[Heterotopic sebaceous glands in the esophagus: case report with review of the literature]

Heterotopia of sebaceous glands is a very rare endoscopically indistinct benign finding in the esophagus. To date only 30 cases have been reported in the literature. The lesions exhibit a considerable variation in number and size. No malignant transformation has yet been reported. From the pathologists' point of view an inflammatory or neoplastic process has to be excluded as the cause of the non-distinctive endoscopic findings.

Application of the OTSC system for the closure of fistulas, anastomosal leakages and perforations within the gastrointestinal tract

Until recently there has been no technique available which reproducibly and safely allowed endoscopic closures of penetrating defects within the digestive tract. With the new "over the scope clipping system" (OTSC system®), which regarding design and function is similar to a bear-trap, a method is available for the endoscopic closure of fistulas and perforations. Here, we present a series of 10 patients, in whom different penetrating defects within the digestive tract could be closed in 9 of 10 cases successfully by the OTSC system®: fistulas (esophagotracheal, esophagopleural, gastrocutaneous and colovesical), perforations (after mucosectomy, after papillotomy and PEG misplacement) and anastomosal leakages (after gastrotomy and gastrectomy). In another case we demonstrate our first experience with the OTSC system® for the prevention of perforations during deep endoscopic R 0 resection of a T 1(sm1)G1 sigmoideal cancer after initial R 1 resection.

Removal of over the scope clips (OTSC) with an Nd:YAG Laser

Until recently there has been no technique available which reproducibly and safely allows endoscopic closures of penetrating defects within the digestive tract. With the new "over the scope clipping system" (OTSC system), which regarding design and function is similar to a bear-trap, a method is available for the endoscopic closure of fistulas and perforations. The OTSC-systems are designed for permanent placement. However, in the case of misplacement or the need to remove the clip after healing of the defect, a technique for destroying and removing the clip should be available. We demonstrate for the first time the successful removal of the deeply penetrating OTSC system by using the Nd:YAG-Laser in 3 cases: (i) after closure of an oesophageal fistula, (ii) after closure of a perforation of the distal common bile duct in the roof of the papilla and (iii) after clip misplacement in a case of a wide oesophagomediastinal fistula resulting in a severe oesophageal stenosis. Clinically relevant thermal lesions were not observed after the procedure. If clinically necessary, the OTSC-system can be safely removed by the Nd:YAG Laser in centres for interventional endoscopy. Because of the small number of cases the method must still be considered as experimental and requires further validation. This will be possible with the help of a newly established OTSC registry ( www.endodo.de ).

[Gangliocytic paraganglioma--a rare cause of an upper gastrointestinal bleeding]

INTRODUCTION

Gangliocytic paraganglioma is a rare tumour, occurring nearly exclusively in the descending part of the duodenum. It is regarded as a mostly benign tumour but of unknown malignant potential, which rarely metastasises to local lymph nodes or distantly.

CASE REPORT

Here we report on a 62-year-old female patient with a marked microcytic anaemia with a haemoglobin concentration of 3.4 mg/dL. Oesophagogastroduodenoscopy showed an ulcerous periampullary tumour in the duodenum with a diameter of approximately 5 cm. Endoscopic ultrasonography showed no evidence of tumour infiltration of the tunica muscularis and of locoregional lymph node metastasis. Therefore, complete endoscopic resection of the tumour was achieved after ligating the tumour base by an endoloop using a dual channel endoscope. In a second step, the tumour base was resected by endoscopic submucosal dissection (ESD) and revealed no residual tumour. The histological evaluation showed a gangliocytic paranganglioma consisting of three specific cell types: epithelioid cells arranged in typical carcinoid-like patterns, spindle cells wrapped around nests of epithelioid cells and ganglion cells. All cell types expressed neuron-specific enolase (NSE) as a neuroendocrine marker. Synaptophysine was expressed mainly by the epithelioid and ganglion cells while the protein S 100 was expressed mainly by the spindle cells, which surround the epithelioid cell nests as a sustentacular network. The proliferation rate determined by Ki67 staining was only < 5 %.

CONCLUSION

Gangliocytic gangliocytomas of the duodenum can be safely removed by endoscopic submucosal dissection as long as there is no evidence of infiltration of the tunica muscularis or of local lymph node metastasis. Because of the unknown malignant potential, these patients have to be controlled by regular ultrasonographic and endosonographic procedures.

["Endoscopy in a stone quarry"--multiple pigment stones 6 weeks after delivery]

A 29-year-old African woman without any history of diseases was referred to our clinic because of recurrent abdominal pain. 6 weeks earlier she had delivered a healthy baby. Laboratory data revealed hypochromic microcytic anemia, elevated cholestatic liver enzymes, and an elevated bilirubin level of 2.2 mg/dl. Abdominal sonography showed choledocholithiasis. The endoscopic retrograde cholangiography showed the presence of more than 100 small stones in the intra- and extrahepatic bile ducts. An endoscopic papillotomy was performed and multiple small black stones were removed from the bile duct by basket into the duodenum. Because of the hypochromic microcytic anemia, the detection of pigment stones and the ethnic background of the patient we suspected a hemoglobinopathy. Hemoglobin electrophoresis showed 97 % HbC. The molecular genetic analysis revealed a homozygous mutation in codon 6 GAG > AAG for the beta globin chain (HbCC). HbC is a structurally abnormal hemoglobin with typical aggregates and tetragonal crystal formation which results in mild chronic hemolytic anemia. The cholezystectomy after 6 weeks was performed without complications.

