A21 ULCERATIVE COLITIS-ASSOCIATED E. COLI PATHOBIONTS POTENTIATE COLITIS IN SUSCEPTIBEL HOSTS

Background

Ulcerative colitis (UC) is a chronic inflammatory condition linked to intestinal microbial dysbiosis, including the expansion of E. coli strains related to extra-intestinal pathogenic E. coli. These “pathobionts” exhibit pathogenic properties, but their potential to promote UC is unclear due to the lack of relevant animal models.

Aims

We explored the potential to establish a mouse model of GI infection by the UC-associated E. coli strain p19A, as well as characterize the pathogenic features of p19A.

Methods

We used a representative UC pathobiont strain (p19A), and mice lacking single immunoglobulin and toll-interleukin 1 receptor domain (SIGIRR), a deficiency increasing susceptibility to gut infections. Vancomycin-pretreated Sigirr-/- mice were subsequently gavaged with the control E. coli DH10B (a derivative of commensal strain K-12) or p19A. One day after infection, mice were exposed to 2.5% dextran sodium sulfate (DSS) in their drinking water for another 4 days.

Results

Strain p19A was found to adhere to the cecal mucosa of Sigirr-/- mice, causing modest inflammation. Moreover, it dramatically worsened DSS-induced colitis. This potentiation was attenuated using a p19A strain lacking α-hemolysin genes, or when we targeted pathobiont adherence using a p19A strain lacking the adhesin FimH, or following treatment with FimH antagonists.

Conclusions

Thus, UC pathobionts adhere to the intestinal mucosa, and worsen the course of colitis in susceptible hosts in a manner dependent on specific virulence factors, including α-hemolysin and FimH.

Funding Agencies

CCC, CIHR

Review of Clinical Presentation and Trajectory of Paediatric Patients with a Diagnosis of Primary Brain Tumour in a Paediatric Tertiary Centre

BACKGROUND: Brain tumours are the second most common group of childhood cancer. Recognition of life-threatening conditions, such as brain tumours, remains a challenge among pediatric patients. Many studies have described the implication of initial presentation, clinical evolution and healthcare system factors in diagnosis delay of brain tumours in children and adolescents. However, few studies have treated these different factors in the same cohort and established their interactions.

OBJECTIVES: To determine the clinical presentation patterns and health care trajectory of children and adolescents with a confirmed diagnosis of primary brain tumours. The secondary objectives were to compare the patterns of presentation between different age groups and different settings of diagnosis.

DESIGN/METHODS: A retrospective chart review in a pediatric university affiliated hospital was conducted. Participants were all patients younger than 18 years of age diagnosed with a brain tumour by neuroimaging between January 2003 and December 2014. Patients with secondary brain tumour and spinal cord tumour were excluded. Data were extracted from medical records and an internal tumour registry of all treated patients at our institution.

RESULTS: From the registry, 288 patients were identified. The mean age at time of diagnosis was 7.44±0.29 years. Boys (59%) and Caucasians (76%) were seen predominantly. Most tumours were infra-tentorial (55%) and had astrocytic origin (29%). The majority (35%) had consulted only once prior to diagnosis, while 14% had consulted at least 4 times prior to diagnosis. The mean time between the onset of symptoms and diagnosis was 147±19 days. The mean time between symptoms onset and first consultation was 84±14 days. The most frequent symptoms and signs at onset and diagnosis were respectively: headache (44% vs 59%, p<0.001), nausea and vomiting (31% vs 58%; p<0.001) and abnormalities of gait (10% vs 32%; p<0.001). 129 patients (45%) were diagnosed in an Emergency Department (ED), while 96 patients (33%) were diagnosed in an outpatient setting. Symptoms and signs that differed significantly for those diagnosed in an ED were: headache (71% vs 42%; p<0.001), nausea and vomiting (73 % vs 32%; p<0.001), lethargy (26% vs 9%; p=0.002), weight loss (15% vs 3%; p=0.004), irritability (9% vs 0%; p=0.003) and endocrine abnormality (2% vs 8%; p=0.02). Clinical presentations of infants up to one year of age (14%) differed from other age groups. They presented mostly with growth abnormality (46%), macrocephaly (40%), irritability (40%), development abnormalities (18%) and sun-setting eyes sign (10%).

