Histopathological changes and onset of severe hepatic steatosis in rats fed a choline-free diet

Hepatic steatosis significantly increases morbidity and mortality associated with major liver surgery. Several rodent models of hepatic steatosis have been previously reported, which aimed to investigate the effect of various pharmaceutical agents and interventional procedures on the pathophysiology of steatotic liver. The aim of the present study was to investigate the time frame of severe hepatic steatosis in rats after they were fed a choline-free diet and any associated histopathological changes. The duration of feeding with a choline-free diet required to develop severe hepatic steatosis was investigated in Wistar rats. The severity of hepatic steatosis in liver specimens was evaluated at 8, 10, 12 and 14 weeks following the onset of the choline-free diet. Comparisons were made with rats receiving standardized laboratory food. Feeding rats for 12–13 weeks with a choline-free diet led to 66% fatty liver infiltration, which exceeded 68% after 14 weeks. Prior to 8 weeks, the fatty infiltration reached 43%, with a gradual increase revealing a stronger rate from 8–12 weeks and a gradual decline after 14 weeks. At 12–13 weeks the fatty infiltration was considered representative of severe hepatic steatosis. Macrovesicular fatty infiltration revealed a significant increase at a steady rate between 8 and 14 weeks, with evidence of the onset of lobular inflammation and steatohepatitis after 14 weeks of feeding with the choline-free diet. Microvesicular fatty infiltration demonstrated a lower growth rate between 8 and 12 weeks while maintaining a steady rate between 12 and 14 weeks. Mixed fatty infiltration maintained its steady rate of hepatic parenchyma from 8.8–9.5%. Rats fed with the standard laboratory diet did not demonstrate fatty infiltration >4.5%, so they did not develop hepatic steatosis. Developing an ideal model of hepatic steatosis is a particular challenge. The findings of the present study indicate that severe hepatic steatosis in rodents may lead to the development of steatohepatitis after feeding with a choline-free diet for at least 14 weeks. This model is of particular interest in experimental liver surgery and associated surgical maneuvers, and is easily reproducible.

Simulation-Based Learning Strategies to Teach Undergraduate Students Basic Surgical Skills: A Systematic Review

OBJECTIVE

We aimed to identify and critically appraise all literature surrounding simulation-based learning (SBL) courses, to assess their relevance as tools for undergraduate surgical education, and create a design framework targeted at standardizing future SBL.

METHODS

We performed a systematic review of the literature using a specific keyword strategy to search at MEDLINE database.

RESULTS

Of the 2371 potentially eligible titles, 472 were shortlisted and only 40 explored active interventions in undergraduate medical education. Of those, 20 were conducted in the United States, 9 in Europe and 11 in the rest of the world. Nineteen studies assessed the effectiveness of SBL by comparing students' attributes before and after interventions, 1 study assessed a new tool of surgical assessment and 16 studies evaluated SBL courses from the students' perspectives. Of those 40 studies, 12 used dry laboratory, 7 wet laboratory, 12 mixed, and 9 cadaveric SBL interventions. The extent to which positive results were obtained from dry, wet, mixed, and cadaveric laboratories were 75%, 57%, 92%, and 100%, respectively. Consequently, the SBL design framework was devised, providing a foundation upon which future SBL interventions can be designed such that learning outcomes are optimized.

CONCLUSIONS

SBL is an important step in surgical education, investing in a safer and more efficient generation of surgeons. Standardization of these efforts can be accelerated with SBL design framework, a comprehensive guide to designing future interventions for basic surgical training at the undergraduate level.

Hands train the brain-what is the role of hand tremor and anxiety in undergraduate microsurgical skills?

Introduction

Physiological hand tremor occurs naturally, due to oscillations of the upper extremities. Tremor can be exacerbated by stress and anxiety, interfering with fine motor tasks and potentially impact on surgical performance, particularly in microsurgery. We investigated the link between tremor, anxiety and performance in a neurosurgical module as part of an international surgical course.

