Biomedical subjects

Jürgen Weitz

Publications and source records attributed to Jürgen Weitz.

At least 19 recordsLinked to original sources

PubMed2007

Detection of disseminated tumor cells in liver biopsies of colorectal cancer patients is not associated with a worse prognosis.

BACKGROUND: Liver metastases occur frequently in colorectal cancer and are probably caused by disseminated tumor cells having been trapped in the liver. The prognostic significance of hematogenous tumor cell dissemination has already been demonstrated for blood and bone marrow of patients with colorectal cancer. The aim of this study was to investigate the frequency and prognostic significance of disseminated tumor cells in liver biopsies of colorectal cancer patients. METHODS: Liver biopsies from 100 patients with UICC stage I-III colorectal cancer were taken prospectively during resection of the primary tumor. Liver biopsies obtained from 16 patients with benign gastrointestinal diseases served as negative controls. Liver samples from seven patients with liver cirrhosis were additionally taken. Liver biopsies were examined using a reverse transcriptase (RT)-PCR assay to amplify cytokeratin (CK) 20 transcripts. The median follow-up of the patients was 55 months. RESULTS: Disseminated tumor cells were detected in liver samples of 10/100 (10%) patients with UICC stage I-III colorectal cancer. Liver specimens from all seven patients with liver cirrhosis were CK 20-positive, whereas 16 patients with other benign gastrointestinal diseases were all CK 20-negative. There was no correlation between tumor cell detection in liver biopsies and survival of the patients. The only significant prognostic factor on uni- and multivariate analysis was the UICC stage. CONCLUSIONS: This study demonstrates that detection of disseminated tumor cells in liver samples from patients with UICC stage I-III colorectal cancer has no prognostic influence. UICC classification was the strongest prognostic factor in this patient series.

Aged↗

PubMed2006

Preoperative bowel preparation: surgical standard or past?

BACKGROUND: Preoperative bowel preparation is still routinely used prior to colorectal surgery. This concept is based on traditional and personal empiricism and usually not evidence based. The objective of the present review was to reassess this dogma against the background of the highest level of evidence published thus far. METHODS: The Medline database was searched using the search terms 'preoperative', 'bowel' and 'preparation' limited to 'randomized controlled trials' and 'meta-analyses'. Ten randomised controlled trials and seven meta-analyses comparing orthograde bowel cleansing to no preoperative bowel preparation were considered for rates of anastomotic leakages, surgical infections and other types of complications, reoperations and mortality. RESULTS: All the most recent meta-analyses showed a significant increase of anastomotic dehiscences in patients with preoperative orthograde bowel cleansing. Additionally, a trend towards higher rates of surgical infectious complications and re-operations was revealed. Mortality remained unchanged by preoperative orthograde bowel cleansing. CONCLUSION: Routine preoperative orthograde bowel cleansing is no longer justified prior to colorectal surgery in general due to increased risk of anastomotic leakages. Further investigations should focus on different types of bowel preparation in situations where preoperative bowel preparation still may have a role such as total mesorectal resection with low anastomosis and protective ileostomy.

Cathartics↗

PubMed2006

Totally laparoscopic versus conventional ileoanal pouch procedure--design of a single-centre, expertise based randomised controlled trial to compare the laparoscopic and conventional surgical approach in patients undergoing primary elective restorative proctocolectomy--LapConPouch-Trial.

BACKGROUND: Restorative proctocolectomy is increasingly being performed minimal invasively but a totally laparoscopic technique has not yet been compared to the standard open technique in a randomized study. METHODS/DESIGN: This is a two armed, single centre, expertise based, preoperatively randomized, patient blinded study. It is designed as a two-group parallel superiority study. Power calculation revealed 80 patients per group in order to recruit the 65 patients to be analysed for the primary endpoint. The primary objective is to investigate intra-operative blood loss and the need for blood transfusions. We hypothesise that intra-operative blood loss and the need for peri-operative blood transfusions are significantly higher in the conventional group. Additionally a set of surgical and non-surgical parameters related to the operation will be analysed as secondary objectives. These will include operative time, complications, postoperative pain, lung function, postoperative length of hospital stay, a cosmetic score and pre-and postoperative quality of life. DISCUSSION: The trial will answer the question whether there is indeed an advantage in the laparoscopic group in regard to blood loss and the need for blood transfusions. Moreover, it will generate data on the safety and potential advantages and disadvantages of the minimally invasive approach.