A facilitated method for endoscopic interventions at the bile duct after Roux-en-Y reconstruction using double balloon enteroscopy

Endoscopic retrograde cholangiography (ERC) after Roux-en-Y reconstruction and modified BII surgery or duodenopancreatectomy is considerably more difficult than ERC under normal anatomic conditions. If the common bile in the afferent loop cannot be reached by a common lateral-viewing duodenoscope because of excessive intestinal length, it has recently become possible to use double balloon enteroscopy (DBE) for ERC to reach the common bile duct. Cannulating the bile duct via DBE in these postoperative settings remains one of the most difficult ERCP manipulations because of the lack of an Albarran lever and the use of extra long ERCP accessories. Here, we report on a facilitated method for endoscopic interventions at the bile duct in postoperative settings with a long afferent loop using DBE. For facilitation of interventions the enteroscope can be exchanged for a 110-cm-long conventional gastroscope after incision of the overtube in three quarters of its circumference. Care has to be taken that the pressure line for the balloon remains intact. The huge benefit of this facilitated method is the use of standard endoscopic material like guides, catheters and papillotomes.

[Pancreaticomediastinal fistula as a rare cause of recurrent pleural effusions]

A 45-year-old male with chronic alcoholism was transferred to our hospital with progressive dyspnoea, bilateral pleural effusions and ascites. Serum concentrations of lipase and CRP were increased. Pleural effusions recurred despite repeated thoracentesis, antibiotic therapy and total parenteral nutrition. A CT scan of chest and abdomen showed a lipomatous pancreas without signs of necrosis. Endosonography (EUS) demonstrated as signs of chronic pancreatitis an increased lobularity of the parenchyma without calcifications and two small cystic lesions in the pancreatic head. The pleural fluid lipase levels were markedly increased compared to a low lipase concentration in ascites. As an explanation for the pleural effusions ERCP showed a retroperitoneal fistula in the head/body region into the mediastinum and a stenosis of the pancreatic duct in the pancreatic head. For the ascites an inflammatory pathogenesis due to the exacerbation of chronic pancreatitis had to be assumed because the analysis showed an exudate with leukocytosis. After papillotomy via the pancreatic duct a 10 French wide 9 cm long stent was inserted into the pancreatic duct bridging the pancreatic fistula. Within 10 days pleural effusions had completely receded. After three weeks pancreaticography showed a total regression of the fistula and the stent was exchanged. After 6 weeks the pancreatic stent was removed with a lasting remission of the pleural effusions.

[ASCO-Update 2005--Highlights of the 41st Meeting of the American Society of Clinical Oncology/ASCO 2005]

Currently, the treatment of gastrointestinal cancers is rapidly changing due to the implementation of novel chemotherapeutic agents as well as the introduction of targeted therapies into treatment protocols. The following review provides an overview of the most important clinical trials in esophageal, gastric, colorectal, pancreatic and hepatobiliary cancer that were presented at the annual meeting of the American Society of Clinical Oncology.

Randomised phase II evaluation of irinotecan plus high-dose 5-fluorouracil and leucovorin (ILF) vs 5-fluorouracil, leucovorin, and etoposide (ELF) in untreated metastatic gastric cancer

An open-label randomised comparison of efficacy and tolerability of irinotecan plus high-dose 5-fluorouracil (5-FU) and leucovorin (LV) (ILF) with etoposide plus 5-FU/LV (ELF) in patients with untreated metastatic or locally advanced gastric cancer. One cycle of ILF comprised six once-weekly infusions of irinotecan 80 mg m⁻², LV 500 mg m⁻², 24-h 5-FU 2000 mg m⁻², and ELF comprised three once-daily doses of etoposide 120 mg m⁻², LV 300 mg m⁻², 5-FU 500 mg m⁻². In all, 56 patients received ILF and 58 ELF. Median age was 62 years, Karnofsky performance 90%, and disease status was comparable for both arms. The objective clinical response rates after 14 weeks treatment (primary end point) were 30% for ILF and 17% for ELF (risk ratio (RR) 0.57, 95% confidence interval (CI) 0.29–1.13, P=0.0766). Overall response rates over the entire treatment period for ILF and ELF were 43 and 24%, respectively (RR 0.56, 95% CI 0.33–0.97; P=0.0467). For ILF and ELF, respectively, median progression-free survival was 4.5 vs 2.3 months, time to treatment failure was 3.6 vs 2.2 months (P=0.4542), and overall survival was 10.8 vs 8.3 months (P=0.2818). Both regimens were well tolerated, the main grade 3/4 toxicities being diarrhoea (18%, ILF) and neutropenia (57%, ELF). The data from this randomised phase II study indicate that ILF provides a better response rate than ELF, and that ILF should be investigated further for the treatment of metastatic gastric cancer.

Weekly oxaliplatin, high-dose folinic acid and 24h-5-fluorouracil (FUFOX) as salvage therapy in metastatic colorectal cancer patients pretreated with irinotecan and folinic acid/5-fluorouracil regimens

Irinotecan (CPT-11), oxaliplatin (OXA) and different folinic acid(FA) modulated 5-fluorouracil (5-FU) regimens are active as first-and second-line chemotherapy of metastatic colorectal cancer. However, the best palliative sequence of these substances is still unclear. After CPT-11 containing regimens the optimal salvage protocol has not yet been defined. Here, we retrospectively analysed the weekly ambulant combination of OXA with continuous FA/5-FU (FUFOX) after two different CPT-11 containing chemotherapeutic regimens.

PATIENTS

During October 1999 and May 2001, 20 patients (median 62; 48-74 years) were included who had disease progression after CPT-11 /bolus FA/5-FU (Saltz; 7 patients, group A) or after FA/5-FU followed by CPT-11 alone (13 patients, group B). OXA(60 mg/m2) was given for 2 hours prior to FA (500 mg/m2) as 2 h-infusion and continuous 5-FU (2.600 mg/m2) for 24 h-infusion on day 1,8,15 and 22 (repeated after week 6).