Methods

Essential Skills in the Management of Surgical Cases (ESMSC) course recruits medical students from European Union (EU) medical schools. Students are asked to suture the dura mater in an ex vivo swine model, of which the first suture completed was assessed. Questionnaires were distributed before and after the module, eliciting tremor risk factors, self-perception of tremor and anxiety. Johnson O’Connor dexterity pad was used to objectively measure dexterity. Direct Observation of Procedural Skills (DOPS) was used to assess skills-based performance. Anxiety was assessed using the Westside Test Anxiety Scale (WTAS). Tremor was evaluated by four qualified neurosurgeons.

Results

Forty delegates participated in the study. Overall performance decreased with greater subjective perception of anxiety (p = 0.032, rho = − 0.392). Although increasing scores for tremor at rest and overall WTAS score were associated with decreased performance, this was not statistically significant (p > 0.05). Tremor at rest did not affect dexterity (p = 0.876, rho = − 0.027).

Conclusions

Physiological tremor did not affect student performance and microsurgical dexterity in a simulation-based environment. Self-perception of anxiety affected performance in this module, suggesting that more confident students perform better in a simulated neurosurgical setting.

Resuscitation with centhaquin and 6% hydroxyethyl starch 130/0.4 improves survival in a swine model of hemorrhagic shock: a randomized experimental study

PURPOSE

To investigate the effects of the combination of centhaquin and 6% hydroxyethyl starch 130/0.4 (HES 130/0.4) in a swine model of hemorrhagic shock.

METHODS

Twenty Landrace-Large White pigs were instrumented and subjected to hemorrhagic shock. The animals were randomly allocated in two experimental groups, the control (group CO, n = 10) and the centhaquin groups (0.015 mg/kg, n = 10, group CH). Acute hemorrhage was induced by stepwise blood withdrawal (18 mL/min) from the internal jugular vein until MAP decreased to 40-45 mmHg, whereas anesthesia remained constant. All animals received HES 130/0.4 solution in the resuscitation phase until their mean arterial pressure (MAP) reached 90% of the baseline. The animals were observed for 60 min, during which no further resuscitation was attempted.

RESULTS

The total amount of blood and the bleeding time did not differ significantly between group CO and group CH (120 ± 13 vs. 120 ± 14 mL, p = 0.6; 20 ± 2 vs. 20 ± 1 min, p = 0.62, respectively). During the hemorrhagic phase, only a difference in heart rate (97.6 ± 4.4 vs. 128.4 ± 3.6 beats/min, p = 0.038) was observed between the two groups. The time required to reach the target MAP was significantly shorter in the centhaquin group compared to controls (13.7 ± 0.4 vs. 19.6 ± 0.84 min, p = 0.012). During the resuscitation phase, a statistical significant difference was observed in MAP (75.2 ± 1.6 vs. 89.8 ± 2.1 mmHg, p = 0.02) between group CO and group CH. During the observation phase, a statistical significant difference was observed in SVR (1109 ± 32.65 vs. 774.6 ± 21.82 dyn s/cm⁵, p = 0.039) and cardiac output (5.82 ± 0.31 vs. 6.9 ± 0.78 L/min, p = 0.027) between the two groups. Two animals of group CO and seven animals of group CH survived for 24 h (p = 0.008). We observed a marked increase in microvascular capillary permeability in group CO compared to group CH, with the wet/dry weight ratio being significantly higher in group CO compared to group CH (4.8 ± 1.6 vs. 3.08 ± 0.6, p < 0.001).

CONCLUSIONS

The combination of centhaquin 0.015 mg/kg and HES 130/0.4 resulted in shorter time to target MAP, lower wet-to-dry ratio, and better survival rates after resuscitation from hemorrhagic shock.

Pharmacologic inhibition of the mitochondrial Na+/Ca2+ exchanger protects against ventricular arrhythmias in a porcine model of ischemia-reperfusion

BACKGROUND

The mitochondrial Na+/Ca2+ exchanger (mNCX) has been implicated in the pathogenesis of arrhythmogenicity and myocardial reperfusion injury, rendering its inhibition a potential therapeutic strategy. We examined the effects of CGP-37157, a selective mNCX inhibitor, on arrhythmogenesis, infarct size (IS), and no reflow area (NRA) in a porcine model of ischemia-reperfusion.