CONCLUSION: In this large comprehensive cohort, headache is the most common presenting symptom of brain tumours. The diagnosis is most frequently made in the ED. Different clinical presentations have been identified and vary between different settings of diagnosis and different age groups. The delay between the onset of symptoms and diagnosis is up to five months. Many patients have to consult multiple times different physicians before the diagnosis is made.

A Randomized Double-Blind Trial Comparing the Effect on Pain of An Oral Sucrose Solution Versus Placebo in Children 1 To 3 Months Old Needing Urethral Catheterization

BACKGROUND: Oral sweet solutions have been accepted as effective analgesics for procedures in the neonatal population. However, there have been a limited number of trials in older infants. These studies have conflicting results.

OBJECTIVES: To compare the efficacy of an oral sucrose solution versus placebo in reducing pain during urethral catheterization in infants 1 to 3 months old in the Emergency Department (ED).

DESIGN/METHODS: A randomized, double-blind clinical trial was conducted in a pediatric university-affiliated hospital ED. Infants, 1 to 3 months of age, were recruited and randomly allocated to receive 2 ml of 88% sucrose solution (SUC) or 2 ml of placebo solution (PLA) orally, 2 minutes before planned urethral catheterization. The primary outcome measure was the difference in pain scores as assessed by the Face, Legs, Activity, Cry and Consolability (FLACC) Pain Scale during at 1 min post procedure. Secondary outcome measures were the difference in pain scores using the Neonatal Infant Pain Scale (NIPS), crying time, variations in heart rate and adverse events.

RESULTS: Seventy-six participants were recruited and completed the study, 37 (group SUC) and 39 (group PLA) respectively. The mean difference in FLACC scores compared to baseline was 5.62±1.32 (SUC) vs. 6.21±1.15 (PLA) (p=.51) during catheterization and 2.70±1.21 (SUC) vs. 2.26±1.41 (PLA) at 1 min (p=.64) and 0.66±1.32 (SUC) vs. 1.26±1.00 (PLA) at 3 mins (p=.38). For the NIPS scores, it was 4.27±1.06 (SUC) vs. 4.69±0.92 (PLA) (p=.56) during procedure and 2.05±0.91 (SUC) vs. 1.97±1.19 (PLA) (p=.92) at 1 min and 0.49±0.89 (SUC) vs. 0.89±0.97 (PLA) (p=.54) at 3 mins. The difference in the mean crying time was not different between both groups: 99±34 secs (SUC) vs. 100±25 (PLA) (p=.99). No significant difference was found in participants’ heart rate variations during procedure 23±8 BPM (SUC) vs. 26±7 (PLA) (p=.60) and after 1 min 19±12 BPM (SUC) vs. 17±7 (PLA) (p=.76) and after 3 mins -1±12 BPM (SUC) vs. 3±6 (PLA) (p=.53). No adverse events were reported. The blinding was successful.

CONCLUSION: In infants 1 to 3 months of age undergoing urethral catheterization in the ED, administration of an oral sweet solution did not statistically decrease pain scores as measured by the FLACC and NIPS scales. Participants' heart rate variations and crying time were not significantly decreased when sucrose was provided.

A Randomized Controlled Trial on Oral Analgesic Utilization for Children Presenting With A Musculoskeletal Trauma in the Emergency Department

BACKGROUND: A single-agent approach to children’s moderate to severe pain is often inadequate. To date, no studies have evaluated the combined use of oral morphine and ibuprofen for optimal pain management of children presenting to an emergency department (ED) for muscu-loskeletal (MSK) trauma.

OBJECTIVES: To assess the efficacy of a combination of oral morphine and ibuprofen for pain management in children with MSK trauma in the ED.

