Heat shock proteins induction reduces stress kinases activation, potentially improving insulin signalling in monocytes from obese subjects

Induction of heat shock proteins (Hsp) 72 and 27 can improve insulin signalling in obesity and type 2 diabetes via inhibition of key stress kinases. In metabolic disease, altered insulin signalling, as illustrated by increased serine phosphorylation of insulin receptor substrate (IRS)-1 (Ser312), is not confined to muscle or liver and can also affect other tissues and cell types, potentially impairing their primary biological function. This study specifically investigated insulin-stimulated glucose metabolism in monocytes and examined the impact of HSP induction on insulin signalling. Control (CG, BMI < 25 kg/m(2)) or obese (OG, BMI > 30 kg/m(2)) participants were included in the study. Glucose transporter (GLUT)4 expression on monocytes, phosphorylated JNK, IKK-β and IRS-1, as well as Hsp27 and Hsp72, were measured in monocytes under fasting conditions. GLUT4 expression was also measured during an oral glucose tolerance test (OGTT). HSP induction as well as JNK, IKK-β activation and IRS-1 serine phosphorylation was investigated following heat stress. Obese patients showed lower GLUT4 levels on monocytes during the OGTT. pJNK, pIKK-β and pIRS-1 levels were increased in OG with pJNK and pIKK-β levels positively correlated with serine pIRS-1 and negatively with GLUT4 supporting their role in insulin resistance. Heat exposure induced Hsp72 and Hps27, but only in CG for the latter, and decreased pJNK, pIKK-β and pIRS-1. Our results show that induction of Hsp72 and 27 via heat stress is associated with inactivation of stress kinases and reduced serine pIRS-1 in monocytes from obese participants. This indicates that metabolic diseases can also affect monocyte metabolism via cellular stress that can be modulated via HSP induction.

The use of reflection in emergency medicine education

Reflection is a cognitive process in which new information and experiences are integrated into existing knowledge structures and mental models, resulting in meaningful learning. Reflection often occurs after an experience is over, promoting professional development and lifelong learning. However, a reflective emergency physician (EP) is also able to apply reflection in real time: self-monitoring, coping with the unexpected, and quickly thinking on his or her feet to solve complicated, unique, and challenging clinical problems. Reflection is a skill that can be taught and developed in medical education. Evidence demonstrating the value of teaching reflection is emerging that substantiates longstanding educational theories. While a few educators have started to explore the use of reflection for emergency medicine (EM) learners, the potential for broader application exists. This review summarizes the literature regarding reflection in medical education and provides a basic primer for teaching reflection.

Circumferential resection margin (CRM) in esophageal (OC) and gastroesophageal (GOJ) cancers

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Background: We hypothesized that CRM size affect survival and local recurrence for OC and GOJ cancer. We also assessed the utility of CT in predicting margin status.

Methods: A retrospective analysis of a prospective database was carried out on all patients who had esophagectomy between January 2000 and July 2008. Patients diagnosed with OC and GOJ tumors on final pathologic examination were included. Distance from the CRM was assessed by a specialist upper GI pathologist. Two radiologists, blinded to postoperative margin status, reviewed preoperative CT scans using 16 separate parameters, comparing them to measured CRM status.

Results: 419 patients were assessed. 223 pts had OC or GOJ type 1 tumors, average age 62 years (range 36–80), mean follow-up 5.8 years (2-9.5). There were 125 deaths and median overall survival (OS) 3.33 years (95% CI 2.76-6.24). 76 patients had recurrence at a median of 1.3 years (0.1-4.7). For 144 patients had OC or GOJ type 1 T3 tumors. Selected results are presented in the Table. There was no CRM size above which there was no further reduction in recurrence. Postoperative chemoradiation did not improve OS (p=0.79) or recurrence (p=0.96) in patients with CRM of 0-1 mm. In 50 patients the CT parameters significantly correlated with margin status were largest axial diameter (p=0.003) and contact with adjacent structures (p=0.005). A complete statistical review with multivariate and subgroup analyses will be presented.

Conclusions: CRM size is strongly correlated with survival and recurrence in OC and type 1 GOJ tumors. Prediction of a close CRM could be used to select for more intensive therapy prior to undergoing radical surgery, such as chemoradiation. Preoperative CT can help in this prediction.

[Table: see text]

No significant financial relationships to disclose.

Factors associated with incomplete small bowel capsule endoscopy studies

AIM: To identify patient risk factors associated with incomplete small bowel capsule endoscopy (CE) studies.

