Endoscopic papillectomy for ampullary lesions of minor papilla

BACKGROUND AND AIMS

Ampullary lesions (ALs) of the minor duodenal papilla are extremely rare. Endoscopic papillectomy (EP) is a routinely used treatment for AL of the major duodenal papilla, but the role of EP for minor AL has not been accurately studied.

METHODS

We identified 20 patients with ALs of minor duodenal papilla in the multicentric database from the Endoscopic Papillectomy vs Surgical Ampullectomy vs Pancreatitcoduodenectomy for Ampullary Neoplasm study, which included 1422 EPs. We used propensity score matching (nearest-neighbor method) to match these cases with ALs of the major duodenal papilla based on age, sex, histologic subtype, and size of the lesion in a 1:2 ratio. Cohorts were compared by means of chi-square or Fisher exact test as well as Mann-Whitney U test.

RESULTS

Propensity score-based matching identified a cohort of 60 (minor papilla 20, major papilla 40) patients with similar baseline characteristics. The most common histologic subtype of lesions of minor papilla was an ampullary adenoma in 12 patients (3 low-grade dysplasia and 9 high-grade dysplasia). Five patients revealed nonneoplastic lesions. Invasive cancer (T1a), adenomyoma, and neuroendocrine neoplasia were each found in 1 case. The rate of complete resection, en-bloc resection, and recurrences were similar between the groups. There were no severe adverse events after EP of lesions of minor papilla. One patient had delayed bleeding that could be treated by endoscopic hemostasis, and 2 patients showed a recurrence in surveillance endoscopy after a median follow-up of 21 months (interquartile range, 12-50 months).

CONCLUSIONS

EP is safe and effective in ALs of the minor duodenal papilla. Such lesions could be managed according to guidelines for EP of major duodenal papilla.

Endoscopic and Surgical Management of Non-Metastatic Ampullary Neuroendocrine Neoplasia: A Multi-Institutional Pancreas2000/EPC Study

INTRODUCTION

Ampullary neuroendocrine neoplasia (NEN) is rare and evidence regarding their management is scarce. This study aimed to describe clinicopathological features, management, and prognosis of ampullary NEN according to their endoscopic or surgical management.

METHODS

From a multi-institutional international database, patients treated with either endoscopic papillectomy (EP), transduodenal surgical ampullectomy (TSA), or pancreaticoduodenectomy (PD) for ampullary NEN were included. Clinical features, post-procedure complications, and recurrences were assessed.

RESULTS

65 patients were included, 20 (30.8%) treated with EP, 19 (29.2%) with TSA, and 26 (40%) with PD. Patients were mostly asymptomatic (n = 46; 70.8%). Median tumor size was 17 mm (12-22), tumors were mostly grade 1 (70.8%) and pT2 (55.4%). Two (10%) EP resulted in severe American Society for Gastrointestinal Enterology (ASGE) adverse post-procedure complications and 10 (50%) were R0. Clavien 3-5 complications did not occur after TSA and in 4, including 1 postoperative death (15.4%) of patients after PD, with 17 (89.5%) and 26 R0 resection (100%), respectively. The pN1/2 rate was 51.9% (n = 14) after PD. Tumor size larger than 1 cm (i.e., pT stage >1) was a predictor for R1 resection (p < 0.001). Three-year overall survival and disease-free survival after EP, TSA, and PD were 92%, 68%, 92% and 92%, 85%, 73%, respectively.

CONCLUSION

Management of ampullary NEN is challenging. EP should not be performed in lesions larger than 1 cm or with a endoscopic ultrasonography T stage beyond T1. Local resection by TSA seems safe and feasible for lesions without nodal involvement. PD should be preferred for larger ampullary NEN at risk of nodal metastasis.

Outcomes of rescue procedures in the management of locally recurrent ampullary tumors: A Pancreas 2000/EPC study

BACKGROUND

Ampullary lesions are rare and can be locally treated either with endoscopic papillectomy or transduodenal surgical ampullectomy. Management of local recurrence after a first-line treatment has been poorly studied.

METHODS

Patients with a local recurrence of an ampullary lesion initially treated with endoscopic papillectomy or transduodenal surgical ampullectomy were retrospectively included from a multi-institutional database (58 centers) between 2005 and 2018.

RESULTS

A total of 103 patients were included, 21 (20.4%) treated with redo endoscopic papillectomy, 14 (13.6%) with transduodenal surgical ampullectomy, and 68 (66%) with pancreaticoduodenectomy. Redo endoscopic papillectomy had low morbidity with 4.8% (n = 1) severe to fatal complications and a R0 rate of 81% (n = 17). Transduodenal surgical ampullectomy and pancreaticoduodenectomy after a first procedure had a higher morbidity with Clavien III and more complications, respectively, 28.6% (n = 4) and 25% (n = 17); R0 resection rates were 85.7% (n = 12) and 92.6% (n = 63), both without statistically significant difference compared to endoscopic papillectomy (P = .1 and 0.2). Pancreaticoduodenectomy had 4.4% (n = 2) mortality. No deaths were registered after transduodenal surgical ampullectomy or endoscopic papillectomy. Recurrences treated with pancreaticoduodenectomy were more likely to be adenocarcinomas (79.4%, n = 54 vs 21.4%, n = 3 for transduodenal surgical ampullectomy and 4.8%, n = 1 for endoscopic papillectomy, P < .0001). Three-year overall survival and disease-free survival were comparable.

CONCLUSION

Endoscopy is appropriate for noninvasive recurrences, with resection rate and survival outcomes comparable to surgery. Surgery applies more to invasive recurrences, with transduodenal surgical ampullectomy rather for carcinoma in situ and early cancers and pancreaticoduodenectomy for more advanced tumors.