Adenomatous Polyposis Coli↗

PubMed2006

Pancreatic resection for M1 pancreatic ductal adenocarcinoma.

BACKGROUND: Improved safety of pancreatic surgery has led to consideration of more aggressive approaches, such as resection for primary pancreatic ductal adenocarcinoma (PDAC) with metastatic disease (M1). METHODS: A total of 29 patients who underwent pancreatic resection with resection of associated metastatic disease (interaortocaval lymph node dissection, liver resection, and/or multiorgan resections) were retrospectively identified from a database of 316 R0/R1 pancreatic resections for PDAC. An explorative data analysis of perioperative and clinicopathological parameters, and overall survival was performed by Kaplan-Meier estimation, log rank test, and Fisher's exact test. RESULTS: The overall in-hospital mortality and morbidity of R0/R1 pancreatic resections for M1 disease (n = 29) was 0% and 24.1%, compared with 4.2% and 35.2% of R0/R1 pancreatic resections for M0 disease (n = 287). The median overall survival time was 13.8 months (95% confidence interval [CI], 11.4-20.5), and the estimated 1-year overall survival rate was 58.9% (95% CI, 34.8-76.7) for patients with M1 disease. The median survival in those with metastatic interaortocaval lymph nodes was 27 months (95% CI, 9.6-27.0), whereas it was 11.4 months (95% CI, 7.8-16.5) and 12.9 months (95% CI, 7.2-20.5) for those with liver and peritoneal metastases, respectively. CONCLUSIONS: Pancreatic resections with M1 disease can be performed with acceptable safety in highly selected patients. The survival after interaortocaval lymph node resection is comparable to that of other lymph nodes that do not constitute M1 disease. Resection of liver and peritoneal metastases, although safe in this series, cannot be generally recommended until further controlled trials can be conducted.

Adenocarcinoma↗

PubMed2006

Long-term results of intraoperative presacral electron boost radiotherapy (IOERT) in combination with total mesorectal excision (TME) and chemoradiation in patients with locally advanced rectal cancer.

BACKGROUND: We analyzed the long-term results of patients with locally advanced rectal cancer using a multimodal approach consisting of total mesorectal excision (TME), intraoperative electron-beam radiation therapy (IOERT), and pre- or postoperative chemoradiation (CRT). PATIENTS AND METHODS: Between 1991 and 2003, 210 patients with locally advanced rectal cancer (65 International Union Against Cancer [UICC] Stage II, 116 UICC Stage III, and 29 UICC Stage IV cancers) were treated with TME, IOERT, and preoperative or postoperative CHT. A total of 122 patients were treated postoperatively; 88 patients preoperatively. Preoperative or postoperative fluoropyrimidine-based CRT was applied in 93% of these patients. RESULTS: Median age was 61 years (range, 26-81). Median follow-up was 61 months. The 5-year actuarial overall survival (OS), disease-free survival (DFS), local control rate (LC), and distant relapse free survival (DRS) of all patients was 69%, 66%, 93%, and 67%, respectively. Multivariate analysis revealed that UICC stage and resection status were the most important independent prognostic factors for OS, DFS, and DRS. The resection status was the only significant factor for local control. T-stage, tumor localization, type of resection, and type of chemotherapy had no significant impact on OS, DFS, DRS, and LC. Acute and late complications > or =Grade 3 were seen in 17% and 13% of patients, respectively. CONCLUSION: Multimodality treatment with TME and IOERT boost in combination with moderate dose pre- or postoperative CRT is feasible and results in excellent long-term local control rates in patients with intermediate to high-risk locally advanced rectal cancer.