METHODS: Data from all CE procedures performed at St. Paul’s Hospital in Vancouver, British Columbia, Canada, between December 2001 and June 2008 were collected and analyzed on a retrospective basis. Data collection for complete and incomplete CE study groups included patient demographics as well as a number of potential risk factors for incomplete CE including indication for the procedure, hospitalization, diabetes mellitus with or without end organ damage, limitations in mobility, renal insufficiency, past history of bowel obstruction, abdominal surgery, abdominal radiation therapy and opiate use. Risk factors were analyzed using a univariable and multivariable logistic regression model.

RESULTS: From a total of 535 CE procedures performed, 158 were incomplete (29.5%). The univariable analysis showed that CE procedures performed for overt gastrointestinal bleeding (P = 0.002), and for patients with a prior history of abdominal surgery (P = 0.023) or bowel obstruction (P = 0.023) were significantly associated with incomplete CE studies. Patients on opiate medications (P = 0.094) as well as hospitalized patients (P = 0.054) were not statistically significant, but did show a trend towards incomplete CE. The multivariable analysis showed that independent risk factors for an incomplete CE procedure include prior history of bowel obstruction [odds ratios (OR) 2.77, P = 0.02, 95% confidence intervals (CI): 1.17-6.56] and procedures performed for gastrointestinal bleeding (Occult OR 2.04, P = 0.037, 95% CI: 1.04-4.02 and Overt OR 2.69, P = 0.002, 95% CI: 1.44-5.05). Patients with a prior history of abdominal surgery (OR 1.46, P = 0.068, 95% CI: 0.97-2.19), those taking opiate medications (OR 1.54, P = 0.15, 95% CI: 0.86-2.76) and hospitalized patients (OR 1.82, P = 0.124, 95% CI: 0.85-3.93) showed a trend towards statistical significance.

CONCLUSION: We have identified a number of risk factors for incomplete CE procedures that can be used to risk-stratify patients and guide interventions to improve completion rates.

Intrahepatic endothelial and Kupffer cells involved in immunosuppressive cytokines and natural killer (NK)/NK T cell disorders in viral acute hepatitis

During acute viral hepatitis, the intrahepatic tolerance sustained by immunosuppressive cytokines such as interleukin (IL)-4, IL-10, transforming growth factor (TGF)-beta and prostaglandin E2 (PGE2), produced by Kupffer cells (KC), liver sinusoidal endothelial cells (LSEC), natural killer (NK) T cells and natural regulatory T cells may be disturbed. NK cells are recruited normally in the liver and produce interferon (IFN)-gamma to control viral replication. The use of mouse hepatitis virus type 3 (MHV3) attenuated variants showing selected tropisms for KC or LSEC have allowed determining their roles in the disturbances of immune tolerance during viral hepatitis. Groups of C57BL/6 mice were infected with the pathogenic L2-MHV3 (KC+, LSEC+), low attenuated 51.6-MHV3 (KC+, LSEC-) or high attenuated CL12-MHV3 (KC-, LSEC-) variants for the first 3 days. Results showed that IL-10, TGF-beta and PGE2 production in the liver decreased in L2-MHV3-infected mice and increased in 51.6-MHV3- and CL12-MHV3-infected mice. The ratio of IFN-gamma/IL-4 in liver decreased in L2-MHV3-infected mice, while it was not (or low) altered in mice infected with the attenuated MHV3 variant mice. Phenotypic analysis of intrahepatic mononuclear cells revealed that apoptotic NK and NK T cells increased in mice infected with the L2-MHV3, but were minor in 51.6-MHV3- and CL12-MHV3-infected mice. The numbers of CD4+ forkhead box P3+ cells increased in the livers from low pathogenic CL12-MHV3 and YAC-MHV3-infected mice. These results indicate that viral permissivity of KC and LSEC is involved in the decrease of IL-10 and PGE2, while KC may play an additional role in the apoptosis of NK and NK T cells during acute viral hepatitis.