Systematic Review with Meta-Analysis: Endoscopic and Surgical Resection for Ampullary Lesions

Ampullary lesions (ALs) can be treated by endoscopic (EA) or surgical ampullectomy (SA) or pancreaticoduodenectomy (PD). However, EA carries significant risk of incomplete resection while surgical interventions can lead to substantial morbidity. We performed a systematic review and meta-analysis for R0, adverse-events (AEs) and recurrence between EA, SA and PD. Electronic databases were searched from 1990 to 2018. Outcomes were calculated as pooled means using fixed and random-effects models and the Freeman-Tukey-Double-Arcsine-Proportion-model. We identified 59 independent studies. The pooled R0 rate was 76.6% (71.8–81.4%, I² = 91.38%) for EA, 96.4% (93.6–99.2%, I² = 37.8%) for SA and 98.9% (98.0–99.7%, I² = 0%) for PD. AEs were 24.7% (19.8–29.6%, I² = 86.4%), 28.3% (19.0–37.7%, I² = 76.8%) and 44.7% (37.9–51.4%, I² = 0%), respectively. Recurrences were registered in 13.0% (10.2–15.6%, I² = 91.3%), 9.4% (4.8–14%, I² = 57.3%) and 14.2% (9.5–18.9%, I² = 0%). Differences between proportions were significant in R0 for EA compared to SA (p = 0.007) and PD (p = 0.022). AEs were statistically different only between EA and PD (p = 0.049) and recurrence showed no significance for EA/SA or EA/PD. Our data indicate an increased rate of complete resection in surgical interventions accompanied with a higher risk of complications. However, studies showed various sources of bias, limited quality of data and a significant heterogeneity, particularly in EA studies.

Study Protocol of the ESAP Study: Endoscopic Papillectomy vs. Surgical Ampullectomy vs. Pancreaticoduodenectomy for Ampullary Neoplasm-A Pancreas2000/EPC Study

Background: Lesions of the Ampulla of Vater are a rare condition and represent <10% of peri-ampullary neoplasms. Nevertheless, ampullary adenomas have the potential for malignant transformation to ampullary carcinomas by an adenoma-to-carcinoma sequence. Thus, adequate patient selection and complete resection (R0) of non-invasive ampullary lesions either by endoscopic papillectomy (EP), surgical ampullectomy (SA), or pancreaticoduodenectomy (PD) is essential. Although PD was traditionally performed, recent studies reported considerable efficacy and fewer complications following EP and SA. Since consistent comparative data are lacking, the Endoscopic Papillectomy vs. Surgical Ampullectomy vs. Pancreaticoduodectomy (ESAP) study will provide evidence for a therapeutic standard and post procedure morbidity in ampullary lesions. Methods: International multicenter retrospective study. Adult patients (>18 years of age) who underwent SA or PD for ampullary neoplasm between 2004 and 2018 or EP between 2007 and 2018 will be evaluated. Main inclusion criteria are ampullary lesions strictly located to the ampulla. This includes adenoma, adenocarcinoma (T1 and T2), neuroendocrine tumors, gastrointestinal stroma tumors and other rare conditions. Exclusion criteria are peri-ampullary lesions, e.g., from the duodenal wall or the head of the pancreas, and interventions for tumor stages higher than T2. The main objective of this study is to analyze rates of complete resection (R0), recurrence and necessity for complementary interventions following EP, SA, and PD. Treatment-quality for each procedure will be defined by morbidity, mortality and complication rates and will be compared between EP, SA, and PD. Secondary objectives include outcome for patients with incomplete resection or initially understated tumors, lesions of the minor papilla, hereditary syndromes, neuroendocrine tumors, mesenchymal lesions, and other rare conditions. Additionally, we will analyze therapy by argon plasma coagulation and radiofrequency ablation. Furthermore, outcome in curative and palliative interventions can be distinguished. Conclusion: The ESAP study will provide evidence for therapeutic algorithms and data for the implementation of guidelines in the treatment of different types of ampullary tumors, including recurrent, or incomplete resected lesions.

Adaptive Optimal Control Using Frequency Selective Information of the System Uncertainty With Application to Unmanned Aircraft

A new efficient adaptive optimal control approach is presented in this paper based on the indirect model reference adaptive control (MRAC) architecture for improvement of adaptation and tracking performance of the uncertain system. The system accounts here for both matched and unmatched unknown uncertainties that can act as plant as well as input effectiveness failures or damages. For adaptation of the unknown parameters of these uncertainties, the frequency selective learning approach is used. Its idea is to compute a filtered expression of the system uncertainty using multiple filters based on online instantaneous information, which is used for augmentation of the update law. It is capable of adjusting a sudden change in system dynamics without depending on high adaptation gains and can satisfy exponential parameter error convergence under certain conditions in the presence of structured matched and unmatched uncertainties as well. Additionally, the controller of the MRAC system is designed using a new optimal control method. This method is a new linear quadratic regulator-based optimal control formulation for both output regulation and command tracking problems. It provides a closed-form control solution. The proposed overall approach is applied in a control of lateral dynamics of an unmanned aircraft problem to show its effectiveness.

Substance-specific importance of EGFR for vascular smooth muscle cells motility in primary culture

Besides their importance for the vascular tone, vascular smooth muscle cells (VSMC) also contribute to pathophysiological vessel alterations. Various G-protein coupled receptor ligands involved in vascular dysfunction and remodeling can transactivate the epidermal growth factor receptor (EGFR) of VSMC, yet the importance of EGFR transactivation for the VSMC phenotype is incompletely understood. The aims of this study were (i) to characterize further the importance of the VSMC-EGFR for proliferation, migration and marker gene expression for inflammation, fibrosis and reactive oxygen species (ROS) homeostasis and (ii) to test the hypothesis that vasoactive substances (endothelin-1, phenylephrine, thrombin, vasopressin and ATP) rely differentially on the EGFR with respect to the abovementioned phenotypic alterations. In primary, aortic VSMC from mice without conditional deletion of the EGFR, proliferation, migration, marker gene expression (inflammation, fibrosis and ROS homeostasis) and cell signaling (ERK 1/2, intracellular calcium) were analyzed. VSMC-EGFR loss reduced collective cell migration and single cell migration probability, while no difference between the genotypes in single cell velocity, chemotaxis or marker gene expression could be observed under control conditions. EGF promoted proliferation, collective cell migration, chemokinesis and chemotaxis and leads to a proinflammatory gene expression profile in wildtype but not in knockout VSMC. Comparing the impact of five vasoactive substances (all reported to transactivate EGFR and all leading to an EGFR dependent increase in ERK1/2 phosphorylation), we demonstrate that the importance of EGFR for their action is substance-dependent and most apparent for crowd migration but plays a minor role for gene expression regulation.