METHODS

Forty pigs underwent myocardial ischemia for 60 minutes, followed by 2 hours of reperfusion. Animals were randomized to receive intracoronary infusion of 0.02 mg/kg CGP-37157 or vehicle, either before ischemia (n=17) or before reperfusion (n=17). Animals were monitored for arrhythmias. Myocardial area at risk (AR), IS, and NRA were measured by histopathology.

RESULTS

AR, NRA, and IS were comparable between groups. Administration of CGP-37157 before ischemia resulted in the following: (a) suppression of ventricular tachyarrhythmias (events/pig: 1.5±1.1 vs 3.5±1.9, p=0.014), (b) easier cardioversion of ventricular tachyarrhythmias (defibrillations required for cardioversion of each episode: 2.6±2.3 vs 6.2±2.1, p=0.006), and (c) decreased maximal depression of the J point (0.75±0.27 mm vs 1.75±0.82 mm, p=0.007), compared to controls. Administration of CGP-37157 before reperfusion expedited ST-segment resolution; complete ST-segment resolution within 30 minutes of reperfusion was observed in 7/8 CGP-37157-treated animals versus 1/9 controls (p=0.003).

CONCLUSIONS

In a porcine model of myocardial infarction, intracoronary administration of CGP-37157 did not decrease IS or NRA. However, it suppressed ventricular arrhythmias, decreased depression of the J point during ischemia and expedited ST-segment resolution after reperfusion. These findings motivate further investigation of pharmacologic mNCX inhibition as a potential therapeutic strategy to suppress arrhythmias in the injured heart.

A Novel Modification of the AOM/DSS Model for Inducing Intestinal Adenomas in Mice

BACKGROUND/AIM

Our aim was to develop an animal model of the precancerous stages of colitis-associated carcinogenesis by modifying the established azoxymethane/dextran sulfate sodium (AOM/DSS) protocol.

MATERIALS AND METHODS

Six mice were treated with varying cycles of DSS following AOM administration as above (group 1: three mice received three 5-day cycles of 3.0% DSS and group 2: three mice received three 7-day cycles of 2.5% DSS; every cycle was followed by a 2-week rest period) and were sacrificed on day 84 of the experiment. By contrast, three female C57BL6 mice (group 3) were treated with a single intraperitoneal dose (10 mg/kg of body weight) of AOM followed by three 5-day cycles of oral 2.5% DSS, with each cycle interrupted by a 2-week rest period. The mice of this group were sacrificed at 60 days.

RESULTS

In groups 1 and 2, cancer was noted in five out of the six mice. In group 3, adenomas with dysplastic lesions were noted in all of the mice, but none had developed adenocarcinoma.

CONCLUSION

Our results suggest that the administration of three 5-day cycles of 2.5% DSS following an initial dose of AOM may successfully induce adenoma formation without the concurrent presence of carcinoma in female C57BL6 mice that are sacrificed on experimental day 60. In turn, this modification of the widely used AOM/DSS protocol may constitute a novel approach for investigating colitis-related colonic adenomas.

Quantitative analysis and study of the mRNA expression levels of apoptotic genes BCL2, BAX and BCL2L12 in the articular cartilage of an animal model of osteoarthritis

Background

Given that apoptosis of chondrocytes is one of the most important factors related to the pathogenesis of osteoarthritis (OA), the recent research interest adds progress not only to the knowledge of the molecular signals that mediate apoptosis but also to find new therapeutic targets. This study attempts to investigate the differential expression of BCL2 family genes in the articular cartilage of an experimental animal model of OA.

Methods

In total, 26 New Zealand white rabbits underwent an anterior cruciate ligament transaction, 26 more were subjected to a placebo surgery and 18 specimens constituted the control non-operated group. Thirteen weeks later, samples of cartilage from the osteoarthritic and non-osteoarthritic knees were collected and subjected to analysis of the BCL2, BAX and BCL2L12 gene expression at the mRNA level.