DESIGN/METHODS: A double-blind, placebo-controlled, multi-centered, three-arm, randomized clinical trial of 500 patients was conducted at three pediatric tertiary care EDs. Patients were randomized (in a 2:1:1 ratio) to receive (orally): (a) morphine (0.2mg/kg) + ibuprofen (10mg/kg) (Group MOR + IBU) or (b) morphine (0.2 mg/kg) + placebo (Group MOR) or (c) ibuprofen (10mg/kg) + placebo (Group IBU). Patients 6 to 17 years of age, who presented to the ED with a MSK trauma, and a score >30 mm on the 100mm visual analogue scale were eligible to participate. Primary outcome was pain intensity score under 30 mm (mild pain) at 60-minutes (T-60) after treatment administration.

RESULTS: A total of 456 patients were included in analyses: 177 (MOR + IBU), 188 (MOR), 91 (IBU). Mean age was 11.9±2.7 years, with a majority of boys (55.3%) and Soft tissue injuries (62%). There were no differences in baseline characteristics in the three groups. Baseline mean pain score was 60.9±16.2 mm. Only 30% (MOR + IBU), 29% (MOR) and 30% (IBU) of patients reached a pain score under 30 mm at T-60 (p=0.83). Mean pain scores at T-60 were 42.3±23.2 mm (MOR + IBU), 43.8 + 23.1 mm (MOR) and 42.3±23.3 mm (IBU) (p=0.83). No severe adverse events were observed in any of the groups, at any of the study measurement points.

CONCLUSION: Combination of morphine with ibuprofen did not provide any additional pain relief for children with MSK injuries, in the ED. None of the study medication provided optimal pain management, as the majority of children did not reach the WHO definition of mild pain. Alternative analgesic combinations should be investigated to optimize pain relief of children who present to the ED with MSK injuries.

Quantitative Assays of the Amount of Diethylenetriaminepentaacetic Acid Conjugated to Water-Soluble Polymers Using Isothermal Titration Calorimetry and Colorimetry

The level of conjugation of diethylenetriaminepentaacetic acid (DTPA) to the polysaccharide sodium hyaluronan (HA) has been measured by a colorimetric assay, isothermal titration calorimetry (ITC), and (1)H NMR spectroscopy. The colorimetric assay is based on the red shift, upon complexation with gadolinium ion (Gd3+), of the wavelength of maximum absorption of the dye arsenazo III. It can be performed in a few minutes using as little as 10 microg of polymer with a detection limit of approximately 0.03 mmol of DTPA (gram of polymer)-1. The ITC measurements yield values of the amount of DTPA linked to HA identical to those obtained by colorimetry. The levels of DTPA conjugation calculated by integration of signals at 3.1-3.2 ppm (DTPA protons) and at 2.0 ppm (HA acetamide protons) in the 1H NMR spectrum of HA-DTPA are consistently overestimated by a factor of approximately 2, compared to the data obtained by ITC and colorimetry. The longer relaxation times of protons of the polymer backbone, compared to those of protons attached to the freely moving DTPA side-chains may account for the discrepancy.

Office management of minor wounds

OBJECTIVE

To review office interventions for minor wounds not requiring sutures, such as abrasions, bites, and lacerations.

QUALITY OF EVIDENCE

Most information on minor wound management comes from descriptive studies. Few comparative studies examine the effectiveness of topical antisepsis for minor wounds. Several clinical trials have demonstrated that tissue adhesives produce short- and long-term cosmetic results equivalent to those achieved with suture materials.

MAIN MESSAGE

Sterile saline is the least toxic solution for wound irrigation. Chlorhexidine (2%) and povidone iodine (10%) have been the most investigated antiseptic solutions. Systemic antibiotics are unnecessary for wounds unlikely to be infected. All bite wounds require special attention. Primary closure of bite wounds is indicated in certain circumstances: less than 12-hour-old nonpuncture wounds, uninfected wounds, and low-risk lesions (such as on the face). In spite of their many advantages, skin tapes should be used for low-tension wounds only. The popularity of tissue adhesives has greatly increased. Since the advent of newer products (with increased bonding strength and flexibility), adhesives are used to manage most lacerations except those in areas of high tension (e.g., joints) and on mucosal surfaces.