RESULTS

FUFOX was administered 252 times. About 1,203 mg OXA per patient was given. Toxicities NC-CrC grade 3 were observed in 10 patients: diarrhoea (4), mucositis (5), nausea/vomiting (2), anaemia (1), leucopenia (1), thrombopenia (1) and hand-foot-syndrome (1), 3 patients showed minor remissions, II patients stable disease. The median time to progression was 16(0-39) weeks. The median survival from start of FUFOX and from start of any palliative therapy was 33 (5-65) and 99 (44-200) weeks for all patients, respectively.

CONCLUSIONS

FUFOX was efficient for additional tumour control in 70% of patients pretreated with CPT-11/5-FU based regimens. Sequential palliative treatment can lead to prolonged survival.

[Prospective feasibility study of chest X-ray vs. thoracic MRI in breath-hold technique at an open low-field scanner]

PURPOSE

MR investigations using a breath-hold sequence at an open low-field MR had to be compared to chest X-rays in patients with a wide spectrum of cardio-thoracic pathologies.

MATERIAL AND METHODS

114 patients and three volunteers who actually received a chest X-ray due to different indications underwent triplanar breath-hold (17 - 20 s) True-FISP sequence using a 0.2 T low-field MR (Siemens Magnetom Open, TR/TE/alpha: 7.3/3.5/80 degrees, SD: 10 mm, Pixel: 2.81 x 1.41 mm) a mean of 5.1 (+/- 8.2) days later.

RESULTS

Signal-to-noise ratio as basics for pattern recognition was 3.2 in nodule, 5.0 in infiltration, and 12.0 in effusion, and therefore True-FISP is usable for the detection of these findings. MRI demonstrated nodules (89 % vs. 57 %), infiltration (81 % vs. 71 %), pleural effusions (86 % vs. 75 %), pericardial effusions (100 % vs. 21 %) and pulmonary congestion (90 % vs. 80 %) clearly more frequently compared to chest X-ray.

DISCUSSION

MRI of the lung has been implemented successfully at an open low-field MR system. Diagnostic safety and accuracy are at least comparable to those of chest X-ray. The lack of superimposition led to a major improvement in the detection of pericardial effusions and nodules, and an increase in identification of infiltration, pleural effusion, and pulmonary congestion.

Identification of a tumor-associated contact-dependent activity which reversibly downregulates cytolytic function of CD8+ T cells

Tumors elicit an immune response in hosts and yet, paradoxically, often grow progressively with fatal consequences. This phenomenon has been attributed to the possible expression by tumor cells of immunomodulatory factors that overcome the anti-tumor effector functions of both specific and non-specific immune cells. This study reports on the ability of the methylcholanthrene-induced fibrosarcoma, Meth A, as well as other tumors of varied histological origins to downregulate the lytic activity of CD8+ T cells. The suppressive activity is contact-dependent and reversible. As tumor-bearing hosts are rarely immunosuppressed systemically, these findings may explain how local events within the tumor bed subvert the specific anti-tumor immune response.

Expression of stress protein gp96, a tumor rejection antigen, in human colorectal cancer

Preparations of stress protein gp96 from tumor cells are active as tumor vaccines by eliciting immune responses against mixtures of individual tumor peptide antigens which are complexed to gp96. Due to the individual antigenicity of tumors, a vaccine consisting of tumor-derived gp96 has to be prepared individually for each patient from autologous tumor tissue. So far, gp96 expression by human tumors has not been analyzed. Here, we report stable and mostly homogenous expression of gp96 by colorectal cancer, which was enhanced compared to surrounding tumor stroma in 70% to 80% of colorectal cancer specimens. Fewer non-metastatic than metastatic primary cancer specimens showed enhanced gp96 expression. Glucose deprivation increased gp96 protein and RNA expression in the human colon cancer cell line HT-29 in accordance with the role of gp96 as a glucose-regulated stress protein. Additionally, TNF-alpha, interferons and other cytokines induced an increase of gp96 RNA expression in HT-29 cells, suggesting that gp96 expression by colorectal cancer cells can be influenced by different methods of immunomodulation. The stable and homogenous expression of gp96 in 19 primary and metastatic colorectal cancer specimens and the up-regulation of gp96 in colon cancer cells by glucose deprivation point to an essential role of this stress protein in colorectal cancer, presumably by protecting against hostile conditions of the tumor micro-environment like glucose deprivation. In view of these results, loss of gp96 expression by colorectal cancer cells as an immune escape mechanism is unlikely.

Expression of stress protein gp96, a tumor rejection antigen, in human colorectal cancer

Preparations of stress protein gp96 from tumor cells are active as tumor vaccines by eliciting immune responses against mixtures of individual tumor peptide antigens which are complexed to gp96. Due to the individual antigenicity of tumors, a vaccine consisting of tumor-derived gp96 has to be prepared individually for each patient from autologous tumor tissue. So far, gp96 expression by human tumors has not been analyzed. Here, we report stable and mostly homogenous expression of gp96 by colorectal cancer, which was enhanced compared to surrounding tumor stroma in 70% to 80% of colorectal cancer specimens. Fewer non-metastatic than metastatic primary cancer specimens showed enhanced gp96 expression. Glucose deprivation increased gp96 protein and RNA expression in the human colon cancer cell line HT-29 in accordance with the role of gp96 as a glucose-regulated stress protein. Additionally, TNF-alpha, interferons and other cytokines induced an increase of gp96 RNA expression in HT-29 cells, suggesting that gp96 expression by colorectal cancer cells can be influenced by different methods of immunomodulation. The stable and homogenous expression of gp96 in 19 primary and metastatic colorectal cancer specimens and the up-regulation of gp96 in colon cancer cells by glucose deprivation point to an essential role of this stress protein in colorectal cancer, presumably by protecting against hostile conditions of the tumor micro-environment like glucose deprivation. In view of these results, loss of gp96 expression by colorectal cancer cells as an immune escape mechanism is unlikely.