Results

Installed osteoarthritic alterations of varied intensity and of grade 1 up to grade 5, were confirmed according to the OARSI system. Contrary to the physiologically healthy samples, in the osteoarthritic samples the mRNA expression levels of BAX and BCL2L12 genes were found significantly upregulated by signals which can activate apoptosis. However, the difference between BCL2 mRNA expression levels in healthy and osteoarthritic samples was not supported statistically.

Conclusions

Since apoptosis is the main feature of the cartilage degeneration in OA, the effective inhibition of apoptosis of chondrocytes can provide novel and interesting therapeutic strategies for the treatment of OA. Therefore, BAX and BCL2L12 are highlighted as potential therapeutic targets in OA.

Lazaroid (U-74389G) ameliorates lung injury due to lipid peroxidation and nitric oxide synthase-dependent reactive oxygen species generation caused by remote systematic ischemia-reperfusion following thoracoabdominal aortic occlusion

INTRODUCTION

Lung ischemia-reperfusion injury after thoracoabdominal aortic occlusion represents a major complication, which increases morbidity and mortality. In the present study we hypothesized that lazaroid U-74389G intravenous administration protects from lung ischemia-reperfusion injury through lipid peroxidation inhibition.

MATERIALS AND METHODS

A total of 24 pigs were randomized in three groups. Group I (n = 8) underwent sham operation, group II (n = 8) underwent thoracoabdominal aortic occlusion for 45min and received placebo and group III (n = 8) received 3 doses of lazaroid (3 mg/kg) 60 and 30min before thoracoabdominal aortic occlusion and at 30min during thoracoabdominal aortic occlusion (duration 45min). Aortic occlusion was performed with aortic balloon-catheters under fluoroscopic guidance. All animals were sacrificed at the 7 t h postoperative day and lung specimens were harvested for molecular analysis.

RESULTS

mRNA levels of leukotrienes LB4 (LTB4R2), LC4 (LTC4S) and nitric oxide synthase (NOS) isoforms including iNOS, nNOS and eNOS were determined with real-time RT-qPCR. Nitric oxide can either induce (iNOS) or inhibit (nNOS and eNOS) lipid peroxidation based on its specific isoform origin. Group III showed significantly reduced mRNA levels of LTB4R2 (-63.7%), LTC4S (-35.9%) and iNOS (-60.2%) when compared with group II (P < 0.05, for all). The mRNA levels of nNOS was significantly increased (+37.4%), while eNOS was slightly increased (+2.1%) in group III when compared with group II (P < 0.05 and P = 0.467 respectively).

CONCLUSION

Lazaroid U-74389G may represent an effective pharmacologic intervention in reducing lung ischemia-reperfusion injury following thoracoabdominal aortic occlusion.

Optimizing engagement of undergraduate students in medical education research: The eMERG training network

Background

The practice of evidence-based medicine and critical appraisal are essential for the modern doctor. Early engagement of medical students in research methodology is considered as a rising need for most medical school curricula; however, few peer-reviewed initiatives have been reported so far. We developed a Medical Education Research Group (eMERG) as part of a novel undergraduate surgical masterclass, which aimed to train undergraduate students on basic research methodology, as well as to motivate them to pursue a clinical and academic career in surgical specialties.

Methods: eMERG consists of an international structured network of senior academics, consultant-level clinicians, senior and junior trainees who support undergraduate trainees. Students are selected from a competitive pool of applicants. Several small prospective studies in skills-based education, as well as systematic reviews on similar topics, have run under the umbrella of this framework, in the form of scholarship awards. Structured feedback questionnaires were distributed to evaluate the experience of the first three years.

Results

12 students have participated in this pilot initiative. 11 manuscripts have been submitted for publication and 8 were accepted following peer-review in MEDLINE-indexed journals. Delegates perceived this experience as an excellent training opportunity which improved their research productivity. Delegates also stated engagement in research developed interest in the relevant surgical speciality, impacting their career aspirations.

Conclusions

eMERG is one of the first reported European educational research networks for undergraduates. Research outcomes and students' perceptions conclude that eMERG enhances engagement with research methodology and motivation towards a career in surgery.

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eMERG is a pilot international research training network where medical students receive support to conduct research in Medical Education.

