Patient and Process Outcomes Among Pediatric Patients Undergoing Appendectomy During the COVID-19 Pandemic - an International Retrospective Cohort study

BACKGROUND

COVID-19 forced healthcare systems to make unprecedented changes in clinical care processes. We hypothesized that the COVID-19 pandemic adversely impacted timely access to care, perioperative processes, and clinical outcomes for pediatric patients undergoing primary appendectomy.

METHODS

We conducted a retrospective, international, multicenter study using matched cohorts within participating centers of the international PEdiatric Anesthesia COVID-19 Collaborative (PEACOC). Patients < 18 years old were matched using age, ASA-PS status, and sex. The primary outcome was the difference in hospital length of stay of patients undergoing primary appendectomy during a 2-month period early in the COVID-19 pandemic (April-May 2020) compared to pre-pandemic (April-May 2019). Secondary outcomes included time to appendectomy and the incidence of complicated appendicitis.

RESULTS

3351 cases from 28 institutions were available with 1684 cases in the pre-pandemic cohort matched to 1618 in the pandemic cohort. Hospital length of stay was statistically significantly different between the two groups: 29 hours (IQR: 18, 67) in the pandemic cohort versus 28 hours (IQR: 18, 79) in the pre-pandemic cohort (adjusted coefficient, 1; 95% CI 0.39 to 1.61, P<0.001), but this difference was small. Eight centers demonstrated a statistically significantly longer hospital length of stay in the pandemic period compared to the pre-pandemic period, while 13 were shorter and 7 did not observe a statistically significant difference. During the pandemic period, there was a greater occurrence of complicated appendicitis, pre-pandemic 313 (18.6%) versus pandemic 389 (24.1%), absolute difference of 5.5% (adjusted OR, 1.32; [95% CI 1.1 to 1.59]; P=0.003). Preoperative SARS CoV-2 testing was associated with significantly longer time-to-appendectomy, 720 minutes (IQR: 430, 1112) with testing versus 414 minutes (IQR: 231, 770) without testing, adjusted coefficient, 306 minutes, (95% CI 241 to 371, P <0.001), and longer hospital length of stay, 31 hours (IQR: 20, 83) with testing versus 24 hours (IQR: 14, 68) without testing, adjusted coefficient, 7.0, (95% CI 2.7 to 11.3, P=0.002).

DISCUSSION

For children undergoing appendectomy, the COVID-19 pandemic did not significantly impact hospital length of stay.

Photocatalytic remediation of methylene blue and antibacterial activity study using Schiff base-Cu complexes

This work describes the design of novel Cu(II) complexes and their application in the photocatalytic degradation of methylene blue (MB). The same photocatalyst exhibits antibacterial activity against Escherichia coli (gram-negative) and Bacillus circulans (gram-positive). The characterisation of the photocatalysts has been done by several up-to-date physical methods. The rationale behind the photocatalysts' beneficial intervention is discussed in this study. Statistical analysis of the degradation of MB is done using a one-way ANOVA, and the significance of means is determined by a multiple comparison test using Turkey HSD. Also, the degradation of MB follows pseudo first-order kinetics with high correlation coefficient values (R² > 0.95), making them useful as simple and low-cost organic dye degradation agents.

Acupuncture-D" - Bilateral Pneumothoraces Following Dry Needling

Presentation A 24-year-old newly graduated junior doctor presented to the emergency department with acute onset chest pain, haemoptysis and exertional dyspnoea following a dry needling session. Diagnosis Chest x-ray showed bilateral pneumothoraces, worse on the right side. Treatment The bilateral pneumothoraces were treated conservatively with supplemental oxygen initially. On the second day of admission, repeat chest x-ray demonstrated a worsening right sided pneumothorax. While vitally stable, the patient however had become increasingly dyspnoeic, and a needle aspiration was performed on the right side with good effect. Conclusion The anatomical location targeted along with the patients low-normal BMI makes her high-risk when considering the skin-to-pleura distance. Although the incidence of pneumothorax is low, it is imperative that we improve awareness both for the treating physician and the diagnosing clinician. We must begin to fill the distinct lack in available literature surrounding the potential adverse effects of dry needling.