Adult↗

PubMed2006

Prognostic impact of hematogenous tumor cell dissemination in patients with stage II colorectal cancer.

Adjuvant chemotherapy is not routinely recommended in patients with colorectal cancer stage UICC II. Some of these patients, however, develop recurrent disease. Therefore, valid prognostic criteria are needed to identify high-risk patients who might benefit from adjuvant therapy. Disseminated tumor cells, detected in blood and bone marrow, may prove to be a valid marker, however, the prognostic relevance of these cells remains debated. In our study, we examined the prognostic significance of disseminated tumor cells in blood and bone marrow of patients with stage II colorectal cancer. Ninety patients with potentially curative (R0) resection of colorectal cancer stage II were prospectively enrolled into the study. Bone marrow and blood samples were examined for disseminated tumor cells by CK 20 RT-PCR. Patient, tumor and treatment factors were analyzed as prognostic factors. Multivariate analysis confirmed tumor cell detection in blood (hazard ratio 2.1, p = 0.03) and T-category (hazard ratio 2.2, p = 0.02) to be independent prognostic factors for relapse-free survival. Tumor cell detection in postoperative blood samples (hazard ratio 7.7, p < 0.001) and number of removed lymph nodes (hazard ratio 6.4, p < 0.001) were independent prognostic factors for disease-specific survival. Detection of circulating tumor cells in blood samples of patients with stage II colorectal cancer identifies patients with poor outcome. This finding should be confirmed by further studies and could then be used as a basis for conducting a randomized trial evaluating the effect of adjuvant chemotherapy in stage II patients.

Aged↗

PubMed2006

Increased detection rate and potential prognostic impact of disseminated tumor cells in patients undergoing endorectal ultrasound for rectal cancer.

BACKGROUND: Hematogenous tumor-cell dissemination during diagnostic and therapeutic procedures in patients with colorectal cancer has been demonstrated. OBJECTIVE: The aim of this study was to investigate the extent of disseminated tumor cells in blood samples of rectal cancer patients after endorectal ultrasound and to determine its prognostic relevance. MATERIALS AND METHODS: Peripheral venous blood samples from 45 patients with rectal cancer were taken before and after endorectal ultrasound. Blood samples were examined using a reverse transcriptase-polymerase chain reaction (RT-PCR) assay to amplify cytokeratin 20 transcripts. Overall survival of the patients was calculated by the Kaplan-Meier method. RESULTS: Disseminated tumor cells were detected in peripheral blood samples of 17 of 45 (38%) patients before and after endorectal ultrasound. Circulating tumor cells were found in 11 of 45 (24%) patients only after endorectal ultrasound (p=0.006). There was a clear trend toward a worse prognosis in patients with tumor cells in blood samples after endorectal ultrasound, but this difference was not statistically significant. CONCLUSION: This study demonstrates significantly increased hematogenous tumor-cell dissemination after endorectal ultrasound in rectal cancer patients. Patients with tumor cells in blood samples after endorectal ultrasound tend to have a worse prognosis. The potential prognostic impact of this finding is presently unclear and has to be further validated in larger clinical trials.

Endoscopy, Gastrointestinal↗

PubMed2006

Successful doxycycline treatment of lymphatic fistulas: report of five cases and review of the literature.

BACKGROUND AND AIMS: Lymphatic fistulas are commonly known complications after lymph node or soft tissue resection, requiring long and sometimes difficult therapy. Doxycycline is an antibiotic agent, which was used in the treatment of pneumothoraces and pleural effusions. The aim of the study was to evaluate the effect of local doxycycline instillation on postoperative lymphatic effusions. MATERIALS AND METHODS: Five patients with postoperative lymphatic fistulas of different locations (inguinal, gluteal, and thoracic) were included. Patients received local doxycycline instillation after a postoperative observation period of 19-27 days without spontaneous closure of the fistulas. RESULTS: Postoperative lymphatic fistulas closed after a single injection of doxycycline in four out of five patients within 2 days, in one patient, injection had to be repeated to achieve closure of the fistula. Drain removal was possible within 4 days after instillation in all patients; no complications occurred. CONCLUSIONS: Doxycycline can be used for treatment of persistent postoperative lymphatic fistulas in different locations. In further studies, this therapeutic concept should be evaluated with larger numbers of patients with regard to the ideal point of time, frequency, and mode of application.

