A59 GLOBAL PROTEOMIC PROFILING OF HUMAN COLONOID MONOLAYERS UNDERGOING IN VITRO CHRONIC DAMAGE

Background

An in vitro damage model has been established in our lab using human colonoids grown as 2D monolayers. Upon being subjected to repeated rounds of air-liquid interface (ALI) growth and injury by submergence, these colonoid monolayers lost their barrier integrity and regrowth potential. Changes in mRNA expression and DNA methylation in genes from this human model of injury were similar to those that occur in Inflammatory Bowel Disease (IBD) and colon cancer. Significant morphological changes were observed in these monolayers after they were subjected to subsequent rounds of submergence injury, compared to when they were differentiated in ALI.

Purpose

Submergence injury is predicted to be involved in unfolded protein response (UPR) activation which can specifically alter translation. Hence proteomics studies will help undertand these changes.

Method

To determine if these changes are mirrored in the proteomes of damaged colonoids, we employed a Single-Plot, Solid-Phase-enhanced Sample Preparation (SP3) technology for Mass Spectrometry (MS) based proteomics analysis to characterize these monolayers at baseline, once they were differentiated in ALI, after one and five rounds of injury after differentiation in ALI, and after stimulation with the Toll-like receptor 5 (TLR5) agonist FliC. Hierarchical clustering, enrichment analysis, volcano plot analysis after pre-processing and normalization of the proteomics data set revealed differentially expressed proteins across various groups of monolayers.

Result(s)

Preliminary proteomic data analysis revealed changes in the profile of proteins involved in cellular differentiation, mitochondrial proteins, hypoxia upregulated proteins, those responsible for the maintenance and reorganization of the cytoskeletal structure and Golgi structure. These changes in protein profile may account for the significant morphological changes observed in these monolayers when subjected to submergence injury. Some outliers in monolayers subjected to microbial stimulation included proteins involved in regulation of extracellular matrix dependent motility and components of Adaptor Protein Complexes. Further studies are needed to ascertain if these account for the protective effect of FliC on these monolayers.

Conclusion(s)

This study suggests that the submergence injury to these healthy human derived colonoid monolayers leads to changes in their protein profile which mirror those seen in case of acute and chronic inflammation like IBD and colon cancer. It corroborates with the findings of gene expression and epigenetic analyses using the in vitro model established in our lab.

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Disclosure of Interest

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Experience with Use of the Oncotype DX Gene Assay Test in a Multicenter Community-Based Healthcare System

Background:Oncotype DX has been validated to quantify the risk of distant recurrence and predict the benefit of chemotherapy (CT) in ER positive, node negative breast cancer treated with tamoxifen. A retrospective study was undertaken to assess the use of the Oncotype DX test at Intermountain Healthcare. Intermountain is a not-for-profit healthcare system with 21 inpatient facilities, 9 comprehensive cancer centers and 42 affiliated medical oncologists ranging from single practitioners to multiphysician groups.Methods: This study contains a group of T1-3 N0 ER+ breast cancer patients who received an Oncotype DX test paired with a control group of non-tested T1-T3 N0 ER+ patients receiving hormone therapy (HT) from the same period. Data comes from a supplemental database containing treatment and follow-up data from individual physician offices combined with data from Intermountain's cancer registry. To ensure data completeness, Genomic Health provided a list of relevant Oncotype DX results for study patients. The analysis was done using multivariate logistic regression and controlled for age, tumor size, grade and T stage.Results: From 2005 to 2008, Oncotype DX testing was performed on tumor specimens from 285 patients. 8 patients had positive nodes and 4 patients were ER negative. In addition, 9 patients did not and will not receive HT (5 refused, 4 contraindicated) and 9 patients have yet to begin HT. 11 patients were lost to follow-up. Of the remaining 244 patients who form the study group, six patients were Her-2 neu positive (1 high recurrence score (RS), 3 intermediate and 2 low). Tumor size ranged from <1 cm to 7 cm, but 80% were <2 cm. 120 study patients (49%) had a low RS, 95 (39%) intermediate and 29 (12%) high. Only 2% of patients in the low RS group received CT, whereas 93% of patients in the high RS group and 40% in the intermediate RS group received CT.An analysis of potential factors affecting CT treatment decision making in the intermediate RS group showed that 60% of the 15 patients under age 50 received CT, compared to 36% of the 80 patients age 50 and over. CT was given in 35% of grade 1, 40% of grade 2 and 50% of grade 3 tumors. 43% of patients with a <1 cm tumor received CT compared to 42% of 1-2 cm tumors and 28% of tumors >2 cm. Compared to our control group of 688 patients, Oncotype DX-tested patients are younger (p<0.01), less likely to have T1a (p=0.03), more likely to have T1c (p<0.01) or T2 (p=0.03) tumors and less likely to undergo CT (p<0.01). Low RS patients are less likely to receive CT (p<0.01) and high RS patients more likely to receive CT (p<0.01), whereas intermediate RS patients showed no significant difference (p=0.07) but were trending toward receiving less CT than the control group.Conclusions:Virtually all patients with a low RS received only HT, while most patients with a high RS also received CT. In patients with an intermediate RS, younger age and higher grade may impact clinicians' decisions to administer CT, while a larger tumor size does not. Overall, patients undergoing Oncotype DX testing are less likely to receive CT. These data indicate that the use of Oncotype DX testing facilitated appropriate therapeutic decisions in most patients.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 6058.

