Indocyanine green: A novel marker for assessment of graft quality during ex situ normothermic machine perfusion of human livers

BACKGROUND

Ex situ machine perfusion facilitates the assessment of livers prior to transplantation. However, currently available markers of liver function poorly predict long-term graft function. Indocyanine green (ICG) is a liver-specific dye which, although common in vivo, has never been comprehensively evaluated for the assessment of graft quality during ex situ machine perfusion. This study aimed to assess the utility of ICG in the ex situ setting.

METHODS

Using a customized long-term perfusion system, human livers that were not suitable for transplantation were perfused using a red cell-based perfusate. ICG was delivered into the perfusate on days 0, 1, and 4 to assess ICG clearance (spectrophotometric absorbance at 805 nm) and ICG fluorescence (near-infrared camera).

RESULTS

Sixteen partial livers were perfused for a median duration of 172 h (7.2 days). On day 0, the median ICG perfusate disappearance rate (PDR) was 7.5%/min and the median ICG retention at 15 min was 9.9%. Grafts that survived ≥7 days had a significantly higher median ICG PDR on day 0 (14.5%/min vs. 6.5%/min, p = 0.005) but not on days 1 or 4. ICG perfusion demonstrated that long-surviving grafts had a significantly lower median red-value (89.8 vs. 118.6, p = 0.011) and a significantly lower median blue-value (12.9 vs. 22.6, p = 0.045) than short-surviving grafts.

CONCLUSION

ICG is a novel marker for the assessment of liver function during ex situ normothermic machine perfusion. ICG PDR and quantitative ICG perfusion can distinguish between long- and short-surviving grafts and demonstrate the utility of ICG in the assessment of graft quality prior to transplant.

Return of the cold: How hypothermic oxygenated machine perfusion is changing liver transplantation

Hypothermic Oxygenated machine PErfusion (HOPE) has recently emerged as a preservation technique which can reduce ischemic injury and improve clinical outcomes following liver transplantation. First developed with the advent solid organ transplantation techniques, hypothermic machine perfusion largely fell out of favour following the development of preservation solutions which can satisfactorily preserve grafts using the cheap and simple method, static cold storage (SCS). However, with an increasing need to develop techniques to reduce graft injury and better utilise marginal and donation after circulatory death (DCD) grafts, HOPE has emerged as a relatively simple and safe technique to optimise clinical outcomes following liver transplantation. Perfusing the graft with cold, acellular, oxygenated perfusate either via the portal vein (PV) alone, or via both the PV and hepatic artery (HA), HOPE is generally commenced for a period of 1-2 h immediately prior to implantation. The technique has been validated by multiple randomised control trials, and pre-clinical evidence suggests HOPE primarily reduces graft injury by decreasing the accumulation of harmful mitochondrial intermediates, and subsequently, the severity of post-reperfusion injury. HOPE can also facilitate real time graft assessment, most notably via the measurement of flavin mononucleotide (FMN) in the perfusate, allowing transplant teams to make better informed clinical decisions prior to transplantation. HOPE may also provide a platform to administer novel therapeutic agents to ex situ organs without risk of systemic side effects. As such, HOPE is uniquely positioned to revolutionise how liver transplantation is approached and facilitate optimised clinical outcomes for liver transplant recipients.

Incorporating a hemodialysis filter into a commercial normothermic perfusion system to facilitate long-term preservation of human split-livers

BACKGROUND

Normothermic machine perfusion (NMP) allows for the assessment and resuscitation of ex-vivo human livers prior to transplantation. Commercially available NMP systems are closed circuits that accumulate metabolic waste and cytokines over time, potentially limiting organ preservation times. Dialysis has been proposed as a method to remove waste and excess fluid from such systems. This study aimed to demonstrate the utility of integrating dialysis into a commercially available system by quantifying solute removal.

METHODS

A dialysis filter was attached in parallel to a commercially available liver perfusion system. Three livers declined for transplantation were split before undergoing long-term NMP with blood using the modified system. During perfusion, dialysate flow rates were set in the range of 100-600 mL/h for short periods of time. At each flow rate, perfusate and spent dialysate samples were collected and analyzed for solute clearance.

RESULTS

The addition of dialysis to a commercial NMP system removed water-soluble waste and helped regulate electrolyte concentrations. Interleukin-6 was successfully removed from the perfusate. Solute clearance was proportional to dialysate flow rate. A guide for our perfusion setup was created for the appropriate selection of dialysis flow rates and duration based on real-time perfusate composition.

