Oral bacteria accelerate pancreatic cancer development in mice

OBJECTIVE

Epidemiological studies highlight an association between pancreatic ductal adenocarcinoma (PDAC) and oral carriage of the anaerobic bacterium Porphyromonas gingivalis, a species highly linked to periodontal disease. We analysed the potential for P. gingivalis to promote pancreatic cancer development in an animal model and probed underlying mechanisms.

DESIGN

We tracked P. gingivalis bacterial translocation from the oral cavity to the pancreas following administration to mice. To dissect the role of P. gingivalis in PDAC development, we administered bacteria to a genetically engineered mouse PDAC model consisting of inducible acinar cell expression of mutant Kras (Kras +/LSL-G12D; Ptf1a-CreER, iKC mice). These mice were used to study the cooperative effects of Kras mutation and P. gingivalis on the progression of pancreatic intraepithelial neoplasia (PanIN) to PDAC. The direct effects of P. gingivalis on acinar cells and PDAC cell lines were studied in vitro.

RESULTS

P. gingivalis migrated from the oral cavity to the pancreas in mice and can be detected in human PanIN lesions. Repetitive P. gingivalis administration to wild-type mice induced pancreatic acinar-to-ductal metaplasia (ADM), and altered the composition of the intrapancreatic microbiome. In iKC mice, P. gingivalis accelerated PanIN to PDAC progression. In vitro, P. gingivalis infection induced acinar cell ADM markers SOX9 and CK19, and intracellular bacteria protected PDAC cells from reactive oxygen species-mediated cell death resulting from nutrient stress.

CONCLUSION

Taken together, our findings demonstrate a causal role for P. gingivalis in pancreatic cancer development in mice.

A fully 3D-printed versatile tumor-on-a-chip allows multi-drug screening and correlation with clinical outcomes for personalized medicine

Optimal clinical outcomes in cancer treatments could be achieved through the development of reliable, precise ex vivo tumor models that function as drug screening platforms for patient-targeted therapies. Microfluidic tumor-on-chip technology is emerging as a preferred tool since it enables the complex set-ups and recapitulation of the physiologically relevant physical microenvironment of tumors. In order to overcome the common hindrances encountered while using this technology, a fully 3D-printed device was developed that sustains patient-derived multicellular spheroids long enough to conduct multiple drug screening tests. This tool is both cost effective and possesses four necessary characteristics of effective microfluidic devices: transparency, biocompatibility, versatility, and sample accessibility. Compelling correlations which demonstrate a clinical proof of concept were found after testing and comparing different chemotherapies on tumor spheroids, derived from ten patients, to their clinical outcomes. This platform offers a potential solution for personalized medicine by functioning as a predictive drug-performance tool.

Methionine aminopeptidase 2 as a potential target in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDA) is an aggressive metastatic cancer with a very low survival rate. This tumor is hypovascularized and characterized by severe hypoxic regions, yet these regions are not impeded by the oxidative stress in their microenvironment. PDA's high resilience raises the need to find new effective therapeutic targets. This study investigated the suitability of methionine aminopeptidase 2 (MetAp2), a metallopeptidase known to play an important role in tumor progression, as a new target for treating PDA. In our examination of patient-derived PDA tissues, we found that MetAp2 is highly expressed in metastatic regions compared with primary sites. At the cellular level, we found that the basal expression levels of MetAp2 in pancreatic cancer cells were higher than its levels in endothelial cells. Pancreatic cancer cells showed a significant suppression of proliferation in a dose-dependent manner upon exposure to TNP-470, a selective MetAp2 inhibitor. In addition, a significant reduction in glutathione (GSH) levels - known for its importance in alleviating oxidative stress - was detected in all treated cells, suggesting a possible anti-cancer activity mechanism that would be feasible for treating highly hypoxic PDA tumors. Furthermore, in an orthotopic pancreatic cancer murine model, systemic oral treatment with a MetAp2 inhibitor significantly reduced tumors' growth. Taken together, our findings indicate that MetAp2 enhances tumor sensitivity to hypoxia and may provide an effective target for treating hypoxic tumors with high expression levels of MetAp2.

Targeting Persistent Biofilm Infections: Reconsidering the Topography of the Infection Site during Model Selection

The physiology of an organism in the environment reflects its interactions with the diverse physical, chemical, and biological properties of the surface. These principles come into consideration during model selection to study biofilm–host interactions. Biofilms are communities formed by beneficial and pathogenic bacteria, where cells are held together by a structured extracellular matrix. When biofilms are associated with a host, chemical gradients and their origins become highly relevant. Conventional biofilm laboratory models such as multiwall biofilm models and agar plate models poorly mimic these gradients. In contrast, ex vivo models possess the partial capacity to mimic the conditions of tissue-associated biofilm and a biofilm associated with a mineralized surface enriched in inorganic components, such as the human dentin. This review will highlight the progress achieved using these settings for two models of persistent infections: the infection of the lung tissue by Pseudomonas aeruginosa and the infection of the root canal by Enterococcus faecalis. For both models, we conclude that the limitations of the conventional in vitro systems necessitate a complimentary experimentation with clinically relevant ex vivo models during therapeutics development.

Calcium carbonate mineralization is essential for biofilm formation and lung colonization

Biofilms are differentiated microbial communities held together by an extracellular matrix. μCT X-ray revealed structured mineralized areas within biofilms of lung pathogens belonging to two distant phyla - the proteobacteria Pseudomonas aeruginosa and the actinobacteria Mycobacterium abscessus. Furthermore, calcium chelation inhibited the assembly of complex bacterial structures for both organisms with little to no effect on cell growth. The molecular mechanisms promoting calcite scaffold formation were surprisingly conserved between the two pathogens as biofilm development was similarly impaired by genetic and biochemical inhibition of calcium uptake and carbonate accumulation. Moreover, chemical inhibition and mutations targeting mineralization significantly reduced the attachment of P. aeruginosa to the lung, as well as the subsequent damage inflicted by biofilms to lung tissues, and restored their sensitivity to antibiotics. This work offers underexplored druggable targets for antibiotics to combat otherwise untreatable biofilm infections.

Senolytic elimination of Cox2-expressing senescent cells inhibits the growth of premalignant pancreatic lesions

OBJECTIVE

Cellular senescence limits tumourigenesis by blocking the proliferation of premalignant cells. Additionally, however, senescent cells can exert paracrine effects influencing tumour growth. Senescent cells are present in premalignant pancreatic intraepithelial neoplasia (PanIN) lesions, yet their effects on the disease are poorly characterised. It is currently unknown whether senolytic drugs, aimed at eliminating senescent cells from lesions, could be beneficial in blocking tumour development.

DESIGN

To uncover the functions of senescent cells and their potential contribution to early pancreatic tumourigenesis, we isolated and characterised senescent cells from PanINs formed in a Kras-driven mouse model, and tested the consequences of their targeted elimination through senolytic treatment.

RESULTS

We found that senescent PanIN cells exert a tumour-promoting effect through expression of a proinflammatory signature that includes high Cox2 levels. Senolytic treatment with the Bcl2-family inhibitor ABT-737 eliminated Cox2-expressing senescent cells, and an intermittent short-duration treatment course dramatically reduced PanIN development and progression to pancreatic ductal adenocarcinoma.

