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1.
Anal Chem ; 95(34): 12867-12874, 2023 Aug 29.
Article in English | MEDLINE | ID: mdl-37581365

ABSTRACT

We have employed a new approach to quantify the amount fraction of nitrous oxide in a synthetic air matrix gas used to prepare high-accuracy reference materials of the same component. Until now, this was the largest contributor to the measurement uncertainty of nitrous oxide in air reference materials at atmospheric amount fractions (∼330 nmol mol-1), as identified in a recent international comparison. A novel preconcentration method has resulted in a measurement of 363 pmol mol-1 of nitrous oxide in a synthetic air matrix gas with an expanded uncertainty of 27 pmol mol-1. This represents a significant breakthrough as using these developments with an optimized dilution hierarchy (to minimize the gravimetric uncertainty) promises to result in SI traceable reference materials with expanded uncertainties as low as 0.032% relative (k = 2). This supports the World Meteorological Organization-Global Atmosphere Watch network compatibility goal for underpinning atmospheric observations.

2.
J Surg Case Rep ; 2022(7): rjac326, 2022 Jul.
Article in English | MEDLINE | ID: mdl-35813453

ABSTRACT

Enteric duplication cysts are rare congenital entities most commonly found in the esophagus, ileum or colon but can be in remote locations such as the biliary tree, liver or pancreas. Pancreatic duplication cysts are very uncommon and usually present in adulthood with pancreatitis or abdominal pain. Here, we present a unique and complex case of an infant with a pancreatic duplication cyst initially presenting with an upper gastrointestinal bleed followed by pancreatitis, cyst infection and gastric outlet obstruction.

3.
Anal Chem ; 93(29): 10141-10151, 2021 Jul 27.
Article in English | MEDLINE | ID: mdl-34260200

ABSTRACT

We present a new instrument, "Boreas", a cryogen-free methane (CH4) preconcentration system coupled to a dual-laser spectrometer for making simultaneous measurements of δ13C(CH4) and δ2H(CH4) in ambient air. Excluding isotope ratio scale uncertainty, we estimate a typical standard measurement uncertainty for an ambient air sample of 0.07‰ for δ13C(CH4) and 0.9‰ for δ2H(CH4), which are the lowest reported for a laser spectroscopy-based system and comparable to isotope ratio mass spectrometry. We trap CH4 (∼1.9 µmol mol-1) from ∼5 L of air onto the front end of a packed column, subsequently separating CH4 from interferences using a controlled temperature ramp with nitrogen (N2) as the carrier gas, before eluting CH4 at ∼550 µmol mol-1. This processed sample is then delivered to an infrared laser spectrometer for measuring the amount fractions of 12CH4, 13CH4, and 12CH3D isotopologues. We calibrate the instrument using a set of gravimetrically prepared amount fraction primary reference materials directly into the laser spectrometer that span a range of 500-626 µmol mol-1 (CH4 in N2) made from a single pure CH4 source that has been isotopically characterized for δ13C(CH4) by IRMS. Under the principle of identical treatment, a compressed ambient air sample is used as a working standard and measured between air samples, from which a final calibrated isotope ratio is calculated. Finally, we make automated measurements of both δ13C(CH4) and δ2H(CH4) in over 200 ambient air samples and demonstrate the application of Boreas for deployment to atmospheric monitoring sites.

4.
J Pediatr Surg ; 55(5): 796-799, 2020 May.
Article in English | MEDLINE | ID: mdl-32085917

ABSTRACT

This interactive session was held at the 51st Annual Meeting of the Canadian Association of Pediatric Surgeons (CAPS) in preparation for the transition of Pediatric Surgery training in Canada to Competency by Design (a CBME-based model of residency training developed by the Royal College of Physicians and Surgeons of Canada).


