Loss of the Rhodobacter capsulatus Serine Acetyl Transferase Gene, cysE1, Impairs Gene Transfer by Gene Transfer Agents and Biofilm Phenotypes.

Biofilms are widespread in the environment, where they allow bacterial species to survive adverse conditions. Cells in biofilms are densely packed, and this proximity is likely to increase the frequency of horizontal gene transfer. Gene transfer agents (GTAs) are domesticated viruses with the potential to spread any gene between bacteria. GTA production is normally restricted to a small subpopulation of bacteria, and regulation of GTA loci is highly coordinated, but the environmental conditions that favor GTA production are poorly understood. Here, we identified a serine acetyltransferase gene, cysE1, in Rhodobacter capsulatus that is required for optimal receipt of GTA DNA, accumulation of extracellular polysaccharide, and biofilm formation. The cysE1 gene is directly downstream of the core Rhodobacter-like GTA (RcGTA) structural gene cluster and upregulated in an RcGTA overproducer strain, although it is expressed on a separate transcript. The data we present suggest that GTA production and biofilm are coregulated, which could have important implications for the study of rapid bacterial evolution and understanding the full impact of GTAs in the environment. IMPORTANCE Direct exchange of genes between bacteria leads to rapid evolution and is the major factor underlying the spread of antibiotic resistance. Gene transfer agents (GTAs) are an unusual but understudied mechanism for genetic exchange that are capable of transferring any gene from one bacterium to another, and therefore, GTAs are likely to be important factors in genome plasticity in the environment. Despite the potential impact of GTAs, our knowledge of their regulation is incomplete. In this paper, we present evidence that elements of the cysteine biosynthesis pathway are involved in coregulation of various phenotypes required for optimal biofilm formation by Rhodobacter capsulatus and successful infection by the archetypal RcGTA. Establishing the regulatory mechanisms controlling GTA-mediated gene transfer is a key stepping stone to allow a full understanding of their role in the environment and wider impact.

The archetypal gene transfer agent RcGTA is regulated via direct interaction with the enigmatic RNA polymerase omega subunit.

Gene transfer agents (GTAs) are small virus-like particles that indiscriminately package and transfer any DNA present in their host cell, with clear implications for bacterial evolution. The first transcriptional regulator that directly controls GTA expression, GafA, was recently discovered, but its mechanism of action has remained elusive. Here, we demonstrate that GafA controls GTA gene expression via direct interaction with the RNA polymerase omega subunit (Rpo-ω) and also positively autoregulates its own expression by an Rpo-ω-independent mechanism. We show that GafA is a modular protein with distinct DNA and protein binding domains. The functional domains we observe in Rhodobacter GafA also correspond to two-gene operons in Hyphomicrobiales pathogens. These data allow us to produce the most complete regulatory model for a GTA and point toward an atypical mechanism for RNA polymerase recruitment and specific transcriptional activation in the Alphaproteobacteria.

Host-specific competitiveness to form nodules in Rhizobium leguminosarum symbiovar viciae.

Fabeae legumes such as pea and faba bean form symbiotic nodules with a large diversity of soil Rhizobium leguminosarum symbiovar viciae (Rlv) bacteria. However, bacteria competitive to form root nodules (CFN) are generally not the most efficient to fix dinitrogen, resulting in a decrease in legume crop yields. Here, we investigate differential selection by host plants on the diversity of Rlv. A large collection of Rlv was collected by nodule trapping with pea and faba bean from soils at five European sites. Representative genomes were sequenced. In parallel, diversity and abundance of Rlv were estimated directly in these soils using metabarcoding. The CFN of isolates was measured with both legume hosts. Pea/faba bean CFN were associated to Rlv genomic regions. Variations of bacterial pea and/or faba bean CFN explained the differential abundance of Rlv genotypes in pea and faba bean nodules. No evidence was found for genetic association between CFN and variations in the core genome, but variations in specific regions of the nod locus, as well as in other plasmid loci, were associated with differences in CFN. These findings shed light on the genetic control of CFN in Rlv and emphasise the importance of host plants in controlling Rhizobium diversity.

A Case-matched Comparative Study of Laparoscopic Versus Open Distal Pancreatectomy.