Abstract PD3-04: PAK-1 amplified breast cancer cell lines are preferentially sensitive to PAK inhibition with G-5555

The small GTP-binding proteins Rac1 and Cdc42 stimulate activity of the serine/threonine kinase p21-activated kinase-1 (PAK-1) to drive growth factor signaling networks and Ras-driven tumorigenesis. Genomic amplification and over-expression of PAK1 are prevalent in luminal breast cancer and correlate with poor clinical outcome. Here we use a novel and selective small molecule inhibitor, G-5555, of the group I PAKs (PAK1, 2, and 3) to evaluate the importance of PAK1 in promoting growth of PAK1 amplified breast cancer cells. Cell lines with amplification of PAK1 were found to be more sensitive to PAK1 inhibition than non-amplified cell lines. Additionally, reverse phase protein array (RPPA) was used to assess the effects of PAK1 inhibition on a wide range of signaling pathways in both amplified and non-amplified cell lines. Reduced levels of phosphorylation of MEK S298 was observed in all cell lines exposed to G-5555 irrespective of amplification status, consistent with PAK1 inhibition in these cell lines. However, modulation of this downstream PAK1 substrate did not correlate with inhibition of cell proliferation or induction of cell death. Cell lines that showed inhibition of proliferation in response to G-5555 also showed enhanced levels of cell death along with apoptosis. Moreover, G-5555 reduced tumor growth in the PAK1 amplified MDA-MB-175 xenograft tumor model. Finally, we compared the in vitro activity of G-5555 with palbociclib, a recently approved inhibitor of the cyclin-dependent kinases CDK4 and CDK6, in PAK1 amplified luminal breast cancer cell lines. Our data supports PAK1 as an attractive target in PAK1 amplified cells and tumors and suggests that inhibiting PAK1 rather than CDK4/6 in this context may be a more attractive therapeutic strategy.

Citation Format: Ong CC, Blackwood E, Jakubiak D, Daemen A, Ramaswamy S, Heise C, Schmidt M, Sanders L, Wilson TR, Huw L, Ndubaku C, Rudolph J, Hoeflich KP, Friedman L, O'Brien T. PAK-1 amplified breast cancer cell lines are preferentially sensitive to PAK inhibition with G-5555. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr PD3-04.

A phase 1, pharmacokinetic (PK) and pharmacodynamic (PD) study of CHIR-258, a novel oral multiple receptor tyrosine kinase (RTK) inhibitor

3043

Background: CHIR-258 is a potent small molecule inhibitor of VEGF, FGF, PDGF and c-KIT RTKs with IC50≤10nM that demonstrates activity in a variety of angiogenesis, tumour and metastasis models. Methods: Patients (pts) with histologically confirmed advanced solid tumors, ECOG PS 0–2 were treated in cohorts of 3–6 with CHIR-258. Treatment was as single daily doses on a repeated 7 days (d) on/7d off schedule (25–100mg), with a subsequent protocol amendment to continuous (cont) daily dosing. The objectives were to determine maximum tolerated dose (MTD) and dose limiting toxicity (DLT), evaluate PK and PD endpoints - ERK phosphorylation in PBL - and describe anti-tumour activity. Results: 35pts (median age 56.5 yrs; 15F/20M) were treated in 4 intermittent dosing cohorts (25, 50, 75, 100 mg/d) and 3 continuous dosing cohorts (100,125, 175 mg/d). The most common drug related adverse events were (grade [gr], number of pts): nausea (gr 1–3, 12); fatigue (gr 1–2, 9); headache (gr 1–3, 8); vomiting (gr 1–2, 7); anorexia (gr 1–2, 7); diarrhoea (gr 1–2, 6); dysgeusia (gr1–2, 6); anaemia (gr 2–3, 4); hypertension (gr 1–3, 3) and reversible asymptomatic drop in left ventricular ejection fraction (gr 2, 2). DLTs were gr 3 hypertension (HTN) in 1 pt with pre-existing HTN (100mg, cont); asymptomatic uncomplicated grade 2 elevation in cardiac troponin I (125mg); gr 3 anorexia/fatigue and gr 3 rise in alkaline phosphatase (both at 175mg). 3 pts have had prolonged stable disease (all 4m+; parotid, renal and imatinib-refractory GIST). The plasma PKs of CHIR-258 were linear over the dose range of 25–175 mg with respect to Cmax and AUC. On d1, the mean Cmax was 13.5(5.3) ng/mL to 109 (26) ng/mL, the mean AUC (0–24) was 224(97.4)ng*h/mL to 1740(466)ng*h/mL, and the t½ was 17h. Trough CHIR-258 concentrations at doses >50 mg/d were above the concentrations known to inhibit target receptor activation in vitro. Data on evaluable samples demonstrate up to 90% inhibition of basal ERK phosphorylation. Conclusions: CHIR-258 was safely administered at continuous daily doses up to 175mg/d. Modulation of p-ERK was demonstrated. Treatment is associated with disease stabilization.