Subject(s)
Internship and Residency/organization & administration , Pediatrics , Surgeons , Canada , Clinical Competence , Humans , Pediatrics/education , Pediatrics/organization & administration , Surgeons/education , Surgeons/organization & administration
5.
Anal Chem ; 91(8): 5310-5315, 2019 Apr 16.
Article in English | MEDLINE | ID: mdl-30917653

ABSTRACT

We have shown that an exchange dilution preparation method reduces the impact of surface adsorption of the target component in high-pressure gas mixtures used for underpinning measurements of amount-of-substance fraction. Gas mixtures are diluted in the same cylinder by releasing an aliquot of the parent mixture. Additional matrix gas is then added to the cylinder. This differs from conventional methods where dilutions are achieved by transferring the parent mixture to another cylinder, which then stores the final reference material. The benefit of this revolutionary approach is that losses due to adsorption to the walls of the cylinder and the valve are reduced as the parent mixture pacifies the surface with only a negligible relative change in amount-of-substance fraction. This development allows for preparation of gas reference materials with unprecedented uncertainties beyond the existing state of the art. It has significant implications for the preparation of high accuracy gas reference materials which underpin a broad range of requirements, particularly in atmospheric monitoring of carbon dioxide, where understanding the adsorption effects is the major obstacle to advancing the measurement science. It has the potential to remove the reliance on proprietary surface pretreatments as the method provides an in situ and consistent alternative.

6.
Horm Res Paediatr ; 91(4): 285-289, 2019.
Article in English | MEDLINE | ID: mdl-30326482

ABSTRACT

BACKGROUND: Vasoactive intestinal peptide-secreting tumours (VIPomas) lead to high-volume secretory diarrhoea with hypokalaemia, as well as hyperglycaemia and hypercalcaemia. Diagnosis is often delayed. CASE DESCRIPTION: We present a 13-year-old girl with a distal pancreatic VIPoma diagnosed on her second hospital presentation who became severely hypotensive on anaesthetic induction prior to tumour removal, likely due to the vasodilatory effect of supraphysiological VIP levels. Prior to the second surgical attempt, an octreotide infusion was started preoperatively to suppress systemic VIP levels and counter the potential for VIP-induced hypotension upon tumour manipulation, and the tumour was successfully resected. Hyperparathyroidism and history of GI tumour resection were subsequently identified in the father, and the two members were found to have a heterozygous variant of uncertain significance in the multiple endocrine neoplasia type 1 (MEN1) gene. However, as this family meets the diagnostic criteria for MEN1 clinically, ongoing surveillance for MEN1 tumours and genetic counseling for at-risk family members are required despite the non-pathogenic genetic result. CONCLUSION: This case highlights the importance of screening for a VIPoma in patients with high-volume secretory diarrhoea and preventing cardiovascular complications with perioperative VIP suppression. Furthermore, careful interpretation of genetic results within the clinical context is required.


Subject(s)
Genetic Variation , Hypotension , Pancreatic Neoplasms , Perioperative Period , Proto-Oncogene Proteins/genetics , Vipoma , Adolescent , Female , Humans , Hypotension/genetics , Hypotension/physiopathology , Pancreatic Neoplasms/genetics , Pancreatic Neoplasms/physiopathology , Pancreatic Neoplasms/surgery , Vipoma/genetics , Vipoma/physiopathology , Vipoma/surgery
7.
Pediatr Emerg Care ; 34(7): e134-e135, 2018 Jul.
Article in English | MEDLINE | ID: mdl-27870784

ABSTRACT

Intussusception is a pediatric abdominal emergency in early childhood involving telescoping of 1 part of the bowel into another part. In most children, the condition is idiopathic with no identifiable lead point. Meckel diverticulum is the most common lead point, followed by polyps and duplication cysts. We describe a case of a boy with intussusception caused by a duplication cyst that was drawn retrograde through the ileocecal valve. The patient presented after a 3-month period of symptomatology and had been considered to have constipation before signs of intestinal obstruction developed. Only mild bowel ischemia was seen during the surgical reduction and resection of the cyst which may suggest an ongoing partial obstruction that eventually became more significant. In children with recurrent abdominal pain, surgeons should consider the possibility of intermittent intussusceptions caused by a duplication cyst.