INTRODUCTION: Although the laparoscopic approach to distal pancreatectomy for benign and malignant diseases is largely replacing open surgery in some centers, well-designed studies comparing these approaches are limited. We present a case-matched study that compares the outcomes of laparoscopic distal pancreatectomy (LDP) to open distal pancreatectomy (ODP). METHODS: Of 112 patients (51 female) who underwent surgery between January 2002 and December 2011, 44 patients were matched on a 1:1 basis (22 LDP, 22 ODP) according to age, sex, and tumor size. Outcomes were compared on an intention-to-treat basis. Data shown represent median where appropriate. RESULTS: The laparoscopic and open groups were comparable for age (57 vs. 59.9 y, P=0.980), sex distribution (P=1.000), tumor size (3 vs. 4 cm, P=0.904), and the frequency of benign versus malignant disease (P=0.920). LDP was associated with significantly lower blood loss (100 vs. 500 mL, P=0.001), higher spleen preservation rate (45% vs. 18%, P=0.029), as well as shorter high dependency unit stay (1 vs. 5 d, P=0.001) and postoperative hospital stay (5 vs. 14 d, P=0.017). There was no significant difference in operating time (245 vs. 240 min, P=0.602) and postoperative morbidity (13.6% vs. 27.2%, P=0.431). In patients with malignant disease, there were no differences in R0 resection margin status (90% vs. 85.7%, P=0.88), the numbers of lymph nodes retrieved (12.7 vs. 14.1, P=0.82), the 1- and 2-year survival rates (89% vs. 81%, P=0.54 and 74.2% vs. 71.5%, P=0.63, respectively), and the mean duration of survival (45 vs. 31 mo, P=0.157). CONCLUSIONS: The laparoscopic approach to distal pancreatectomy offers advantages over open surgery in terms of reductions in operative trauma and duration of postoperative recovery without compromising the oncologic resection.

Source of nitrogen associated with recovery of relative growth rate in Arabidopsis thaliana acclimated to sustained cold treatment.

To determine (1) whether acclimation of carbon metabolism to low temperatures results in recovery of the relative growth rate (RGR) of plants in the cold and (2) the source of N underpinning cold acclimation in Arabidopsis thaliana, we supplied plants with a nutrient solution labelled with (15) N and subjected them to a temperature shift (from 23 to 5 °C). Whole-plant RGR of cold-treated plants was initially less than 30% of that of warm-maintained control plants. After 14 d, new leaves with a cold-acclimated phenotype emerged, with the RGR of cold-treated plants increasing by 50%; there was an associated recovery of root RGR and doubling of the net assimilation rate (NAR). The development of new tissues in the cold was supported initially by re-allocation of internal sources of N. In the longer term, the majority (80%) of N in the new leaves was derived from the external solution. Hence, both the nutrient status of the plant and the current availability of N from external sources are important in determining recovery of growth at low temperature. Collectively, our results reveal that both increased N use efficiency and increases in nitrogen content per se play a role in the recovery of carbon metabolism in the cold.

Perioperative Enteral Immunonutrition Modulates Systemic and Mucosal Immunity and the Inflammatory Response in Patients With Periampullary Cancer Scheduled for Pancreaticoduodenectomy: A Randomized Clinical Trial.

OBJECTIVES: Nutritional deficiencies and immune dysfunction in cancer patients may contribute to postoperative septic morbidity. This trial compared the effects of perioperative enteral immunonutrition (EIN) versus standard enteral nutrition (SEN) on systemic and mucosal immunity in patients undergoing pancreaticoduodenectomy for periampullary cancer. METHODS: Thirty-seven patients were randomized (EIN, n = 17; SEN, n = 20) to receive feed for 14 days preoperatively and 7 days postoperatively. Mediators of systemic immunity (interleukin 1α, tumor necrosis factor α, lymphocytes subsets, and complement components) and of mucosal immunity in duodenal biopsies, nutritional markers and parameters were evaluated. RESULTS: The groups were comparable for demographics, the concentrations of mediators of systemic and mucosal immunity at time of recruitment, and for the duration and amount of feed received. Preoperative EIN rather than SEN was associated with significant reductions in plasma tumor necrosis factor α and total hemolytic complement. Enteral immunonutrition-fed patients had significantly higher total lymphocyte count on the third postoperative day and significantly greater rise in CD4/CD8 ratio from day 3 to day 7 postoperatively compared with SEN-fed patients. CONCLUSIONS: The perioperative administration of EIN rather than SEN is associated with a favorable modulation of the inflammatory response and enhancement of systemic immunity in patients undergoing pancreaticoduodenectomy for periampullary cancer.