Myocardial metabolic monitoring with the microdialysis technique during and after open heart surgery

BACKGROUND

Post-operative ischemia after coronary artery bypass grafting (CABG) is well described but effective intervention requires immediate diagnosis. One possible way of increasing efficacy of peri-operative myocardial monitoring is using the microdialysis technique.

METHODS

In 30 patients undergoing routine CABG, a microdialysis catheter was inserted in the left heart in an area of abnormal ventricular contraction. A second catheter was placed in normal tissue of the right ventricle. Microdialysis measurements were performed at time intervals before, during and 24 h after cardiopulmonary bypass (CPB) and retrospectively compared with standard clinical monitoring and clinical course.

RESULTS

During CPB, both ventricles showed signs of poor tissue oxygenation. Glycerol was significantly higher in the left myocardium (146 +/- 67 vs. 72 +/- 36 micromol/l) and the glucose/lactate ratio (GLR), as a marker of nutritional disorder of the right ventricle (41 +/- 15% vs. 67 +/- 17%, P < 0.05), had significantly better values at this time point. Myocardial lactate concentrations were significantly higher in the dyskinetic segments (2.82 +/- 0.81 vs. 1.5 +/- 0.81 microM). During this period, no abnormal clinical standard monitoring results were observed. Post-operative significantly increased lactate/pyruvate ratios of three patients were clinically associated with peri-operative myocardial infarction (108 +/- 67 vs. 38 +/- 9, P < 0.05). The lactate/pyruvate ratio started rising before any other standard monitoring tools showed abnormal values.

CONCLUSIONS

Peri-operative microdialytic measurements of parameters related to ischemia can be safely performed in a clinical setting, resulting in faster and more reliable detection of ongoing or new ischemia.

Detection of Helicobacter pylori specific DNA in human atheromatous coronary arteries and its association to prior myocardial infarction and unstable angina

BACKGROUND

Chronic infections have been proposed to play a role in the aetiology or progression of atherosclerotic plaques. Increased risk of coronary artery disease has been suggested in patients seropositive for Helicobacter pylori.

AIM

To analyse coronary specimens in patients with severe (coronary artery disease) for Helicobacter pylori specific DNA.

PATIENTS AND METHODS

Atherosclerotic plaques were obtained in 46 consecutive patients (9 female, 37 male, mean age 62.7+/-9.17 years) during coronary bypass procedures. Serum was analysed for IgG -/cagA-antibodies specific for Helicobacter pylori. Polymerase chain reaction and sequence analysis were used to identify bacterial DNA. Coronary artery biopsies from 19 autopsies without coronary artery disease were examined as a control group.