An educational approach for early student self-assessment in clinical periodontology

BACKGROUND

Self-assessment is a mandated educational requirement for use in dental undergraduate programmes. It is weakly supported for use in early clinical training and studies are criticized for the conceptual and methodology shortfalls. The aim of the study was to compare the alignment of student self-assessment to both staff assessment and written exams in early clinical training using an educational approach.

METHODS

In 2014-2015, 55 third-year dental students completed three educational sessions comprising of (a) classroom teaching (lecture, video) with post-lesson written exam and (b) clinical activity with student self-assessment, staff assessment and student reflection. An intra-individual analysis approach, staff validation, and student scoring standardization were implemented. Cognitive (clinical competency) and non-cognitive (professionalism) items were separated in the analyses.

RESULTS

There were medium correlations (Spearman's rho, r) between student self-assessment and staff assessment scores for cognitive items (r, 0.32) and for non-cognitive items (r, 0.44) for all three combined sessions. There were large correlations for individual sessions. Compared to the post-lesson written exam, students showed small correlation (r, 0.22, 0.29) and staff showed medium correlation (r, 0.31, 0.34) for cognitive and non-cognitive items. Students showed improvements in their mean scores for both cognitive (t-test; p > 0.05) and non-cognitive items (t-test; p = 0.000). Mean scores of students were not different statistically from that of staff (p > 0.05).

CONCLUSIONS

Students may adequately act as self-assessors at the beginning of their clinical work in periodontology. Self-assessment may potentially improve the clinical performance. Self-assessment may be nurtured through clear guidelines, educational training strategies, feedback and reflection leading to better evaluative judgement and lifelong learning.

Role of laboratory biomarkers in assessing the severity of COVID-19 disease. A cross-sectional study

BACKGROUND

Corona virus disease 2019 (Covid-19) has high infectivity and mortality rate. Covid-19 patients can suddenly deteriorate and develop life threatening complications. Hence, there is a need to identify laboratory biomarkers in order to categorize high risk patients. The main purpose of the study is to investigate the role and correlation of laboratory parameters such as total leucocyte count (TLC), absolute lymphocyte count, platelet count, C-Reactive Proteins (CRP), serum ferritin, serum lactate dehydrogenase (LDH), serum procalcitonin and D-dimer in severe and non-severe Covid-19 patients.

METHODOLOGY

This retrospective cross-sectional study was conducted at Latifa Women and Child Hospital in the UAE after obtaining ethical committee clearance. Based on the symptoms and the criteria by National Institute of Health, USA, 109 patients were divided into three groups: Non-severe with 75, severe with 18 and critical with 16 patients. Laboratory data of these patients were assessed through the electronic medical records (SALAMA). Statistical analysis was done using Statistical Packages for Social Sciences (SPSS) version 25.0 (SPSS/PC; SPSS-25.0, Chicago, USA). Laboratory test profiles were expressed as mean (SD). Independent 't' test and ANOVA were used to study the significance of means. P value less than 0.05 was considered significant.

RESULT

Males were more severely affected than females. Severe and critically ill Covid-19 patients had a significantly higher TLC, serum LDH, ferritin and CRP and lower absolute lymphocyte count. PCT and D-dimer were significantly elevated in critical group.

CONCLUSION

Along with clinical presentation and radiological findings, biochemical parameter may also be considered as important predictors for assessing severity in covid-19 patients.

Use of therapeutic caffeine in acute care postoperative and critical care settings: a scoping review

BACKGROUND

Caffeine is the most utilised psychoactive drug worldwide. However, caffeine withdrawal and the therapeutic use of caffeine in intensive care and in the perioperative period have not been well summarised. Our objective was to conduct a scoping review of caffeine withdrawal and use in the intensive care unit (ICU) and postoperative patients.

METHODS

PubMed, Embase, CINAHL Complete, Scopus and Web of Science were systematically searched for studies investigating the effects of caffeine withdrawal or administration in ICU patients and in the perioperative period. Areas of recent systematic review such as pain or post-dural puncture headache were not included in this review. Studies were limited to adults.