[Table: see text]

Phase I trial of chir-258 in multiple myeloma

17502

Background: CHIR-258 is an orally active small molecule receptor tyrosine kinase (RTK) inhibitor which has potent activity against multiple RTKs involved in tumor growth and angiogenesis (IC50 ≤13 nM for FGFR, VEGFR, PDGFR, C-KIT, and FLT3). Approximately 15% of newly diagnosed MM patients harbor a t(4;14) translocation, which results in ectopic expression of FGFR3 and MMSET and is associated with poor treatment outcome [0]and reduced survival. CHIR-258 inhibits proliferation and induces apoptosis in FGFR3-expressing MM tumor xenografts as well as FGFR3-expressing primary MM cells (Trudel et al, Blood 2005). CHIR-258 was synergistic with dexamethasone (dex) in vitro. Methods: CHIR-258 was administered once daily in a dose-escalating phase 1 study to patients with relapsed/refractory MM. Drug tolerability and safety, pharmacokinetics (PK) and pharmacodynamics (PD) were assessed. Results: as of December 2005, 9 total pts have been treated (50, 100, and 200mg qd cohorts) [6M, 3F; median age: 58 (range: 44–68), median of 3 prior therapies(range:1–7)]. Prior tx: 9/9 pts-thalidomide; 8/9 -Velcade; 8/9-transplant; 8/9- had progressed through dex. 4 of 9 pts treated were FGFR3+ and 4 pts remain on study (3 are FGFR3+). No CR or PR have been observed; stable disease has been noted. CHIR-258 has been generally well tolerated, and most drug related AEs were CTC grade 1 or 2, including: headache, dysgeusia, fatigue and anorexia. No neuropathy. One DLT has been observed to date: neutropenia (200mg cohort). Five pts had dex added to CHIR-258 of which 3 are ongoing (all FGFR3+). FGFR3+ pts receiving dex and CHIR-258 have a greater decline in urine and serum paraproteins (pp) vs CHIR-258 alone. Plasma exposure and Cmax increased proportionally across the doses. Conclusions: CHIR-258 is a novel inhibitor of RTKs involved in MM growth and proliferation. FGFR3+ pts have a more marked reduction in pp than FGFR3- pts. CHIR-258 has generally been well tolerated and further accrual continues.

[Table: see text]

On-chip PCR amplification of very long templates using immobilized primers on glassy surfaces

In this paper we describe a novel method for visualizing very long DNA fragments (for example >6 kb) which are difficult to spot with commonly used arrayers or capillary samplers with very small nanoliter volumes, using directly bound primers on "on-chip" polymerase chain reaction (PCR). We have used the genomes of the M13 bacteriophage (7.2 kb) the human mitochondrion (16.5 kb) as examples of long DNA templates to test the PCR and were able to elicit robust reactivity. Over 75% of the immobilized primers could be elongated to their fullest extent. In addition we were able to elicit the PCR reaction with double stranded templates in which one primer was immobilized and the other suspended in the reaction solution. These synthesized PCR products were visualized by either confocal microarray scanning or fluorescence microscopy using Cy5-dye fluorescence of the modified free primer, or the fluorescence of intercalating dyes.

Efficient induction of apoptosis by ONYX-015 adenovirus in human colon cancer cell lines regardless of p53 status

The ONYX-015 virus is a mutated adenovirus that in theory selectively replicates and induces cytolysis in tumor cells lacking functional p53. The present study investigated whether ONYX-015 viral infection alone or in combination with conventional chemotherapeutic agents could significantly increase apoptosis in human colon cancer cell lines, regardless of p53 status, compared to untreated cells. A pair of colon cancer cell lines that differ only in their p53 status (RKO with wild-type p53 and RKOp53 with deficient p53) was tested. Two chemotherapeutic agents, 5-fluorouracil (5-FU) and CPT-11, were tested in combination with ONYX-015. Final concentrations of these agents corresponded to peak plasma levels achievable in patients. ONYX-015 concentration was 10 p.f.u./cell. In RKO and RKOp53 cell lines, ONYX-015 viral infection alone or in combination with 5-FU or CPT-11 induced a significant increase in apoptosis compared to chemotherapeutic agents alone, regardless of p53 status. Moreover, the combination of ONYX-015 and chemotherapeutics induced more apoptosis than chemotherapeutics alone in the two colon cancer cell lines independently of their p53 status. We conclude that ONYX-015 virus infection alone or in combination with 5-FU or CPT-11 induced apoptosis in human colon cancer cell lines, independently of p53 status.

Unusual appearance of an en plaque meningioma of the cervical spinal canal. A case report and literature review

STUDY DESIGN

A case report of a patient with cervical spinal cord and nerve root compression caused by a meningioma en plaque together with calcification of the posterior longitudinal ligament is presented,with a review of the literature.

OBJECTIVE

To present the diagnosis of a calcified dural meningioma en plaque, with extradural extension into the ligamentum flavum, in a woman with cervical myelopathy and neuropathy.

SUMMARY OF BACKGROUND DATA

This case demonstrates that the cervical spine can be involved in dural meningioma en plaque with calcifications, in a manner mimicking ossification of the ligamentum flavum, which has never been previously reported.

METHODS

A patient presenting with cervical cord and nerve root compression caused by ossification of the posterior longitudinal ligament and a concurrent calcified dural meningioma en plaque was treated surgically and has made a gradual recovery. Imaging studies,surgical findings, and histopathologic evaluation were analyzed to support the diagnosis.

RESULTS

At surgery, ossification of the posterior longitudinal ligament was noted, along with a calcified lesion involving the posterior cervical dura and the adjacent ligamentum flavum. A calcified meningioma was diagnosed by histopathologic examination of the dural-based lesion.

CONCLUSION

Although previously not described, the diagnosis of calcified dural meningioma en plaque should be considered in all patients presenting with spinal cord and/or nerve root compression,even at cervical levels. Although ossification of the posterior longitudinal ligament and ossification of the ligamentum flavum are more common etiologies of partially circumferential spinal calcification, dural-based meningiomas with extension into the surrounding ligaments demand early recognition because they can be associated with a poorer prognosis.