Expression of stress protein gp96, a tumor rejection antigen, in human colorectal cancer

Preparations of stress protein gp96 from tumor cells are active as tumor vaccines by eliciting immune responses against mixtures of individual tumor peptide antigens which are complexed to gp96. Due to the individual antigenicity of tumors, a vaccine consisting of tumor-derived gp96 has to be prepared individually for each patient from autologous tumor tissue. So far, gp96 expression by human tumors has not been analyzed. Here, we report stable and mostly homogenous expression of gp96 by colorectal cancer, which was enhanced compared to surrounding tumor stroma in 70% to 80% of colorectal cancer specimens. Fewer non-metastatic than metastatic primary cancer specimens showed enhanced gp96 expression. Glucose deprivation increased gp96 protein and RNA expression in the human colon cancer cell line HT-29 in accordance with the role of gp96 as a glucose-regulated stress protein. Additionally, TNF-alpha, interferons and other cytokines induced an increase of gp96 RNA expression in HT-29 cells, suggesting that gp96 expression by colorectal cancer cells can be influenced by different methods of immunomodulation. The stable and homogenous expression of gp96 in 19 primary and metastatic colorectal cancer specimens and the up-regulation of gp96 in colon cancer cells by glucose deprivation point to an essential role of this stress protein in colorectal cancer, presumably by protecting against hostile conditions of the tumor micro-environment like glucose deprivation. In view of these results, loss of gp96 expression by colorectal cancer cells as an immune escape mechanism is unlikely.

Weekly oxaliplatin, high-dose infusional 5-fluorouracil and folinic acid as palliative third-line therapy of advanced colorectal carcinoma

The efficacy of oxaliplatin combined with high-dose 5-fluorouracil (5-FU) and folinic acid (FA) as an outpatient salvage treatment for patients with metastasized colorectal cancer was retrospectively analyzed in one center. Tumor progression had occurred for the majority of patients during two regimens (n = 11) otherwise during one (n = 1) regimen of prior 5-FU-based chemotherapy, which had been applied in a standardized sequential fashion. As third-line therapy oxaliplatin was infused intravenously over 2 h at a dose of 60 mg/m2 prior to a 2-h infusion of FA (500 mg/m2). 5-FU (2,600 mg/m2) was subsequently given over 24 h. A favorable response was observed in 9/12 (75%) of the heavily pretreated patients, including partial remissions in 3/12, minor responses in 2/12 and stable disease in 4/12 patients. The median progression free time was 23 weeks (interquartile range i. r. 0-28) for all patients, the median survival time from start of third-line therapy 55 weeks (i. r. 40-86). The median survival time from the beginning of first-line palliative chemotherapy was 34 months (i. r. 25-45 months). The highest toxicity was WHO grade III and was observed in six patients: Nausea (2), diarrhea (3), vomiting (2) and peripheral neuropathy (1). The quality of life was not adversely affected by the oxaliplatin/5-FU/FA-regimen as assessed by the EORTC QLQ-C30 questionnaire. Thus, the results show the efficiency and low toxicity of oxaliplatin/high-dose 5-FU/FA as palliative third-line therapy of patients with metastasized colorectal cancer and emphasize that sequential palliative chemotherapy may lead to extended survival of these patients.

Stress protein/peptide complexes derived from autologous tumor tissue as tumor vaccines

Vaccination of inbred mice with tumor-derived stress proteins hsp70, hsp90, and gp96/grp94 elicits a protective immunity to the tumor from which the vaccine was purified. There is now comprehensive experimental evidence that the antigenicity of tumor-derived hsp70, hsp90, and gp96 preparations results from diverse arrays of endogenous peptide antigens complexed with these stress proteins. Vaccination with tumor-derived stress protein/peptide complexes leads to their uptake and processing by professional antigen-presenting cells and to presentation of associated tumor peptide antigens to cytotoxic T cells. This induces a tumor-specific cytotoxic T cell response. The attractiveness of the concept of using tumor-derived stress proteins as vaccines is derived from two observations: (i) tumor stress protein vaccines mirror the individual antigenicity of a tumor, which results from random mutations due to genetic instability; and (ii) stress proteins represent powerful adjuvants for the peptide antigens complexed to them.

T cell specificity and cross reactivity towards enterobacteria, bacteroides, bifidobacterium, and antigens from resident intestinal flora in humans

BACKGROUND

T cell responses to normal intestinal bacteria or their products may be important in the immunopathogenesis of chronic enterocolitis.

AIMS

To investigate the T cell specificity and cross reactivity towards intestinal bacteria.

PATIENTS/METHODS

T cell clones were isolated with phytohaemagglutinin from peripheral blood and biopsy specimens of inflamed and non-inflamed colon from five patients with inflammatory bowel disease (IBD) and two controls. T cell clones were restimulated with anaerobic Bacteroides and Bifidobacteria species, enterobacteria, and direct isolates of aerobic intestinal flora. T cell phenotype was analysed by single-cell immunocyte assay.