Natural regulatory (CD4+CD25+FOXP+) T cells control the production of pro-inflammatory cytokines during Plasmodium chabaudi adami infection and do not contribute to immune evasion

Different functions have been attributed to natural regulatory CD4+CD25+FOXP+ (Treg) cells during malaria infection. Herein, we assessed the role for Treg cells during infections with lethal (DS) and non-lethal (DK) Plasmodium chabaudi adami parasites, comparing the levels of parasitemia, inflammation and anaemia. Independent of parasite virulence, the population of splenic Treg cells expanded during infection, and the absolute numbers of activated CD69+ Treg cells were higher in DS-infected mice. In vivo depletion of CD25+ T cells, which eliminated 80% of CD4+FOXP3+CD25+ T cells and 60-70% of CD4+FOXP3+ T cells, significantly decreased the number of CD69+ Treg cells in mice with lethal malaria. As a result, higher parasite burden and morbidity were measured in the latter, whereas the kinetics of infection with non-lethal parasites remained unaffected. In the absence of Treg cells, parasite-specific IFN-gamma responses by CD4+ T cells increased significantly, both in mice with lethal and non-lethal infections, whereas IL-2 production was only stimulated in mice with non-lethal malaria. Following the depletion of CD25+ T cells, the production of IL-10 by CD90(-) cells was also enhanced in infected mice. Interestingly, a potent induction of TNF-alpha and IFN-gamma production by CD4+ and CD90(-) lymphocytes was measured in DS-infected mice, which also suffered severe anaemia earlier than non-depleted infected controls. Taken together, our data suggest that the expansion and activation of natural Treg cells represent a counter-regulatory response to the overwhelming inflammation associated with lethal P.c. adami. This response to infection involves TH1 lymphocytes as well as cells from the innate immune system.

Province-wide population survey of acute appendicitis in Canada. New twists to an old disease

BACKGROUND

This study, sponsored and conducted by Le Collège des Médecins du Québec, audited the management of acute appendicitis in the Province of Québec (Population 7.6 million), Canada, over a period of 1 year (April 2002-March 2003).

METHODS

A questionnaire was sent to the Health Records Department of all hospitals surgically treating appendicitis in the province. Data from 85 (100%) hospitals were received and reviewed.

RESULTS

During the study period, 7,599 appendectomies were performed, and 5,707 (75%) were selected for study (55% men). The rate of normal and perforated appendix was 5.4% and 15.9% respectively. Median hospital stay for simple and perforated appendicitis was 2.6 and 5.8 days, respectively. At least one imaging procedure was done in 86% of cases (23% computed tomography [CT], 55% ultrasound). Antibiotics were not given in 7% of cases and in 8% of patients with a perforation. Seventeen percent of patients did not receive preoperative or intraoperative doses, and postoperatively, 69% of patients received unnecessary doses. Laparoscopy was used in 35% of cases and was associated with a reduction in postoperative stay for simple (2.6 versus 2.9 days, p < 0.001) and perforated appendicitis (4.6 versus 5.9 days, p = 0.004). A low rate of laparoscopy (<25%) was found in 53% of teaching (University and Affiliated) and 45% of nonteaching institutions. Conversion to open surgery was necessary in 9.7% of simple appendicitis and 29.3% of perforated ones (p < 0.001).

CONCLUSIONS

Although results of this survey are comparable to those of similar published series, a few concerns emerge. Many have to do with patient noncompliance with recommended antibiotic usage for acute appendicitis. Further, although laparoscopy seems to be slowly making its way into the surgical armamentarium, the low rate of laparoscopic appendectomies in teaching hospitals raises the issue of appropriate resident training.

Physicians' attitudes to the pharmacological treatment of patients with stable angina pectoris

BACKGROUND

Little is known about how physicians' knowledge of and attitudes to practice guidelines for stable angina may influence their implementation.

AIM

To explore the association between physicians' demographics, their knowledge, and opinions about stable angina and their self-reported adherence to guideline recommendations.

DESIGN

Questionnaire-based survey.

METHODS

We surveyed 1228 Quebec physicians using a questionnaire based on the 'awareness-to-adherence' conceptual framework to measure their adherence with recommendations for the pharmacological treatment of stable angina. Independent predictors of adherence with the targeted recommendations were determined by stepwise linear regression analysis.

RESULTS

We received 877 (71.4%) responses from the 1228 eligible physicians. More than 90% of respondents were aware of and agreed with the targeted recommendations. However, the adoption rate varied, even among physicians who generally agreed with the guidelines. Factor analysis indicated that most physicians agreed with recommendations concerning ASA. More negative attitudes were expressed toward beta-blockers and hypolipaemic drugs. Respondents trusted the recommendations of a variety of scientific and professional organizations. Awareness, agreement, and adoption were the strongest predictors of adherence for the three recommendations. Physician demographics and practice characteristics did not predict adherence.

DISCUSSION

Physicians were aware of and agreed with the recommendations, so additional large-scale dissemination of the guidelines would be unlikely to improve prescription patterns. However, negative attitudes about beta-blockers and hypolipaemic therapy affected adherence to recommendations for these drugs. Continuing medical education interventions involving local opinion leaders might address some of the obstacles identified.