Safety and feasibility of injection with an E1B-55 kDa gene-deleted, replication-selective adenovirus (ONYX-015) into primary carcinomas of the pancreas: a phase I trial

Novel therapies are needed for locally advanced pancreatic carcinoma. ONYX-015 (dl1520) is an E1B-55 kDa region-deleted adenovirus that selectively replicates in and lyses tumor cells with abnormalities in p53 function (eg gene mutation). We carried out a phase I dose escalation study of ONYX-015 in patients with unresectable pancreatic cancer. ONYX-015 was administered via CT-guided injection (n = 22 patients) or intraoperative injection (n = 1) into pancreatic primary tumors every 4 weeks until tumor progression. Interpatient dose escalation was carried out with at least three patients per dose level from 10(8) p.f.u. up to the 10(11) p.f.u. dose level (two patients treated at this dose). The majority of patients had abnormally low cellular immunity (CD4 counts and hypersensitivity skin testing). Injection of ONYX-015 into pancreatic carcinomas was well-tolerated. Mild, transient pancreatitis was noted in only one patient. Dose-escalation proceeded to the highest dose level. Neutralizing antibodies rose post-treatment in all patients. After injection, ONYX-015 was detectable in the blood 15 min later, but not between 1 and 15 days later. Viral replication was not documented, however, in contrast to trials in other tumor types. No objective responses were demonstrated. Intratumoral injection of an E1B-55 kDa region-deleted adenovirus into primary pancreatic tumors was feasible and well-tolerated at doses up to 10(11) p.f.u. (2 x 10(12) particles), but viral replication was not detectable.

High-performance liquid chromatography/fluorescence detection of S-methylglutathione formed by glutathione-S-transferase T1 in vitro

Glutathione-S-transferase T1 (GSTT1-1) is a major isoenzyme for the biotransformation of halomethanes. The enzyme activity is located, among other places, in human liver and erythrocytes and is subject to a genetic polymorphism. Metabolism of the halomethanes via GSTT1-1 yields S-methylglutathione (MeSG). A new HPLC assay for the enzymatic formation of MeSG was developed. The glutathione conjugate was derivatized with 9-fluorenylmethyl chloroformate, followed by reverse-phase HPLC with gradient elution and fluorescence detection. The limit of detection was as low as about 39 pmol MeSG on-column. Including derivatization and HPLC analysis, samples could be run at 42-min intervals, thus enabling a high sample throughput. The entire method was validated for analyte recovery (78.2%) and for variations in detector response with replicated injections (11.8%) and with analyses on each of 11 consecutive days (15.2%) with erythrocyte lysate incubations as the matrix. The time-, protein-, and substrate-dependences of the enzymatic catalysis with the model substrates methyl bromide (MeBr) and methyl chloride (MeCl) were studied. Due to its strong electrophilic character, MeBr caused a high level of spontaneous MeSG formation from glutathione in a protein-free medium and a substrate-trapping side reaction in the presence of proteins. Therefore, enzymatic MeSG formation rates may only be determined with MeBr concentrations of at least 3000 ppm in the presence of limited amounts of protein (e.g. 100 microl erythrocyte lysate). In contrast, MeCl showed a lower alkylating potential allowing enzymatic catalysis to be the dominant reaction in incubations with 10,000 ppm MeCl and 2 ml erythrocyte lysate.

Efficacy with a replication-selective adenovirus plus cisplatin-based chemotherapy: dependence on sequencing but not p53 functional status or route of administration

Replication-selective adenoviruses are being developed as novel anticancer therapeutics. Clinical trials with dl 1520, an E1B-Mr 55,000 gene-deleted adenovirus (ONYX-015), have demonstrated selective viral replication and biological activity in head and neck and ovarian carcinomas, but durable objective responses were not demonstrated. However, clinical results suggested potentially synergistic interactions with platinum-containing chemotherapy. To better characterize and optimize this interaction, we carried out combined modality treatment with ONYX-015 and cisplatin-based chemotherapy in three nude mouse-human tumor xenograft models with differing tumor locations or p53 functional status. Superior efficacy was demonstrated with combination therapy over either agent alone in all three models, independent of the route of ONYX-015 administration (intratumoral or i.p.). Virus replication was not demonstrably inhibited by cisplatin plus 5-fluorouracil chemotherapy. To assess the role of p53 function or cisplatin resistance in this interaction, we treated ovarian carcinomas that were matched except for p53 functional status (A2780, A2780/CP70). Combination therapy led to improved survival over either agent alone in both the p53(-) and the p53(+) carcinomatosis models. Efficacy was highly dependent on the sequencing of the agents; treatment with ONYX-015 prior to, or simultaneously with, chemotherapy was significantly superior to chemotherapy followed by ONYX-015. These results support further evaluation of replication-selective adenoviruses and cisplatin-based chemotherapy in clinical trials.

Efficacy of a replication-selective adenovirus against ovarian carcinomatosis is dependent on tumor burden, viral replication and p53 status

Intraperitoneal (i.p.) recurrence of cisplatin-refractory and p53 mutant ovarian cancer is a major clinical problem, despite surgery and chemotherapy. dl1520 (ONYX-015) is an E1B-55 kDa gene-deleted adenovirus engineered selectively to replicate in and destroy cancer cells lacking functional p53. However, a correlation between efficacy and p53 function has not been definitively studied in vivo to date, and efficacy following i.p. administration had not been previously described. We therefore carried out experiments to address these issues in three nude mouse-human ovarian carcinomatosis xenograft models. Intraperitoneal treatment with dl1520 led to complete tumor eradication and/or significantly improved survival in two p53(-) nude mouse-human ovarian tumor xenograft models. OVCAR3 i.p. xenografts underwent complete regressions in 11 of 12 mice (versus one of seven controls; P = 0.001), while mice bearing cisplatin-resistant A2780 tumors had significantly improved survival versus controls (P = 0.05). In contrast, the A2780 p53(+) ovarian cancer xenograft was resistant to dl1520. The efficacy of i.p. dl1520 in the p53(-) models correlated strongly with tumor burden present at the time of treatment initiation, and no efficacy was seen with non-replicating/UV-inactivated dl1520. Selectively replicating viruses such as dl1520 hold promise as i.p. therapies for p53-deficient and chemotherapy-resistant ovarian carcinomas. A phase I clinical trial of i.p. dl1520 (ONYX-015) is underway in patients with cisplatin-resistant ovarian carcinoma.