CONCLUSION

Minor wounds not requiring sutures can be managed easily in the office.

Predictive factors for short-term symptom persistence in children after emergency department evaluation for constipation

BACKGROUND

Children with symptoms and signs of constipation are commonly assessed in pediatric emergency departments (EDs). Little is known about their outcome following the ED visit.

OBJECTIVES

To describe the clinical characteristics of children presenting to the ED with constipation and the ED interventions; to measure short-term symptom resolution at 48 hours and 7 days after the ED visit; and to identify predictive factors associated with poor symptom resolution at 48 hours and 7 days after the ED visit.

DESIGN/METHODS

Cohort study conducted between July 10, 1997, and September 10, 1997, in a tertiary care pediatric hospital ED. All children (aged 1-18 years) with idiopathic constipation were included. Constipation was diagnosed if there were at least 2 of the following: abdominal pain, infrequent bowel movements, hard feces, fecal soiling, pain on defecation, and/or clinical evidence of excessively retained feces. Data on the presenting symptoms, signs, and ED treatment plan were collected on study enrollment and then in 2 standardized 10-minute telephone interviews at 48 hours and 7 days after the ED visit. At each follow-up, patient disposition was measured and dichotomized based on symptom resolution to "improved" vs "not improved." The presenting features and ED management were compared between groups using chi(2) analyses and t tests.

RESULTS

Consent and full questionnaire completion was obtained in 102 children. The mean + SD age was 6.5 + 3.8 years; 47 (46%) were male. The predominant presenting symptom was abdominal pain (83 [81%]); the most frequent sign was palpable abdominal stool (67 [66%]). A high-fiber diet (75 [74%]) and mineral oil (48 [47%]) were prescribed most frequently. Enemas were given to 64 (63%) of the children. Improvement was found in 32 (31%) of the children at 48 hours and in the majority at 7 days (77 [75%]). Risk factors for poor symptom resolution at both 48 hours and 1 week included: female sex (odds ratio [OR] = 2.6; 95% confidence interval [CI] = 1.0 6.6); history of recurrent abdominal pain (OR = 2.8; 95% CI = 1.2-6.5); duration of primary presenting symptom longer than 2 days (OR = 2.4; 95% CI = 1.0-6.4); and history of medical visits for the same symptom (OR = 2.3; 95% CI = 1.0-5.3). There was no difference in outcome based upon ED treatment (enema vs oral or no therapy) (OR = 1.0; 95% CI = 0.4-2.3).

CONCLUSIONS

Most children with constipation evaluated in the ED have acute symptoms and rapid improvement, regardless of presentation characteristics or ED management. In this study, 4 risk factors for poor outcome were found consistently at 48 hours and 7 days. This subgroup of children deserve closer clinical attention. Emergency department therapy did not influence short-term symptom resolution. Further studies are warranted to examine the effects of therapy for constipation in the ED setting. Arch Pediatr Adolesc Med. 2000;154:1204-1208.

Utilization analysis of an observation unit for children with asthma

BACKGROUND

Short-stay observation unit (OU) care for children with asthma has the potential to reduce hospitalization rates for this common pediatric condition. In the effort to increase the efficiency of such a unit, knowledge of predictive factors for successful discharge is important.

OBJECTIVES

1) To define clinical predictive factors determined at the time of initial presentation in the emergency department (ED) that would identify which children with asthma are most likely to be successfully discharged from an OU. 2) To compare the management provided in the initial 3 hours upon arrival at the ED between the children who are eventually successfully discharged from an OU to those who require an inpatient admission. 3) To compare the length of stay in the OU between the patients who eventually go home to those who require an inpatient admission.