RESULTS

Analysis of 96 T cell clones isolated from peripheral blood and biopsy specimens from two patients with IBD showed that both Bifidobacterium and Bacteroides species specifically stimulate proliferation of CD4+TCRalphabeta+ T cell clones from both sites and that cross reactivity exists between these anaerobic bacteria and different enterobacteria. Analysis of 210 T cell clones isolated from three patients with IBD and two controls showed that indigenous aerobic flora specifically stimulate T cell clones from peripheral blood and biopsy specimens from a foreign subject. Some of these flora specific T cell clones were cross reactive with defined enterobacteria. In addition, T cell clones stimulated by their own indigenous aerobic flora were identified in patients with IBD.

CONCLUSION

Immune responses to antigens from the intestinal microflora involve a complex network of T cell specificities.

Dominant TCRB-V-J chain usage and clonal expansion of sarcoma-reactive CD4+ HLA-DR-restricted T cells suggest a limited set of immunodominant sarcoma antigens

Tumor-reactive CD4+ T cells have been isolated from tumor patients, and their specifity but not T-cell receptor (TCR) repertoire has been analyzed. Since we have described CD4+ sarcoma-reactive T-cell clones, we now sought to determine whether the TCR repertoire of these clones provides information on the spectrum of recognized sarcoma antigens. We analyzed the TCR beta (TCRB) chain repertoire of 19 CD4+ HLA-DR-restricted T-cell clones reactive with the autologous sarcoma cell line MZ-MES-1, with HLA-DR-matched tumor cell lines of different tissue origins and B-cell blasts. We identified 7 different clonotypes, which used a limited set of TCRBV and TCRBJ segments. Although the CDR3 of the different clonotypes was diverse, repeated restimulation with sarcoma cells led to a monoclonal expansion of T cells with particular TCR clonotypes in 5/6 mixed lymphocyte tumor cell cultures (MLTC). One clonotype was found in 2 independent MLTC experiments. Sarcoma-reactive T cells were demonstrated in patient tumor-infiltrating lymphocytes (TIL) and peripheral blood mononuclear cells (PBMC) by clonotypic PCR. Our results indicate a limited number of immunodominant antigens expressed by the sarcoma cells. The junctional diversity of the TCR clonotypes shows that these antigens did not lead to extensive negative thymic selection as classical autoantigens would have. Therefore, the recognized antigens might represent cryptic autoantigens related to cellular transformation or proliferation.

Contrary roles of IL-4 and IL-12 on IL-10 production and proliferation of human tumour reactive T cells

The cytokine profile of tumour reactive T cells is likely to play a central role in their function. However, little is known about how cytokine patterns of tumour reactive T cells can be regulated. Here, the authors investigated the influence of exogenous regulatory cytokines in addition to interleukin-2 (IL-2) on cytokine patterns and the proliferation of T cells recognizing an autologous sarcoma cell line. In this system, IL-4 and IL-12 showed the most polarizing influences on tumour reactive T cells. Exogenous IL-4 induced a predominant production of IL-4 while decreasing the interferon-gamma (IFN-gamma) and IL-10 production by tumour reactive T cells. It also stimulated the growth of tumour reactive CD4+ T cell clones. In contrast, IL-12 substantially increased the production of IL-10 and IFN-gamma. This was accompanied by a growth inhibition of tumour reactive T cells. The growth of CD4+ tumour reactive T cells was also suppressed by exogenous IL-10. This study shows that cytokine patterns and proliferation tumour reactive T cells can be significantly influenced by exogenous cytokines and confirms the hypothesis of a negative feedback loop of IL-12 by the induction of IL-10 in the context of human tumour reactive T cells.

Tumor-specific cell surface expression of the-KDEL containing, endoplasmic reticular heat shock protein gp96

Heat shock protein (HSP) gp96/grp94 contains a signal peptide at the amino terminus and a -KDEL sequence at the carboxy terminus and is a major component of the lumen of the mammalian endoplasmic reticulum (ER). We show, by a number of immunolocalization methods using light and electron microscopy, that a significant proportion of intact gp96 molecules is also expressed on the cell surface. Surface gp96 molecules truly represent surface expression and do not result from adventitious deposition of gp96 released by dead cells on to the live cells in culture. Cell surface expression of gp96 is enhanced by heat shock and exposure to reducing agents. Gp96 molecules are not released from plasma membranes by repeated salt washes, and gp96 is not an integral membrane protein. Our observations suggest that gp96 and perhaps other HSPs are anchored to the cell surface as part of larger molecular complexes, which also transport them to the cell surface.

Impaired HLA-class-I stability in a sarcoma cell line which stimulates exclusively HLA-class-II-restricted autologous T cells

Defects in the generation and transport of antigenic peptides within tumor cells will lead to the expression of unstable HLA-class-I molecules on the cell surface. These defects will allow tumor cells to escape an MHC-class-I-restricted T-cell response. Recently, we described an exclusively HLA-class-II-restricted autologous T-cell response against a human sarcoma cell line MZ-MES-1 in vitro. Here, we show that surface HLA-class-I molecules of MZ-MES-1 cells are unstable at physiological temperature. HLA-class-I surface expression of MZ-MES-1 cells could be strongly enhanced by culture at low temperature in contrast to various other cell lines analyzed in parallel. Furthermore, culture at low temperature decreased shedding of HLA-class-I molecules by MZ-MES-1 cells. Incubation with allele-specific HLA-class-I-binding peptides strongly increased HLA-class-I surface expression of MZ-MES-1 sarcoma cells and TAP-deficient T2 cells in contrast to other tumor and B-cell lines tested in parallel. IFN-gamma enhanced the expression of TAP, LMP and HLA-class-I proteins in MZ-MES-1 cells. However, the impaired stability of HLA-class-I surface molecules of MZ-MES-1 could not be reversed by IFN-gamma. These results show a new example of impaired HLA-class-I stability of a human tumor which coincides with lack of HLA-class-I-restricted autologous T cells recognizing this tumor. It underlines the importance of MHC-class-II-restricted T-cell responses against tumors with these defects.