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eMERG structure can serve as a novel model to convey research experience from one generation to another, and in the same time, motivate and aspire students to develop leadership skills.

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eMERG was developed in a financial crisis environment with promising research outputs and positive students' feedback.

Comparison of the Acute Hematopoietic Capacities of Erythropoietin and U-74389G Concerning Hematocrit Levels

AIM

This study compared the hematopoietic capacities of erythropoietin (Epo) and antioxidant drug U-74389G, based on 2 preliminary studies. The provided results on hematocrit levels augmentation were co-evaluated in a hypoxia reoxygenation protocol of an animal model.

MATERIALS AND METHODS

Hematocrit levels were evaluated at the 60th reoxygenation min (for groups A, C and E) and at the 120th reoxygenation min (for groups B, D and F) in 60 rats. Groups A and B received no drugs, rats from groups C and D were administered with Epo; whereas rats from groups E and F were administered with U-74389G.

RESULTS

The first preliminary study of Epo non-significantly increased the hematocrit levels by 0.24%+1.38% (p-value=0.8586). The second preliminary study of U-74389G significantly raised the hematocrit levels by 3.16%+1.33% (p-value=0.0196). These 2 studies were co-evaluated since they came from the same experimental setting. The outcome of the co-evaluation was that U-74389G has approximately 12.66-fold higher hematopoietic potency than Epo (p-value=0.0000).

CONCLUSION

The anti-oxidant capacities of U-74389G provide satisfactory acute hematopoietic properties; presenting approximately 12.66-fold hematocrit level rise than epo (p-value=0.0000).

Treatment with Bioartificial Liver Improves Lung Injury in a Swine Model of Partial Hepatectomy and Ischemia/Reperfusion

Purpose

Hepatic ischemia/reperfusion injury can lead to remote lung injury by inducing oxidative stress and inflammation. this study aims to investigate whether support of liver function with a bioartificial liver can attenuate remote lung injury after extended hepatectomy.

Methods

Fourteen domestic pigs were subjected to liver ischemia for 150 minutes and 70–75% hepatectomy. Six hours after initiation of hepatic reperfusion the animals were randomly allocated to a 6-hour treatment with a bioartificial liver (group B, n=7) or observation (group C, n=7). Hemodynamic and metabolic parameters were monitored for 24 hours following reperfusion. Lung biopsies were used for histological, nitrotyrosine and mrNA analysis.

Results

Oxygenation gradually deteriorated in group C, but was not significantly impaired in group B. Histological evaluation revealed improvements in alveolar collapse, necrotized pneumonocytes and lymphocyte infiltration in group B. Nitrotyrosine content of the lung was lower in group B compared to group C (55±12 vs. 132±22 nM/mg protein, p<0.01). Lung mRNA expression of interleukin-6, Stat-3 and E-selectin also decreased in group B. Expression of transforming growth factor-α mRNA did not differ between groups.

Conclusions

Application of a bioartificial liver was associated with improvement in several parameters of post-hepatectomy lung injury. the mechanisms appear to involve reduced nitrosative stress and attenuation of the native inflammatory process in the lung.

Developing a novel international undergraduate surgical masterclass during a financial crisis: our 4-year experience

BACKGROUND

Essential Skills in the Management of Surgical Cases (ESMSC) is a novel 3-day international undergraduate surgical masterclass. Its current curriculum (Cores integrated for Research-Ci4R) is built on a tetracore, multiclustered architecture combining high-fidelity and low-fidelity simulation-based learning (SBL), with applied and basic science case-based workshops, and non-technical skills modules. We aimed to report our experience in setting up ESMSC during the global financial crisis.

METHODS

We report the evolution of our curriculum's methodology and summarised the research outcomes related to the objective performance improvement of delegates, the educational environment of the course and the use of mixed-fidelity SBL. Feedback from the last three series of the course was prospectively collected and analysed using univariate statistics on IBM SPSS V.23.