Murine viral hepatitis involves NK cell depletion associated with virus-induced apoptosis

Mouse hepatitis virus type 3 (MHV3), a coronavirus, is an excellent animal model for the study of immunological disorders related to acute and chronic hepatitis. In this study, we have verified if the fulminant hepatitis induced by MHV3 could be related to an impairment of innate immunity. Groups of three C57BL/6 mice were infected with the pathogenic L2-MHV3 or attenuated YAC-MHV3 viruses, and the natural killer (NK) cell populations from liver, spleen and bone marrow were analysed. The percentage of intrahepatic NK1.1(+)T cell receptor (TCR)- cells did not increase while NK1.1(+)TCR(inter) cells decreased in both L2-MHV3- and YAC-MHV3-infected mice. Concurrently, splenic and myeloid NK1.1+ cells decreased in L2-MHV3-infected mice. However, the cytotoxic activity of NK cells increased in liver and decreased in bone marrow from pathogenic L2-MHV3-infected mice while no modification was detected in YAC-MHV3-infected mice. Flow cytometric analysis revealed that both normal and larger splenic or myeloid NK cells decreased more in pathogenic L2-MHV3-infected mice than in attenuated YAC-MHV3-infected mice. In vitro viral infections of interleukin (IL)-15-stimulated lymphoid cells from liver and bone marrow revealed that L2-MHV3 induced higher decreases in cell viability of NK1.1+ cells than the YAC-MHV3 variant. The NK cell decreases were due to the viral permissivity leading to cytopathic effects characterized by cell rounding, syncytia formation and apoptosis. Larger NK+ syncytia were observed in L2-MHV3-infected cells than in YAC-MHV3-infected cells. These results suggest that NK cell production is impaired by viral infection favouring fulminant hepatitis.

Drug treatment of stable angina pectoris and mass dissemination of therapeutic guidelines: a randomized controlled trial

BACKGROUND

Public agencies responsible for implementing health care policies often adapt and disseminate clinical practice guidelines, but the effectiveness of mass dissemination of guidelines is unknown.

AIM

To study the effects of guideline dissemination on physicians' prescribing practices for the treatment of stable angina pectoris.

DESIGN

Randomized controlled trial.

METHODS

A sample of 3293 Quebec physicians were randomly assigned to receive a one-page summary of clinical practice guidelines on the treatment of stable angina (in February 1999), to receive the summary and a reminder (in February and March 1999, respectively), or to receive no intervention (controls). The prescribing profiles of participants, as well as sociodemographic characteristics of the physicians and their patients, were examined for June-December 1999.

RESULTS

The intervention had no effect on prescription rates of beta-blockers, antiplatelet agents, or hypolipaemic drugs. Compared to 1997 data for the same physicians, there was an overall 10% increase in appropriate prescription rates, irrespective of the intervention.

DISCUSSION

In-house production and dissemination of clinical practice guidelines may not improve physicians' practice patterns if there is pre-existing substantial scientific consensus on the issue.

Are patients suffering from stable angina receiving optimal medical treatment?

There is good evidence for the use of antiplatelet, beta-blocker and lipid-lowering drugs in the treatment of ischaemic heart disease, but few data on how these medications are used in treating stable angina pectoris. We examined prescription profiles for a sample of patients aged > or =65 years with stable angina, to compare the profiles to local guidelines and to explore the determinants of these profiles, in a cross-sectional study. We identified 11 141 individuals from the Quebec provincial out-patient pharmaceutical database for the period 1 June 1996 to 31 May 1997, and examined the percentage of these patients with and without associated co-morbidities receiving antiplatelet, beta-blocker and lipid-lowering medications. We used hierarchical modelling to examine the role of patient and physician characteristics in explaining the variation in the use of these medications. Calcium-channel blockers were the class of anti-ischaemic drugs most prescribed (63%). Beta-blockers were prescribed in 52.1% of patients. Antiplatelet and lipid-lowering drugs were prescribed to 56.8% and 32.6%, respectively. Increasing age and female gender made patients less likely to be prescribed these treatments. General practitioners were less likely than cardiologists to prescribe beta-blockers and lipid-lowering drugs (OR 0.79, CI 95% 0.68-0.91 and OR 0.77, CI 95% 0.66-0.91, respectively). There is a general under-use of antiplatelet, beta-blocker and lipid-lowering medications in the treatment of stable angina pectoris patients, possibly leading to adverse patient outcomes.