RESULTS

Of the 46 coronary artery disease patients, 32 (69.6%) were Helicobacter pylori seropositive. Positive results for Helicobacter pylori DNA showed 18 seropositive and 4 seronegative (with anamnesis of eradication therapy). A total of 22 patients (47.8%) of the coronary artery disease group but none of controls revealed positive DNA. In the coronary artery disease group, a correlation between DNA presence and prior myocardial infarction (p=0.008) and unstable angina (p<0.001) was found.

CONCLUSION

Identification of DNA in atherosclerotic plaques of patients with severe coronary artery disease supports the hypothesis that Helicobacter pylori infection may influence the development of atherosclerosis. Our results may indicate an direct involvement of Helicobacter pylori in the progression and instability of plaques in these patients.

Genomic-scale analysis of gene expression in resting and activated T cells

Recent advances in gene array technology and isolation of lymphocytes now allow comprehensive analysis of gene expression in many different types of T cells. So far only a few sets of results have been published. However it is already clear that these analyses provide accurate measurements of gene expression in T cells. This technology offers the first opportunity to examine global and subtle changes in gene expression in response to specific stimuli.

Routine minimal invasive vein harvesting reduces postoperative morbidity in cardiac bypass procedures. Clinical report of 1400 patients

OBJECTIVE

Minimal invasive endoscopic vein harvesting has not gained widespread acceptance although potential improvements in wound healing and patient comfort are undebatable. The main objections to routine application have been impaired graft quality and prolonged operation time. The feasibility of introducing the minimal invasive approach to vein harvesting into a high volume cardiac bypass surgery program was to be investigated in 1400 patients.

METHODS

Our preferred technique is based on standard videoscopic equipment for endoscopic surgery. No disposables are used. The subcutaneous tissue above the saphenous vein is tunnelled by exclusively sharp dissection. No shear stresses are applied to the vein graft or its side branches. Side branches are closed by clips or bipolar coagulation. The differences between endoscopic and conventional surgical vein harvesting with regard to operation time, graft quality, wound healing disturbances and postoperative pain were compared in two groups of 300 concurrently operated patients. Subsequently, a further 1100 patients underwent endoscopic vein harvesting, giving a total experience of 1400 endoscopic procedures.

RESULTS

After a learning curve of approximately 100 procedures for an experienced surgeon, harvesting time using minimal invasive techniques was 16 +/- 4 min/graft vs. 10 +/- 2 min for the conventional technique (P < 0.01). Severe wound healing disturbances requiring re-intervention were observed in 0.1% following endoscopic harvesting, moderate wound healing disturbances were observed in 1.7% of patients. By comparison, conventional harvesting led to severe wound healing disturbances in 5% and to moderate disturbances in 8% (P < 0.05). Incidence of peri-operative myocardial infarction as an indirect measure of graft quality was 1.7% with endoscopic vs. 2.3% (n.s.) with conventional technique. Early postoperative mobilisation was faster, pain and need of analgesics were distinctly reduced in patients with endoscopic harvesting. Overall operation time was not significantly prolonged by the described technique.

CONCLUSIONS

Minimal invasive endoscopic vein harvesting can be developed into a routine procedure resulting in a lower incidence of wound complications, less postoperative pain and much superior cosmetic results. Graft quality appears to be comparable to standard saphenectomy. There is, however, a higher demand of surgical training and expertise.

Activation changes the spectrum but not the diversity of genes expressed by T cells

During activation T cells are thought to change their patterns of gene expression dramatically. To find out whether this is true for T cells activated in animals, the patterns of genes expressed in resting T cells and T cells 8 and 48 hr after activation were examined by using Affymetrix gene arrays. Gene arrays gave accurate comparisons of gene expression in the different cell types because the expression of genes known to vary during activation changed as expected. Of the approximately 6,300 genes assessed by the arrays, about one-third were expressed to appreciable extents in any of the T cells tested. Thus, resting T cells express a surprisingly large diversity of genes. The patterns of gene expression changed considerably within 8 hr of T cell activation but returned to a disposition more like that of resting T cells within 48 hr of exposure to antigen. Not unexpectedly, the activated T cells expressed genes associated with cell division at higher levels than resting T cells. The resting T cells expressed a number of cytokine receptor genes and some genes thought to suppress cell division, suggesting that the state of resting T cells is not a passive failure to respond to extant external stimuli.