CONCLUSIONS

These findings reveal that senescent PanIN cells support tumour growth and progression, and provide a first indication that elimination of senescent cells may be effective as preventive therapy for the progression of precancerous lesions.

Splenic infarction complicated with abscess after pelvic trauma as the first presentation of patent foramen ovale - A case report

Hypercoagulability after trauma is a known entity. Following significant trauma, most guidelines advise anticoagulation treatment for venous thromboembolism (VTE) prophylaxis. VTE following minor trauma convoyed with arterial or systemic embolization dictate the need to search for uncommon source of thromboembolic complications. This is a report of an unusual case of pulmonary and systemic emboli complicated by splenic abscess following minor trauma in a patient with Diabetes Mellitus as the first presentation of patent foramen ovale (PFO).

A single cell atlas of the human liver tumor microenvironment

Malignant cell growth is fueled by interactions between tumor cells and the stromal cells composing the tumor microenvironment. The human liver is a major site of tumors and metastases, but molecular identities and intercellular interactions of different cell types have not been resolved in these pathologies. Here, we apply single cell RNA-sequencing and spatial analysis of malignant and adjacent non-malignant liver tissues from five patients with cholangiocarcinoma or liver metastases. We find that stromal cells exhibit recurring, patient-independent expression programs, and reconstruct a ligand-receptor map that highlights recurring tumor-stroma interactions. By combining transcriptomics of laser-capture microdissected regions, we reconstruct a zonation atlas of hepatocytes in the non-malignant sites and characterize the spatial distribution of each cell type across the tumor microenvironment. Our analysis provides a resource for understanding human liver malignancies and may expose potential points of interventions.

Rapid Clearing for High Resolution 3D Imaging of Ex Vivo Pancreatic Cancer Spheroids

The currently accepted imaging methods have been a central hurdle to imaging the finer details of tumor behavior in three-dimensional (3D) ex vivo multicellular culture models. In our search for an improved way of imaging tumor behavior in its physiological-like niche, we developed a simple, efficient, and straightforward procedure using standard reagents and imaging equipment that significantly enhanced 3D imaging up to a ~200-micron depth. We tested its efficacy on pancreatic spheroids, prototypes of high-density tissues that are difficult to image. We found we could both save time with this method and extract information about pancreatic tumor spheroids that previously was difficult to obtain. We were able to discern clear differences in the organization of pancreatic tumor spheroids generated from different origins, suggesting cell-specific, inherent, bottom-up organization with a correlation to the level of malignancy. We also examined the dynamic changes in the spheroids at predetermined time points, providing important information related to tissue morphogenesis and its metabolic state. Lastly, this process enabled us to assess a drug vehicle's potential to penetrate dense tumor tissue by improving our view of the inert particles' diffusion in the 3D spheroid. This clearing method, a simple procedure, can open the door to more accurate imaging and reveal more about cancer behavior.

Fap2 Mediates Fusobacterium nucleatum Colorectal Adenocarcinoma Enrichment by Binding to Tumor-Expressed Gal-GalNAc

Fusobacterium nucleatum is associated with colorectal cancer and promotes colonic tumor formation in preclinical models. However, fusobacteria are core members of the human oral microbiome and less prevalent in the healthy gut, raising questions about how fusobacteria localize to CRC. We identify a host polysaccharide and fusobacterial lectin that explicates fusobacteria abundance in CRC. Gal-GalNAc, which is overexpressed in CRC, is recognized by fusobacterial Fap2, which functions as a Gal-GalNAc lectin. F. nucleatum binding to clinical adenocarcinomas correlates with Gal-GalNAc expression and is reduced upon O-glycanase treatment. Clinical fusobacteria strains naturally lacking Fap2 or inactivated Fap2 mutants show reduced binding to Gal-GalNAc-expressing CRC cells and established CRCs in mice. Additionally, intravenously injected F. nucleatum localizes to mouse tumor tissues in a Fap2-dependent manner, suggesting that fusobacteria use a hematogenous route to reach colon adenocarcinomas. Thus, targeting F. nucleatum Fap2 or host epithelial Gal-GalNAc may reduce fusobacteria potentiation of CRC.

Cutaneous tube ureterostomy: a fast and effective method of urinary diversion in emergency situations

Aim

To report on a simple and rapid method of urinary diversion. This method was applied successfully in different clinical scenarios when primary reconstruction of the ureters was not possible.

Materials and methods

The disconnected ureter is catheterized by a feeding tube. The tube is secured with sutures and brought out to the lateral abdominal wall as cutaneous tube ureterostomy (CTU).

Results

This method was applied in three different clinical scenarios: a 40-year-old man who sustained multiple high-velocity gunshots to the pelvis with combined rectal and bladder trigone injuries and massive bleeding from a comminuted pubic fracture. Damage control included colostomy and bilateral CTUs. A 26-year-old woman had transection of the right lower ureter during abdominal hysterectomy. Diagnosis was delayed for 3 weeks when the patient developed sepsis. The right kidney was diverted with a CTU. A 37-year-old male suffered from bladder perforation and hemorrhagic shock. Emergency cystectomy was done and urinary diversion was accomplished with bilateral CTUs. In all cases, effective drainage of the urinary system was achieved with normalization of kidney function.

Conclusion

When local or systemic conditions preclude definitive repair and damage control surgery is needed, CTU provides fast and effective urinary diversion.

Defining the need for blood and blood products transfusion following suicide bombing attacks on a civilian population: a level I single-centre experience

INTRODUCTION

Knowledge of patterns of blood use in the care of mass casualty settings is important for preparedness of medical centre resources and for maximising survival when blood supplies are limited. Our objectives were to review of our experience with the use of blood products and define the utilisation of blood transfusion following suicide bombing attacks.

PATIENTS AND METHODS

We conducted a retrospective analysis of blood and blood product transfusion following civilian bombing attacks at a level I trauma centre in Jerusalem, Israel from 2000 to 2005. The study group consisted of 137 patients who were admitted following 17 suicide bombing attacks which were carried out in Jerusalem during the 5-year period. Demographic data, number of units of blood and blood products transfused and the need for massive transfusions were recorded and analyzed.

RESULTS

Fifty-three patients received blood transfusions (38.7%). There were 33 males (62.2%) with a median ISS of 13 (range 4-25). These 53 patients received 524 PRBC, 42 WB, and 449 FFP. The mean number of PRBC transfused/admitted patient was 3.82 units (range 0-59). Thirty patients (21.9%) received 236 PRBC (45% of total PRBC) at the first 2h. The ratio of ordered to transfused blood was 946:524. The FFP:PRBC ratio for all transfused patients was 1:1.17. The number of PRBC transfused per attack correlated with the number of patients admitted per attack. The most commonly transfused blood type was A (52.3%). Only 18 units of uncrossed-matched blood were transfused (3.3% of total). 14 patients (10.2%) received massive transfusions. These patients received 399 PRBC (76.1% of total units transfused) and the average number of PRBC transfused was 28.5/patient (10-59).

CONCLUSIONS

More than 1/3 of casualties admitted following civilian bombing attacks received transfusions, most in the first 2h. Large-scale attacks will require more blood and blood products than small-scale attacks. Twice the number of PRBC ordered than transfused reflects a known trend for over-triage during the initial assessment following bombing attacks. One tenth of patients received massive transfusion.