An adenovirus E1A mutant that demonstrates potent and selective systemic anti-tumoral efficacy

Replication-selective oncolytic viruses constitute a rapidly evolving and new treatment platform for cancer. Gene-deleted viruses have been engineered for tumor selectivity, but these gene deletions also reduce the anti-cancer potency of the viruses. We have identified an E1A mutant adenovirus, dl922-947, that replicates in and lyses a broad range of cancer cells with abnormalities in cell-cycle checkpoints. This mutant demonstrated reduced S-phase induction and replication in non-proliferating normal cells, and superior in vivo potency relative to other gene-deleted adenoviruses. In some cancers, its potency was superior to even wild-type adenovirus. Intravenous administration reduced the incidence of metastases in a breast tumor xenograft model. dl922-947 holds promise as a potent, replication-selective virus for the local and systemic treatment of cancer.

a controlled trial of intratumoral ONYX-015, a selectively-replicating adenovirus, in combination with cisplatin and 5-fluorouracil in patients with recurrent head and neck cancer

ONYX-015 is an adenovirus with the E1B 55-kDa gene deleted, engineered to selectively replicate in and lyse p53-deficient cancer cells while sparing normal cells. Although ONYX-015 and chemotherapy have demonstrated anti-tumoral activity in patients with recurrent head and neck cancer, disease recurs rapidly with either therapy alone. We undertook a phase II trial of a combination of intratumoral ONYX-015 injection with cisplatin and 5-fluorouracil in patients with recurrent squamous cell cancer of the head and neck. There were substantial objective responses, including a high proportion of complete responses. By 6 months, none of the responding tumors had progressed, whereas all non-injected tumors treated with chemotherapy alone had progressed. The toxic effects that occurred were acceptable. Tumor biopsies obtained after treatment showed tumor-selective viral replication and necrosis induction.

A phase I study of Onyx-015, an E1B attenuated adenovirus, administered intratumorally to patients with recurrent head and neck cancer

An E1B 55 kDa gene-deleted adenovirus, Onyx-015, which reportedly selectively replicates in and lyses p53-deficient cells, was administered by a single intratumoral injection to a total of 22 patients with recurrent head and neck cancer. The objectives of this Phase I study were to determine the safety, feasibility, and efficacy of this therapy and determine any correlation to p53 status. Six cohorts were investigated with a dose escalation from 10(7)-10(11) plaque-forming units. Toxicity was assessed using NCIC criteria. Tumor response was assessed by clinical and radiological measurement. Blood samples were taken to detect adenovirus DNA and neutralizing antibody to adenovirus. Tumor biopsies were taken to detect adenovirus by in situ hybridization. Treatment was well tolerated, with the main toxicity being grade 1/2 flu-like symptoms. Dose-limiting toxicity was not reached at the highest dose of 10(11) plaque-forming units. Twenty-one of the 22 patients treated showed an increase in neutralizing antibody to adenovirus. In situ hybridization showed viral replication in 4 of 22 patients treated, all of whom had mutant p53 tumors. Using conventional response criteria, no objective responses were observed. However, magnetic resonance imaging scans were suggestive of tumor necrosis at the site of viral injection in five patients, three of whom were classified using nonconventional criteria as partial responders, and two of whom were classified using nonconventional criteria as minor responders. Of these five cases, four had mutant p53 tumors. The response duration for the three partial responders was 4, 8, and 12 weeks. An additional eight patients had stable disease in the injected tumors lasting from 4-8 weeks. These preliminary results show that intratumoral administration of Onyx-015 is feasible, well tolerated, and associated with biological activity. Further investigation of Onyx-015, particularly with a more frequent injection protocol and in combination with systemic chemotherapy, is warranted.

Interleukin-12 gene transfer results in CD8-dependent regression of murine CT26 liver tumors

BACKGROUND

Interleukin (IL)-12 has potent antitumor effects in animal models. We hypothesized that direct transfer of the IL-12 gene to established tumors would result in tumor regression without significant toxicity.

METHODS

Liver tumors were established by direct injection of CT26, a murine adenocarcinoma, into the livers of BALB/c mice, followed by three transfections with either murine IL-12, murine granulocyte-macrophage colony-stimulating factor, or luciferase cDNA using particle-mediated gene transfer. To assess the mechanism of this effect, immunohistochemical staining and depletion experiments with anti-CD4 or -CD8 antibodies were performed.

RESULTS

Progressive growth of primary tumors and carcinomatosis were present by day 16 after transfection with luciferase or murine granulocyte-macrophage colony-stimulating factor. At 50 days, complete regression of tumor was evident in seven of eight IL-12-treated mice (P < .001). In IL-12-transfected livers, immunohistochemical staining revealed an increase in CD8+ T cells. Selective depletion of CD4+ or CD8+ T cells was performed before and during transfection with murine IL-12. At 50 days, 75% of control mice were tumor-free. Only 46% of CD4+ cell-depleted mice (P = .143) and 7% of CD8+ cell-depleted mice (P < .001) were tumor-free.

CONCLUSIONS

IL-12 gene transfer using particle-mediated gene transfer results in complete regression of established CT26 liver tumors in 88% of mice; this effect is dependent on CD8+ T cells.