Adult↗

PubMed2006

Intraoperative electron-beam therapy for primary and recurrent retroperitoneal soft-tissue sarcoma.

PURPOSE: This study assesses the long-term outcome of patients with retroperitoneal soft-tissue sarcomas treated by maximal resection in combination with intraoperative electron-beam therapy (IOERT) and postoperative external-beam radiotherapy. METHODS AND MATERIALS: From 1991 to 2004, 67 patients were treated with curative intent for primary (n = 26) or recurrent (n = 41) retroperitoneal soft-tissue sarcoma. All patients underwent maximal resection in combination with IOERT (mean dose, 15 Gy), 45 patients underwent additional postoperative EBRT, and 20 patients were previously irradiated. RESULTS: The 5-year actuarial overall survival (OS), disease-free survival, local control (LC), and freedom from metastatic disease of all patients was 64%, 28%, 40%, and 50%, respectively. The 5-year LC inside the IOERT field was 72%. For patients who completed IOERT and EBRT after R0-resection 5-year and 10-year OS was 80%, and 5-year and 10-year LC was 100%. Only 1 of the 21 patients after R0-resection and only 8 of 34 patients after R1-resection compared with 9 of 12 patients after R2-resection experienced inside IOERT-field relapse. Grade II or higher late complications were seen in 21% of the patients, but only 2 patients required surgical intervention because of late complications. CONCLUSION: In selected patients, IOERT results in excellent local control and survival, with acceptable morbidity.

Adolescent↗

PubMed2006

Expression of cytokeratin-20 in pancreatic cancer: an indicator of poor outcome after R0 resection.

BACKGROUND: After complete removal of the neoplasm (R0 resection), approximately 80% of pancreatic cancer patients will die of the disease within 5 years. The expression panel of cytokeratins (CK) is linked closely with cell differentiation. The aim of the study was to investigate the expression of CK-20 in pancreatic cancer tissue and to correlate CK-20 expression with survival in R0-resected pancreatic cancer patients. METHODS: Tissue samples of 63 patients with pancreatic cancer were subjected to CK-20 reverse-transcription polymerase chain reaction. Thirty-four of 63 patients underwent R0 resection and were followed-up for survival statistics. From these 34 patients, 26 (76%) neoplasms were CK-20 positive and 8 (24%) samples were CK-20 negative. The mean follow-up period for the entire group was 17 months (range, 4-36 mo), the follow-up period in censored patients was 23 months (range, 10-36 mo). RESULTS: In the R0-resected group, 3 of 8 (38%) patients with CK-20-negative neoplasms, and 16 of 26 (62%) patients with CK-20-positive neoplasms (P = .15) died of recurrent disease. The median survival time of patients with CK-20-positive neoplasms was 13 months (range, 4-36), the median survival in R0-resected patients with CK-20-negative neoplasm was 26 months (range, 13-35; P = .06). The survival difference observed in patients with CK-20-negative neoplasms could not be attributed to intergroup variations in tumor stage or tumor grade. CONCLUSIONS: A majority of primary ductal pancreatic adenocarcinomas express CK-20. This seems to be associated with poorer survival in R0-resected patients. Our data suggest that ductal pancreatic adenocarcinomas negative for CK-20 constitute a subgroup of patients showing a more favorable disease outcome. The expression of CK-20 in resected pancreatic cancer may be of interest as a prognostic parameter.

Carcinoma, Pancreatic Ductal↗

PubMed2006

Tumor infiltrating T lymphocytes in colorectal cancer: Tumor-selective activation and cytotoxic activity in situ.