RESULTS

Of 2268 articles screened, 26 were included and grouped into two themes of caffeine use in in the perioperative period and in the ICU. Caffeine withdrawal in the postoperative period increases the incidence of headache, which can be effectively treated prophylactically with perioperative caffeine. There were no studies investigating caffeine withdrawal or effect on sleep wake cycles, daytime somnolence, or delirium in the intensive care setting. Administration of caffeine results in faster emergence from sedation and anaesthesia, particularly in individuals who are at high risk of post-extubation complications. There has only been one study investigating caffeine administration to facilitate post-anaesthetic emergence in ICU. Caffeine administration appears to be safe in moderate doses in the perioperative period and in the intensive care setting.

CONCLUSIONS

Although caffeine is widely used, there is a paucity of studies investigating withdrawal or therapeutic effects in patients admitted to ICU and further novel studies are a priority.

Application of the Rapid Entire Body Assessment (REBA) in assessing chairside ergonomic risk of dental students

Introduction High prevalence of musculoskeletal disorders (MSDs) have been reported among operators in dentistry related to prolonged demanding and awkward operative tasks, in which non-neutral vertebral positions and risky joint articulations are adopted. The aim of the study was to investigate the feasibility and reliability of the application of the Rapid Entire Body Assessment (REBA) among dental students utilising three digital photographs of the operator to determine chairside ergonomic risk.Materials and methods Third-year dental students (n = 28) obtained profile, back and frontal digital photographs of student operators in a clinical session. REBA scorings were assigned per student utilising the photographs by student groups and independently by a physiotherapist. Statistical comparisons were done for both scorings.Results There was substantial interrater reliability (kappa = 0.625; p <0.001) and moderate concordance level (Kendall's Tau-b of 0.568; p <0.01) between the scores derived from students and staff. Medium- and high-risk students based on the REBA scores accounted for 64% and 75% of the class as determined by students and staff, respectively.Discussion The high percentage of medium-to-high-risk REBA values matched the prevalence of MSDs reported by dental students in the literature. Compared to staff, students with moderate reliability were able to produce REBA scores adequately.Conclusion REBA utilising digital photographs may be an easily applicable and moderately reliable tool for alerting static ergonomic risk for clinical dental students. Modification of at-risk behaviour early in training may limit the establishment of bad posture habits and aid in the prevention of MSDs during their clinical years and post-graduation.

Self-reported stress, coping ability, mental status, and periodontal diseases among police recruits

OBJECTIVE

This cross-sectional study aimed to investigate self-reported stress level and coping ability as well as mental status (anxiety and depression) via the 12-item General Health Questionnaire (GHQ-12) questionnaire and periodontal status among police academy recruits during their 8 months of training.

METHODS

Eighty-five consenting police recruits were examined at baseline during the first month of training and again during the last month of training. Full mouth plaque score (FMPS), full mouth bleeding score, basic periodontal examination, self-reported stress level (scale of 1-10) and GHQ-12 questionnaire (mental status) were recorded at both visits. Ability to cope (yes/no) with stress was recorded at the final visit. Periodontal diagnosis was derived based on clinical examination. t test and regression analyses (p < .05) were performed.

RESULTS

High stress (odds ratio: 1.25) and inability to cope with stress (odds ratio: 1.31) were statistically significant (p < .05) predictors of high FMPS. Inability to cope with stress (odds ratio: 1.45) was also a statistically significant (p < .05) predictor for periodontitis compared to gingivitis. Mental status (anxiety and depression) may play a greater role in gingivitis (mean 1.75) as opposed to periodontitis (mean 1.00) as reflected by the higher mean GHQ-12 (t test, p = .04).

CONCLUSIONS

In this study, both self-reporting of stress level and ability to cope with stress were statistically significant predictors of higher plaque score (FMPS). Ability to cope with stress was also a statistically significant predictor of periodontitis compared to gingivitis. Recording of both self-reported stress level and ability to cope may be valuable variables to note in the management of plaque and periodontal diseases.