An inverse relationship between T cell receptor affinity and antigen dose during CD4(+) T cell responses in vivo and in vitro

Multimeric peptide/class II MHC staining reagents were synthesized and shown to bind with appropriate specificity to T cell hybridomas. A small, expanded population of T cells detected with one of these reagents in peptide-immunized C57BL/10 mice persisted for several months. This population expanded further on secondary immunization. Equating the extent of binding of this reagent to T cell receptor affinity, we saw little correlation of immunizing peptide dose to T cell receptor affinity at the peak of the primary response. However, there was an inverse relation between peptide dose and the apparent receptor affinity of the T cells that were present several months after a primary response or after a secondary stimulation either in vivo or in vitro.

The use of hypnosis in gastroscopy: a comparison with intravenous sedation

A total of 124 subjects who were undergoing routine endoscopy were randomly assigned to one of three groups. All three groups received lignocaine throat spray. The first group additionally received midazolam, the second received hypnosis, whilst the third only received lignocaine throat spray. Although hypnotized patients were deemed by an independent observer to be less agitated than the other two groups (p < 0.03), they reported the gastroscopy to be significantly more uncomfortable (p < 0.042) and scored higher in their memory for the procedure (p < 0.001). They also took slightly longer to induce than the midazolam group. The midazolam group on the other hand rated the procedure as significantly more comfortable although paradoxically were seen by an independent observer as being more agitated. They were also significantly more amnesic. The endoscopist encountered more procedural difficulties with this group but this did not reach levels of significance. Hypnosis was not shown to be an effective alternative to intravenous sedation in gastroscopy.

Primary antibody deficiency and Crohn's disease

Five patients with primary antibody deficiency were investigated because of intermittent but persistent diarrhoea of several years duration despite immunoglobulin replacement therapy. We found no evidence of Giardia lambia or other intestinal pathogens to explain their gastrointestinal symptoms. All five had definite radiological evidence of small bowel Crohn's disease and three had histological specimens available with abnormalities consistent with Crohn's disease. One patient had a non-caseating granuloma in an oral ulcer. A second patient with stricturing disease in the small bowel had a mucosal inflammatory infiltrate with non-caseating granulomas. A third had transmural inflammation but no granulomas. All five patents were diagnosed as having Crohn's disease and have responded symptomatically to steroid therapy.

Role of acid and salivary epidermal growth factor in gastric mucosal adaptation to naproxen in man

BACKGROUND

Non-steroidal anti-inflammatory drugs (NSAIDs) frequently damage the gastrointestinal tract, but with continued administration this usually resolves by a process of adaptation. There is evidence that the acute injury can be reduced by acid suppression, and animal models have shown that salivary epidermal growth factor (EGF) is an important factor in gastric mucosal adaptation. We therefore wanted to assess the effect of acid suppression and salivary EGF output during naproxen-induced acute gastric injury and subsequent adaptation.

METHODS

Healthy subjects were given a 14-day course of naproxen with different regimens of ranitidine and placebo. Before and on three occasions during treatment subjects provided a salivary sample for EGF and underwent gastroscopy to assess gastric damage.

RESULTS

Similar gastric damage occurred after 24 h in all groups and resolved in most subjects. Base-line salivary EGF output was similar in all groups but increased in the placebo/ranitidine group on day 3 and in the ranitidine group on day 9.

CONCLUSIONS

Acid suppression with ranitidine did not prevent acute gastric injury. Adaptation may be associated with an increase in salivary EGF output.

Percutaneous dilatational tracheostomy done early after cardiac surgery--outcome and incidence of mediastinitis

During November 95 to April 97, 45 percutaneous dilatational tracheostomies were performed in a nonselected patient series of 2788 open cardiac surgery cases. Tracheostomy was performed as early as the 2nd postoperative day (median: 6th day), when extubation was not foreseen within the next few days. Duration of intubation was 13 days (mean). We observed 6 complications in 5 patients (13.3%), namely bleeding, misplacement of the tube, subcutaneous emphysema, and superficial infection of the tracheostoma. Mediastinitis and wound infection of the sternal wound did not occur in any single case. There was no death due to tracheostomy. Clinically evident tracheal stenosis and inadequate granulation of the stoma were not observed after extubation. In our opinion, percutaneous dilatational tracheostomy is justifiable, shows good results, and entails minimal risk if done early after cardiac surgery, and it is also superior to standard surgical tracheostomy. Increased incidence of mediastinitis was not seen.