PTEN/MMAC1 is infrequently mutated in pT2 and pT3 carcinomas of the prostate

Deletion of the q23-24 region of human chromosome 10 is one of the most frequent genetic alterations in prostate cancer, suggesting that inactivation of a tumor suppressor gene in this region is involved in the development or progression of this carcinoma. A candidate gene, PTEN/MMAC1, has been identified from this chromosomal region; mutations of this gene have been found in various advanced tumors and cell lines including those of prostate cancer. To further define the role of PTEN/MMAC1 in the development of prostate cancer and its spectrum of genetic alterations, we analysed 40 pT2 or pT3 prostate tumors for allelic loss, mutations, and homozygous deletions using PCR-based methods. Six tumors showed loss of heterozygosity for one of the ten markers analysed, while one tumor showed loss of two markers. None of the markers within PTEN/MMAC1 was lost. Direct sequencing of PCR amplified exons and intron/exon junctions of all 40 tumors revealed three sequence variants, one of which was a point mutation in exon 9, while the other two were polymorphisms. Using multiplex PCR, no homozygous deletions were detected in any of the neoplasms. Our results showing a low frequency of alterations of PTEN/MMAC1 in pT2 and pT3 prostate cancers suggest that this gene plays an insignificant role in the development of most low stage carcinomas of the prostate.

Effects of chronic hormone replacement on the renin-angiotensin system in cynomolgus monkeys

OBJECTIVE

To characterize the effects of estrogen, estrogen combined with progestin, and no treatment in ovariectomized cynomolgus monkeys during long-term reproductive hormone replacement.

METHODS

Forty-five surgically postmenopausal cynomolgus monkeys fed a lipid-lowering diet were administered a conjugated equine estrogen (Premarin, 7.2 micrograms/day for the first 8 months, then 166 micrograms/day for the remaining 22 months), alone or in combination with 650 micrograms/day medroxyprogesterone acetate (Cycrin) for 30 months, or left with no hormone replacement therapy. Animals were anesthetized with ketamine-pentobarbital, and samples were taken for measurements of plasma renin activity, angiotensin converting enzyme activity, and angiotensin peptides, angiotensin I (Ang I), angiotensin II (Ang II), and angiotensin-(1-7) [Ang-(1-7)].

RESULTS

Chronic replacement therapy with estrogen resulted in a significant elevation of the plasma renin activity [11.7 +/- 2.0 ng/ml per h control versus 22.8 +/- 4.6 ng/ml per h with estrogen (P < 0.05) versus 32.8 +/- 4.9 ng/ml per h with combination therapy (P < 0.01)], whereas estrogen or combination therapy caused a significant reduction in angiotensin converting enzyme activity [229 +/- 8 nmol/ml per min control versus 189 +/- 10 nmol/ml per min with estrogen (P < 0.05) versus 196 +/- 11 nmol/ml per min with combination therapy (P < 0.05)]. Both of these changes in angiotensin processing enzymes observed during replacement therapy resulted in significant increases in plasma Ang I levels [46.7 +/- 12.5 pg/ml control versus 175.5 +/- 65.9 pg/ml with estrogen (P < 0.05) and 561.7 +/- 373.6 pg/ml with combination therapy (P < 0.05)]. Plasma Ang II and Ang-(1-7) levels were not significantly changed. The mean blood pressure did not change with either treatment.

CONCLUSION

These studies reveal that, although chronic estrogen replacement activates renin activity and Ang I, it causes a shift in the processing of angiotensin peptides such that the concurrent reduction in angiotensin converting enzyme activity leads to unchanged plasma Ang II levels. Thus, the potentially harmful effects of estrogen-induced hyperreninemia are balanced by its actions interfering with the formation of the vasoactive product Ang II.

ONYX-015, an E1B gene-attenuated adenovirus, causes tumor-specific cytolysis and antitumoral efficacy that can be augmented by standard chemotherapeutic agents

The 55-kilodalton (kDa) protein from the E1B-region of adenovirus binds to and inactivates the p53 gene, which is mutated in half of human cancers. We have previously shown that the replication and cytopathogenicity of an E1B, 55-kDa gene-attenuated adenovirus, ONYX-015, is blocked by functional p53 in RKO and U20S carcinoma lines. We now report that normal human cells were highly resistant to ONYX-015-mediated, replication-dependent cytolysis. In contrast, a wide range of human tumor cells, including numerous carcinoma lines with either mutant or normal p53 gene sequences (exons 5-9), were efficiently destroyed. Antitumoral efficacy was documented following intratumoral or intravenous administration of ONYX-015 to nude mouse-human tumor xenografts; efficacy with ONYX-015 plus chemotherapy (cisplatin, 5-fluorouracil) was significantly greater than with either agent alone.

Intraoperative monitoring of motor pathways during operative fixation of acute acetabular fractures

OBJECTIVE

To determine whether intra-operative spontaneous electromyography (EMG) was superior to somatosensory evoked potentials (SSEP) in the prevention of iatrogenic sciatic nerve injury.

DESIGN

Prospective, consecutive.

SETTING

Tertiary referral, teaching Hospital in New York City.

PATIENTS

Seventy-four patients with acutely displaced acetabular fractures.

MAIN OUTCOME MEASURE

Group A consisted of 24 patients who underwent intraoperative sciatic nerve monitoring using SSEP only. Group B consisted of 50 patients who underwent monitoring using both SSEP and spontaneous EMG. Motor potentials were recorded from the tibialis anterior, peroneus longus, abductor hallucis, and flexor hallucis longus muscles. All patients had independent preoperative and postoperative evaluations by the same neurologist.

RESULTS

One iatrogenic sciatic nerve injury occurred in group A and none in group B. Prolonged sciatic nerve compromise, demonstrated by significant intraoperative SSEP changes, occurred 2.4 times per case in group A and only 0.8 times per case in group B. In group B, spontaneous EMG noted compromise an average of 3.6 times per case (p < 0.0001).

