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B Kremer

Publications and source records attributed to B Kremer.

At least 55 records · Page 3Linked to original sources
PubMed2001

The mitochondrial toxin 3-nitropropionic acid induces differential expression patterns of apoptosis-related markers in rat striatum.

The mitochondrial toxin 3-nitropropionic acid (3-NP) causes selective striatal lesions in rats and serves as an experimental model for the neurodegenerative disorder Huntington's disease (HD). Apoptotic cell death has been implicated for the neuronal degeneration that occurs in HD brains. The present study was designed to investigate whether the 3-NP-induced cell death in rats involves apoptosis and an altered expression of Bcl-2 family proteins. Systemic administration of 3-NP via subcutaneous Alzet pumps resulted in lesions of variable severity with neuronal loss and gliosis in the striatum. Using the terminal transferase-mediated biotinylated-UTP nick end-labelling (TUNEL) of DNA, TUNEL-positive cells exhibiting typical apoptotic morphology were detected only in the striatum of rats with a severe lesion. Furthermore, the neuronal expression of the pro-apoptotic protein Bax was strongly increased in the core of the severe lesion. Expression of the anti-apoptotic marker Bcl-2 was unchanged in this location, but was enhanced in the margins of the lesions. A moderately increased expression of both Bax and Bcl-2 was observed in dark neurones in the mild lesion and in the subtle lesion. The presence of nuclear DNA fragmentation, strong granular Bax expression and an increased Bax/Bcl-2 ratio in the centre of severe lesions suggests the occurrence of apoptotic cell death following 3-NP administration. In contrast, the dark compromised neurones observed in 3-NP-treated animals revealed an equally enhanced expression of both Bax and Bcl-2, but lacked TUNEL-labelling, and are therefore not apoptotic.

Animals↗
PubMed2001

Orthotopic transplantation model of human gastrointestinal cancer and detection of micrometastases.

AIM: To establish a relevant animal model of human gastrointestinal cancer, which can be used for repetitive investigations, so as to improve our understanding and management of carcinogenesis and cancer metastasis. METHODS: Intact tissues of human colorectal and pancreatic cancers were transplanted in nude mice. The biological characteristics of the original and the corresponding transplanted tumors were investigated by HE staining, PAS staining and immunostaining. The metastases in the livers and lungs of nude mice were investigated by immunostaining with biotinylated mab KL-1 and by RT-PCR using CK20 specific primers. RESULTS: There were totally 9 of 16 surgical specimens growing in nude mice subcutaneously and/or orthotopically (4 of 6 colorectal and 5 of 10 pancreatic cancer). Tumor cell content of the specimens and freezing of tissue specimens are important factors influencing the growth of transplanted tumor. In the group of fresh tumor tissues with greater than 50% tumor cell content, the success rate of the transplantation was 100% (3 cases of pancreatic cancer and 3 cases of colorectal cancer). The orthotopically trans-planted tumors resemble the original tumor morphologically and biologically, including TAA expression such as CEA by immunohistochemistry, and CEA level in the serum of mice. Ki-67 labeling index and the expression of TAA especially K-ras, 17-1A and RA-96, are associated with the potential of tumor growth in nude mice. Micrometastases in the lungs and livers of tumor bearing mice can be detected by immunostaining with biotinylated mab KL-1 and CK20-specific RT-PCR. CONCLUSION: An orthotopic transplantation model for human colon and pancreatic cancer in nude mice has been set up. We have also established sensitive detection methods with CK-immunohistochemistry and CK20-RT-PCR to study xenotransplanted human cancer and its metastatic cancer cells in the liver and lung of nude mice. This study may be helpful in understanding the mechanism of cancer metastasis and in developing new diagnostic methods and therapeutic strategies for metastases including micrometastases.

Animals↗
PubMed2001

Systemic and local immunosuppression in pancreatic cancer patients.

Pancreatic cancer is characterized by an extremely poor prognosis. For the development of more effective immunotherapies, the systemic and local immunological escape mechanisms need to be further elaborated. These mechanisms may include the secretion of immunosuppressive cytokines, the local hindrance of tumor-infiltrating lymphocytes (TILs), or the loss of the signal transducing CD3 zeta-chain of TILs. In this study, we have analyzed these parameters in 116 patients suffering from pancreatic ductal adenocarcinoma. Mean concentrations of interleukin (IL)-10 and transforming growth factor-beta1/2 were considerably higher than in control sera (P < 0.0001). Disseminated tumor cells were found in 16 of 39 cases. In 28 of 33 surgical specimens, TILs did not reach tumor cells in significant numbers, being "trapped" in the peritumoral tissues. We suggest this as a simple but highly effective tumor escape mechanism. In cases of a TIL/tumor cell contact, CD3 zeta was mostly lost. Overall, 27 of 33 surgical specimens, 9 of 19 peritumoral lymph nodes, and 13 of 25 peritoneal lavage specimens showed significant loss of CD3 zeta (P < 0.02). Elevated concentrations of IL-10/TGF-beta1/2 were, in all but one of three cases, correlated with a CD3 zeta loss in corresponding specimens. Patients with disseminated tumor cells also showed a CD3 zeta loss in all but two corresponding tumor specimens. These results present strong evidence for an active systemic immunosuppression in pancreatic cancer, as shown by elevated IL-10 and TGF-beta1/2 serum levels as well as the presence of disseminated tumor cells. Killing of tumor cells by potentially cytotoxic TILs is obviously suppressed by the prevention of a direct TIL/tumor cell contact and the inactivation of TILs, as shown by a severe loss of CD3 zeta. In addition to active immunization strategies, successful immunotherapies have to focus on restoring in vivo T-cell function to improve the almost always fatal prognosis of pancreatic cancer.