RESULTS

311 medical students across the European Union (EU) were selected from a competitive pool of 1280 applicants during seven series of the course between 2014 and 2017. During this period, curriculum 14 s evolved to the final Ci4R version, which integrates a tetracore structure combining 32 stations of in vivo, ex vivo and dry lab SBL with small group teaching workshops. Ci4R was positively perceived across different educational background students (p>0.05 for any comparison).

CONCLUSIONS

ESMSC is considered an innovative and effective multidisciplinary teaching model by delegates, where it improves delegates objective performance in basic surgical skills. Our experience demonstrates provision of high-quality and free surgical education during a financial crisis, which evolved through a dynamic feedback mechanism. The prospective recording and subsequent analysis of curriculum evolution provides a blueprint to direct development of effective surgical education courses that can be adapted to local needs.

Comparison of the excretory capacities of erythropoietin and U-74389G concerning serum creatinine levels

Introduction This study compared the excretory effects, the erythropoietin (Epo) and antioxidant drug U-74389G exert on serum creatinine levels through kidneys. 2 preliminary studies were used for this purpose including respectively one drug used in a renal ischemia–reperfusion (IR) protocol of an animal model. The preliminary studies are part of the present work. The subjects were pretreated in preliminary studies but the results of the same subjects were simply compared in the current work.

Materials and methods The serum creatinine levels were evaluated at the 60th reperfusion min (for groups A, C and E) and at the 120th reperfusion min (for groups B, D and F) after IR in the 60 rats. Groups A and B received no drugs, rats from groups C and D were administered with Epo, whereas rats from groups E and F were administered with U-74389G.

Results The first preliminary study recommended a non-significant excretory effect of Epo (p-value = 0.4430 > 0.05) than placebo for serum creatinine levels. The second preliminary study proved a very significant excretory effect of U-74389G (p-value = 0.0005 < 0.05) than placebo for serum creatinine levels. These 2 studies were co-evaluated since they came from the same experimental setting. The outcome of the co-evaluation was that U-74389G has at least 5-fold significant excretory action (p-value = 0.0000 < 0.05) than Epo for serum creatinine levels.

Conclusions The U-74389G presents surprising effective excretory potencies for serum creatinine levels maybe of great importance in hemodialysis patients.

Targeting hepatocarcinogenesis model in C56BL6 mice with pan-aurora kinase inhibitor Danusertib

Background: To elucidate the expression of Aurora kinases (AURK) and the anticancer effects of pan-aurora kinase inhibitor Danusertib in hepatocarcinogenesis model in C56Bl6 mice.

Methods: Thirty mice C56Bl6 were randomly divided into Group A or control, Group B animals who underwent experimental hepatocarcinogenesis with diethylnitrosamine (DEN), and Group C animals with DEN-induced hepatocarcinogenenesis that treated with pan-aurora kinase inhibitor Danusertib. Primary antibodies for immunochistochemistry (IHC) included rabbit antibodies against Ki-67, DKK1, INCENP, cleaved caspase-3, NF-κB p65, c-Jun, β-catenin. Hepatocyte growth factor receptor (C-MET/HGFR) and Bcl-2 antagonist of cell death (BAD) serum levels were determined using a quantitative sandwich enzyme immunoassay technique.

Results: Inhibition of AURK reduced the number of DEN-induced liver tumours. Apoptosis and proliferation was very low in both DEN-induced and anti- AURK groups respectively. The hepatocellular adenoma cells of DEN-treated mice uniformly had ample nuclear INCENP whereas in anti- AURK markedly decreased. Expression of β-catenin, NF-kB and c-Jun did not differ in liver tumors of both AURK -depleted and non-depleted mice.

Conclusions: Depletion of AURK reduced the number of DEN-induced hepatic tumours. However, their size did not differ significantly between the groups.

The Role of Anxiety in Simulation-Based Dexterity and Overall Performance: Does It Really Matter?

BACKGROUND

Essential Skills in the Management of Surgical Cases (ESMSC) is an international undergraduate surgical masterclass which combines ex vivo, dry lab and high fidelity in vivo simulation-based learning (SBL). It consists of 32 stations of skills-based learning, including open reduction internal fixation (ORIF) of fractures. Current literature suggests early involvement in skills-based learning at the undergraduate level is vital.