Laparoscopic versus open cystgastrostomy for pancreatic pseudocysts: a case-matched comparative study.

BACKGROUND: Cystgastrostomy is the commonest method of internal drainage of pancreatic pseudocysts (PPs). While large and persistent retrogastric pancreatic pseudocysts are amenable to laparoscopic cystgastrostomy, the potential benefits of this minimally invasive laparoscopic approach over open surgery remain to be demonstrated. The aim of this study was to compare the outcomes of the laparoscopic and open approaches for cystgastrostomy. METHODS: Patients who underwent laparoscopic cystgastrostomy (LCG) were matched on a 3:1 basis to those who underwent open cystgastrostomy (OCG) according to age, sex distribution, and size of pseudocyst. The outcomes of the two approaches were compared on an intention-to-treat basis. Data shown represent medians. RESULTS: A total of 54 patients underwent cystgastrostomy (35 LCG, 19 OCG) between 1997 and 2011. The final case matched cohort consisted of 40 patients (12 female and 28 male) of which 30 underwent LCG (two converted to open surgery) and 10 underwent OCG. The laparoscopic and open groups were comparable for age (55 vs. 59 years, P = 0.80), sex distribution, and size of pseudocyst (10 vs. 13 cm, P = 0.51). The laparoscopic approach had a significantly shorter operating time (62 vs. 95 min, P = 0.035) and carried a significantly lower risk of postoperative morbidity (10% vs. 60%, P = 0.024) and shorter postoperative hospital stay (6.2 vs. 11 days, P = 0.038). There was one operative death after OCG (10%). CONCLUSION: The laparoscopic approach to cystgastrostomy for large and persistent retrogastric pancreatic pseudocysts is associated with a shorter operating time, smoother and more rapid recovery, and a shorter hospital stay compared with open surgery. The laparoscopic approach should be considered the preferable approach where expertise is available.

Excess adiposity and survival in patients with colorectal cancer: a systematic review.

Excess adiposity is an established risk factor for incident colorectal cancer (CRC) but whether this association extrapolates to poorer survival is unclear. We undertook a systematic review to examine relationships between measures of adiposity and survival in patients with CRC. For distinction, we included pre-diagnosis exposure and CRC-related mortality. We performed dose-response meta-analyses and assessed study quality using eight domains of bias. Six study categories were identified based on (i) timing of adiposity measurement relative to survival analysis time zero and (ii) clinical setting. Several types of adiposity measurements were reported; body mass index (BMI) was the commonest. For pre-diagnosis cohorts, baseline BMI negatively impacted on CRC-related mortality in men only (risk estimate per 5 kg m(-2) = 1.19, 95% confidence intervals: 1.14-1.25). The other groups were pre-diagnosis BMI but diagnosis as time zero; population-based cohorts; treatment cohorts; observational analyses within adjuvant chemotherapy trials; patients with metastatic CRC - each had several biases (e.g. treatment selection, reverse causality) and sources of confounding (e.g. chemotherapy 'capping'). Overall, there was insufficient evidence for a strong link between adiposity and survival. These findings demonstrate an important principle: an established link between an exposure (here, adiposity) and increased cancer incidence does not necessarily extrapolate into an inferior post-treatment outcome.

Early Experience with a Hepatobiliary and Pancreatic Quality Improvement Program.

This project aims to assess the impact of the introduction of a hepatobiliary and pancreatic (HPB) Quality Improvement Program (QIP) on postoperative complications following liver, biliary and pancreatic surgery. A prospective analysis of postoperative complications over a six month period was performed. Complications were analysed and graded according to internationally agreed definitions. Justification was sought and errors identified. Weekly meetings were performed to review each complication enabling an action plan to be created to prevent future recurrence. Rates were compared with previously audited and published results, using the chi-square test. A total of 326 procedures were performed over the six months including 30 pancreatectomies, 45 liver resections and 251 other procedures. 37 patients developed complications (11.3%) with 47 complications in total including two deaths. Using the ISGPS grading, eight complications were identified; two grade A, four grade B and two grade C. There were three grade A ISGLS complications and one grade B. 30 complications were justified as unavoidable, 16 as avoidable and one as indeterminate. Action plans included continued monitoring (n=41), formulation of new policy (n=3), individual counselling (n=4), educational offering (n=4). When compared with 2010 complication rates, 114 complications occurred in 233 liver operations during the baseline period, compared with 17 complications in 45 liver operations during the QIP period, OR=0.63 (95% CI: 0.33 to 1.22), p=0.17 and 86 complications occurred in 99 pancreatic resections during the baseline period, compared with 20 complications in 30 pancreatic resections during the QIP period OR=0.30 (95% CI: 0.12 to 0.79), p=0.01 The HPB QIP is a rigorous approach to grade every complication and death. A statistically significant reduction in pancreas related complications has already been obtained. Further work is required to determine the persistence and magnitude of this quality improvement.