T cells can be activated by peptides that are unrelated in sequence to their selecting peptide

We tested the ability of CD4+ T cells, selected in the thymus by reaction with class II protein bound to a single peptide, to react with the same class II protein bound to other peptides. The T cells reacted with all peptides tested, including one that was quite unlike the selecting peptide in T cell receptor binding residues. The receptors on class II/peptide-reactive T cells from class II/single peptide mice were similar but not identical to some of those from normal animals. Thus, class II bound to a single peptide selects a subset of T cells that is related to that selected by class II bound to many peptides.

A prospective study of abdominal computerized tomography and colonoscopy in the diagnosis of colonic disease in an elderly population

OBJECTIVE

The aim of this prospective study was to compare the accuracy of abdominal computed tomography (CT) and colonoscopy in diagnosing colonic pathology in an elderly population.

METHODS

Patients over the age of 70 for whom an outpatient diagnostic colonoscopy had been requested, were invited to attend for a CT scan of the abdomen following oral colonic preparation. CT was carried out within 1 month of the colonoscopy and all images were evaluated by a single consultant radiologist with no prior knowledge of the colonoscopy result.

RESULTS

Of 72 patients who fulfilled entry criteria and attended for colonoscopy, 55 (29 female) had abdominal CT of the abdomen (mean age 76.6 years, range 70-92). Colonoscopy was successful in 67% of cases and the following colonoscopic diagnoses were made: diverticular disease (26), normal (14), colonic carcinoma (6), polyps (9) colitis (2) and angiodysplasia (1). There was agreement between colonoscopic and CT diagnoses in 38 patients (69%) including all those with carcinoma of the colon. There was disagreement in 12 patients with diverticular disease, CT missed three polyps in three patients and angiodysplasia in one patient. CT provided additional important information in 9 patients: gastric leiomyosarcoma (1), aortic aneurysm (1), absence of metastases (3), liver metastases (2), cirrhosis and portal hypertension (1) and a large pleural effusion (1). One patient thought to have a carcinoma of the colon by both techniques was subsequently found to have a diverticular mass at laparotomy. Two patients undergoing colonoscopy had colonic perforations and one of these died.

CONCLUSION

CT may provide an alternative to colonoscopy in diagnosis of colonic disease in the elderly population.

[Primary cutaneous Nocardia farcinica infection following heart transplantation]

A 57-year-old man, treated with immunosuppressive drugs for 3 months after a heart transplantation, developed a painful swelling of the left upper leg and fever. Needle biopsy of the lesion obtained pus from which Nocardia farcinica was cultured. Azathioprine treatment was discontinued and the dosage of cyclosporine reduced. Following antibiotic sensitivity tests, imipenem (4 g/d intravenously) and amikacin (1 g/d intravenously) were administered and the abscess split open. Although the fever responded and dissemination of the infection was excluded the response to treatment was not satisfactory. The drug dosages were repeatedly reduced in response to a rise in serum creatinine concentration to 3.4 mg/dl, deafness, double vision and generalized seizures: the local lesion got worse, but further surgical intervention then brought improvement. After 7 weeks of administration of the above antibiotics, treatment was changed to doxycycline (100 mg/d by mouth). 3 months later computed tomography could no longer demonstrate the lesion.

Obstructive bronchial aspergillosis after heart transplantation

Obstructive bronchial aspergillosis is a rarely observed consequence of Aspergillus infection. It occurs not only in patients with the acquired immunodeficiency syndrome (AIDS), but also after heart transplantation (HTx) if T cells are reduced markedly by the application of antithymocyte globulin (ATG) in addition to immunosuppression with corticosteroids. In contrast to invasive aspergillosis or Aspergillus tracheobronchitis, the course of this form of Aspergillus infection may not be accompanied by symptoms, because bronchial inflammation with pseudomembranes, ulcers or destruction of mucosa and intrapulmonary infiltrates are absent. To prevent invasive aspergillosis following HTx, intensive antifungal therapy is necessary in cases of bronchial obstructive aspergillosis, because this form of Aspergillus infection seems to represent a stage before recognizable invasive disease, as in other immunocompromised patients.