Phosphorylation of ribosomal protein S6 attenuates DNA damage and tumor suppression during development of pancreatic cancer

The signaling pathways that mediate the development of pancreatic ductal adenocarcinoma (PDAC) downstream of mutant Kras remain incompletely understood. Here, we focus on ribosomal protein S6 (rpS6), an mTOR effector not implicated previously in cancer. Phosphorylation of rpS6 was increased in pancreatic acinar cells upon implantation of the chemical carcinogen 7,12-dimethylbenz(a)anthracene (DMBA) or transgenic expression of mutant Kras. To examine the functional significance of rpS6 phosphorylation, we used knockin mice lacking all five phosphorylatable sites in rpS6 (termed rpS6(P-/-) mice). Strikingly, the development of pancreatic cancer precursor lesions induced by either DMBA or mutant Kras was greatly reduced in rpS6(P-/-) mice. The rpS6 mutants expressing oncogenic Kras showed increased p53 along with increased staining of γ-H2AX and 53bp1 (Trp53bp1) in areas of acinar ductal metaplasia, suggesting that rpS6 phosphorylation attenuates Kras-induced DNA damage and p53-mediated tumor suppression. These results reveal that rpS6 phosphorylation is important for the initiation of pancreatic cancer.

Trauma care and case fatality during a period of frequent, violent terror attacks and thereafter

BACKGROUND

From September 1999 through January 2004 during the second Intifada (al-Aqsa), there were frequent terror attacks in Jerusalem. We assessed the effects on case fatality of introducing a specialized, intensified approach to trauma care at the Hebrew University-Hadassah Hospital Shock Trauma Unit (HHSTU) and other level I Israeli trauma units. This approach included close senior supervision of prehospital triage, transport, and all surgical procedures and longer hospital stays despite high patient-staff ratios and low hospital budgets. Care for lower income patients also was subsidized.

METHODS

We tracked case fatality rates (CFRs) initially during a period of terror attacks (1999-2003) in 8,127 patients (190 deaths) at HHSTU in subgroups categorized by age, injury circumstances, and injury severity scores (ISSs). Our comparisons were four other Israeli level I trauma centers (n = 2,000 patients), and 51 level I U.S. trauma centers (n = 265,902 patients; 15,237 deaths). Detailed HHSTU follow-up continued to 2010.

RESULTS

Five-year HHSTU CFR (2.62 %) was less than half that in 51 U.S. centers (5.73 %). CFR progressively decreased; in contrast to a rising trend in the US for all age groups, injury types, and ISS groupings, including gunshot wounds (GSW). Patients with ISS > 25 accounted for 170 (89 %) of the 190 deaths in HHSTU. Forty-one lives were saved notionally based on U.S. CFRs within this group. However, far more lives were saved from reductions in low CFRs in large numbers of patients with ISS < 25. CFRs in HHSTU and other Israeli trauma units decreased more through the decade to 1.9 % up to 2010.

CONCLUSIONS

Sustained reductions in trauma unit CFRs followed introduction of a specialized, intensified approach to trauma care.

Complications of high grade liver injuries: management and outcomewith focus on bile leaks

Background

Although liver injury scale does not predict need for surgical intervention, a high-grade complex liver injury should alert the physician to expect an increased risk of hepatic complications following trauma. The aim of the current study was to define hepatic related morbidity in patients sustaining high-grade hepatic injuries that could be safely managed non-operatively.

Patients and methods

This is a retrospective study of patients with liver injury admitted to Hadassah-Hebrew University Medical Centre over a 10-year period. Grade 3-5 injuries were considered to be high grade. Collected data included the number and types of liver-related complications. Interventions which were required for these complications in patients who survived longer than 24 hours were analysed.

Results

Of 398 patients with liver trauma, 64 (16%) were found to have high-grade liver injuries. Mechanism of injury was blunt trauma in 43 cases, and penetrating in 21. Forty patients (62%) required operative treatment. Among survivors 22 patients (47.8%) developed liver-related complications which required additional interventional treatment. Bilomas and bile leaks were diagnosed in 16 cases post-injury. The diagnosis of bile leaks was suspected with abdominal CT scan, which revealed intraabdominal collections (n = 6), and ascites (n = 2). Three patients had continuous biliary leak from intraabdominal drains left after laparotomy. Nine patients required ERCP with biliary stent placement, and 2 required percutaneous transhepatic biliary drainage. ERCP failed in one case. Four angioembolizations (AE) were performed in 3 patients for rebleeding. Surgical treatment was found to be associated with higher complication rate. AE at admission was associated with a significantly higher rate of biliary complications. There were 24 deaths (37%), the majority from uncontrolled haemorrhage (18 patients). There were only 2 hepatic-related mortalities due to liver failure.

Conclusions

A high complication rate following high-grade liver injuries should be anticipated. In patients with clinical evidence of biliary complications, CT scan is a useful diagnostic and therapeutic tool. AE, ERCP and temporary internal stenting, together with percutaneous drainage of intra-abdominal or intrahepatic bile collections, represents a safe and effective strategy for the management of complications following both blunt and penetrating hepatic trauma.

Efficient transgene expression from naked DNA delivered into an arterio-venous fistula model for kidney dialysis

BACKGROUND

Patients with kidney failure frequently require the formation of an arterio-venous fistula (AVF) in which a vein is connected to an artery resulting in arterialization of the vein to allow adequate blood flow into an external 'artificial kidney'. In most patients, neo-intimal hyperplasia (NIH) ensues, causing narrowing and subsequent occlusion of the vein, leading to significant morbidity. The cellular events causing venous NIH may serve as ideal targets for molecular-based therapies. However, therapeutic gene delivery into the vascular system is seriously impeded by problems related to the low efficacy and toxicity of targeted viral vector delivery.

MATERIALS AND METHODS

To explore the feasibility of a plasmid-based vascular gene delivery system, we established a rat AVF model that develops NIH. Plasmids encoding for reporter or therapeutic genes were delivered into the blood vessels at the time or after AVF formation.

RESULTS

Intra-luminal injection of plasmid into the AVF resulted in extensive and long-term reporter gene expression at the venous limb mainly at the site of NIH formation. Transgene expression was confined to endothelial cells and myofibroblasts that migrate inwards from the adventitia and form the NIH lesion. There was no detrimental tissue reaction to plasmid delivery, contrasting with the severe inflammatory response observed after adenovirus infection. Intra-vascular delivery of a plasmid carrying the endothelial nitric oxide synthase gene resulted in sustained production of nitric oxide, previously shown to mitigate NIH formation.

CONCLUSIONS

These findings open the possibility of vascular transduction with naked DNA bearing therapeutic genes in areas prone to NIH to ameliorate vein graft pathologies using simple and clinically applicable vector delivery methods.

Transesophageal endoscopic myotomy for achalasia: recognizing potential pitfalls before clinical application

BACKGROUND

Laparoscopic Heller esophagomyotomy is the standard of care for achalasia treatment. This procedure, although effective, must be performed with the patient under general anesthesia and is associated with several serious potential complications. The authors aimed to develop a method of performing transesophageal endoscopic esophagomyotomy (TEEM) that would obviate the need for both general anesthesia and external incisions while offering lower intra- and postoperative complications.