DESIGN

Case control study.

SETTING

Urban, tertiary-care pediatric ED.

PARTICIPANTS

From a collected database of all patients with asthma 1 to 18 years of age, presenting to the ED from July 1, 1993 to June 30, 1994 (n = 2248), a random sample of 350 patients was identified. All children meeting the definition of "case" or "control" from this sample were included. Cases were defined as children with asthma who were successfully discharged after a stay in the OU. Controls were defined as children with asthma who were not successfully discharged; that is, children who required subsequent inpatient admission.

RESULTS

Of the 350 children with asthma in the randomly selected subset sample, 47 cases and 21 controls were identified. In both cases and controls, patients had similar characteristics regarding mean age, sex, mean weight, previous history of asthma, and mean length of illness. The use of medications in the 24 hours prior to presentation to the ED was similar between both groups. No differences were found in the mean respiratory rate upon presentation between the cases and the controls (40/min vs. 44/min; P = 0.2), mean oxygen saturation (95 vs. 94%; P = 0.4). However, there was a significant difference in the requirement of supplemental oxygen between cases and controls (15 vs. 43%; P = 0.01; OR = 0.23:0.07 to 0.76). No further differences were found in the first 3 hours of ED management. The number of albuterol and ipratropium nebulizations was similar. The use, dosage, and timing of systemic steroids were also similar between the groups. The cases remained in the OU for a shorter period of time (8.7 hours vs 9.2 hours; 95% C.I.: -2.8 to 1.8) than the controls.

CONCLUSION

No clinical predictive factors determined at the time of arrival to the ED were identified for children with asthma who were successfully discharged from the OU except for a lesser need of oxygen supplementation. The patients observed in the OU had similar management in the initial 3 hours of arrival and similar length of stay in the OU, regardless of their disposition outcome. Maximal OU efficiency remains limited by the lack of clear predictive factors for successful discharge. Further study in this area is indicated.

Effect of a pediatric observation unit on the rate of hospitalization for asthma

STUDY OBJECTIVE

To determine the asthma admission rate and the rate of repeat visits to the emergency department for asthma within 72 hours before and after the introduction of an observation unit (OU). When necessary, admission to the ward from the OU is usually made within 12 hours.

METHODS

We conducted a before-and-after study with retrospective data collection in an urban tertiary care pediatric ED. Our subjects were patients aged 1 to 18 years who presented to the ED with asthma. The pre-OU group comprised patients seen between July 1, 1991, and June 30, 1992, before the opening of the OU. The post-OU group consisted of children seen between July 1, 1993, and June 30, 1994, after the opening of the OU.

RESULTS

The pre- and post-OU groups had 1,979 and 2,248 asthma visits, respectively. The admission rate decreased from 31% in the pre-OU group to 24% in the post-OU group (P < .01). The frequency of inpatient admissions of less than 24 hours decreased from 17% in the pre-OU group to 10% in the post-OU group (P < or = 01). The rate of repeat ED visits within 72 hours was 3% in the pre-OU group and 5% in the post-OU group (P = .01).

CONCLUSION

The use of an OU in the ED was associated with a reduction in the hospitalization rate for children with acute asthma exacerbation. However, we also noted an increased rate of repeat visits to the ED after the introduction of the OU.

Synthesis of 3 alpha- and 3 beta-dimers from selected bile acids

New dimers of bile acids have been synthesized by linking the hydroxyl groups on C3 of the steroid skeleton with a spacer via the formation of ester or ether bonds. 3 alpha-Dimers of lithocholic acid and cholic acid were prepared by forming ester linkages between the C3 hydroxyl group and dicarboxylic acids of different lengths, i.e., suberoyl chloride (eight carbons) and sebacoyl chloride (ten carbons). These dimers were obtained in three steps with an overall yield of about 70%. Regioselective hydrolysis of the methyl ester protecting groups on the bile acids was carried out successfully under mild alkaline conditions (aqueous lithium hydroxide with tetrahydrofuran). A 3 beta-dimer of lithocholic acid has also been synthesized by linking the C3 positions of two bile acids with diethylene glycol by the formation of ether linkages. The carboxylic acid groups of the bile acid dimer can be liberated by the removal of the methyl ester protecting groups.