Double-Blind Randomized Placebo-Controlled Trial of Single-Dose Intravenous Acetaminophen for Pain Associated With Adenotonsillectomy in Pediatric Patients With Sleep-Disordered Breathing

OBJECTIVES

Adequate pain control is an important component in the postoperative outcome for pediatric adenotonsillectomy patients with sleep-disordered breathing (SDB). Intravenous acetaminophen appears to be a favorable analgesic adjunct owing to its predictable pharmacokinetics and opioid-sparing effects; however, its role in pediatric adenotonsillectomy pain management remains unclear.

METHODS

In this prospective, randomized, double-blinded, controlled study, subjects with the diagnosis of SDB, aged 2 to 8 years, who required extended postoperative admission, received intravenous acetaminophen (15 mg/kg) or saline placebo intraoperatively in addition to morphine (0.1 mg/kg) for postoperative surgical analgesia. Pain scores in the postanesthesia care unit (PACU) using the FLACC (Faces, Leg, Activity, Cry, Consolability) score were used to determine the need for supplemental analgesic agents in the PACU. The PACU time and time to the first request for pain medication on the inpatient ward were also measured.

RESULTS

A total of 239 patients were included in the final data analysis (118 in the intravenous acetaminophen group and 121 in the saline placebo group). The 2 groups did not differ in the proportion of patients reaching FLACC scores = 4 in the PACU (p = 0.223); mean FLACC scores in the PACU (p = 0.336); mean PACU time (p = 0.883); or time to requesting pain medication on the inpatient ward (p = 0.640).

CONCLUSIONS

A single intraoperative dose of intravenous acetaminophen did not alter the postoperative course of pediatric patients with SDB following adenotonsillectomy.

Effects of partial sleep deprivation on reaction time in anesthesiologists

BACKGROUND

Fatigue in anesthesiologists may have implications that extend beyond individual well-being.

AIM

The aim of the present study was to evaluate the impact of sleep deprivation on the reaction time in anesthesiologists either after an overnight call or regular working hours. Moderation of this effect by coping strategies was observed.

METHODS

Psychomotor vigilance test was used to assess reaction time in 23 anesthesiologists at two time-points: (i) on a regular non-call day and (ii) after a 17-h in-house call. Student's paired t-test was used to compare Psychomotor Vigilance Task data at these two moments. Change score regression was performed to determine the association between coping strategies, assessed using the Coping Strategy Indicator instrument, and decline in reaction time after night call.

RESULTS

Twenty-one colleagues completed the psychomotor vigilance test measurements after two decided to end their participation for personal reasons. Post-call psychomotor vigilance test mean reaction time decreased by an average of 31.2 ms (95% CI: 0.5, 61.9; P = 0.047) when compared to regular day. Reliance on specific coping mechanisms, indicated by Coping Strategy Indicator scale scores, included problem-solving (28 ± 4), followed by seeking social support (23 ± 5) and avoidance (19 ± 4). The change score regression model (r² = 0.48) found that greater reliance on avoidance was associated with greater increase in reaction time after night call.

CONCLUSION

Reaction time increased considerably in anesthesiologists after a night call duty. Greater subjective reliance on avoidance as a coping strategy was associated with greater deterioration in performance.

Assessment of adenotonsillar size and caregiver-reported sleep symptoms among 3-6 year old children undergoing adenotonsillectomy

INTRODUCTION

Adenotonsillectomy remains the accepted first-line treatment for obstructive sleep apnea syndrome (OSAS) in children. Tonsillar size may be especially relevant in risk stratification as it may impact symptoms of sleep disordered breathing (SDB). This study assesses correlations among subjective tonsillar grading, measured tonsillar size, and degree of adenoid obstruction in patients age 3-6 years with caregiver-reported symptoms.

METHODS

Children 3-6 years old undergoing adenotonsillectomy for OSAS were enrolled prospectively. The subjective tonsillar grade and degree of adenoid obstruction were recorded on physical examination by the otolaryngologist, and the objective tonsillar size was obtained from pathology reports. Spearman's rho was used to assess agreement among measures of tonsillar size and adenoid obstruction; and to correlate these measures with caregiver-reported SDB symptoms obtained from a pre-operative standardized questionnaire.