METHODS

The TEEM procedure was performed on eight pigs. For six of the pigs, the procedure aimed at survival. A mid-esophageal mucosal incision was performed using an endoscope, and a submucosal plane was developed. The lower esophageal sphincter (LES) muscle fibers were clearly visualized and divided. The mucosal incision was closed using fibrin sealant. After 2 weeks of survival, a gastrografin swallow study and necropsy were performed.

RESULTS

The TEEM procedure was performed successfully in all eight porcine models. The myotomy included the LES fibers and extended 4 to 6 cm proximally to the esophagus. The proximal gastric muscle was divided up to 1 to 2 cm. No injuries to the abdominal or mediastinal structures occurred. One pig died on postoperative day 1 due to an unrecognized pneumothorax. Two pigs had ischemic ulcers at the myotomy site. The last three pigs had an uneventful recovery. The mucosal incision site healed completely in all the survived pigs, and except for the pig with mediastinal sepsis, all ate heartily and gained weight as expected.

CONCLUSION

The TEEM procedure is technically feasible. Due to the morbidity encountered in the first three pigs, the reported technique was modified to include a slimmer endoscope, a shorter tunnel, and a partial-thickness myotomy. These changes together with an understanding of the pitfalls involved in this procedure led to successful results for the next three pigs. Nevertheless, the authors believe that TEEM is not yet ready for prime time. Perfection of the technique and development of dedicated instruments are mandatory before safe translation of this method to human patients.

Involvement of CCR6/CCL20/IL-17 axis in NSCLC disease progression

Objectives

Autocrine and paracrine chemokine/chemokine receptor-based interactions promote non-small-cell-lung-cancer (NSCLC) carcinogenesis. CCL20/CCR6 interactions are involved in prostatic and colonic malignancy pathogenesis. The expression and function of CCL20/CCR6 and its related Th-17 type immune response in NSCLC is not yet defined. We sought to characterize the role of the CCL20/CCR6/IL-17 axis in NSCLC tumor growth.

Methods

A specialized histopathologist blindly assessed CCL20/CCR6 expression levels in 49 tissue samples of NSCLC patients operated in our department. Results were correlated to disease progression. Colony assays, ERK signaling and chemokine production were measured to assess cancer cell responsiveness to CCL20 and IL-17 stimulation.

Results

CCL20 was highly expressed in the majority (38/49, 77.5%) of tumor samples. Only a minority of samples (8/49, 16.5%) showed high CCR6 expression. High CCR6 expression was associated with a shorter disease-free survival (P = 0.008) and conferred a disease stage-independent 4.87-fold increased risk for disease recurrence (P = 0.0076, CI 95% 1.52–15.563). Cancerous cell colony-forming capacity was increased by CCL20 stimulation; this effect was dependent in part on ERK phosphorylation and signaling. IL-17 expression was detected in NSCLC; IL-17 potentiated the production of CCL20 by cancerous cells.

Conclusion

Our findings suggest that the CCL20/CCR6 axis promotes NSCLC disease progression. CCR6 is identified as a potential new prognostic marker and the CCL20/CCR6/IL-17 axis as a potential new therapeutic target. Larger scale studies are required to consolidate these observations.

A transgenic model for conditional induction and rescue of portal hypertension reveals a role of VEGF-mediated regulation of sinusoidal fenestrations

Portal hypertension (PH) is a common complication and a leading cause of death in patients with chronic liver diseases. PH is underlined by structural and functional derangement of liver sinusoid vessels and its fenestrated endothelium. Because in most clinical settings PH is accompanied by parenchymal injury, it has been difficult to determine the precise role of microvascular perturbations in causing PH. Reasoning that Vascular Endothelial Growth Factor (VEGF) is required to maintain functional integrity of the hepatic microcirculation, we developed a transgenic mouse system for a liver-specific-, reversible VEGF inhibition. The system is based on conditional induction and de-induction of a VEGF decoy receptor that sequesters VEGF and preclude signaling. VEGF blockade results in sinusoidal endothelial cells (SECs) fenestrations closure and in accumulation and transformation of the normally quiescent hepatic stellate cells, i.e. provoking the two processes underlying sinusoidal capillarization. Importantly, sinusoidal capillarization was sufficient to cause PH and its typical sequela, ascites, splenomegaly and venous collateralization without inflicting parenchymal damage or fibrosis. Remarkably, these dramatic phenotypes were fully reversed within few days from lifting-off VEGF blockade and resultant re-opening of SECs' fenestrations. This study not only uncovered an indispensible role for VEGF in maintaining structure and function of mature SECs, but also highlights the vasculo-centric nature of PH pathogenesis. Unprecedented ability to rescue PH and its secondary manifestations via manipulating a single vascular factor may also be harnessed for examining the potential utility of de-capillarization treatment modalities.

A mouse model for sleeve gastrectomy: applications for diabetes research

INTRODUCTION

Discovery of enhanced glucose tolerance following bariatric surgery has sparked renewed interest in the investigation of unchartered underlying pathways of glucose homeostasis. Delineation of this pathway may ultimately be the first step in the creation of a novel therapy for type II diabetes. Nevertheless, the technical complexity and formidable nature of these surgeries coupled with the fragile nature of small rodents has made the creation of a mouse model to study these effects incredibly challenging. We have created a simplified sleeve gastrectomy mouse model to study the effects of bariatric surgery on glucose tolerance and beta cell proliferation.

METHODS

Nineteen mice were randomized to undergo either sleeve gastrectomy (SG) (9) or sham operation (SH) (10). Weight and serum glucose were measured three times weekly and serum insulin measurements and pancreatic harvest were performed at the time of sacrifice. Five mice from each group were sacrificed after one week and the remainder sacrificed after one month.

RESULTS

Survival of mice was 100% for both groups. The SG group demonstrated an initial drop in weight and serum glucose as compared to SH, which normalized by one month following surgery. Serum insulin levels and rate of beta cell proliferation were similar in both groups after one week and one month.

CONCLUSION

The simplified sleeve gastrectomy is a technically straightforward, low-mortality technique for creating a bariatric mouse model which most faithfully replicates bariatric surgery performed in humans. This model can be a valuable tool to investigate the glucose tolerance and beta cell effects of bariatric surgery.

An endoscopic repair option for acquired esophagorespiratory fistulas

Benign acquired esophagorespiratory fistulas (BERFs) represent a broad spectrum of anatomic pathology presenting in a wide variety of clinical settings. These fistulas can lead to severe respiratory compromise and rarely close spontaneously. Surgical fistula closure has been the traditional therapeutic approach, but is associated with significant morbidity and mortality. The recent advent of endoscopic technologies suggests that minimally invasive procedures may offer a safe alternative to surgery for the treatment of esophagorespiratory fistulas. In this article, we present our experience in treating complex benign esophagorespiratory fistulas of diverse etiologies utilizing a primarily minimal invasive, endoscopic, or combined surgical and endoscopic approaches. Our experience demonstrates that an endoscopic-based approach is safe and technically feasible and can, potentially, spare a subset of patients from open surgery. A multidisciplinary decision-making process, based on individualized parameters, is a prerequisite for a successful outcome.