OBJECTIVE: To examine whether tumor-selective infiltration, activation, and cytotoxic activity of tumor infiltrating T lymphocytes (TIL) can be demonstrated in situ in colorectal cancer samples. SUMMARY BACKGROUND DATA: Recent studies indicated a correlation between the presence of TIL and an improved prognosis in colorectal cancer. However, tumor-selective activation and cytotoxic activity of CD8 TIL in situ in colorectal cancer patients have not yet been examined. METHODS: Tumor samples from 49 patients and corresponding normal mucosa samples from 23 patients with colorectal cancer (UICC stages II-IV) were examined for TIL. Two-color fluorescence immunohistochemistry and multicolor flowcytometric (FACS) analysis were used for quantification of CD8 T cells and measurement of their activation status (CD69-expression) and cytotoxic activity (CD107a-expression) in situ. Presence of tumor antigen-reactive T cells in tumor, blood, and bone marrow was evaluated by IFN-gamma Elispot analysis. RESULTS: While absolute numbers of CD8 T cells were similar, CD4 T helper cells were significantly increased in tumor tissue compared with normal mucosa. There was a significantly higher proportion of activated and cytotoxically active CD8 TIL in colorectal cancer compared with normal mucosa. Increased activation, cytotoxic activity, and functional reactivity of TIL were correlated with the presence of functional tumor antigen-reactive T cells in the blood and bone marrow. The proportion of activated TIL decreased significantly with higher tumor stage. CONCLUSIONS: Tumor-selective activation and cytotoxic activity of CD8 TIL and tumor-selective migration of CD4 T helper cells were demonstrated in colorectal cancer for the first time. Our data support the immunogenicity of colorectal cancer and suggest clinical significance of tumor-specific immune responses.

Adenocarcinoma↗

PubMed2006

Living-donor kidney transplantation: risks of the donor--benefits of the recipient.

For patients with end-stage renal disease, kidney transplantation is the optimal therapy. Due to organ shortage, however, most patients have to wait on dialysis for a considerable period of time prior to transplantation. Living-donor kidney transplantation is a valid option to expand the organ pool and to reduce waiting time. The risk-benefit ratio of living-donor kidney transplantation needs to be evaluated critically, as healthy persons voluntarily donate an organ for transplantation. The available data from the literature seem to prove that the donor operation can be performed with a minimal perioperative risk. Regarding the long-term course after kidney donation, the published data suggest that the risk is minimal for well-selected healthy donors who are closely followed postoperatively. The potential donor, however, needs to be completely informed regarding the potential short- and long-term risks of kidney donation prior to the planned procedure. From the recipient point of view, transplantation of a kidney from a living donor is a very good if not the optimal option, as the short- and long-term outcomes seem to be favorable compared with cadaveric kidney transplantation. With donor safety being constantly monitored, it seems to be justified to further pursue living-donor kidney transplantation programs.

Graft Survival↗

PubMed2006

Review of the clinical experience with a modified release form of tacrolimus [FK506E (MR4)] in transplantation.

Non-compliance in solid transplantation recipients is a major factor in acute graft rejection, which influences patient survival. Nowadays, tacrolimus is one of the most widely used immunosuppressant agents together with cyclosporine following kidney and liver transplantation with a standardized twice-daily dosing regimen. To improve the patients' compliance to the prescribed immunosuppressive therapy, FK506E (MR4), a modified release (MR) oral dosage form of tacrolimus has been developed for a once-daily dosing regimen. This report reviews the most recent results of clinical trials with MR tacrolimus after kidney and liver transplantation.

Delayed-Action Preparations↗

PubMed2005

High frequencies of functional tumor-reactive T cells in bone marrow and blood of pancreatic cancer patients.