CONCLUSIONS

Dialysis circuits can efficiently remove waste and regulate perfusate composition, and can be easily incorporated to improve the performance of commercially available systems. Quantification of the effect of dialysis on perfusate composition enables refined dialysis control to optimize electrolyte profiles and avoid the over- or under-correction of key solutes.

Harnessing whole human liver ex situ normothermic perfusion for preclinical AAV vector evaluation

Developing clinically predictive model systems for evaluating gene transfer and gene editing technologies has become increasingly important in the era of personalized medicine. Liver-directed gene therapies present a unique challenge due to the complexity of the human liver. In this work, we describe the application of whole human liver explants in an ex situ normothermic perfusion system to evaluate a set of fourteen natural and bioengineered adeno-associated viral (AAV) vectors directly in human liver, in the presence and absence of neutralizing human sera. Under non-neutralizing conditions, the recently developed AAV variants, AAV-SYD12 and AAV-LK03, emerged as the most functional variants in terms of cellular uptake and transgene expression. However, when assessed in the presence of human plasma containing anti-AAV neutralizing antibodies (NAbs), vectors of human origin, specifically those derived from AAV2/AAV3b, were extensively neutralized, whereas AAV8- derived variants performed efficiently. This study demonstrates the potential of using normothermic liver perfusion as a model for early-stage testing of liver-focused gene therapies. The results offer preliminary insights that could help inform the development of more effective translational strategies.

Outcomes of patients with gallbladder cancer presenting with acute cholecystitis

The main purpose of this study is to explore the outcomes of patients found to have gallbladder cancer during investigation and diagnosis of acute cholecystitis. The incidence of primary gallbladder cancer co-existing in acute cholecystitis is not well defined in the literature, with anecdotal reports suggesting that they experience worse outcomes than patients with gallbladder cancer found incidentally.

METHODS

A retrospective review of all patients with gallbladder cancer managed at the Canberra Health Service between 1998 and May 2022 were identified and reviewed.

RESULTS

A total of 65 patients were diagnosed with primary gallbladder cancer during the study period with a mean age of 70.4 years (SD 11.4, range 59-81.8 years) and a female preponderance (74% versus 26%) with a ratio of 2.8. Twenty (31%) patients presented with acute calculus cholecystitis and were found to have a primary gallbladder cancer. This group of patients were older and predominantly female, but the difference was not statistically significant. The overall 5-year survival in the cohort was 20% (stage 1 63%, stage 2 23%, stage 3 16%, and stage 4 0%). There was no statistically significant difference in survival between those who presented with acute cholecystitis vs other presentations.

CONCLUSIONS

A third of the patients with gallbladder cancer presented with acute cholecystitis. There was no statistically significant difference in survival in those with bile spillage during cholecystectomy as well those presenting with acute cholecystitis.

Microbial Contamination During Long-term Ex Vivo Normothermic Machine Perfusion of Human Livers

BACKGROUND

Normothermic machine perfusion permits the ex vivo preservation of human livers before transplantation. Long-term perfusion for days-to-weeks provides the opportunity for enhanced pretransplant assessment and potential regeneration of organs. However, this risks microbial contamination and infection of the recipient if the organ is transplanted. An understanding of perfusate microbial contamination is required to inform infection control procedures and antimicrobial prophylaxis for this technology.

METHODS

We modified a liver perfusion machine for long-term use by adding long-term oxygenators and a dialysis filter. Human livers that were not suitable for transplantation were perfused using a red-cell-based perfusate under aseptic and normothermic conditions (36 °C) with a goal of 14 d. Cephazolin was added to the perfusate for antimicrobial prophylaxis. Perfusate and bile were sampled every 72 h for microbial culture.

RESULTS

Eighteen partial human livers (9 left lateral segment grafts and 9 extended right grafts) were perfused using our perfusion system. The median survival was 7.2 d. All organs surviving longer than 7 d (9/18) had negative perfusate cultures at 24 and 48 h. Half of the grafts (9/18) became culture-positive by the end of perfusion. Microbial contaminants included Gram-negative ( Pseudomonas species, Proteus mirabilis, Stenotrophomonas maltophilia ) and Gram-positive bacteria ( Staphylococcus epidermidis , Enterococcus faecalis , and Bacillus species) as well as yeast ( Candida albicans ).