RESULTS

The cohort included 103 boys and 97 girls of median age 4.8 (interquartile range [IQR]: 3.9, 5.9) years. Median subjective tonsillar grade was 3+ (IQR: 3+, 4+) while median tonsillar size was 2.7 cm (IQR: 2.5, 3) and median adenoid obstruction was 60% (IQR: 50%, 80%). The subjective tonsillar grade and measured tonsillar size were strongly correlated (ρ = 0.31, p < 0.001), whereas adenoid obstruction was uncorrelated with either subjective tonsillar grade (ρ = 0.01, p = 0.860) or measured size (ρ = -0.05, p = 0.497). Tonsillar grade was positively correlated with 3 common caregiver-reported SDB symptoms (loud snoring, trouble breathing at night, and daytime sleepiness). Objective tonsillar size was positively correlated only with difficulty organizing tasks or activities, and adenoid obstruction was positively correlated only with stopping breathing during sleep.

CONCLUSION

Subjective tonsillar grading by the otolaryngologist achieved better correlation than measured tonsillar size or degree of adenoid obstruction with caregiver-reported SDB symptoms in children 3-6 years of age undergoing adenotonsillectomy.

A cross-sectional study of dentine sensitivity in periodontitis patients in Trinidad and Tobago

OBJECTIVE

This cross-sectional study aimed to determine the prevalence, distribution and associated factors of dentine sensitivity (DS) among periodontitis patients in Trinidad.

METHODS

Sequential patients meeting the periodontitis criteria (BPE 4/4*) were included and completed a questionnaire on DS prior to a full periodontal examination. Clinically elicited symptoms of DS and presence of cervical tooth wear were recorded.

RESULTS

DS prevalence was 73.1% (n = 130; mean age 50 years). Mean number of sensitive teeth increased with increased severity of gingival recession. Most common initiating factors of DS were cold stimuli (70.5%), brushing (25.3%) and sour food (11.6%). Correlations were obtained for DS and race, toothbrush texture hardness, cervical tooth wear and gingival recession severity (P < 0.05; binary logistic regression). Cervical tooth wear was recorded in 46.3% of DS patients. Full-mouth plaque scores (FMPS) and full-mouth bleeding scores (FMBS) were statistically significantly (P < 0.05; Mann-Whitney U) test lower for DS versus non-DS patients. Patients reported a low usage (27.4%) and satisfaction (53.8%) rating for desensitizing agents.

CONCLUSIONS

The high prevalence of DS was comparable to other studies on periodontitis patients. Progressive periodontal disease and toothbrush abrasion were possible aetiological factors for DS in this study. Knowledge of local dietary practices and the role of acidic (sour) foods in eliciting DS may aid in management. The high prevalence of cervical tooth wear and the lower FMPS and FMBS among DS patients may reflect more aggressive tooth brushing. DS does not seem to be a limitation to plaque control in DS versus non-DS patients in this study.

RNA helicase DDX3: a novel therapeutic target in Ewing sarcoma

RNA helicase DDX3 has oncogenic activity in breast and lung cancers and is required for translation of complex mRNA transcripts, including those encoding key cell-cycle regulatory proteins. We sought to determine the expression and function of DDX3 in sarcoma cells, and to investigate the antitumor activity of a novel small molecule DDX3 inhibitor, RK-33. Utilizing various sarcoma cell lines, xenografts and human tissue microarrays, we measured DDX3 expression at the mRNA and protein levels, and evaluated cytotoxicity of RK-33 in sarcoma cell lines. To study the role of DDX3 in Ewing sarcoma, we generated stable DDX3-knockdown Ewing sarcoma cell lines using DDX3-specific small hairpin RNA (shRNA), and assessed oncogenic activity. DDX3-knockdown and RK-33-treated Ewing sarcoma cells were compared with wild-type cells using an isobaric mass-tag quantitative proteomics approach to identify target proteins impacted by DDX3 inhibition. Overall, we found high expression of DDX3 in numerous human sarcoma subtypes compared with non-malignant mesenchymal cells, and knockdown of DDX3 by RNA interference inhibited oncogenic activity in Ewing sarcoma cells. Treatment with RK-33 was preferentially cytotoxic to sarcoma cells, including chemotherapy-resistant Ewing sarcoma stem cells, while sparing non-malignant cells. Sensitivity to RK-33 correlated with DDX3 protein expression. Growth of human Ewing sarcoma xenografts expressing high DDX3 was inhibited by RK-33 treatment in mice, without overt toxicity. DDX3 inhibition altered the Ewing sarcoma cellular proteome, especially proteins involved in DNA replication, mRNA translation and proteasome function. These data support further investigation of the role of DDX3 in sarcomas, advancement of RK-33 to Ewing sarcoma clinical trials and development of RNA helicase inhibition as a novel anti-neoplastic strategy.