Subject(s)
Cecum/pathology , Cysts/complications , Intussusception/etiology , Cecum/surgery , Child, Preschool , Cysts/surgery , Humans , Intussusception/diagnosis , Intussusception/surgery , Laparotomy/methods , Male , Ultrasonography
8.
J Surg Educ ; 73(3): 496-503, 2016.
Article in English | MEDLINE | ID: mdl-26830927

ABSTRACT

PURPOSE: Similar to other countries, the practice of General Surgery in Canada has undergone significant evolution over the past 30 years without major changes to the training model. There is growing concern that current General Surgery residency training does not provide the skills required to practice the breadth of General Surgery in all Canadian communities and practice settings. PROCEDURE: Led by a national Task Force on the Future of General Surgery, this project aimed to develop recommendations on the optimal configuration of General Surgery training in Canada. A series of 4 evidence-based sub-studies and a national survey were launched to inform these recommendations. MAIN FINDINGS: Generalized findings from the multiple methods of the project speak to the complexity of the current practice of General Surgery: (1) General surgeons have very different practice patterns depending on the location of practice; (2) General Surgery training offers strong preparation for overall clinical competence; (3) Subspecialized training is a new reality for today's general surgeons; and (4) Generation of the report and recommendations for the future of General Surgery. A total of 4 key recommendations were developed to optimize General Surgery for the 21st century. CONCLUSIONS: This project demonstrated that a high variability of practice dependent on location contrasts with the principles of implementing the same objectives of training for all General Surgery graduates. The overall results of the project have prompted the Royal College to review the training requirements and consider a more "fit for purpose" training scheme, thus ensuring that General Surgery residency training programs would optimally prepare residents for a broad range of practice settings and locations across Canada.


Subject(s)
Education, Medical, Graduate/trends , General Surgery/education , General Surgery/trends , Canada , Career Choice , Clinical Competence , Forecasting , Humans , Internship and Residency , Practice Patterns, Physicians'/statistics & numerical data , Professional Practice Location , Surveys and Questionnaires
10.
Can Urol Assoc J ; 5(3): 182-5, 2011 Jun.
Article in English | MEDLINE | ID: mdl-21672480

ABSTRACT

BACKGROUND: : Our objective was to compare personality traits between urologists and other surgeons, as well as between surgeons and non-surgeons. METHODS: : Eighty-six surgeons (57 faculty, 29 residents) completed the Revised NEO Personality Inventory (NEO PI-R), a validated measure of normal personality traits. Subjects agree or disagree with 240 statements to generate a score in each of the 5 major character traits: extraversion (E), openness (O), conscientiousness (C), agreeableness (A) and neuroticism (N). Each factor is subdivided into 6 component facets. Scores for urology faculty and residents were compared to the other surgical groups and 21 pediatricians. RESULTS: : The 3 groups differed significantly on extraversion (p < 0.001). Post-hoc analyses indicated that urologists obtained significantly higher extraversion scores than other surgeons (p < 0.05) and non-surgeons (p < 0.001) Other surgeons also scored significantly higher than non-surgeons on the extraversion factor (p < 0.05). No significant differences emerged on openness, conscientiousness, agreeableness or neuroticism. Of the 6 extraversion facets, urologists obtained significantly higher scores on gregariousness and excitement-seeking (p < 0.05) than non-urologist surgeons, and significantly higher scores on gregariousness (p < 0.05), activity (p < 0.01), excitement seeking (p < 0.001), and positive emotions (p < 0.05) than non-surgeons. Non-urologist surgeons obtained significantly higher scores than non-surgeons on Activity and Excitement-seeking (p < 0.01).There were no significant differences in the facets of warmth or assertiveness. INTERPRETATION: : Urologists appear to be more extraverted compared to other surgeons. Both groups of surgeons were more extraverted than non-surgeons. If these findings can be confirmed on a wider basis, the data may be helpful in resident selection, mentoring, evaluation and career counselling.

11.
Can Fam Physician ; 56(6): e226-32, 2010 Jun.
Article in English | MEDLINE | ID: mdl-20547505

ABSTRACT

OBJECTIVE: To identify and quantify the reasons general practitioners and family physicians consider retraining and their reasons for not pursuing further training. DESIGN: Population-based mailed survey. SETTING: British Columbia. PARTICIPANTS: Family physicians and general practitioners identified by the College of Physicians and Surgeons of British Columbia. MAIN OUTCOME MEASURES: Practising physicians' level of awareness of the University of British Columbia's re-entry training program, the number and demographic characteristics of those who had considered retraining, their specialties of interest, and the barriers and possible inducements to retraining. RESULTS: Only half of the survey respondents were aware of the re-entry training program at the University of British Columbia. A small but substantial number of practising general practitioners and family physicians were interested in taking specialty training from the Royal College of Physicians and Surgeons of Canada. While several training programs were particularly popular (ie, anesthesia and psychiatry--18.5% of respondents for each), almost every specialty training program was mentioned. Physicians identified the length and hours of training, financial issues, family issues, and the need for relocation as obstacles to retraining. The availability of part-time training, regional training, and return-of-service financial assistance were all identified as potential inducements. CONCLUSION: To meet the needs of practising physicians, re-entry training programs will need to consider flexibility, where feasible, with regard to choice of specialty, intensity, and location of postgraduate training.