CONCLUSIONS

Microbial contamination of perfusate is common during long-term perfusion of human livers with both exogenous and endogenous sources. Enhanced infection control practices and review of targeted antimicrobial prophylaxis are likely to be necessary for translation into the clinical arena.

IgG4-related sclerosing cholangitis mimicking cholangiocarcinoma

A man in his 70s presented to the emergency department with painless obstructive jaundice. Initial blood test results show a predominantly cholestatic picture with elevated tumour markers, and imaging findings are concerning for a pancreatic head neoplasm or cholangiocarcinoma with involvement of the entire common bile duct. The patient underwent staging laparoscopy and biopsies including peritoneal washing, but did not identify any features of malignancy. Immunoglobulin G and immunoglobulin G4 testing were subsequently tested and shown to be elevated. The provisional diagnosis of immunoglobulin G4-related sclerosing cholangitis was made, and steroid treatment was empirically started. Treatment with steroids was successful, with complete resolution of symptoms and abnormal imaging findings and near complete resolution of liver function test results after 1 month.

Histological Assessment of the Bile Duct before Liver Transplantation: Does the Bile Duct Injury Score Predict Biliary Strictures?

INTRODUCTION

Histological injury to the biliary tree during organ preservation leads to biliary strictures after liver transplantation. The Bile Duct Injury (BDI) score was developed to assess histological injury and identify the grafts most likely to develop biliary strictures. The BDI score evaluates the bile duct mural stroma, peribiliary vascular plexus (PVP) and deep peribiliary glands (DPGs), which were correlated with post-transplant biliary strictures. However, the BDI score has not been externally validated. The aim of this study was to verify whether the BDI score could predict biliary strictures at our transplant centre.

METHODS

Brain-dead donor liver grafts transplanted at a single institution from March 2015 to June 2016 were included in this analysis. Bile duct biopsies were collected immediately before transplantation and assessed for bile duct injury by two blinded pathologists. The primary outcome was the development of clinically significant biliary strictures within 24 months post-transplant.

RESULTS

Fifty-seven grafts were included in the study which included 16 biliary strictures (28%). Using the BDI score, mural stromal, PVP and DPG injury did not correlate with biliary strictures including Non-Anastomotic Strictures. Severe inflammation (>50 leucocytes per HPF) was the only histological feature inversely correlated with the primary outcome (absent in the biliary stricture group vs. 41% in the no-stricture group, p = 0.001).

CONCLUSIONS

The current study highlights limitations of the histological assessment of bile duct injury. Although all grafts had bile duct injury, only inflammation was associated with biliary strictures. The BDI score was unable to predict post-transplant biliary strictures in our patient population.

Bouveret syndrome: two approaches one stone

Bouveret syndrome is a rare cause of gastric outlet obstruction, a consequence of a large impacted gallstone leading to the formation of a bilioenteric fistula. We present a case of a 79-year-old female who presented with a history of persistent nausea and vomiting. Computed tomography of the abdomen revealed a large gallstone impacted in the second part of the duodenum, complicated by a cholecystoduodenal fistula, leading to gastric outlet obstruction. After nasogastric decompression, the patient underwent an upper gastrointestinal endoscopy and attempted stone retrieval which was unsuccessful. Consequently, she underwent laparotomy, gastrotomy, and extraction of the stone. This case highlights the pitfalls of managing Bouveret syndrome via an endoscopic or an open surgical approach.

Long-term ex situ normothermic perfusion of human split livers for more than 1 week

Current machine perfusion technology permits livers to be preserved ex situ for short periods to assess viability prior to transplant. Long-term normothermic perfusion of livers is an emerging field with tremendous potential for the assessment, recovery, and modification of organs. In this study, we aimed to develop a long-term model of ex situ perfusion including a surgical split and simultaneous perfusion of both partial organs. Human livers declined for transplantation were perfused using a red blood cell-based perfusate under normothermic conditions (36 °C) and then split and simultaneously perfused on separate machines. Ten human livers were split, resulting in 20 partial livers. The median ex situ viability was 125 h, and the median ex situ survival was 165 h. Long-term survival was demonstrated by lactate clearance, bile production, Factor-V production, and storage of adenosine triphosphate. Here, we report the long-term ex situ perfusion of human livers and demonstrate the ability to split and perfuse these organs using a standardised protocol.