Pancreatic cancer is characterized by aggressive growth and treatment resistance. New approaches include immunotherapeutic strategies but the type and extent of spontaneous immune responses against tumor antigens remains unclear. A dominance of TH2 cytokines in patients' sera reported previously suggests systemic tumor-induced immunosuppression, potentially inhibiting the induction of tumor-reactive T cells. We characterized the localization, frequencies, and functional potential of spontaneously induced memory T cells specific for individual tumor antigens or the tumor-associated antigen mucin-1 in the peripheral blood and bone marrow of 41 pancreatic cancer patients. We found high numbers of tumor-reactive T cells in all bone marrow samples and in 50% of the blood samples. These cells secreted the TH1 cytokine IFN-gamma rather than TH2 cytokines upon stimulation with tumor antigens. Although consistently induced during pancreatic cancer, T cells specific for pancreatic antigens were not detected during chronic pancreatitis, suggesting that their evaluation may be of diagnostic use in both diseases. Freshly isolated T cells from cancer patients recognized autologous tumor cells and rejected them in vitro and in a xenotransplant model in vivo, suggesting their therapeutic potential. Thus, tumor antigen-specific T cell responses occur regularly during pancreatic cancer disease and lead to enrichment of tumor cell-reactive memory T cells in the bone marrow. The bone marrow can therefore be considered an important organ for antitumor immune responses in pancreatic cancer.

Adolescent↗

PubMed2005

Surgical treatment of primary hepatic epithelioid hemangioendothelioma.

Epithelioid hemangioendothelioma is a very rare tumor of vascular origin. It can develop in different tissues such as soft tissue, lung, or liver. Hepatic epithelioid hemangioendothelioma (HEH) mostly affects females. The malignant potential of HEH often remains unclear in the individual patient. It can range from benign hemangioma to malignant hemangioendotheliosarcoma. Here we present our experience with five patients with primary HEH, who were treated with curative intention in our department. All patients in our series with confirmed histological HEH did not show extrahepatic extension and consequently underwent surgical treatment. In three patients, liver transplantation (LTx) was performed (two cadaveric and one living related). In one patient, a right-sided hemihepatectomy with partial resection of the diaphragm was performed. One patient died while she was on the waiting list for LTx due to rapid tumor progression. Postoperative follow-up ranged from 1 to 13 years. No adjuvant chemotherapy was applied. Until now, no recurrence of local tumor or distant metastases could be observed during follow-up in our series. Early detection and surgical intervention in case of HEH can potentially offer curative treatment. The treatment of first choice appears to be radical liver resection. In our view, LTx represents a potentially important option for patients with a nonresectable tumor. Despite the long waiting time, its often unclear dignity, and a proven progressive growth pattern, living related LTx also plays a potentially important role. The 5-year overall survival rate of patients with HEH in the literature varies from 43% to 55%. Long-term survival of patients with HEH is significantly higher compared to other hepatic malignancies. The role of adjuvant therapy currently remains unclear.

Adult↗

PubMed2005

Colocalization of the tetraspanins, CO-029 and CD151, with integrins in human pancreatic adenocarcinoma: impact on cell motility.

PURPOSE: Patients with pancreatic adenocarcinoma have a poor prognosis due to the extraordinary high invasive capacity of this tumor. Altered integrin and tetraspanin expression is suggested to be an important factor. We recently reported that after protein kinase C activation, colocalization of alpha6beta4 with the tetraspanin CO-029 strongly supports migration of a rat pancreatic adenocarcinoma. The finding led us to explore whether and which integrin-tetraspanin complexes influence the motility of human pancreatic tumors. EXPERIMENTAL DESIGN: Integrin and tetraspanin expression of pancreatic and colorectal adenocarcinoma was evaluated with emphasis on colocalization and the impact of integrin-tetraspanin associations on tumor cell motility. RESULTS: The majority of pancreatic and colorectal tumors expressed the alpha2, alpha3, alpha6, beta1, and beta4 integrins and the tetraspanins CD9, CD63, CD81, CD151, and CO-029. Expression of alpha6beta4 and CO-029 was restricted to tumor cells, whereas alpha1, alpha2, alpha3, alpha6, beta1, and CD9, CD81, CD151 were also expressed by the surrounding stroma. CD63, CD81, and beta1 expression was observed at comparably high levels in healthy pancreatic tissue. alpha3beta1 frequently colocalized and coimmunoprecipitated with CD9, CD81, and CD151, whereas alpha6beta4 colocalized and coimmunoprecipitated mostly with CD151 and CO-029. Notably, protein kinase C activation strengthened only the colocalization of CD151 and CO-029 with beta4 and was accompanied by internalization of the integrin-tetraspanin complex, decreased laminin 5 adhesion, and increased cell migration. CONCLUSION: alpha6beta4 is selectively up-regulated in pancreatic and colorectal cancer. The association of alpha6beta4 with CD151 and CO-029 correlates with increased tumor cell motility.