Subject(s)
Career Choice , Family Practice/education , Internship and Residency , Specialization , Adult , Age Factors , British Columbia , Certification , Education, Medical, Continuing , Education, Professional, Retraining/statistics & numerical data , Female , General Practice/education , Humans , Internship and Residency/statistics & numerical data , Male , Middle Aged , Surveys and Questionnaires
12.
J Pediatr Surg ; 43(5): 899-905, 2008 May.
Article in English | MEDLINE | ID: mdl-18485963

ABSTRACT

BACKGROUND/PURPOSE: Little is known about the quality of life (QOL) of children with Hirschsprung's disease (HD) as they grow older. The purpose of this study was to measure the QOL and bowel function of these children as they mature. METHODS: All children who were surgically treated for HD at British Columbia Children's Hospital, Vancouver, British Columbia, Canada between 1986 and 2003 were invited to participate. Each family was sent 3 previously validated questionnaires exploring current QOL and bowel function. RESULTS: Fifty-one families participated (49%), with children between the ages of 3 and 21 years. Fecal continence improved significantly with age (P = .04) and was the strongest predictor of QOL scores of all variables in our study. There was no statistically significant difference in QOL scores between children with HD and healthy children, although a clinically relevant impairment in QOL may be present, especially in psychosocial scores. CONCLUSIONS: Fecal continence is an important predictor of overall QOL in children surgically treated for HD. Although continence tends to improve with age, a number of older children still have ongoing continence problems, and they seem to be a group at risk for impaired QOL. Our study indicates that interventions for children with incontinence may offer gains in QOL as well as bowel function.


Subject(s)
Constipation/physiopathology , Fecal Incontinence/physiopathology , Hirschsprung Disease/physiopathology , Abnormalities, Multiple/epidemiology , Adolescent , Adult , Analysis of Variance , Child , Child, Preschool , Comorbidity , Constipation/epidemiology , Fecal Incontinence/classification , Fecal Incontinence/epidemiology , Female , Follow-Up Studies , Hirschsprung Disease/epidemiology , Hirschsprung Disease/surgery , Humans , Male , Postoperative Period , Quality of Life , Severity of Illness Index , Sex Distribution , Surveys and Questionnaires
13.
Am J Surg ; 193(5): 551-5; discussion 555, 2007 May.
Article in English | MEDLINE | ID: mdl-17434353

ABSTRACT

BACKGROUND: The ideal assessment of technical skills should be defensible and practical. The purpose of this study was to evaluate the utility of a Global Rating Scale (GRS) Assessment tool of resident operating room performance. METHODS: Residents were assessed in the operating room on multiple occasions during a 6-month study period using a 9-item GRS. Data were analyzed to assess scale reliability and sensitivity to year of training. Feasibility was evaluated with a post-study questionnaire. RESULTS: Seven residents had a total of 32 procedures assessed. One-way analysis of variance (ANOVA) showed that scores increased with year of training (P = .009). Reliability was excellent. (Cronbach's alpha .91). The post-study survey identified feedback and faculty interaction as strengths of this tool, but time constraint was a barrier. CONCLUSIONS: The GRS tool is a valid and reliable method that has the potential to be a practical, useful assessment tool of resident operating room performance.