Pain management following myringotomy and tube placement: intranasal dexmedetomidine versus intranasal fentanyl

PURPOSE

Despite the brevity of the procedure, bilateral myringotomy and tympanostomy tube placement (BMT) can result in significant postoperative pain and discomfort. As the procedure is frequently performed without intravenous access, non-parenteral routes of administration are frequently used for analgesia. The current study prospectively compares the efficacy of intranasal (IN) dexmedetomidine with IN fentanyl for children undergoing BMT.

METHODS

This prospective, double-blinded, randomized clinical trial included pediatric patients undergoing BMT. The patients were randomized to receive either IN dexmedetomidine (1 μg/kg) or fentanyl (2 μg/kg) after the induction of general anesthesia with sevoflurane. All patients received rectal acetaminophen (40 mg/kg) and the first 50 patients also received premedication with oral midazolam. Postoperative pain and recovery were assessed using pediatric pain and recovery scales, and any adverse effects were monitored for.

RESULTS

The study cohort included 100 patients who ranged in age from 1 to 7.7 years and in weight from 8.6 to 37.4 kg. They were divided into 4 groups with 25 patients in each group: (1) midazolam premedication+IN dexmedetomidine; (2) midazolam premedication+IN fentanyl; (3) no premedication+IN dexmedetomidine; and (4) no premedication+IN fentanyl. Pain scores were comparable when comparing groups 2, 3 and 4, but were higher in group 1 (midazolam premedication with IN dexmedetomidine). There was no difference in total time in the post-anesthesia care unit (PACU) or time from arrival in the PACU until hospital discharge between the 4 groups. The heart rate (HR) was significantly lower in group 3 when compared to the other groups at several different times after arrival to the PACU. No clinically significant difference was noted in blood pressure.

CONCLUSION

Following BMT, when no premedication is administered, there was no clinical advantage when comparing IN dexmedetomidine (1 μg/kg) to IN fentanyl (2 μg/kg). The addition of oral midazolam as a premedication worsened the outcome measures particularly for children receiving IN dexmedetomidine.

A comparison of two forms of teaching instruction: video vs. live lecture for education in clinical periodontology

INTRODUCTION

This crossover controlled study aimed to compare the knowledge and skill attained by third-year dental students in three clinical exercises in the discipline of periodontology through video and live lecture instruction.

METHODS

Students (n = 35) segregated into two group either viewed a video or attended a live lecture repeated over three clinical teaching sessions. Pre-test and post-test written assessments were completed and comparisons between video and live lecture done (analysis of variance, P < 0.05). Students were assessed on clinic by a simple checklist. A questionnaire was administered after all three sessions to determine preferences and opinions on video and live lecture.

RESULTS

For the combined three sessions, both video (n = 48) and live lecture (n = 47) groups attained similar mean pre-test scores. The mean post-test score was statistically significantly greater (P = 0.049) for the live lecture (74.9%, SD 14.9) compared to the video group (68.6%, SD 16.3). All students attained clinical proficiency via the simple checklist. In adding to their clinical skill, more students favoured video (97%) vs. live lecture (78.8%). Most students (97%) favoured a future combination of video and lecture.

DISCUSSION

While students were deemed clinically competent via a simple checklist, the live lecture group performed better than the video group via the in-depth post-test assessment. Students had a preference for video and would like it integrated in the lecture rather than act as a substitute for the lecture.

CONCLUSION

The use of video alone in clinical periodontology training may have limitations unless supplemented by appropriate learning activities.