Safety of laparoscopic repair of incisional hernias in liver transplant recipients

INTRODUCTION

Incisional hernia is a common complication following liver transplantation occurring in 5%-34% of patients. Traditionally, open repair was standard due to fear of abdominal adhesions, postoperative complications and lack of experience with laparoscopic techniques. Laparoscopic incisional hernia repair (LIHR) has now become routine in non-transplant patients, with improved postoperative outcomes. In this study, we compared outcomes after laparoscopic and open incisional hernia repair after liver transplantation at a high-volume liver transplant center.

METHODS

We performed a retrospective cohort study including all incisional hernia repairs performed on post-liver transplant patients at a major liver transplant center in Australia from 2010 to 2021. Donor, recipient, intraoperative and postoperative variables were collected from the electronic medical record focusing on laparoscopic and open repairs.

RESULTS

Between January 2010 and March 2021, 138 patients underwent incisional hernia repair: 40 laparoscopic (29%) and 98 open (71%). No difference in wound infection (2.5% vs. 7.7%, p = .243); wound dehiscence (.00% vs. 2.3%, p = .332) or hernia recurrence (16.3% vs. 23.0%, p = .352) was seen between treatment groups. For larger incisional hernias (>5 cm) we found that a laparoscopic repair reduced length of stay compared to open-repair (3.89 vs. 4.57 days, p = .026).

CONCLUSION

Laparoscopic repair of larger incisional hernias reduced postoperative length of hospital stay, whilst potential advantages may include reduced wound complications and hernia recurrence. Importantly, laparoscopic repair did not increase postoperative complication rates and represents a safe technique for repair in this demographic.

Liver splitting during normothermic machine perfusion: a novel method to combine the advantages of both in-situ and ex-vivo techniques

BACKGROUND

Split liver transplantation permits the transplant of two recipients using a single donor liver. Liver splitting can be performed using the ex-vivo technique (more convenient), or the in-situ technique (shorter cold ischaemic time). We aimed to develop a technique for liver splitting during normothermic machine perfusion which combines the advantages of both techniques and permits graft assessment prior to transplant.

METHODS

Human livers declined for transplantation were perfused at 36 °C using a modified-commercial perfusion machine. We developed a six-step method to split whole livers into left lateral segment grafts and extended right grafts. Both partial livers were then perfused on separate machines for individual assessment.

RESULTS

Using our technique, 10 whole livers were successfully split during normothermic perfusion resulting in 20 partial grafts. Apart from a single graft which failed due to a technical error, all grafts survived for 24-h after splitting. Survival was demonstrated by lactate clearance, bile production and synthesis of coagulation factors.

CONCLUSIONS

Liver splitting during normothermic machine perfusion has the potential to revolutionise split liver transplantation. We describe a novel technique that reliably achieves two grafts from a single donor liver. This raises the possibility of semi-elective transplantation, and sophisticated graft assessment prior to implant.

Intraoperative Cholangiography in Laparoscopic Cholecystectomy: A Systematic Review and Meta-Analysis

Background/Objectives

Routine intraoperative cholangiography (IOC) for laparoscopic cholecystectomy (LC) remains controversial. The primary outcomes of this meta-analysis were detection rates of choledocholithiasis, bile duct injuries (BDI), and missed stones in LCs.

Methods

A systematic literature search was conducted for the time period January 1, 1990 to July 31, 2022. Some studies reported LCs with conversion to open therefore subgroup analysis in BDI rates was performed for studies which included LCs with and without conversion to open. Studies including primary open cholecystectomies were excluded. I² statistics were used for heterogeneity analysis.

Results

Fourteen studies involving 440659 patients were included. In studies comparing routine and selective IOC policies in LC, 61.1% of patients underwent routine IOC; 38.9% underwent selective IOC. In studies comparing IOC to no IOC in LC, 17.3% of patients had IOC; 82.7% did not. Between the selective and routine IOC groups there was no difference in choledocholithiasis detection rate (odds ratio [OR] = 1.33, p = 0.20, 95% confidence interval [CI] = 0.86 - 2.04), no difference in the rate of missed stones (OR = 1.59, p = 0.58; 95% CI = 0.31 - 8.29), and no difference in BDI rates in selective compared to routine IOC (OR = 0.92, p = 0.92; 95% CI = 0.20 - 4.22). There was no difference in the BDI detection rates in LC with and without IOC (OR = 1.12, p = 0.77; 95% CI = 0.52 - 2.38).