Tumor-specific cell surface expression of the-KDEL containing, endoplasmic reticular heat shock protein gp96

Heat shock protein (HSP) gp96/grp94 contains a signal peptide at the amino terminus and a -KDEL sequence at the carboxy terminus and is a major component of the lumen of the mammalian endoplasmic reticulum (ER). We show, by a number of immunolocalization methods using light and electron microscopy, that a significant proportion of intact gp96 molecules is also expressed on the cell surface. Surface gp96 molecules truly represent surface expression and do not result from adventitious deposition of gp96 released by dead cells on to the live cells in culture. Cell surface expression of gp96 is enhanced by heat shock and exposure to reducing agents. Gp96 molecules are not released from plasma membranes by repeated salt washes, and gp96 is not an integral membrane protein. Our observations suggest that gp96 and perhaps other HSPs are anchored to the cell surface as part of larger molecular complexes, which also transport them to the cell surface.

Weekly high-dose leucovorin versus low-dose leucovorin combined with fluorouracil in advanced colorectal cancer: results of a randomized multicenter trial. Study Group for Palliative Treatment of Metastatic Colorectal Cancer Study Protocol 1

PURPOSE

To determine the most effective dose of leucovorin (folinic acid [FA]) within a weekly bolus fluorouracil (FU) schedule, we conducted a randomized multicenter trial to compare therapeutic effects and toxicity of high-dose FA versus low-dose FA combined with FU at equal doses in both treatment groups.

PATIENTS AND METHODS

Patients with measurable inoperable or metastatic colorectal cancer were randomized to receive weekly FU 500 mg/m2 by intravenous (IV) bolus combined with high-dose FA 500 mg/m2 (group A) or low-dose FA 20 mg/m2 (group B) by 2-hour infusion.

RESULTS

Of 291 assessable patients (group A, n = 148; group B, n = 143), we observed, in group A, complete response (CR)/partial response (PR) in 32 (21.6%), no change (NC) in 64 (43.2%), and progressive disease (PD) in 52 (35.1%); and in group B, CR/PR in 25 (17.5%), NC in 63 (44.1%), and PD in 55 (38.5%). The median response duration was 24.8 weeks in group A and 23.1 weeks in group B. Median progression-free intervals were 29.3 weeks (group A) and 30 weeks (group B). The median survival time was 55.1 weeks in group A and 54.1 weeks in group B. Overall toxicity was moderate. Mild nausea and vomiting, and stomatitis were common side effects in both groups. The incidence of World Health Organization (WHO) grade III/IV diarrhea was significantly higher in group A (40 v 23 patients). Severe side effects were observed only in a minority of patients in both arms. WHO grade IV diarrhea was observed in seven patients: four in group A and three in group B. The rate of toxicity-related adjustments of dose and schedule was comparable in both groups.

CONCLUSION

High-dose FA/FU is not superior to low-dose FA/FU within a weekly treatment schedule. Response rates and survival were comparable in both treatment arms. Treatment-related toxicity was higher in group A (high-dose FA). Therefore, low-dose FA combined with weekly FU may be considered the preferred treatment for metastatic colorectal cancer.

Heat shock protein-peptide complexes for use in vaccines

The heat shock proteins gp96, HSP70, and HSP90 are complexed to a diverse array of cellular proteins and peptides as a consequence of their chaperone functions. There is good experimental evidence that vaccination with these heat shock protein-peptide complexes elicit immune responses against chaperoned peptide antigens. As shown with gp96, this requires internalization of the heat shock protein-peptide complexes by macrophages and processing of the chaperoned peptides for class I restricted presentation. Via this process, primarily CD8+ antigen-specific T cells are primed by gp96 vaccination. This might represent a general mechanism for priming of MHC-class I restricted T cells by professional antigen-presenting cells. At least gp96 has been shown to be associated with peptides that are not selected by the MHC haplotype of the harboring cell. This allows for immunization with gp96-peptide complexes across MHC barriers, for example against shared tumor antigens or viral antigens.

Specificities and functions of CD4+ HLA class II-restricted T cell clones against a human sarcoma: evidence for several recognized antigens

CD4+ T cells play an important role for tumor immunity in animal tumor models, yet there are few reports about the role of CD4+ HLA class II-restricted T cells in the immune response against human tumors. Against a human sarcoma exclusively CD4+, T cell clones could be established. These T cell clones were cytotoxic and secreted TNF and additional cytokines in response to the IFN-gamma-treated, HLA class II-positive autologous sarcoma cells. Several Ags were recognized by representative T cell clones: an Ag presented by HLA-DR and specific for the sarcoma; Ags presented by both HLA-DR alleles of the sarcoma, HLA-DR4 and -15, and shared by allogenic HLA-DR matched cell lines of different tissue lineages, including B cell blasts; and a sarcoma Ag presented by HLA-DP or DQ. Cytokine profiles of sarcoma-reactive T cell clones were dependent on the cytokine environment present during establishment of the T cell clones. The addition of exogenous IL-4 shifted the cytokine patterns of sarcoma-reactive T cell clones from Th1-like patterns to Th0/Th2-like patterns and decreased IL-10 production. TNF, IFN-gamma, IL-4, and supernatants of T cell clones induced HLA-DR expression on the sarcoma cells and, thus, were able to enhance Ag presentation. This autologous T cell response to a human sarcoma represents a new model for HLA class II-restricted T cell responses to human tumors.