Providing more through less: current methods of retraction in SIMIS and NOTES cholecystectomy

BACKGROUND

As the field of minimally invasive surgery continues to develop, surgeons are confronted with the challenge of performing conventional laparoscopic surgeries through fewer incisions while maintaining the same degree of safety and surgical efficiency. Most of these methods involve elimination of the ports previously designated for retraction. As a result, minimally invasive surgeons have been forced to develop minimally invasive and ingenious methods for providing adequate retraction for these procedures. Herein we present our experience using endoloops and internal retractors to provide retraction during Single Incision Minimally Invasive Surgery (SIMIS) and Natural Orifice Transluminal Endoscopic Surgery (NOTES) cholecystectomy. We also present a review of the alternative retraction methods currently being employed for these surgeries.

METHODS

SIMIS was performed on 20 patients and NOTES was performed on 5 patients at our institution. Endoloops or internal retractors were used to provide retraction for all SIMIS procedures. Internal retractors provided retraction for all NOTES procedures.

RESULTS

Successful cholecystectomy was accomplished in all cases. One SIMIS surgery required conversion to standard laparoscopy due to complex anatomy. There were no intraoperative complications. Although adequate retraction was accomplished in all cases, the internal retractors were found to provide superior and more versatile retraction compared to that of endoloops.

CONCLUSION

Adequate retraction greatly simplifies SIMIS and NOTES surgery. Endograb internal retractors were easy to use and were found to provide optimal retraction and exposure during these procedures without complications.

Renal clear cell carcinoma emerging in a transplanted kidney 3 years after return to dialysis. Case report and review of the literature

We present a female patient with end-stage renal disease who was referred to the emergency department with sudden, excruciating pain over the right lower abdomen and flank. Radiologic evaluation following admission revealed a mass, solid in nature, located at the upper pole of the transplanted kidney. The patient was treated with empiric antibiotics and analgesics, and her symptoms subsided over the course of the week. Based on the clinical course and radiological findings, a self-limiting, spontaneous haemorrhage was thought to be the cause of the patient's symptoms. Nevertheless, background malignancy could not be ruled out. Therefore, an interval, elective graft nephrectomy was scheduled. Pathology confirmed the diagnosis of renal clear cell carcinoma.

Focal liver necrosis appears early after partial hepatectomy and is dependent on T cells and antigen delivery from the gut

INTRODUCTION

Progressive liver failure may develop following removal of a large part of the liver or transplantation of a small for size liver graft. The pathophysiology of this clinical syndrome is only partially understood.

METHODS

We assessed liver damage and hepatocyte 5-bromo-2'-deoxyuridine (BrdU) incorporation following partial hepatectomy (PH) in C57BL/6, BALB/C and immune-deficient mice. Hepatic lymphocyte subpopulations were characterized. Lipopolysaccharide (LPS) treatment and bowel decontamination determined the role of gut antigens.

RESULTS

Discrete, round necrotic lesions were observed as early as 2 h following 70%, but not 30% PH. In immune competent mice the extent of hepatocyte necrosis inversely correlated with BrdU incorporation. T, natural killer and natural killer T cells were recruited to the liver early after PH; however, only T-cell depletion abrogated hepatic necrosis. Hepatic injury was significantly reduced in non-obese diabetic/severe combined immunodeficient mice undergoing PH, while BrdU incorporation was not affected. Liver injury was augmented by LPS injection and reduced by gut decontamination.

CONCLUSIONS

A distinct pattern of early focal hepatic necrosis is observed following extensive PH in mice. T cells infiltrating the liver immediately after PH and gut-derived antigens are indispensable for the observed liver necrosis and may thus provide therapeutic targets to ameliorate liver damage following PH.

Midgut volvulus following laparoscopic gastric banding--a rare and dangerous situation

Intestinal malrotation is usually encountered in infants. Its main complication is midgut volvulus, a situation that presents itself with bilious vomiting. This symptom allows for early surgical treatment. A delay in diagnosis and treatment may lead to catastrophic sequelae, such as extensive bowel necrosis and death. This situation is rare but well known in adults. Laparoscopic gastric banding is a popular option for treating morbid obesity. One of the consequences of this procedure may be impaired vomiting when there is an obstruction below the band. In this paper, we present a case in which a patient suffered from midgut volvulus 4 years after a laparoscopic gastric banding. Owing to impaired vomiting, the diagnosis was delayed, therefore, severely endangering the patient. This case prompted us to suggest that malrotation should be actively sought after before or during any bariatric procedure.

Femtosecond laser: a new intradermal DNA delivery method for efficient, long‐term gene expression and genetic immunization

A femtosecond laser beam gene transduction (SG-LBGT) system is described as a novel and efficient method of intradermal (i.d.) nonviral gene delivery in mice by permeabilizing cells utilizing femtosecond laser pulses. Using this approach, significant gene expression and efficient dermal transduction lasting for >7 months were obtained. The ability of this new DNA gene transfer method to enhance genetic vaccination was tested in BALB/C mice. A single i.d. injection of a plasmid (10 microg) containing the hepatitis B virus (HBV) surface antigen (HBsAg), followed by pulses of laser, induced high titers of HBsAg-specific antibodies lasting for >210 days and increased levels of IgG1, IgG2a, IFNgamma, and IL-4, indicating the activation of both Th1 and Th2 cells. Moreover, mice vaccinated using the SG-LBGT followed by challenge with pHBV showed increased protection against viral challenge, as detected by decreased levels of HBV DNA, suggesting an efficient Th1 effect against HBV-infected replicating cells. Tumor growth retardation was induced in vaccinated mice challenged with an HBsAg-expressing syngeneic tumor. In most of the parameters tested, administration of plasmid followed by laser application was significantly more effective and prolonged than that of plasmid alone. Tissue damage was not detected and integration of the plasmid into the host genomic DNA probably did not occur. We suggest that the LBGT method is an efficient and safe technology for in vivo gene expression and vaccination and emphasizes its potential therapeutic applications for i.d. nonviral gene delivery.

Replication-deficient adenovirus induces host topoisomerase I activity: implications for adenovirus-mediated gene expression

Replication-deficient adenoviruses are useful vectors for the transfer of therapeutic transgenes to malignant and non-malignant tissues. Yet their clinical application is limited by the potential toxicity of viral infection and the transient nature of transgene expression. Although transgene expression from adenovirus vectors is initially higher than expression of transgenes transduced by other viral or non-viral vectors, it is often insufficient to generate a significant therapeutic effect. We addressed this issue by searching for DNA-targeted viral-induced host responses potentially restricting transgene expression. Nuclear protein extracts from livers of rats systemically infected with replication-deficient adenovirus exhibited enhanced topoisomerase I activity compared with extracts from uninfected animals. Consequently, the inhibition of topoisomerase I by the anti-cancer drug topotecan greatly enhanced transgene expression in adenovirus-infected hepatic cells, colon cancer and prostate cancer cell cultures, mouse liver, human ex vivo tumor specimens, and mouse tumor in vivo. The enhancement could not be ascribed to non-specific genotoxic stress, cell death, or cell-cycle perturbation. These findings are significant for gene therapy as they reveal novel aspects of the host anti-adenovirus response and set the stage for the development of a rational molecular-pharmacological approach to increase the effectiveness, and safety, of adenovirus-mediated cancer therapeutics.

