) were delivered and placed on the AP support for a goal of 10-14 days. Cannulation used right jugular drainage and umbilical vein reinfusion. Early (ETC; 115-120 d; n = 7) and late (LTC; 125-131 d; n = 7) tissue controls were delivered and immediately sacrificed. Spleens were formalin fixed, H&E stained, and graded for injury, response to inflammation, and extramedullary hematopoiesis (EMH). CD68 and CD163 stains were used to assess for macrophage activation and density. Clinical variables were correlated with splenic scores. Groups were compared using Fisher's Exact Test and descriptive statistics. p < 0.05 indicated significance. RESULTS: Mean survival for AP lambs was 12 ±â€¯5 d. There was no necrosis found in any of the groups. Vascular congestion and sinusoidal histiocytosis did not significantly differ between AP and control groups (p = 0.72; p = 0.311). There were significantly more pigmented macrophages (p = 0.008), CD163 (p = <0.001), and CD68 (p = <0.001) stained cells in the AP group. ETC and LTC demonstrated more EMH than AP spleens (p = <0.001). CONCLUSIONS: During AP support, spleens appear to develop normally and exhibit an appropriate inflammatory response. After initiation of AP support, EMH transitions away from the spleen. STUDY TYPE: Research Paper/Therapeutic Potential. LEVEL OF EVIDENCE: N/A.