Specificities and functions of CD4+ HLA class II-restricted T cell clones against a human sarcoma: evidence for several recognized antigens

CD4+ T cells play an important role for tumor immunity in animal tumor models, yet there are few reports about the role of CD4+ HLA class II-restricted T cells in the immune response against human tumors. Against a human sarcoma exclusively CD4+, T cell clones could be established. These T cell clones were cytotoxic and secreted TNF and additional cytokines in response to the IFN-gamma-treated, HLA class II-positive autologous sarcoma cells. Several Ags were recognized by representative T cell clones: an Ag presented by HLA-DR and specific for the sarcoma; Ags presented by both HLA-DR alleles of the sarcoma, HLA-DR4 and -15, and shared by allogenic HLA-DR matched cell lines of different tissue lineages, including B cell blasts; and a sarcoma Ag presented by HLA-DP or DQ. Cytokine profiles of sarcoma-reactive T cell clones were dependent on the cytokine environment present during establishment of the T cell clones. The addition of exogenous IL-4 shifted the cytokine patterns of sarcoma-reactive T cell clones from Th1-like patterns to Th0/Th2-like patterns and decreased IL-10 production. TNF, IFN-gamma, IL-4, and supernatants of T cell clones induced HLA-DR expression on the sarcoma cells and, thus, were able to enhance Ag presentation. This autologous T cell response to a human sarcoma represents a new model for HLA class II-restricted T cell responses to human tumors.

New cell lines of gastric and pancreatic cancer: distinct morphology, growth characteristics, expression of epithelial and immunoregulatory antigens

Two new cell lines from stomach cancers and one from a pancreatic carcinoma are presented. MZ-GC-1 was established from a hepatic metastasis of a well differentiated gastric adenocarcinoma. MZ-GC-2 was derived from ascites induced by a poorly differentiated gastric adenocarcinoma. MZ-PC-1 originated from the pleural effusion of a moderately well differentiated pancreatic ductal adenocarcinoma. MZ-GC-1 cells were adherent and partially polarized, connected tightly via desmosomes. In contrast MZ-GC-2 cells consisted of slightly adherent or floating subpopulations and displayed no desmosomes. MZ-PC-1 cells were adherent and showed polarized growth, connected by apical junctional complexes. Cell doubling times were 7 days for MZ-GC-1 and 45 h for MZ-GC-2 and MZ-PC-1 cells. MZ-GC-2 and MZ-PC-1 gave rise to nude mouse tumours, resembling the original lesions. Chromosome analysis of the cell lines revealed a high range of numerical abnormalities. Each cell line had cytokeratin patterns fitting well to typical in vivo patterns. Furthermore the cell lines expressed a panel of antigens typical for gastrointestinal epithelia. Unique for MZ-PC-1 were high amounts of secreted Ca19-9. gamma-Interferon enhanced HLA-class I antigens up to twofold and induced ICAM-1 expression on each cell line. HLA-class II antigens were differentially enhanced by gamma-interferon. Due to their distinct characteristics the three tumour cell lines may be useful models in the investigation of the cell biology and immunogenicity of gastrointestinal tumours.

Treatment of advanced pancreatic cancer with 5-fluorouracil, folinic acid and interferon alpha-2A: results of a phase II trial

Interferon alpha-2a (IFN-alpha) and folinic acid (FA) have been shown to modulate the cytotoxic effects of 5-fluorouracil (5-FU) in the treatment of cancer. A phase II study was initiated to evaluate the effect of a combination of 5-FU/FA/IFN-alpha in patients with advanced pancreatic cancer. Sixty previously untreated patients with advanced adenocarcinoma of the pancreas were treated with 500 mg m-2 FU via an intravenous bolus 1 h after the initiation of a 2 h infusion of 500 mg m-2 FA. Before starting the FA infusion, 6 million units (MU) of IFN-alpha was administered subcutaneously. The treatment was repeated once a week. Of 57 evaluable patients, eight (14%) had a partial response (PR), eight (14%) a minor response (MR) and 28 (49%) no change of disease (NC). Thirteen patients (23%) had progressive disease (PD). The median survival time was 10 months for all patients, 22 months for patients with partial remission and 5 months for patients with progressive disease. Many patients with tumour-related pain whose tumours were affected in terms of PR, MR, NC were free of pain during treatment with this regimen (22/36 patients). The common toxicities observed were fever (56%), nausea (37%) and diarrhoea (33%). These data suggest that biochemical modulation of 5-FU with FA and IFN-alpha has some positive effects in the treatment of pancreatic cancer of moderate toxicity.

Frequency analysis of tumor-reactive cytotoxic T lymphocytes in peripheral blood of a melanoma patient vaccinated with autologous tumor cells

A limiting-dilution assay was developed and used to determine the frequency of autologous tumor-reactive cytotoxic T lymphocytes (CTL) in peripheral blood of a melanoma patient MZ2, who has been free of detectable disease since several years. In this patient, the frequencies of tumor-reactive CTL spontaneously varied only by a factor of 1.5. After vaccinations with autologous mutagenized and lethally irradiated tumor cells a two- to tenfold increase in frequencies of tumor-reactive CTL was found within the first 2 weeks. Thereafter, CTL frequencies returned to values measured prior to vaccinations. We conclude, that the limiting-dilution assay applied in this study can detect changes in the T cell response to autologous tumor cells. The frequency of tumor-reactive CTL determined with this approach can serve as an immunological parameter for monitoring the T cell response to autologous tumor cells in individual cancer patients receiving tumor cell vaccinations.