Dexmedetomidine-ketamine sedation during upper gastrointestinal endoscopy and biopsy in a patient with Duchenne muscular dystrophy and egg allergy

Sedation during invasive procedures provides appropriate humanitarian care as well as facilitating the completion of procedure. Although generally safe and effective, adverse effects may occur especially in patients with co-morbid diseases. In many cases, given its rapid onset and offset, propofol is chosen to provide sedation during various invasive procedures. We present a nine-year-old, 45 kg child with Duchenne muscular dystrophy (DMD) who presented for esophagogastroduodenoscopy (EGD). Given the egg allergy, which was a relative contraindication to the use of propofol, and the potential risk of malignant hyperthermia due to DMD, a combination of dexmedetomidine and ketamine was used for procedural sedation. Dexmedetomidine was administered as a loading dose of 1 μg/kg along with a single bolus dose of ketamine (1 mg/kg). This was followed by a dexmedetomidine infusion at 0.5 μg/kg/hour. The patient tolerated the procedure well and was discharged to home. Previous reports regarding the use of dexmedetomidine and ketamine for procedural sedation are reviewed and the potential efficacy of this combination is discussed.

Twist contributes to hormone resistance in breast cancer by downregulating estrogen receptor-α

The role of estrogen receptor-α (ER) in breast cancer development, and as a primary clinical marker for breast cancer prognosis, has been well documented. In this study, we identified the oncogenic protein, TWIST1 (Twist), which is overexpressed in high-grade breast cancers, as a potential negative regulator of ER expression. Functional characterization of ER regulation by Twist was performed using Twist low (MCF-7, T-47D) and Twist high (Hs 578T, MDA-MB-231, MCF-7/Twist) expressing cell lines. All Twist high expressing cell lines exhibited low ER transcript and protein levels. By chromatin immunoprecipitation and promoter assays, we demonstrated that Twist could directly bind to E-boxes in the ER promoter and significantly downregulate ER promoter activity in vitro. Functionally, Twist overexpression caused estrogen-independent proliferation of breast cells, and promoted hormone resistance to the selective estrogen receptor modulator tamoxifen and selective estrogen receptor down-regulator fulvestrant. Importantly, this effect was reversible on downregulating Twist. In addition, orthotopic tumors generated in mice using MCF-7/Twist cells were resistant to tamoxifen. These tumors had high vascular volume and permeability surface area, as determined by magnetic resonance imaging (MRI). Mechanistically, Twist recruited DNA methyltransferase 3B (DNMT3B) to the ER promoter, leading to a significantly higher degree of ER promoter methylation compared with parental cells. Furthermore, we demonstrated by co-immunoprecipitation that Twist interacted with histone deacetylase 1 (HDAC1) at the ER promoter, causing histone deacetylation and chromatin condensation, further reducing ER transcript levels. Functional re-expression of ER was achieved using the demethylating agent, 5-azacytidine, and the HDAC inhibitor, valproic acid. Finally, an inverse relationship was observed between Twist and ER expression in human breast tumors. In summary, the regulation of ER by Twist could be an underlying mechanism for the loss of ER activity observed in breast tumors, and may contribute to the generation of hormone-resistant, ER-negative breast cancer.

Effect of cuffed and uncuffed endotracheal tubes on the oropharyngeal oxygen and volatile anesthetic agent concentration in children

BACKGROUND

Over the past 5 years, there has been a change in the clinical practice of pediatric anesthesiology with a transition to the use of cuffed instead of uncuffed endotracheal tubes (ETTs) in infants and children. As the trachea is sealed, one advantage is to eliminate the contamination of the oropharynx with oxygen which should be advantageous during adenotonsillectomy where there is a risk of airway fire. The current study prospectively assesses the oropharyngeal oxygen and volatile anesthetic agent concentration during adenotonsillectomy in infants and children.