Unusual cause of seizure

INTRODUCTION

This case report of camphor ingestion in a 15-month-old child illustrates the potential toxicity of a common household product. Details of the patient presentation are reported along with a review of the literature.

METHODS

Patient information was collected using the records of Poison Control, the Emergency Department, and the Health Records at the Hospital for Sick Children in Toronto, Ontario, Canada. A comprehensive review of the literature was conducted using the MEDLINE database for the time period 1966 to April 1995.

DISCUSSION

Oral ingestion of camphor is unusual, given that these products have both unpleasant taste and texture. This patient ingested 70 ml of an over-the-counter medicated ointment containing 4.73% camphor, 2.6% menthol, and 1.2% eucalyptus oil. While the concentration of camphor in this product is low, an estimated 280 mg/kg of camphor was consumed. With significant ingestion of camphor (> 50 mg/kg), neurologic toxicity is common. In this patient, prolonged generalized tonic-clonic seizure activity was noted approximately two hours post single acute ingestion of camphor. This delay in onset of seizure activity is atypical, as seizures have previously been noted to occur in the 90 minutes following ingestion.

CONCLUSION

Readily available medicated ointments containing camphor have potential for serious or fatal consequences when ingested by children.

Pulmonary and systemic immunoregulatory changes during the development of experimental asbestosis

Initial studies on the effects of low dose exposure to asbestos on pulmonary and systemic immune responses have revealed a bi-phasic pattern characterized by an early enhancement followed by inhibition of lymphocyte responses to several mitogens. In the present study, we sought to define the cellular and humoral factors, responsible for the observed effects. The early enhancement of peripheral blood and pulmonary lymphocyte responses to mitogens may be due, at least in part, to the loss of the inhibitory capacity of alveolar macrophages from asbestos exposed animals to suppress lymphocyte response. Furthermore, macrophages from low dose exposed animals actually enhanced lymphocytes responses to Con A and PHA. The latter inhibition observed following 6-12 months of exposure may be due to the in vivo generation of suppressor lymphocytes. Unfractionated lymphocytes from blood or alveolar space as well as enriched T cells from high dose exposed animals suppressed the proliferative responses of pulmonary or circulating lymphocytes to PHA and Con A, but not to PWM. Similarly, pre-incubation of normal blood or pulmonary lymphocytes in serum from high dose exposed animals for 24 h induced the appearance of suppressor cell activity in these populations when further tested in a co-culture assay with normal fresh lymphocytes. Taken together, these studies demonstrate the multi-faceted effects of asbestos on the immune system. The eventual fibrogenic process of asbestosis may result from the interplay of several mechanisms, some of which are suggested in this work.

Asbestos-induced lung inflammation. Role of local macrophage-derived chemotactic factors in accumulation of neutrophils in the lungs

In a recently developed sheep model of progressive low-dose pulmonary exposure to asbestos, initial alveolar lymphocyte and macrophage activation was followed by pulmonary neutrophilia in higher-dose exposed animals. This was observed after 18 months of exposure to intratracheal instillations of asbestos fibers and coincided with progressive alveolitis and decreased lung compliance. Alveolar macrophages from those animals were found to produce a chemotactic factor which attracted in vitro peripheral blood neutrophils. It attracted neutrophils more efficiently from higher-exposure than lower-exposure animals. Supernatants of control macrophages exposed to asbestos in vitro were also chemotactic for PMN. Similarly, bronchoalveolar lavage fluids from the animals showed chemotactic activity for peripheral blood neutrophils. It is suggested that chronic exposure to asbestos activates alveolar macrophages to produce chemotactic factors which in turn attract neutrophils from the vascular compartment and may thus contribute to the inflammatory process in asbestosis.