Subject(s)
Clinical Competence/statistics & numerical data , General Surgery/education , General Surgery/standards , Internship and Residency , Feasibility Studies , Reproducibility of Results , Surveys and Questionnaires
14.
Am J Surg ; 193(5): 561-6; discussion 566, 2007 May.
Article in English | MEDLINE | ID: mdl-17434355

ABSTRACT

BACKGROUND: Vascular surgery (VS) has been removed from the Canadian general surgery (GS) objectives and has become a primary certificate specialty in the United States, leaving its status in GS uncertain. The purpose of this study was to determine GS residents' perceived competence in VS and to assess their knowledge of VS. METHODS: GS residents at a university-based program answered (1) a survey of attitudes and experience in VS and (2) a short-answer examination to assess fundamental vascular knowledge. RESULTS: Twenty-nine of 35 residents participated (83%). Residents reported being inadequately trained in 10 of 13 procedures surveyed despite 6 of these being reported as essential. Although 26 of 29 residents reported an intention to perform vascular procedures, none planned on pursuing a fellowship. The mean examination score was 47%. CONCLUSIONS: Despite mandatory VS rotations, GS residents feel inadequately trained in VS and have marginal knowledge. Current trainees may lack the skills and abilities to deal with vascular emergencies.


Subject(s)
Clinical Competence , General Surgery/education , Internship and Residency , Vascular Surgical Procedures/education , Forecasting , Surveys and Questionnaires
15.
J Pediatr Surg ; 41(12): 2059-61, 2006 Dec.
Article in English | MEDLINE | ID: mdl-17161205

ABSTRACT

BACKGROUND: Pyloroplasty and pyloric dilatation are methods used to ameliorate the symptoms of nonobstructive delayed gastric emptying in children. Our purpose was to review the results of these methods with respect to symptomatic improvements. METHODS: We retrospectively reviewed the records of children who, exclusive of fundoplications, in the 11-year period before December 31, 2005, had undergone at our institution a Heineke-Mikulicz pyloroplasty (HMP) and/or a fluoroscopically guided balloon pyloric dilatation (FGBD). We recorded evidence of either short- or long-term subjective improvement of symptoms. RESULTS: Twenty-three children underwent HMP. Five had no prior medical treatment. Of the 23, 3 had no subjective improvement in symptoms. Of the 20 who had subjective evidence of improvement recorded, 13 (56.5%) proved to be long-term and 7 short-term improvement. Eight children had FGBD. All 8 had prior medical treatment that had failed. There were 3 who displayed no subjective evidence of improvement, whereas 5 had subjective evidence of improvement-3 (37.5%) long term and 2 short term. CONCLUSIONS: Heineke-Mikulicz pyloroplasty and FGBD in this study demonstrated only in limited numbers long-term improvement of symptoms. Efforts to understand more fully gastric emptying and to define those children who should undergo FGBD or HMP are needed.


Subject(s)
Gastric Emptying , Gastric Outlet Obstruction/surgery , Pylorus/surgery , Adolescent , Catheterization , Child , Child, Preschool , Female , Gastric Outlet Obstruction/physiopathology , Humans , Infant , Male , Retrospective Studies , Treatment Outcome
16.
J Pediatr Surg ; 40(5): 859-62, 2005 May.
Article in English | MEDLINE | ID: mdl-15937831

ABSTRACT

BACKGROUND/PURPOSE: Gastrostomy tube insertion is frequently performed in children. Percutaneous endoscopic gastrostomy (PEG) insertion, considered by many to be the "gold standard," is unavoidably associated with a risk of intestinal perforation and frequently requires a second anesthetic for its replacement with a low-profile "button." We hypothesized that a laparoscopic technique with low-pressure insufflation would yield comparable outcomes, a lower procedural complication rate, and require fewer anesthetics per patient. METHODS: A retrospective review of all surgeon-placed gastrostomy tubes (exclusive of those associated with fundoplication or other procedures) between January 2002 and December 2003 was undertaken. Data collected included type of procedure (PEG vs laparoscopic), indication, patient demographics (including neurologic comorbidity), operative time, complications (procedure-specific and nonspecific), and number of procedural anesthetics to "achieve" a low-profile tube. Groups were compared by univariate and multiple logistic regression analyses. RESULTS: One hundred nineteen gastrostomy tubes (26 laparoscopic = 21.8%) were inserted. The PEG and laparoscopic gastrostomy groups were comparable from the perspectives of age, size, indications for tube placement, and operative time. The complication rate after PEG placement was significantly higher than after LG (14% vs 7.7%; P = .023), and 72 (77.4%) of PEG patients required a second anesthetic for tube change. CONCLUSIONS: Laparoscopic gastrostomy tube insertion is safe and easy to perform, with outcomes comparable to that of PEG tube insertion. It obviates the need for a second procedural anesthetic and may emerge as the gold standard for gastrostomy tube placement.