METHODS

Following the induction of general anesthesia in patients scheduled for adenoidectomy, tonsillectomy or adenotonsillectomy, the trachea was intubated. The use of a cuffed or uncuffed ETT and the use of spontaneous (SV) or positive pressure ventilation (PPV) were at the discretion of the anesthesia team. The oxygen concentration was kept at 100% oxygen until the study was completed. Following placement of the mouth gag, the otolaryngolist placed into the oropharynx a small bore catheter, which was attached to a standard anesthesia gas monitoring device which sampled the gas at 150mL/min. The concentration of the oxygen and the concentration of the anesthetic agent in the oropharynx were measured for 5 breaths.

RESULTS

The cohort for the study included 200 patients ranging in age from 1 to 18 years. With the use of a cuffed ETT and either SV or PPV, the oxygen concentration in the oropharynx was 20-21% and the volatile agent concentration was 0% in all 118 patients. With the use of an uncuffed ETT and the administration of 100% oxygen, there was significant contamination of the oropharynx noted during both PPV and SV. The mean oxygen concentration was 71% during PPV with an uncuffed ETT and 65% during SV with an uncuffed ETT. In these patients, the oropharyngeal oxygenation concentration exceeded 30% in 73 of the 82 patients (89%). The oropharyngeal oxygen and agent concentration was greater when the leak around the uncuffed ETT was ≥10cmH(2)O versus less than 10cmH(2)O and when the leak around the uncuffed ETT was ≥15cmH(2)O versus less than 15cmH(2)O.

CONCLUSIONS

With the use of an uncuffed ETT and the administration of 100% oxygen, there was significant contamination of the oropharynx noted during both PPV and SV. The oropharyngeal concentration of oxygen is high enough to support combustion in the majority of patients. The use of a cuffed ETT eliminates oropharyngeal contamination with oxygen during the administration of anesthesia and may be useful in limiting the incidence of an airway fire.

Effect of Reduced Exposure Times on the Microhardness of Nanocomposites Polymerized by QTH and Second-generation LED Curing Lights

Reduced polymerization times suggested with newer generation LED-curing lights may not be suitable to ensure sufficient conversion of all types of nanocomposites at depths of 2 mm.

Interleukin-6 induces an epithelial-mesenchymal transition phenotype in human breast cancer cells

Breast tumor interleukin-6 (IL-6) levels increase with tumor grade, and elevated serum IL-6 correlates with poor breast cancer patient survival. Epithelial-mesenchymal transition (EMT) phenotypes such as impaired E-cadherin expression or aberrant Vimentin induction are associated with enhanced metastasis and unfavorable clinical outcome in breast cancer. Despite this fact, few tumor microenvironment-derived extracellular signaling factors capable of provoking such a phenotypic transition have been identified. In this study, we showed that IL-6 promoted E-cadherin repression among a panel of estrogen receptor-alpha-positive human breast cancer cells. Furthermore, ectopic stable IL-6 expressing MCF-7 breast adenocarcinoma cells (MCF-7(IL-6)) exhibited an EMT phenotype characterized by impaired E-cadherin expression and induction of Vimentin, N-cadherin, Snail and Twist. MCF-7(IL-6) cells formed xenograft tumors that displayed loss of E-cadherin, robust Vimentin induction, increased proliferative indices, advanced tumor grade and undifferentiated histology. Finally, we showed aberrant IL-6 production and STAT3 activation in MCF-7 cells that constitutively express Twist, a metastatic regulator and direct transcriptional repressor of E-cadherin. To our knowledge, this is the first study that shows IL-6 as an inducer of an EMT phenotype in breast cancer cells and implicates its potential to promote breast cancer metastasis.

Cardiovascular diagnostics mining on Borneo island: from labour-intensive to prototype

Mining for medical data poses different challenges compared with mining other types of data. The wide range of imaging modalities of medical data leads to data integration and compatibility issues. The analysis of imaging modalities is further complicated by the different format and attributes used by the different imaging equipment by different vendors. Human factors such as interest of adapting data mining into diagnosis and planning process raised the difficulty of engaging the users into the development of a practical and useful data miner. Requirement engineering technique prototyping further enhanced the engagement of users towards the data-miner. Data from different equipment and different vendors are also merged for efficient data analysis and subsequently charting and reporting. We have also successfully engaged the medical doctors into believing the data miner's capability after they reviewed and walkthrough the prototype.