Complications arising in simple and polycystic liver cysts.

Liver cysts are common, affecting 5%-10% of the population. Most are asymptomatic, however 5% of patients develop symptoms, sometimes due to complications and will require intervention. There is no consensus on their management because complications are so uncommon. The aim of this study was to perform a collected review of how a series of complications were managed at our institutions. Six different patients presenting with rare complications of liver cysts were obtained from Hepatobiliary Units in the United Kingdom and The Netherlands. History and radiological imaging were obtained from case notes and computerised radiology. As a result, 1 patient admitted with inferior vena cava obstruction was managed by cyst aspiration and lanreotide; 1 patient with common bile duct obstruction was first managed by endoscopic retrograde cholangiopancreatography and stenting, followed by open fenestration; 1 patient with ruptured cysts and significant medical co-morbidities was managed by percutaneous drainage; 1 patient with portal vein occlusion and varices was managed by open liver resection; 1 patient with infected cysts was treated with intravenous antibiotics and is awaiting liver transplantation. The final patient with a simple liver cyst mimicking a hydatid was managed by open liver resection. In conclusion, complications of cystic liver disease are rare, and we have demonstrated in this series that both operative and non-operative strategies have defined roles in management. The mainstays of treatment are either aspiration/sclerotherapy or, alternatively laparoscopic fenestration. Medical management with somatostatin analogues is a potentially new and exciting treatment option but requires further study.

Two out of three required: a case of incomplete Carney triad.

A 48-year-old woman presented with chest symptoms. Multiple lesions seen on chest imaging were found to be pulmonary chondromas following surgical resection. Whole body magnetic resonance scan performed to investigate the possibility of Carney triad demonstrated a gastric lesion. This was resected and found to be a gastrointestinal stromal tumor. No evidence of paragangliomata was found on imaging. A diagnosis of incomplete Carney triad was made. Carney triad is a rare multiple neoplastic association of pulmonary chondroma, gastrointestinal stromal tumor, and paraganglioma. At least 2 tumors are required for diagnosis. Most patients are young women. No genetic cause has been identified. Management involves surgical resection of tumors and follow-up for recurrence and investigation for other elements of the triad.

Improving Outcomes with Surgical Resection and Other Ablative Therapies in HCC.

With rising incidence and emergence of effective treatment options, the management of hepatocellular carcinoma (HCC) is a complex multidisciplinary process. There is still little consensus and uniformity about clinicopathological staging systems. Resection and liver transplantation have been the cornerstone of curative surgical treatments with recent emergence of ablative techniques. Improvements in diagnostics, surgical techniques, and postoperative care have lead to dramatically improved results over the years. The most appropriate treatment plan has to be individualised and depends on a variety of patient and tumour-related factors. Very small HCCs discovered on surveillance have the best outcomes. Patients with advanced cirrhosis and tumours within Milan criteria should be offered transplantation. Resection is best for small solitary tumours with preserved liver function. Ablative techniques are suitable for low volume tumours in patients unfit for either resection or transplantation. The role of downstaging and bridging therapy is not clearly established.

Treatment options for symptomatic degenerative joint disease secondary to Legg-Calvé-Perthes disease.

The treatment options for neglected Legg-Calvé-Perthes disease (LCPD) leading to symptomatic degenerative joint disease always have posed a challenge for the orthopedic surgeon. In addition, the literature is disorganized in this regard. Therefore, a structured literature review of the treatment options for the symptomatic sequelae of LCPD, especially in the context of joint replacement and resurfacing, is very much needed.

International multicentre prospective study on microwave ablation of liver tumours: preliminary results.