Heart transplantation in patients with muscular dystrophy associated with end-stage cardiomyopathy

Until now, patients with muscular dystrophy and concomitant cardiomyopathy have been accepted for heart transplantation only reluctantly, because of a higher perioperative risk caused by physical disability and a suspected rapid onset of cardiomyopathy of the transplanted heart. Of a total of 582 heart transplant recipients, six patients had muscular dystrophy associated with end-stage cardiomyopathy. In three patients, preoperative neurologic diagnostic investigation revealed type Duchenne muscular dystrophy (three male); one female patient had Emery-Dreifuss; one male patient had Becker-Kiener dystrophy, and the specific classification could not be established in one male patient. Mean age was 25 years, ranging from 9 to 45 years. The postoperative follow-up ranges from 10 months to 7 years, with a mean of 40 months. All patients received triple-drug immunosuppression, consisting of azathioprine, cyclosporine, and steroids. All patients had an uneventful postoperative course. Postoperative time of intubation was not prolonged in these patients compared to other patients. All patients are physically rehabilitated. One patient died suddenly 27 months after operation. Annual recatheterization studies showed normal left ventricular ejection fraction (59.5 +/- 13.4% SD). Signs of coronary artery disease could not be observed. No progression of preexisting muscular dystrophy could be diagnosed, until now.

Aspergillosis with Aspergillus osteomyelitis and diskitis after heart transplantation: surgical and medical management

This is the report of a 49-year-old man, who could be cured of aspergillosis with Aspergillus osteomyelitis and diskitis of the lumbar spine by medical and surgical therapy after heart retransplantation. Aspergillus osteomyelitis and diskitis is a rare complication of invasive aspergillosis. Lumbar involvement is the main manifestation, followed by rare locations in the tibia, ribs, wrist, sternum, pelvis, and knee. It is nearly always secondary to pulmonary aspergillosis, which occurs in about 6% to 14% of patients after heart transplantation. For treatment, a combined surgical and medical approach is recommended, which enables quick pain relief for the patient and histologic and microbiologic diagnosis and stabilization of the spine. Because of definitive cure of osteomyelitis cannot be guaranteed by removal of the abscess, medical therapy after surgery is necessary for years.

Circular DNA molecules imaged in air by scanning force microscopy

Routine and reproducible imaging of DNA molecules in air with the scanning force microscope (SFM) has been accomplished. Circular molecules of plasmid DNA were deposited onto red mica and imaged under various relative humidities. In related experiments, the first images of the Escherichia coli RNA polymerase-DNA complex have also been obtained. This has been possible by (1) the use of specially modified SFM tips with a consistent radius of curvature of 10 nm or less, to minimize the amount of image distortion introduced by the finite dimensions of commercially available tips, (2) the optimization of a method to deposit and bind DNA molecules to the mica surface in a stable fashion, and (3) careful control of the sample humidity, to prevent solvation of the molecules and detachment from the surface by the scanning tip or stylus. Contact forces in the range of a few nanonewtons are routinely possible in air and in the presence of residual humidity. The spatial resolution of the images appears determined by the radius of curvature of the modified styli, which can be estimated directly from the apparent widths of the DNA molecules in the images.

Effects of sucralfate on gastroduodenal bicarbonate secretion and prostaglandin E2 metabolism

The mechanism of action of sucralfate has been investigated. Using homogenized rabbit mucosa, the drug increased arachidonic acid conversion to prostaglandin E2 without affecting catabolism. Luminal administration of sucralfate (0.5 g/liter) caused marked stimulation of bicarbonate secretion by isolated amphibian gastric mucosa but not duodenal mucosa. In a higher dose (1 g/liter), duodenal bicarbonate secretion was also stimulated. These effects are likely to be due to endogenous prostaglandin formation since they are inhibited by indomethacin. The results suggest that the cytoprotective action of sucralfate is due to stimulation of endogenous prostaglandin formation and may involve various mucosal defensive factors.