AIMS

To compare students' dexterity and skills-based performance with demographic and educational background parameters.

METHODS

112 medical students from European Union countries including the United Kingdom, Germany, Greece, Cyprus, Germany, and Bulgaria were selected from a competitive pool of candidates to attend the course. Students undertook ORIF in an ex vivo swine model, and in a simulated fracture on a bamboo rod. Skills-based performance was assessed by two consultant surgeons with validated direct observation of procedural skills (DOPS) forms. Anxiety was self-assessed using the Westside Anxiety Scale prior to the ORIF stations. Dexterity was measured with the O'Connor tweezer dexterity test.

RESULTS

Female students had significantly higher dexterity scores (median difference 7, p =.003). Right-handed students achieved higher dexterity than left-handed students (median difference 7, p =.043). There was no difference in students' performance across different medical schools, and across year groups (p <.05 for any correlation). Self-reported anxiety was not correlated with high fidelity skills-based performance (r = 0.032, p =.74).

CONCLUSION

Anxiety does not seem to play a significant role in Simulation Skills-Based learning. Undergraduate surgical curricula should incorporate SBL-based modules to enhance practical skills learning and motivate future orthopedic surgeons.

Induction of anaesthesia with remifentanil after bolus midazolam administration in Landrace/Large White swine

OBJECTIVE

To investigate an alternative combination for anaesthesia induction in swine.

STUDY DESIGN

Randomized, 'blinded' experimental study.

ANIMALS

Forty-five Landrace/Large White swine weighing 20.0±1.5 kg.

METHODS

Pulse oximetry, heart rate (HR) and blood pressure were measured after premedication with ketamine, midazolam and atropine as well as after intubation following induction with a fixed dose of 0.2 mg kg^-1 midazolam combined with 1, 2, 3, 4 or 5 μg kg^-1 remifentanil (groups R1, R2, R3, R4 and R5, respectively). Intubation was evaluated using a numerical scoring system assessing jaw relaxation, resistance to the laryngoscope, vocal cord position, vocal cord movement and response to intubation. The time required to intubate and necessity for an additional midazolam dose were recorded. Baseline and post-intubation variables were compared with paired t tests, whereas for differences between the remifentanil groups the Spearman's rank correlation coefficient was estimated. Multivariate regression analysis was performed to disentangle the effect of remifentanil dose and the additional midazolam.

RESULTS

Higher dose of remifentanil was associated with better vocal cord position (p<0.001), better response to intubation (p<0.001), shorter time required for intubation (p=0.030) and less frequent necessity for additional administration of midazolam (p=0.004). In total, 39.5% of the animals required additional midazolam. In groups R1, R4 and R5, there were decreases in HRs (p=0.009, p=0.008 and p=0.032, respectively) between baseline and post-intubation phase; in groups R3 and R4, there were decreases in systolic blood pressure (p=0.040 and p=0.019, respectively). In the multivariate analysis, remifentanil dose was not associated with the observed changes in haemodynamic variables. One animal developed apnoea and four electrocardiographic anomalies; all resolved without pharmaceutical interventions.

CONCLUSIONS AND CLINICAL RELEVANCE

A combination of 0.2 mg kg^-1 midazolam with 4 or 5 μg kg^-1 remifentanil may provide an alternative method of anaesthesia induction for swine.

Effects of Wnt-1 blockade in DEN-induced hepatocellular adenomas of mice

Recent evidence has suggested that downregulation of the Wnt/β-catenin signaling pathway may contribute to the development and growth of HCC. Consequently, elements of this pathway have begun to emerge as potential targets for improving outcomes of anti-HCC. Thus, the present study sought to examine the effects of Wnt-1 blockade using the classical diethylnitrosamine (DEN)-induced chemical carcinogenesis mouse model of HCC. The depletion of Wnt-1 using neutralizing antisera was done for ten consecutive days at the age of 9 months and mice were examined for the following 20 days. At that time, DEN-treated mice had multiple variably-sized hepatic cell adenomas. Anti-Wnt-1 was particularly potent in suppressing the expression of critical elements of the Wnt/β-catenin signaling pathway, such as β-catenin and Frizzled-1 receptor, however, not Dickkopf-related protein 1. This effect co-existed with the suppression of Cyclin D1, FOXM1, NF-κΒ and c-Jun commensurate with proliferation and apoptosis blockade in hepatocellular adenomas, and reduced Bcl-2 and c-Met in the serum of mice. Nonetheless, tumor size and multiplicity were found to be unaffected, suggesting that apoptosis may be equally important to proliferation in the context of counteracting DEN induced hepatocellular adenomas of mice.