CONCLUSIONS

The results of this study support spontaneous EMG as feasible and superior to SSEP monitoring in detecting intraoperative sciatic nerve comprise in acute acetabular fracture surgery. Spontaneous EMG permits earlier detection of intraoperative sciatic nerve comprise, allowing a more rapid response of the surgical team to noxious nerve stimuli. This may prevent permanent neurologic sequellae.

An adenovirus mutant that replicates selectively in p53-deficient human tumor cells

The human adenovirus E1B gene encodes a 55-kilodalton protein that inactivates the cellular tumor suppressor protein p53. Here it is shown that a mutant adenovirus that does not express this viral protein can replicate in and lyse p53-deficient human tumor cells but not cells with functional p53. Ectopic expression of the 55-kilodalton EIB protein in the latter cells rendered them sensitive to infection with the mutant virus. Injection of the mutant virus into p53-deficient human cervical carcinomas grown in nude mice caused a significant reduction in tumor size and caused complete regression of 60 percent of the tumors. These data raise the possibility that mutant adenoviruses can be used to treat certain human tumors.

Radiometric characterization of a Penning discharge in the vacuum ultraviolet

We present a Penning discharge as a possible radiometric transfer standard source in the vacuum UV, primarily in the spectral region below 20 nm. Following the concept of Finley et al., we have designed a Penning source using NdFeB permanent magnets. Emphasis was put on simple operation, quick electrode exchangeability, and easy source readjustment. The radiant intensities of the emission lines from different ionization stages of both buffer gas atoms and atoms sputtered from the cathodes have been studied in various discharge conditions. For selected Al and buffer gas emission lines we determined the absolute radiant intensities by a comparison with the calculable spectral radiant power of the Berlin Electron Storage Ring. A comparison with data from our hollow-cathode transfer standard source is given.

Primary acute simian immunodeficiency virus infection of intestinal lymphoid tissue is associated with gastrointestinal dysfunction

Human immunodeficiency virus (HIV)-associated intestinal abnormalities can occur before immunodeficiency or infection with opportunistic enteropathogens. Rhesus macaques infected with simian immunodeficiency virus (SIV) develop an AIDS-like illness that frequently includes enteropathy. The development of enteropathy and its association with SIV infection in the intestinal tract was examined. By 1 week after infection, SIV-infected macrophages and T lymphocytes were detected in gut-associated lymphoid tissue. In contrast to findings in the asymptomatic stage, SIV-infected macrophages were numerous in primary and terminal stages of infection. An acute enteropathy syndrome was observed in the primary acute stage of infection. Functional abnormalities of absorptive epithelium, indicated by D-xylose malabsorption and decreased sucrase activity, occurred before the onset of diarrhea or opportunistic enteric infections. These findings indicate that macrophages and T cells in the intestinal tract are early targets of SIV infection and may play a critical role in the development of SIV-associated intestinal dysfunction.

Simian immunodeficiency virus infection of the gastrointestinal tract of rhesus macaques. Functional, pathological, and morphological changes

Gastrointestinal dysfunction and wasting are frequent complications of human immunodeficiency virus (HIV) infection. Nutrient malabsorption, decreased digestive enzymes and HIV transcripts have been documented in jejunal mucosa of HIV-infected patients; however, the pathogenesis of this enteropathy is not understood. Rhesus macaques infected with simian immunodeficiency virus (SIV) also exhibit diarrhea and weight loss; therefore, we investigated the use of this animal model to study HIV-associated intestinal abnormalities. A retrospective study of intestinal tissues from 15 SIV-infected macaques was performed to determine the cellular targets of the virus and examine the effect of SIV infection on jejunal mucosal morphology and function. Pathological and morphological changes included inflammatory infiltrates, villus blunting, and crypt hyperplasia. SIV-infected cells were detected by in situ hybridization in stomach, duodenum, jejunum, ileum, cecum, and colon. Using combined immunohistochemistry and in situ hybridization, the cellular targets were identified as T lymphocytes and macrophages. The jejunum of SIV-infected animals had depressed digestive enzyme activities and abnormal morphometry, suggestive of a maturational defect in proliferating epithelial cells. Our results suggest that SIV infection of mononuclear inflammatory cells in intestinal mucosa may alter development and function of absorptive epithelial cells and lead to jejunal dysfunction.

Distribution of SIV infection in the gastrointestinal tract of rhesus macaques at early and terminal stages of AIDS

Intestinal tissues from SIV-infected rhesus macaques with subclinical as well as with terminal SIV disease were evaluated for SIV infection. SIV-infected mononuclear cells were detected throughout the gastrointestinal tract in all animals. In early infection, SIV-infected cells were diffusely distributed in lymphoid tissue and lamina propria, whereas in late stages of the disease, the viral infection was more severe and widely disseminated. Lymphoid cells of the lamina propria and gut-associated lymphoid tissue were the primary targets of SIV.

Human immunodeficiency virus infection of enterocytes and mononuclear cells in human jejunal mucosa

Intestinal malabsorption is a recognized cause of malnutrition in patients infected with human immunodeficiency virus. However, the relationships among human immunodeficiency virus infection, morphological changes in the intestine, and development of intestinal malabsorption are not well established. Nine patients infected with human immunodeficiency virus underwent tests of intestinal absorption and jejunal biopsies for morphometric measurements, enzyme assays, and virus detection by in situ hybridization. Steatorrhea and low lactase activities were found in more than 85% of the patients. All biopsy specimens were abnormal with reversal of the ratio of villus length to crypt depth in seven and enlarged enterocyte nuclear size in nine. Human immunodeficiency virus was detected in five jejunal biopsy specimens, within villus enterocytes of one patient who had the most severe malabsorption of the group and in four other biopsy specimens in mononuclear infiltrating cells of the lamina propria. These results suggest that human immunodeficiency virus infection of the small intestinal mucosa is an early event that is associated with altered enterocyte differentiation and function.