A novel system to study adenovirus tropism to normal and malignant colon tissues

We describe here a new organ culture system for the evaluation of viral tropism to colon carcinomas and normal colon tissues. Organ cultures of mouse and human colon retained viability for several days and thus facilitated studies of viral tropism. Two adenoviral vectors (AD) were compared in the study: AD5, that utilizes the CAR receptor, demonstrated poor infectivity to both normal and carcinoma tissues, while a capsid-modified-AD, recognizing haparan-sulfate receptor, demonstrated efficient infectivity of both tissues. Immunohistochemistry analysis demonstrated different viral tropism; while AD5 infected only the colon epithelia, the capsid-modified-adeno infected both the epithelia and mesothelial layers. To investigate other determinants in the tissue that influence viral tropism, human cancer tissues were pretreated with collagenase and infected with the AD viruses. Increased infectivity and altered tropism were noted in the treated tumor tissue. Taken together, this ex vivo system indicated that receptor utilization and extracellular-matrix components influence AD viral tropism in solid tissues.

Suicide bombing attacks: Can external signs predict internal injuries?

OBJECTIVE

To report the distribution and types of injuries in victims of suicide bombing attacks and to identify external signs that would guide triage and initial management.

SUMMARY BACKGROUND DATA

There is a need for information on the degree to which external injuries indicate internal injuries requiring emergency triage.

METHODS

The medical charts and the trauma registry database of all patients who were admitted to the Hadassah Hospital in Jerusalem from August 2001 to August 2004 following a suicide bombing attack were reviewed and analyzed for injury characteristics, number of body areas injured, presence of blast lung injury (BLI), and need for therapeutic laparotomy. Logistic analysis was performed to identify predictors of BLI and intra-abdominal injury.

RESULTS

The study population consisted of 154 patients who were injured as a result of 17 attacks. Twenty-eight patients suffered from BLI (18.2%) and 13 patients (8.4%) underwent therapeutic laparotomy. Patients with penetrating head injury and those with > or =4 body areas injured were significantly more likely to suffer from BLI (odds ratio, 3.47 and 4.12, respectively, P < 0.05). Patients with penetrating torso injury and those with > or =4 body areas injured were significantly more likely to suffer from intra-abdominal injury (odds ratio, 22.27 and 4.89, respectively, P < 0.05).

CONCLUSION

Easily recognizable external signs of trauma can be used to predict the occurrence of BLI and intra-abdominal injury. The importance of these signs needs to be incorporated into triage protocols and used to direct victims to the appropriate level of care both from the scene and in the hospital.

Impact of HLA-C and Bw epitopes disparity on liver transplantation outcome

The occurrence of graft rejection episodes after orthotopic liver transplantation (OLT) despite the use of immunosuppressive drugs designed to suppress T lymphocyte functions, indicates the involvement of other types of cells in this process. The activity of natural killer cells and their killer immunoglobulin-like receptors (KIR) is regulated by human leukocyte antigen (HLA) class I determinants; C and Bw epitopes. Because recipient/donor pairs are usually HLA mismatched, recipient natural killer alloreactivity may be the mediating factor in rejection. In this retrospective study, we have analyzed rejection occurrence and outcome in 66 OLT recipients, 42 with and 24 without C or Bw epitope disparity in the rejection direction. Recipients transplanted from donors with no C epitope disparity had significantly fewer rejection episodes in the first year after transplantation compared with recipients transplanted across C epitope disparity (p = 0.0002). Moreover, this effect was more pronounced when the outcome was analyzed in OLT recipients across negative crossmatching for the anti-HLA class I and II antibodies. In contrast, Bw epitope disparity did not affect the outcome. In conclusion, C epitopes disparity between recipients and donors in the rejection direction appears to influence posttransplant liver outcome. This finding may be helpful in the choice of appropriate liver donor and planning immune suppression.

Air transportation of patients with end-stage liver disease to distant liver transplantation centers

The Israeli population does not meet its transplantation organ needs. Therefore, liver transplantation (LTX) candidates are sometimes transported to centers abroad. We aimed to assess the demographic and clinical issues concerning this policy. Records of all candidates transported (2000-2004) were retrospectively reviewed. Data included etiology, disease severity, outcome, distances traveled and destinations, and medical complication arising en route. Forty-three candidates were transported overseas: 12 patients with fulminant hepatic failure (FHF) and 31 with cirrhosis. Average MELD score was 19.94, and the APACHE II score for patients with FHF was 20.5. Destinations included the United States, Colombia, Belgium, Germany, China, and Italy. Average distance traveled was 4,660 miles. Two patients were intubated and sedated during flight. All patients safely reached their destinations: 8 died prior to transplantation, 5 died after transplantation, 3 are awaiting transplantation, 3 recovered spontaneously, and the rest successfully underwent transplantation and returned home. In conclusion, our results suggest that long-distance transportation of patients awaiting liver transplantation is safe and technically feasible provided precaution measures are taken. Therefore, allocation regions may be broadened to include larger and more distant populations.

Can External Signs of Trauma Guide Management?

BACKGROUND

Following a suicide bombing attack, scores of victims suffering from a combination of blast injury, penetrating injury, and burns are brought to local hospitals.

OBJECTIVE

To identify external signs of trauma that would assist medical crews in recognizing blast lung injury (BLI) and effectively triaging salvageable and nonsalvageable victims.

DESIGN

Retrospective analysis of all 15 suicide bombing attacks that occurred in Israel from April 1994 to August 1997.

SETTING

National survey.

PATIENTS

One hundred fifty-three victims died and 798 were injured as a result of 15 attacks. Medical records were reviewed for external signs of trauma, such as burns and penetrating injuries, and the presence of BLI. Main Outcome Measure The odds ratio for BLI and death.

RESULTS

Three settings were targeted: buses, semiconfined spaces, and open spaces. Sixty survivors (7.5%) suffered from BLI, which was more common in buses (37 of 260) than semiconfined spaces (14 of 279) and open spaces (9 of 259) (P<.001). Victims with BLI were more likely to suffer from penetrating injury to the head or torso, burns covering more than 10% of the body surface area, and skull fractures (odds ratios, 4, 11.6, and 55.8, respectively; P<.001). Victims who died at the scene were more likely to suffer from burns, open fractures, and amputations in comparison with survivors (odds ratios, 6.5, 18.6, and 50.1, respectively; P<.001).

CONCLUSIONS

Following a suicide bombing attack, external signs of trauma should be used to triage victims to the appropriate level of care both at the scene and in the hospital. Triage of salvageable and nonsalvageable victims should take into account the presence of amputations, burns, and open fractures.

Patterns of transgene expression and viral clearance from the transplanted liver following ex vivo adenovirus-mediated gene transfer

BACKGROUND/AIMS

In the rat liver transplant model, the liver graft can be transduced ex vivo by adenovirus encoding CTLA-4Ig (AdCTLA-4Ig) to achieve high level of immunosuppression in the liver after transplantation. To characterize the pattern of transgene expression following ex vivo gene transfer to the liver and examine whether immunosuppression would promote adenovirus persistence, we followed the life span of vector DNA and transgene expression in the transplanted liver.