Conclusion

This is the largest meta-analysis on this topic to date. There was no statistically significant difference in choledocholithiasis detection, missed stones, or BDI rates in the analyzed groups.

Long-term normothermic perfusion of human livers for longer than 12 days

In this case report, we preserved human livers for up to 13 days under normothermic conditions using a modified commercial perfusion system. Two whole livers were split into two left lateral segment grafts and two extended right grafts without interruption to blood flow and then perfused on separate machines. Not only does this provide the basis for a meaningful study of liver function in the long term, but this could also facilitate the development of a model of ex situ liver regeneration.

Are split liver grafts a suitable option in high-risk liver transplant recipients?

PURPOSE OF REVIEW

To assess the outcomes of split liver transplantation (SLT) in adults and children and evaluate its role in high-risk recipients with a high model for end-stage liver disease (MELD) score, an urgent indication or requiring retransplantation.

RECENT FINDINGS

Split liver grafts in general have equivalent long-term survival outcomes to whole grafts despite an increase in biliary complications. Recent success and technical advances have encouraged use of these grafts in high-risk recipients. Split liver grafts can be used successfully in recipients with a high MELD score if there is adequate weight-matching. There are mixed results in urgent indication recipients and for retransplantation such that use in this group of patients remains controversial.

SUMMARY

SLT addresses donor shortages by facilitating the transplant of two recipients from the same donor liver. By using careful donor and recipient selection criteria, SLT can achieve equivalent long-term outcomes to whole grafts. These grafts have been used successfully in recipients with a high MELD score, but should be used selectively in urgent indication recipients and for retransplantation.

Addressing the challenges of split liver transplantation through technical advances. A systematic review

BACKGROUND

Split liver transplantation addresses donor shortages by facilitating the transplant of two recipients using one donor liver. Some still consider these grafts inferior due to prolonged cold ischaemia time and at times difficult vascular reconstruction. Techniques such as in-situ splitting, machine perfusion and interposition grafts may address these challenges and thereby address these concerns. The aim of this review is to assess these technical advances in split liver transplantation, their utility and outcomes.

METHODS

A systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Keywords included 'split liver transplantation', 'arterial reconstruction', and 'machine perfusion'. Data found was synthesised into sections including: methods of splitting, full-left full-right splitting, donor cholangiography, machine perfusion and arterial reconstruction.

RESULTS

A total of 78 articles met inclusion criteria after screening of 151 eligible articles. These were subdivided into the following categories: in-situ (25), ex-vivo (25), full-left full-right splitting (15), donor cholangiography (2), machine perfusion (6), and arterial reconstruction (5). The in-situ splitting technique reduces the cold ischaemia time compared to the ex-vivo technique which may improve graft quality and liver splitting during normothermic machine perfusion is a novel technique with the potential to incorporate the best aspects of both techniques. Interposition grafts are often required during split liver transplantation but have an increased risk of hepatic artery thrombosis.

CONCLUSION

Advancements in technique have allowed many of the unique challenges of split liver transplantation to be overcome. Overall, this supports the use of split liver transplantation in broader and riskier settings and we advocate for liver transplant surgeons to not hesitate in using these grafts liberally and expanding their recipient selection criteria.

Surgical management of symptomatic right-sided Bochdalek hernias in adults: when is a minimally invasive approach appropriate?

BACKGROUND

Right-sided Bochdalek hernias are uncommon congenital diaphragmatic hernias that can be challenging to manage because they can contain bowel, omentum, kidney or liver.

METHODS

We describe our experience at a single centre and integrate this with all reported cases in the literature to evaluate how this rare problem has been managed and when a minimally invasive approach is appropriate.

RESULTS

A total of 31 patients were identified, four patients from our institution and 27 case reports from the literature. A minimally invasive approach was utilized in 15 of 31 patients (including two of four at our institution) and was more common if the operation was performed in the elective setting (10/12 versus 4/19). If a bowel resection was required, an open approach was more common (9/17 versus 1/14). The commonest method of repair was a primary suture repair (18/31), and the mesh was used in 13 cases, particularly in the elective setting (9/12 versus 4/19).

CONCLUSION

Right-sided Bochdalek hernias are an uncommon and challenging problem. These hernias can contain bowel, kidney and even liver but can still be successfully repaired using minimally invasive techniques, especially in the elective setting and when an emergency bowel resection is not required.