Subject(s)
Enteral Nutrition , Gastroscopy/statistics & numerical data , Gastrostomy/standards , Intubation, Gastrointestinal/standards , Laparoscopy/statistics & numerical data , Child , Child, Preschool , Equipment Design , Female , Gastroscopy/methods , Gastrostomy/instrumentation , Gastrostomy/methods , Humans , Intestinal Perforation/prevention & control , Intubation, Gastrointestinal/instrumentation , Intubation, Gastrointestinal/methods , Laparoscopy/methods , Male , Postoperative Complications/epidemiology , Postoperative Complications/prevention & control , Reoperation , Retrospective Studies , Risk , Suture Techniques , Treatment Outcome
17.
Surgery ; 136(3): 641-6, 2004 Sep.
Article in English | MEDLINE | ID: mdl-15349113

ABSTRACT

BACKGROUND: The effectiveness of interventions for developing critical appraisal skills in practicing physicians has not been studied, despite the documented importance of reading the literature in caring for patients and in continuing professional development. The objective of this study was to evaluate whether an Internet-based intervention would lead to enhanced critical appraisal skills in practicing surgeons. METHODS: General surgeons who agreed to participate were randomized into 2 groups. The intervention was a curriculum in critical appraisal skills that included a clinical and methodologic article, a listserve discussion, and clinical and methodologic critiques. The control group received only the clinical articles. The primary outcome measure was a previously validated 2-hour test of critical appraisal. RESULTS: Of the 55 surgeons who completed the examination, subjects in the intervention group performed better on the test of critical appraisal skills than those in the control group (mean score: intervention group, 58% +/- 8 vs control group, 50% +/- 8), with a large effect size of 1.06 standard deviation units (t+3.92, P <.0001). Training conditions accounted for 22% of the variance in total scores. CONCLUSIONS: A multifaceted, Internet-based intervention resulted in improved critical appraisal skills of practicing general surgeons.


Subject(s)
Education, Medical, Continuing/methods , General Surgery/education , Internet , Journalism, Medical , Adult , General Surgery/standards , Humans , Professional Competence , Reading , Teaching
19.
J Pediatr Surg ; 38(12): 1726-9, 2003 Dec.
Article in English | MEDLINE | ID: mdl-14666453

ABSTRACT

BACKGROUND/PURPOSE: The purpose of this analysis was to investigate outcomes in newborns with esophageal atresia (EA) or tracheoesophageal fistula (TEF) with respect to prognostic classifications and complications. METHODS: Charts of all 144 infants with EA/TEF treated at British Columbia Children's Hospital (BCCH) from 1984 to 2000 were reviewed. Patient demographics, frequency of associated anomalies, and details of management and outcomes were examined. RESULTS: Applying the Waterston prognostic classification to our patient population, survival rate was 100% for class A, 100% for class B, and 80% for class C. The Montreal classification survival rate was 92% for class I and 71% for class II (P =.08). Using the Spitz classification, survival rate was 99% for type I, 84% for type II, and 43% for type III (P <.05). The Bremen classification survival rate was 95% "without complications" and 71% "with complications." Complications included stricture (52%), gastroesophageal reflux (31%), anastomotic leakage (8%), recurrent fistula (8%), and pneumonia (6%). Seventeen patients underwent fundoplication for gastroesophageal reflux, 16 pre-1992 and one post-1992. CONCLUSIONS: Comparing the major prognostic classifications, the Spitz classification scheme was found to be most applicable. In our institution, the trend in management of gastroesophageal reflux after repair of EA/TEF has moved away from fundoplication toward medical management.


Subject(s)
Esophageal Atresia/classification , Tracheoesophageal Fistula/classification , Abnormalities, Multiple/mortality , Esophageal Atresia/mortality , Esophageal Atresia/surgery , Female , Fundoplication , Humans , Infant, Newborn , Male , Postoperative Complications , Prognosis , Survival Rate , Tracheoesophageal Fistula/mortality , Tracheoesophageal Fistula/surgery , Treatment Outcome
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