METHODS

Rat liver grafts were perfused ex vivo with adenovirus carrying the reporter gene beta-galactosidase (AdlacZ). The period of transgene expression was assessed at predetermined intervals after transplantation into syngeneic, allogeneic or nude (athymic) recipients. Clearance of vector DNA was assessed by PCR analysis of liver DNA after transplantation.

RESULTS

Graft transduction with AdCTLA-4Ig or systemic cyclosporine treatment effectively abrogated the alloimmune response but did not result in sustained lacZ expression. The course of viral DNA clearance from the liver was also unaffected by immunosuppression as was the implied nucleolytic cleavage of viral DNA.

CONCLUSIONS

In the transplant setting, local expression of CTLA-4Ig or systemic immunosuppression does not solve the problem of viral clearance from the liver. Non-adaptive immune mechanisms may have a significant role in the host response to adenovirus after liver transplantation.

Suicide bombing attacks: update and modifications to the protocol

OBJECTIVE

To review the experience of a large-volume trauma center in managing and treating casualties of suicide bombing attacks.

SUMMARY BACKGROUND DATA

The threat of suicide bombing attacks has escalated worldwide. The ability of the suicide bomber to deliver a relatively large explosive load accompanied by heavy shrapnel to the proximity of his or her victims has caused devastating effects.

METHODS

The authors reviewed and analyzed the experience obtained in treating victims of suicide bombings at the level I trauma center of the Hadassah University Hospital in Jerusalem, Israel from 2000 to 2003.

RESULTS

Evacuation is usually rapid due to the urban setting of these attacks. Numerous casualties are brought into the emergency department over a short period. The setting in which the device is detonated has implications on the type of injuries sustained by survivors. The injuries sustained by victims of suicide bombing attacks in semi-confined spaces are characterized by the degree and extent of widespread tissue damage and include multiple penetrating wounds of varying severity and location, blast injury, and burns.

CONCLUSIONS

The approach to victims of suicide bombings is based on the guidelines for trauma management. Attention is given to the moderately injured, as these patients may harbor immediate life-threatening injuries. The concept of damage control can be modified to include rapid packing of multiple soft-tissue entry sites. Optimal utilization of manpower and resources is achieved by recruiting all available personnel, adopting a predetermined plan, and a centrally coordinated approach. Suicide bombing attacks seriously challenge the most experienced medical facilities.

REDUCED INCIDENCE OF HYPERURICEMIA, GOUT, AND RENAL FAILURE FOLLOWING LIVER TRANSPLANTATION IN COMPARISON TO HEART TRANSPLANTATION: A LONG-TERM FOLLOW-UP STUDY

BACKGROUND

Hyperuricemia and gout are common complications of heart transplantation, reaching a prevalence of 84% and 30%, respectively, in heart transplant recipients. In contrast, they are seldom reported following orthotopic liver transplantation (OLT).

METHODS

We retrospectively evaluated 75 consecutive liver transplant recipients and 47 consecutive heart transplant recipients, followed for at least 3 years after transplantation in a single transplantation center in Jerusalem, Israel. Data was collected on demographic and clinical variables, levels of uric acid, the occurrence of gout, renal function, and variables effecting hyperuricemia, such as weight and medications.

RESULTS

Clinical gout was significantly more prevalent in heart recipients than in liver recipients (25.5% and 2.6%, respectively). Hyperuricemia was present in 100% of heart recipients, with an average uric acid level of 451 micromol/l, as compared with 85.7% and 403 micromol/l for liver recipients (P < 0.001 for both variables). Univariate analysis identified several parameters which significantly influenced the difference in hyperuricemia and gout among the two groups including age, gender, rejection episodes, hypertension, diabetes mellitus, the level of uric acid prior to transplantation, and the use of cyclosporine A, diuretics, steroids, and aspirin. Use of tacrolimus and azathioprine were associated with decreased incidence of hyperuricemia and gout. Multivariate analysis identified the type of transplantation as the only independent risk factor predicting the development of hyperuricemia and gout.

CONCLUSION

Clinical gout and hyperuricemia were significantly more prevalent in heart recipients than in liver recipients. The disparity can be explained by differences in age, gender and renal function among the groups, as well as by the use of different medication regimens.

Urinary tract infection: is there a need for routine renal ultrasonography?

AIMS

To assess the yield of routine renal ultrasound (RUS) in the management of young children hospitalised with first uncomplicated febrile urinary tract infection (UTI).

METHODS

All children aged 0-5 years who had been hospitalised over a two year period with first uncomplicated febrile UTI in a medium size institutional regional medical centre were included. Children with known urinary abnormalities and/or who had been treated with antibacterial agents within seven days before admission were excluded. All included children underwent renal ultrasonography during hospitalisation and voiding cystouretrography (VCUG) within 2-6 months. The yield of RUS was measured by its ability to detect renal abnormalities, its sensitivity, specificity, and positive and negative predictive values for detecting vesicoureteral reflux (VUR), and by its impact on UTI management.

RESULTS

Of 255 children that were included in the study, 33 children had mild to moderate renal pelvis dilatation on RUS suggesting VUR, of whom only nine had VUR on VCUG. On the other hand, in 36 children with VUR on VCUG the RUS was normal. The sensitivity, specificity, positive predictive value, and negative predictive value of abnormal RUS for detecting VUR were 17.7%, 87.6%, 23.5%, and 83.2% respectively. In none of the patients with abnormal RUS was a change in the management at or following hospitalisation needed.

CONCLUSION

Results show that the yield of RUS to the management of children with first uncomplicated UTI is questionable.

Toward further expansion of the organ pool for adult liver recipients: splitting the cadaveric liver into right and left lobes

BACKGROUND

Current methods of living donor right lobe transplantation can be expanded for use in the cadaveric setting. The aim of this study is to discuss alternative methods for the management of large-for-size cadaveric livers and determine the feasibility of splitting these organs into left and right hemi-livers using similar techniques to those used in the living donor setting.

METHODS

The indication for an in situ right-left split procedure was an offer of a large liver for a small recipient with a recipient-donor ratio of greater than 1.5. A total of three livers were split. Mean donor age was 33.3 (range, 22-40) years. Mean weight was 118 (range, 90-150) kg. All donors were without significant medical history and were hemodynamically stable, with normal liver function and short hospital stay. Mean duration of the procurement procedure was 235 (range, 210-270) min. Mean cold ischemia time was 8.5 hr. Mean recipient weight was 58.3 kg, and mean donor to recipient weight ratio was 2.0 (1.6-2.6). United Network for Organ Sharing statuses at the time of transplantation were 1 (n=1), 2A (n=1), and 2B (n=4).

RESULTS

Immediate graft function was seen in five recipients. Delayed nonfunction was identified in one recipient of a left lobe, who did not undergo transplantation because of sepsis that resulted in death at 30 days. A second mortality occurred in a left lobe recipient, from a fungal brain abscess at 90 days. Complications related to the split included bile leaks in two patients, one necessitating operative revision.

CONCLUSIONS

Splitting of livers from appropriate brain-dead donors into right and left lobes is technically and logistically feasible. The large-for-size organ provides a more substantial amount of liver tissue to each of the adult recipients, which may result in a greater graft to recipient weight ratio than the current standard that is used in the living donor grafting. The importance of this variable will need to be studied, because it may positively impact on the ability of the reduced-size graft to withstand donor-related organ system stress and injury, which is associated with brain death and the inevitable longer period of cold preservation.