Investigating general medication prescription by general practitioners during a 12-month randomized controlled weight loss trial

Much healthcare expenditure is on pharmaceutical drugs. Expenditure on medications has increased both in absolute terms, and as a proportion of total health expenditure. No previous studies have investigated the prescribing costs by general practitioners when managing patients during a weight loss intervention. This study evaluated the medication costs by individual class during a 1-year study in which 268 participants were randomized to one of two weight loss programmes, either standard care (SC) as defined by national guidelines, or a commercial provider (Weight Watchers) (CP). The baseline body mass index of participants (mean ± standard deviation) was 32.0 ± 2.5 kg m^-2 , their body weight was 87.5 ± 11.8 kg, and age 47.4 ± 11.7 years. Weight loss for the SC and CP groups was -2.6 and -6.1 kg, respectively (between group difference; P < 0.0001). The greater weight loss in the CP group compared to SC was accompanied by larger reductions in waist circumference and fat mass. The CP group also had significantly greater improvements than SC in high-density lipoprotein cholesterol. Despite SC participants being prescribed and spending more on medications than the CP group with no better weight or metabolic outcomes, this was not of statistical significance. For both groups the highest proportion of prescriptions (≥30% of medications) was for control of risk factors for cardiovascular disease. In conclusion, this study indicates that obesity treatment via a shared care approach with a CP results in greater weight loss and some better clinical outcomes, but despite lower medication costs overall, this was not significant when compared to SC treatment.

The effect of diabetes mellitus on costs and length of stay in patients with peripheral arterial disease undergoing vascular surgery

OBJECTIVE

To determine the impact of diabetes mellitus (DM) and other comorbidities on length of stay (LOS) and costs in patients with peripheral arterial disease (PAD) admitted to a vascular surgical unit.

METHODS

A retrospective study was conducted between January 2011 and July 2012 at a tertiary referral hospital in Sydney. Demographic, laboratory, and operative data were obtained from the Australasian Vascular Audit database and hospital diagnostic-related group (DRG) reports. Patients with confirmed PAD with or without DM requiring hospital admission for a diagnosis of claudication, rest pain, ulcer/gangrene, and infection that required lower limb surgical intervention were included. Associations between LOS, surgical procedure, and DRG were explored.

RESULTS

Five hundred and sixty-eight admissions (492 patients) were identified: 292 admissions with PAD and 276 admissions with PAD in conjunction with DM (PADDM). Mean LOS for patients with PAD was 10 ± 13.7 days compared with 15 ± 18.2 days for PADDM (p < .01; 95% confidence interval 2.7-8.0). LOS and costs were greatest in patients with PADDM undergoing major amputation (37 ± 13.7 days; US$42,236; p < .01). Analysis of variance indicated that the best predictors of LOS were the presence of DM, bypass surgery, amputation, chronic kidney disease (CKD) stage V, infection, and emergency admission. Over 18 months, the estimated total inpatient costs associated with lower limb intervention for PAD with and without DM amounted to US$7,598,597. People with DM incurred greater inpatient costs, averaging US$1,912 more per episode of admission and a total of US$528,029 over 18 months.

CONCLUSION

The impact of diabetes as a comorbid condition in patients with PAD is significant, both clinically and economically. Factors that predict increased LOS in patients with PAD are DM, bypass surgery, amputation, CKD stage V, infection, and emergency admission.

An intragastric balloon produces large weight losses in the absence of a change in ghrelin or peptide YY