Systemic treatment and primary tumor location in patients with metastatic colorectal cancer

PURPOSE

Tumor location (right-sided vs. left-sided) is known to exert a significant influence on the prognosis of primary colorectal cancer (CRC). Given the genetic continuity between primary and metastatic lesions, we aimed to summarize the existing literature on the prognostic implications of primary tumor site as well as to examine the response to chemotherapy by primary tumor location in patients with metastatic CRC (mCRC).

METHODS

A structured review of the literature was performed between 6/1/2016-7/1/2016 using the Pubmed database. Original research articles published between 1/1/2000- 07/01/2016 were considered eligible. The primary endpoints were overall survival (OS)/ progression free survival (PFS) and response to systemic treatment in patients with mCRC.

RESULTS

Eleven studies were included. Tumor site was a strong independent predictor of worse OS/PFS in 9 studies, with right-sided tumors having worse prognosis in all cases. Furthermore, 6 studies demonstrated an inferior response to systemic treatment or worse prognosis following the administration of specific regimens among patients with right-sided cancers. As such, there is significant evidence that right-sided lesions are associated with poor outcomes and resistance to systemic treatment.

CONCLUSION

Consequently, primary tumor location should be a consideration, when the administration of systemic therapy is contemplated in mCRC.

THE ACUTE EFFECT OF ERYTHROPOIETIN ON GLUCOSE LEVELS DURING ISCHEMIA REPERFUSION INJURY IN RATS

The aim of this experimental study was to examine the effect of erythropoietin on rat model and particularly in an ischemia reperfusion (HR) protocol. The effect of that molecule was studied biochemically using blood mean glucose (Gl) levels. Materials and methods: 40 rats of mean weight 247.7 g were used in the study. Gl levels were measured at 60 min (groups A and C) and at 120 min (groups B and D) of reperfusion. Erythropoietin was administered only in groups C and D. Results were that Epo administration non-significantly increased the gl levels by 5.59% +6.46% (p=0.3208). Reperfusion time non-significantly increased the gl levels by 5.63%+6.45% (p=0.4098). However, erythropoietin administration and reperfusion time together produced a non significant combined effect in increasing the gl levels by 4.94%+3.81% (p= 0.1892). Conclusions: Results of this study indicate that erythropoietin administration, reperfusion time, or their interaction non-significantly increase the blood glucose levels in short-term. Opposite bibliographic data are considered more reliable, until a greater sample provide clearer results.

An Experimental Model on the Biomechanical Behaviour of the Flexor Tendons in New Zealand Rabbits

BACKGROUND

In order to introduce new pharmacological agents with the intent to inhibit the adhesion formation, it is important to test such products on laboratory animals under a protocol that can evaluate the quantitative and qualitative aspects of healing of the tendons. Most experimental models focus on the tensile strength and histological analysis of the tendons, failing to sufficiently quantify the degree of the adhesion formation.

METHODS

The experiment included six male New Zealand rabbits that underwent surgery of their right forepaws. The deep flexor tendon of the middle finger was transected and repaired and after six weeks the rabbits were killed. In order to assess the extent of adhesions, the functional stiffness of the tendons and the range of motion of the specimens' fingers was studied using a tensile testing machine. The setup used allowed the simultaneous recording of the specimens' motion and the pulling force values.

RESULTS

The mean values of the left and right forepaws were expressed in the same chart showing a clear difference between the operated and non operated forepaws.

CONCLUSIONS

Using a relatively simple set up in the laboratory we had the chance to focus on a more elaborate analysis of the data with the help of low cost and accessible software.