Role of plasmapheresis in the management of acute hepatic failure in children

OBJECTIVE

To assess the efficacy of plasmapheresis in the treatment of children with acute hepatic failure.

SUMMARY BACKGROUND DATA

Acute liver failure is expressed with severe encephalopathy, coagulopathy, and subsequent multisystem organ failure, resulting in a high death rate. Liver transplantation is considered the best option, with long-term 1-year survival rates exceeding 88%. It has been suggested that plasmapheresis may improve coagulopathy and prevent bleeding complications while maintaining adequate fluid, electrolyte, and acid-base balance.

METHODS

Forty-nine patients with acute liver failure underwent a total of 243 therapeutic plasma exchanges (TPE). Indications for treatment included candidacy for liver transplant and prolonged prothrombin time. Pheresis was performed daily until the patient recovered, died, or was transplanted. Four patients were anhepatic during pheresis.

RESULTS

Coagulation profiles after TPE significantly improved compared with mean preexchange values while maintaining euvolemia. No bleeding episodes were observed during the course of treatment. There was no sustained improvement in neurologic function. Spontaneous recovery was observed in three patients; the remaining either underwent transplantation (32/49) or were not considered transplant candidates because of irreversible neurologic insults (11/49) or sepsis (3/49).

CONCLUSION

For children with acute liver failure, TPE is extremely effective in preventing life-threatening bleeding while maintaining appropriate volume status in small children. This method of treatment has no effect on the neurologic complications of liver failure and has no impact on the ability of the liver to regenerate.

Combined colon and hepatic resection for synchronous colorectal liver metastases

BACKGROUND AND OBJECTIVES

The surgical strategy for the treatment of resectable synchronous hepatic metastases of colorectal cancer remains controversial. This study was performed to assess the outcome of combined resection of colorectal cancer and liver metastases.

METHODS

The perioperative data, morbidity, and survival of the patients who underwent combined colon and liver resections for synchronous colorectal liver metastases from 1988 to 1999 were compared to the parameters of the patients who underwent colon resection followed by resection of liver metastases in a staged setting.

RESULTS

198 hepatic resections were performed, of which 112 procedures in 103 patients were done for metastatic colorectal carcinoma. Twenty six patients (25%) had combined hepatic and colon resection and were compared to 86 patients with metachronous metastases who underwent colon and hepatic resection in the staging setting. Postoperative morbidity was 27 and 35%, respectively. There was no hospital mortality in the combined group vs. 2.3% in the staged group. Blood loss, intensive care unit (ICU) stay and length of postoperative stay (LOS) were similar in both groups. The 5 years cumulative survival of the group after combined surgery was 28% vs. 27% of the group after isolated hepatic resections (P = 0.21).

CONCLUSION

Combined colon and hepatic resection is a safe and efficient procedure for the treatment of synchronous colorectal liver metastases. It can be performed with acceptable morbidity and no perioperative mortality. The survival after combined procedure is comparable to the one achieved after staged procedure of colon resection followed by liver resection.

Modified AdCTLA-4 vector blocks alloimmune response in vitro

BACKGROUND

Gene transfer of the costimulatory blockade molecule CTLA-4Ig into cold-preserved rat liver allografts results in indefinite allograft survival. Despite local delivery, this mode of immunomodulation is associated with systemic immunosuppression. In an effort to restrict immunosuppression to the graft, we have constructed a novel adenoviral vector, AdCTLA-4ex-TAG, in which the Ig sequence of CTLA-4Ig DNA has been deleted to destabilize the gene product to promote rapid extrahepatic degradation while maintaining its immunosuppressive activity within the graft milieu.

METHODS

(1) Vector construction. CTLA-4 extracellular binding domain (CTLA-4ex) was prepared by PCR-based cloning methods and fused in frame to a genetic element encoding an epitope TAG allowing identification of the transgene product CTLA-4exTAG. CTLA-4exTAG was subcloned into a shuttle vector enabling isolation of AdCTLA-4exTAG. (2) In vitro transfection: AdCTLA-4exTAG was transfected into MH(1)C(1) cells and then supernatant was recovered for Western blot analysis. (3) In vitro alloimmune response was characterized by CFSE proliferation assay. (4) Extrahepatic effect of AdCTLA-4exTAG was characterized by the ability to control tumor growth after implantation of a regressive, immune sensitive cancer cell line (REGb) in the skin of BDIX rats after liver transduction with AdCTLA-4exTAG.

RESULTS

Expression and secretion of the recombinant protein were documented by Western blot after infection of the MH(1)C(1) cell line() with AdCTLA-4exTAG. Addition of infected MH(1)C(1) cell supernatant resulted in abrogation of alloimmune response as shown by markedly diminished division of CD4(+) T cells in a CFSE proliferation assay. Extrahepatic tumor regressed normally after liver transduction with AdCTLA-4exTAG.

CONCLUSIONS

These results show efficient in vitro expression of CTLA-4exTAG after transfection with AdCTLA-4exTAG. The modified protein retains its ability to abrogate in vitro alloimmune response. Efficient control of extrahepatic tumor growth after liver-directed delivery of AdCTLA-4exTAG suggests that the immunosuppressive effect of this vector is restricted to the liver. These results set the ground for the utilization of this novel adenoviral vector in the transplant setting.

Mallory-Weiss Syndrome: Possible Link to Water Immersion and Subsequent Air Flight

Mallory-Weiss Syndrome (MWS) lesions account for up to 15 per cent of upper gastrointestinal bleeding episodes. Typically these lesions present as a consequence of vomiting that is often associated with alcoholism. Recently other conditions such as pregnancy, migraine, hiatal hernia, gastric ulcer, biliary disease, and various medications have been associated with MWS. We report on a 32-year-old male who developed a MSW lesion after a prolonged period of swimming followed by an extended commercial airplane flight. The hemodynamic changes associated with swimming (increased central distribution of blood volume) and the pressure changes in commercial aircraft (a reduction of 0.3 atmospheres of pressure) are discussed. We conclude that the combination of these factors contributed to the development of a MWS lesion and gastrointestinal bleeding in this patient. We recommend that both air travel and athletic activities be considered as possible contributing factors in the evaluation of the cause of new-onset gastrointestinal bleeding.

Mallory-Weiss syndrome: possible link to water immersion and subsequent air flight

Mallory-Weiss Syndrome (MWS) lesions account for up to 15 per cent of upper gastrointestinal bleeding episodes. Typically these lesions present as a consequence of vomiting that is often associated with alcoholism. Recently other conditions such as pregnancy, migraine, hiatal hernia, gastric ulcer, biliary disease, and various medications have been associated with MWS. We report on a 32-year-old male who developed a MSW lesion after a prolonged period of swimming followed by an extended commercial airplane flight. The hemodynamic changes associated with swimming (increased central distribution of blood volume) and the pressure changes in commercial aircraft (a reduction of 0.3 atmospheres of pressure) are discussed. We conclude that the combination of these factors contributed to the development of a MWS lesion and gastrointestinal bleeding in this patient. We recommend that both air travel and athletic activities be considered as possible contributing factors in the evaluation of the cause of new-onset gastrointestinal bleeding.