Adenocarcinoma↗

PubMed2005

Control of T-cell-mediated immune response by HLA class I in human pancreatic carcinoma.

PURPOSE: Cell surface HLA class I molecules present peptides derived from human cellular proteins to T cells. In the present study, we investigated the expression of HLA class I in human pancreatic carcinoma. EXPERIMENTAL DESIGN: The expression of HLA class I antigen and the extent of tumor infiltration by T cells were investigated in 46 primary tumors and in 14 metastases of pancreatic cancer by standard immunohistochemistry. RESULTS: The locus-specific expression of HLA I was reduced in 61% of primary tumors and in 93% of metastases. The total loss of this molecule complex was detected in 6% of primary tumors and in 43% of metastases. Pancreatic carcinoma and peritumoral tissue showed a significantly higher infiltration by CD3+, CD4+, and CD8+ T-cells compared with the tumor-distant pancreatic tissue. The negative expression of HLA class I was uniformly accompanied by a low density of tumor-infiltrating cytotoxic T-cells whereas the HLA class I-positive tumors were characterized by a substantial lymphocyte accumulation. However, the infiltration by cytotoxic T-cells was not correlated with the density of tumor cells. Patients with a high accumulation of cytotoxic cells showed a longer median survival. CONCLUSIONS: Pancreatic carcinoma frequently induces a cellular immune response that results in intratumoral and peritumoral T-cell infiltration. The expression of HLA class I is frequently lost in pancreatic carcinoma, which represents an effective mechanism to escape the tumor infiltration by cytotoxic T-cells. However, the infiltration by cytotoxic cells represents a favorable prognostic sign in pancreatic cancer patients.

Adenocarcinoma↗

PubMed2005

Short description of an alternative simplified method for screening recombinant clones within the "AdEasy-System" by Duplex-PCR.

BACKGROUND: Recombinant adenoviral vectors are highly efficient for in vitro and in vivo gene delivery. They can easily be produced in large numbers, transduce a wide variety of cell types and generate high levels of transgene expression. The AdEasy system is a widely used system for generating recombinant adenoviral vectors, which are created with a minimum of enzymatic manipulations and by employing homologous recombination in E. coli. In this paper we describe an alternative simplified method for screening recombinant DNA within the AdEasy system. This Duplex-PCR-method is independent of the transgene or insert and can be used for the complete AdEasy system. It is characterized by a simple standard protocol and the results can be obtained within a few hours. The PCR is run with two different primer sets. The primers KanaFor and KanaRev hybridizise with the Kanamycin resistence gene and AdFor and AdRev detect the adenoviral backbone. In case of recombinant clones, two diagnostic fragments with a size of 384 bp and 768 bp are generated. RESULTS: The practicability of this method was verified with three different transgenes: Cytosin Deaminase (AdCD), p53 (Adp53) and Granulocyte Macrophage Colony Stimulating Factor (AdGM-CSF). Recombinant clones are indicated by two diagnostic fragments and are then suitable for further processing. CONCLUSION: In summary, the presented protocol allows fast detection of recombinants with an easy technique by minimizing the amount of necessary steps for generating a recombinant adenovirus. This method is time sparing and cost-effective.

Adenoviridae↗