BACKGROUND: Microwave ablation (MWA) is increasingly utilized in the treatment of hepatic tumours. Promising single-centre reports have demonstrated its safety and efficacy, but this modality has not been studied in a prospective, multicentre study. METHODS: Eighteen international centres recorded operative and perioperative data for patients undergoing MWA for tumours of any origin in a voluntary Internet-based database. All patients underwent operative MWA using a 2.45-GHz generator with a 5-mm antenna. RESULTS: Of the 140 patients, 114 (81.4%) were treated with MWA alone and 26 (18.6%) were treated with MWA combined with resection. Multiple tumours were treated with MWA in 40.0% of patients. A total of 299 tumours were treated in these 140 patients. The median size of ablated lesions was 2.5 cm (range: 0.5-9.5 cm). Tumours were treated with a median of one application (range: 1-6 applications) for a median of 4 min (range: 0.5-30.0 min). A power setting of 100 W was used in 78.9% of cases. Major morbidity was 8.3% and in-hospital mortality was 1.9%. CONCLUSIONS: These multi-institution data demonstrate rapid ablation time and low morbidity and mortality rates in patients undergoing operative MWA with a high rate of multiple ablations and concomitant hepatic resection. Longterm follow-up will be required to determine the efficacy of MWA relative to other forms of ablative therapy.

Pancreatoduodenectomy as a source of human small intestine for Ussing chamber investigations and comparative studies with rat tissue.

A clear understanding of oral drug absorption is an important aspect of the drug development process. The permeability of drug compounds across intact sections of small intestine from numerous species, including man, has often been investigated using modified Ussing chambers. The maintenance of viable, intact tissue is critical to the success of this technique. This study therefore aimed to assess the viability and integrity of tissue from patients undergoing pancreatoduodenectomy, for use in cross-species Ussing chamber studies. Electrical parameters (potential difference, mV; short-circuit current, µA.cm(-2) ; resistance, Ω.cm(2) ) were monitored over the duration of each experiment, as was the permeability of the paracellular marker atenolol. The permeability values (Papp; cm/s × 10(-6) ) for a training-set of compounds, displaying a broad range of physicochemical properties and known human fraction absorbed values, were determined in both rat and human jejunum, as well as Caco-2 cell monolayers. The results indicate that human jejunum sourced from pancreatoduodenectomy remained viable and intact for the duration of experiments. Permeability values generated in rat and human jejunum correlate well (R(2) = 0.86), however the relationship between permeability in human tissue and Caco-2 cells was comparatively weak (R(2) = 0.58). Relating permeability to known human fraction absorbed (hFabs) values results in a remarkably similar relationship to both rat and human jejunum Papp values. It can be concluded that human jejunum sourced from pancreatoduodenectomy is a suitable source of tissue for Ussing chamber permeability investigations. The relationship between permeability and hFabs is comparable to results reported using alternative test compounds.

A modified Jones procedure for managing clawing of lesser toes in pes cavus: long-term follow-up in 8 patients.

UNLABELLED: Pes cavus is a complex foot deformity in which surgical correction remains challenging. We treated lesser-toe clawing in 11 feet of 8 patients (5 women, 1 bilateral; 3 men, 2 bilateral) with a modified Jones procedure and assessed long-term functional outcomes. We reviewed case notes and completed the Bristol Foot Score, the modified American Orthopaedic Foot & Ankle Society Midfoot Score, and a patient satisfaction questionnaire by means of telephone interviews. Mean age of the patients at the time of surgery was 30 years (range, 10-58 years). Mean time from surgery to the last clinical follow-up was 7 years (range, 0.5-17 years), and mean time from surgery to the telephone interview was 9 years (range, 1-18 years). At the final clinical review, all 11 feet were improved, although 6 had minor complications. The mean Bristol Foot Score was 27 (range, 16-55), and the mean modified American Orthopaedic Foot & Ankle Society Midfoot Score was 76 (range, 47-90), indicative of excellent results. Half of the patients had mild persistent foot pain, but all were satisfied with the outcome. Based on our experience with this group of patients, the modified Jones procedure yields satisfactory correction of lesser toe clawing in patients with flexible pes cavus. LEVEL OF CLINICAL EVIDENCE: 4.

Immune evasion mechanisms in colorectal cancer liver metastasis patients vaccinated with TroVax (MVA-5T4).