Studies on synthetic peptide substrates for F XII enzymes

Screening of chromogenic peptide substrates have shown that FXIIa readily splits substrates of D-Pro-Phe-Arg-pNA (S-2302) and -Gly-Arg-pNA (e.g. S-2222) types. The latter type is preferred in a system where kallikrein is present. By using the substrate S-2222 a method for the determination of beta FXIIa inhibitors has been designed. Chromatography data show that C1-esterase inhibitor is the major inhibitor of beta FXIIa in plasma. Preliminary studies have also been performed on the assay of FXII in human plasma. The procedure to obtain a complete activation of FXII has still to be studied.

Factors prognostic for survival in patients with malignant melanoma spread to the regional lymph nodes

To establish clinical and histologic determinants of survival, records of all UCLA patients with resectable melanoma metastatic to the lymph nodes during the years 1954-1976 were reviewed. These 150 patients were treated first with wide excision, lymphadenectomy, and with radiation/chemotherapy and/or additional surgery only if further recurrences developed. None received adjuvant immunotherapy or chemotherapy. In 97 of 139 patients with identified primary tumors, slides of the primary lesion were reviewed. Putative prognostic factors included age, sex, parity, site of primary tumor, presence of satellitosis, clinical status of nodes, histologic characteristics of primary lesion (Clark's level, thickness of tumor, presence/width of ulceration, and number of mitoses/HPF), time from biopsy of primary tumor to lymphadenectomy, and number of positive nodes. kaplan-Meier estimates of survival for the entire group at one, two, five, and ten years were 73, 55, 37, and 33%, respectively. Median follow-up period of survivors was four years. Univariate analyses using the log-rank test showed that thickness of the primary lesion (p less than 0.001), width of ulceration (p = 0.003), absence of ulceration (p = 0.024), and number of positive nodes (p = 0,.033) were prognostic for survival. In multivariate analysis by the Cox procedure, thickness of the primary (p = 0.001) and number of melanoma-containing nodes (p = 0.043) were prognostic for survival. Location of the primary tumor became marginally significant (p = 0.12) in the multrivariate model. These findings demonstrate the prognostic importance of characteristics of both the primary lesion and extent of regional dissemination. Future prospective randomized trials for (adjuvant) therapy of Stage II melanoma should be stratified by these variables.

Pathogenesis of aortoduodenal fistula: experimental and clinical correlates

An aortoduodenal fistula (ADF) is believed to stem from erosion of a rigid prosthesis into the fixed retroperitoneal duodenum. Experimental and clinical data do not support a mechanical etiology, but indicate that the pathogenesis is an unrecognized graft infection with pseudoaneurysm formation. A 5 cm segment of Dacron was interposed in the infrarenal aortas of 24 dogs that were divided into four groups of six animals each. In group 1 (control) the duodenum was fixed by sutures to the proximal anastomosis of the Dacron graft. At 6 weeks' follow-up, no ADFs or deaths had occurred among this group. In group 2 the duodenum was fixed to the aortoprosthetic anastomosis and the dogs received an intravenous infusion of 10(8) S. aureus; two of these dogs developed ADF (P less than 0.01). In group 3 the duodenum was incorporated as a patch on the anterior aspect of the aortoprosthetic suture line, creating a false aneurysm; three of these animals died as a result of ADF. A false aneurysm was created in group 4 dogs, as in group 3, but in addition, 10(8) S. aureus was administered intravenously; here five to six animals developed ADF. Clinical and bacteriological evidence of graft infection was present in seven of 11 patients with ADF who were seen over an 18 year period. Five had pseudoaneurysm formation at the proximal anastomosis. Operation was performed in eight patients; three had closure of the aortic leak and repair of the duodenum with omentum interposition. All resulted in recurrent fistula and delayed hemorrhage. Simple graft excision in two patients without reconstitution of peripheral circulation resulted in lower extremity gangrene. The three survivors had graft excision and axillofemoral bypass. These data suggest that the etiology of ADF is primary low-grade infection. Successful operation necessitates excision of the graft, duodenal closure, and an extraanatomical axillofemoral bypass graft.