Protective cellular immunity against a spontaneous mammary carcinoma from ras transgenic mice

Mammary carcinomas of v-Ha-ras transgenic mice closely resemble human breast cancer in their multi-step nature and in the requirement of genetic, hormonal and somatic mutational events for full-scale malignancy. We demonstrate that spontaneous breast cancers derived from v-Ha-ras transgenic FVB (H-2q) mice are highly immunogenic and that they elicit a protective T cell response. A continuous tumor cell line OM-2 has been established from a progressively growing mammary tumor and three sublines OM-10, OM-12 and OM-14 have been derived by in vivo passage of OM-2. All lines express the v-Ha-ras gene product and surface MHC class I. The parental OM-2 line is highly immunogenic and behaves like a regressor tumor. The regression of OM-2 is mediated by CD8+ T lymphocytes, although CD4+ lymphocytes also appear to play a limited role. Cytotoxic T lymphocytes (CTLs) obtained from mice immunized with OM-2 show MHC class I-restricted, specific T cell cytotoxicity against OM-2 but not normal fibroblasts derived from ras transgenic mice. The anti-OM-2 CTLs lyse the OM-2 sublines OM-12 and OM-14, although to a lesser degree than OM-2, and do not lyse OM-10, in spite of the fact that all cell lines express comparable levels of activated ras and MHC class I. Our studies represent the first analysis of protective T cell response to breast cancer and demonstrate that contrary to expectation, the spontaneous breast cancers are highly immunogenic and that the immune response does not appear to be directed to activated ras.

Membranes activate tumor- and virus-specific precursor cytotoxic T lymphocytes in vivo and stimulate tumor-specific T lymphocytes in vitro: implications for vaccination

Plasma membranes contain the entire antigenic repertoire of a cell in the form of processed antigens presented as peptides by major histocompatibility complex (MHC) class I molecules. We report here that plasma membranes but not internal membranes of cognate tumors stimulate murine fibrosarcoma and human melanoma-specific cytotoxic T lymphocyte (CTL) clones in vitro in an antigen-specific. MHC class I-restricted manner. Although stimulation of CTLs by class I-peptide complexes on reconstituted membranes has been documented before, this is the first demonstration of stimulation of cloned CTLs by natural, endogenously processed MHC class I-peptide complexes on plasma membranes. In addition to their ability to stimulate CTLs in vitro, immunization of syngeneic mice with membranes derived from ultraviolet-induced tumor cells, SV40 transformed fibroblasts, or influenza-infected fibroblasts elicits an antigen-specific, MHC class I restricted primary CTL response. To the best of our knowledge, this is also the first demonstration of the ability of cellular membranes to prime an MHC class I-restricted CTL responses in vivo. The ability of membranes to prime a CTL response in vivo suggests that they may be used as T-cell vaccines against tumors or infectious viruses. This approach circumvents the difficulties in generation of human tumor cell lines and identification of CTL-recognized determinants for vaccination and avoids some of the risks associated with whole-cell vaccination such as inoculation of patients with immunosuppressive factors, transforming DNA, or infectious viruses.

Heat shock protein vaccines against cancer

Vaccination of mice with heat shock proteins (HSPs) derived from a tumor makes the mice resistant to the tumor from which the HSP was obtained. This phenomenon has been demonstrated with three HSPs--gp96, hsp90, and hsp70. Vaccination with HSPs also elicits antigen-specific cytotoxic T lymphocytes (CTLs). The specific immunogenicity of HSPs derives apparently, not from the HSPs per se, but from the peptides bound to them. These observations provide the basis for a new generation of vaccines against cancer. The HSP-based cancer vaccines circumvent two of the most intractable hurdles to cancer immunotherapy. One of them is the possibility that human cancers, like cancers of experimental animals, are antigenically distinct. The prospect of identification of immunogenic antigens of individual cancers from patients is daunting to the extent of being impractical. The observation that HSPs chaperone antigenic peptides of the cells from which they are derived circumvents this extraordinary hurdle. Second, most current approaches to cancer immunotherapy focus on determining the CTL-recognized epitopes of cancer cell lines. This approach requires the availability of cell lines and CTLs against cancers. These reagents are unavailable for an overwhelming proportion of human cancers. In contrast, the HSP-based vaccines do not depend on the availability of cell lines or CTLs nor do they require definition of the antigenic epitopes of cancer cells. These advantages, among others, make HSPs attractive and novel immunogens against cancer.

Recovery of retinal pigment epithelial function after ischemia in the rabbit

Survival of the rabbit retinal pigment epithelium (RPE) after ischemia was studied. The ischemia was induced by elevating intraocular pressure; retinal and RPE function were monitored by electrophysiologic recordings. The b-wave recovered to control amplitude in 1-4 hr after 30-60 min of ischemia, but it never recovered more than about 50% amplitude after 90 min of ischemia. The c-wave recovered after 30 min of ischemia but was replaced by a negative response after 60-90 min of ischemia. The RPE hyperosmolarity response was normal after 60 min of ischemia, but it was severely depressed after 90 min of ischemia. The RPE response to acetazolamide (cornea positive in the rabbit) was lost after both 60 and 90 min of ischemia. These results suggest that different components of RPE function have different tolerances to ischemia and is consistent with evidence that the RPE electrophysiologic responses differ in mechanism and response to disease.

Tumor-specific immunogenicity of stress-induced proteins: convergence of two evolutionary pathways of antigen presentation?

Stress-induced proteins (hsps) elicit tumor-specific immunity to a number of murine tumors. Specificity of this immunity is puzzling in view of the fact that no tumor-specific DNA sequence polymorphisms have been identified in stress-induced genes, nor is there evidence for tumor-specific posttranslational modification of hsps. In this light, the possibility that hsps may not be antigenic per se, but may be carriers of antigenic moieties such as peptides, and may be accessory antigen-presenting molecules, is considered. A model where an hsp molecule such as gp96 acts as an intermediate in presentation of peptides to MHC is discussed and it is suggested that the hsp and MHC antigens are mediators of independent but functionally convergent phylogenetic pathways.