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT?: The development of obesity is a multi-factorial process that results in an alteration in the neuroendocrine hormones that help regulate appetite and body weight. Weight loss has been shown to alter this neuroendocrine balance so as to promote weight regain. An intragastric balloon is an effective method to achieve significant weight loss in obese patients and is well suited for those patients who are looking for an alternative to lifestyle modification alone, and those who are not ready or suitable for surgical intervention. Limited research has shown that the weight loss achieved with an intragastric balloon is mediated by altered secretion of the hormones that regulate appetite and weight. WHAT DOES THIS STUDY ADD?: There are currently limited data on the effects of intragastric balloons on appetite and weight-related hormones. In the current study, we have investigated a broad range of gut hormones and adipokines and their response to weight loss induced by differing methods, and the subsequent effect this may have on weight regain. This is an important research area as novel therapies and long-term strategies are needed to counteract the unfavourable changes to the neuroendocrine control of appetite and satiety associated with diet-induced weight loss. This study aims to determine the effect of weight loss achieved with different methods on fasting levels of appetite hormones. Sixty-six obese adults with metabolic syndrome were randomized to intragastric balloon (IGB) for 6 months, with a 12-month behavioural modification programme (IGB group, 'IGBG') or a 12-month behavioural modification programme alone (control group, 'CG'). Anthropometric assessments and blood samples were taken every 3 months and total ghrelin, peptide YY (PYY), adiponectin and leptin were measured. Significant weight-loss differences favouring the IGBG were evident between groups at all time points. Ghrelin increased when the IGB was in situ (+39.3 pmol L(-1) vs. baseline) and returned to baseline after its removal (-34.7 pmol L(-1) ). Adiponectin and PYY levels remained stable in the IGBG, with transient increases noted in the CG. There were no significant between-group differences for ghrelin, PYY or adiponectin. In the IGBG, despite a decrease in leptin at 6 months (-11.7 ng mL(-1) ), levels increased to baseline after IGB removal (-3.7 ng mL(-1) ). In summary, weight loss associated with the IGB did not alter fasting levels of PYY or adiponectin. There was a return of ghrelin and leptin levels to baseline values after IGB removal. No compensatory rise in ghrelin was evident in either group 12 months after initial weight reduction, suggesting that such treatment strategies may lead to better long-term sustainable weight loss.

Overview of endocrinopathies associated with β-thalassaemia major

BACKGROUND

  Thalassaemia major is a common and serious medical problem worldwide that is associated with a range of complications, including effects on multiple endocrine pathways. Minimizing or preventing comorbidities is important for these individuals who need life-long multidisciplinary care and treatment. However, there are limited overviews of the endocrine complications associated with this illness, nor any consensus regarding management guidelines.

METHOD

  A retrospective cohort analysis of β-thalassaemia patients attending an ambulatory transfusion clinic at Royal Prince Alfred Hospital was conducted from June 2008.

RESULTS

  All of our subjects (n=29) had at least one endocrinopathy present with 16 patients (55%) having three or more (≥3) endocrinopathies. Hypogonadism was the most prevalent followed by osteoporosis and growth failure (less than 3rd centile) with a frequency of 16/29 (55%), 14/29 (48%) and 10/29 (35%) patients respectively. Those with more endocrinopathies (≥3) had a longer duration of transfusion therapy when compared with those with fewer endocrinopathies.

CONCLUSION

  A summary of our clinical guidelines, which have been used to monitor and manage these complications, is presented along with a discussion on the results and pathophysiology of the associated endocrinopathies.

Modulating multidrug resistance gene in leukaemia cells by short interfering RNA

INTRODUCTION

The multidrug resistance gene, MDR1, is one of the genes responsible for resistance to chemotherapy in the treatment of leukaemia and other cancers. The discovery of RNA interference in mammalian cells has provided a powerful tool to inhibit the expression of this gene. However, very little is known about the transfection of leukaemia cells with short interfering RNA (siRNA) targeted at MDR1. This study aims to evaluate the effectiveness of two chemically-synthesised siRNA in modulating MDR1 gene and inhibiting P-glycoprotein expression in leukaemic cells. We also evaluated two siRNA delivery methods in this study.

METHODS

K562/Adr was transfected with two MDR1-targeted siRNA or negative control siRNA, by using cationic lipid-based transfection reagents or electroporator. Gene expression of MDR1 was quantified by real-time polymerase chain reaction and calculated as a percentage relative to the negative control siRNA. P-glycoprotein expression was evaluated via flow cytometry and drug sensitivity after treatment was assessed by cytotoxicity assays.

RESULTS

The percentage of MDR1 gene knockdown from cells transfected with an electroporator was significantly higher (84.4 percent, p-value is 0.094) compared to cells transfected with cationic lipid-based transfection reagents (52.8 percent). Both siRNA significantly reduced the expression of MDR1 by 84.9 percent (p-value is 0.001) and 86.0 percent (p-value is 0.011), respectively. P-glycoprotein expression was down-regulated and drug sensitivity was increased after treatment with the siRNA.

CONCLUSION

This study shows that the two siRNA sequences are capable of modulating MDR1 and P-glycoprotein expressions and increased drug sensitivity. Transfection with an electroporator was superior to chemical transfection for leukaemia cells.