We have recently reported the results of a phase II trial in which two TroVax [modified vaccinia ankara (MVA) encoding the tumour antigen 5T4] vaccinations were given to patients both pre- and post-surgical resection of liver metastases secondary to colorectal cancer (CRC). 5T4-specific cellular responses were assessed at the entry and 2 weeks after each vaccination by proliferation of fresh lymphocytes and ELISA for antibody responses; 18 from the 19 CRC patients mounted a 5T4-specific cellular and/or humoral response. Here, we present a comparison of individual and between patient responses over the course of the treatments using cryopreserved peripheral blood mononuclear cells (PBMC) samples from the baseline until after the fourth vaccination at 14 weeks. Assays used were proliferation assay with 5T4-Fc fusion protein, overlapping 32mer 5T4 peptides, MVA-LacZ and MVA-5T4 infected autologous monocytes. Responses to 5T4 protein or one or more peptide pools were pre-existing in 12/20 patients and subsequently 10 and 12 patients showed boosted and/or de novo responses, respectively. Cumulatively, 13/20 patients showed proliferative responses by week 14. We also assessed the levels of systemic T regulatory cells, plasma cytokine levels, phenotype of tumour-infiltrating lymphocytes including T regulatory cells and tumour HLA class I loss of expression. More than half of the patients showed phenotypes consistent with relative immune suppression and/or escape highlighting the complexity of positive and negative factors challenging any simple correlation with clinical outcome.

Temperature dependence of respiration in roots colonized by arbuscular mycorrhizal fungi.

* The arbuscular mycorrhizal (AM) symbiosis is ubiquitous, and the fungus represents a major pathway for carbon movement in the soil-plant system. Here, we investigated the impacts of AM colonization of Plantago lanceolata and temperature on the regulation of root respiration (R). * Warm-grown AM plants exhibited higher rates of R than did nonAM plants, irrespective of root mass. AM plants exhibited higher maximal rates of R (R(max)-R measured in the presence of an uncoupler and exogenous substrate) and greater proportional use of R(max) as a result of increased energy demand and/or substrate supply. The higher R values exhibited by AM plants were not associated with higher maximal rates of cytochrome c oxidase (COX) or protein abundance of either the COX or the alternative oxidase. * Arbuscular mycorrhizal colonization had no effect on the short-term temperature dependence (Q(10)) of R. Cold-acclimated nonAM plants exhibited higher rates of R than their warm-grown nonAM counterparts. By contrast, chilling had a negligible effect on R of AM-plants. Thus, AM plants exhibited less cold acclimation than their nonAM counterparts. * Overall, these results highlight the way in which AM colonization alters the underlying components of respiratory metabolism and the response of root R to sustained changes in growth temperature.

An MVA-based vaccine targeting the oncofetal antigen 5T4 in patients undergoing surgical resection of colorectal cancer liver metastases.

We investigated the use of a therapeutic vaccine, TroVax in patients undergoing surgical resection of colorectal cancer liver metastases. Systemic immunity generated by vaccination before and after resection of metastases was measured in addition to assessing safety and analyzing the function and phenotype of tumor-associated lymphocytes. Twenty patients were scheduled to receive 2 TroVax vaccinations at 2-week intervals preoperatively and 2 postoperatively; if immune responses were detected, 2 further vaccinations were offered. Blood was taken at trial entry and 2 weeks after each vaccination; tumor biopsies were collected at surgery. 5T4-specific cellular responses were assessed by lymphocyte proliferation and enzyme-linked immunosorbent spot, with antibody responses by enzyme-linked immunosorbent assay. Immunohistochemistry characterized the phenotype of tumor-infiltrating lymphocytes. Seventeen of 19 colorectal cancer patients showed 5T4 expression in the liver metastases or surrounding stroma and 18 mounted a 5T4-specific cellular and/or humoral response. In patients who received at least 4 vaccinations and potentially curative surgery (n=15), those with above median 5T4-specific proliferative responses or T-cell infiltration into the resected tumor showed significantly longer survival compared with those with below median responses. Seven of 8 patients who had preexisting proliferative responses to 5T4 were longer-term survivors; these patients showed significantly higher proliferative responses after vaccination than those who subsequently died. These data suggest that the magnitude of 5T4 proliferative responses and the density of CD3 cells in colorectal cancer liver metastases are associated with longer survival. These observations warrant more studies to identify the precise underlying mechanisms.