Adult↗
PubMed2001

[Endoluminal therapy of neoplastic changes of the gastrointestinal tract: questionable and reliable aspects. Early stomach carcinoma: surgical treatment].

Early gastric cancer (EGC) is defined as gastric carcinoma limited to the mucosa and submucosa of the gastric wall, corresponding to UICC stage pT1a or pT1b. The overall prognosis is excellent, with 5-year survival rates up to 95% reported by Japanese institutions as well as in some series from Europe and the USA. However, the therapeutic concept still is indifferent. New staging methods and advances in the endoscopic and laparoscopic treatment opened new fields of therapeutic approaches. Therefore, referring to the results of japanese studies, for defined subtypes of EGC an endoscopic approach can be recommended. This, however, is related to a close follow up of these patients. In case of a surgical resection, radical D2-lymphadenectomy should be performed, especially in patients with submucosal invasion.

Aged↗
PubMed2000

Ductal lesions in patients with chronic pancreatitis show K-ras mutations in a frequency similar to that in the normal pancreas and lack nuclear immunoreactivity for p53.

BACKGROUND: Chronic pancreatitis (CP) is considered to be a risk factor for the development of pancreatic carcinoma. The detection of K-ras mutations in the duodenal or pancreatic juice has been held to be a reliable tool for its early diagnosis. However, K-ras mutations also occur in hyperplastic ductal epithelium, making it difficult to interpret their role in pancreatic carcinogenesis. METHODS: The study included 30 resection specimens, 15 from patients with alcoholic CP, and 15 from patients with idiopathic CP. The mean duration of disease was 6.8 years. A total of 429 ductal lesions were classified according to the World Health Organization classification (1996) and microdissected. K-ras analysis was performed by means of polymerase chain reaction (45 cycles), constant denaturing gel electrophoresis, and sequencing. Immunostaining was performed with antibodies against p53, Ki-S5, carcinoembryonic antigen, and two types of mucins. RESULTS: The 30 specimens demonstrated all types of ductal lesions. Severe cellular atypia was not observed. A total of 429 ductal lesions were analyzed. Approximately 4.4% of the lesions (19 of 429) from 27% of the patients (8 of 30) showed K-ras mutations, but they were unrelated to the duration or type of CP. Immunostaining for mutated p53 protein always was negative. Increased proliferative activity was noted only in patients with papillary hyperplasia. No patient developed pancreatic carcinoma within a follow-up period of at least 3 years. CONCLUSIONS: Ductal lesions in patients with CP exhibit K-ras mutations without additional indications of neoplastic transformation such as severe dysplasia or mutated p53 protein. Therefore, for diagnostic and therapeutic purposes, the detection of K-ras mutations should be supplemented by the demonstration of additional genetic alterations or clinical signs of malignancy.

Adolescent↗
PubMed2000

The grade of pancreatic ductal carcinoma is an independent prognostic factor and is superior to the immunohistochemical assessment of proliferation.

Tumour grade is one of the prognostic factors in pancreatic ductal adenocarcinoma, but its value is controversial. In this study, the predictive value and the reproducibility of the WHO grading system were reconsidered and the possibility of supplementing it with the immunohistochemically assessed proliferative activity was investigated. Seventy resected ductal adenocarcinomas of the head of the pancreas were evaluated. A total of 60 HPF fields on two to four sections per tumour were screened for glandular differentiation, mucin production, mitosis, and nuclear atypia by two observers with different degrees of experience. Each criterion was scored and the grade was calculated from the mean value of all single scores. Corresponding slides were immunohistochemically stained with the proliferation marker Ki-S5. The percentage of positive nuclei was assessed and a proliferation index (PI) assigned (<10%=1; 10-50%=2; >50%=3). Multivariate analysis (Cox regression) identified grade and R stage as the most significant factors for predicting survival. The PI determined on the basis of Ki-S5 staining did not prove to be an independent prognostic factor. In 30 of 70 carcinomas, it correlated with the tumour grade. Within a given tumour grade, the cases with the least favourable prognosis could be distinguished on the basis of their PI. The inter-observer variability was considerable, with the main differences occurring in the group of G1 tumours. According to the refined WHO criteria, the histopathological grade of pancreatic ductal carcinoma is an important independent prognostic factor, but reproducibility depends on the expertise of the observer. Criteria that relate to cellular and structural differentiation seem to be more predictive than those related to proliferation.

Aged↗
PubMed2000

Surgery for ductal adenocarcinoma of the pancreatic head: staging, complications, and survival after regional versus extended lymphadenectomy.

The purpose of this study was to evaluate the influence of regional versus extended lymphadenectomy on survival after partial pancreaticoduodenectomy for pancreatic cancer. From October 1988 to December 1991 (Department of Surgery, University of Hamburg) and from January 1992 to March 1998 (Department of Surgery, University of Kiel) 72 patients with histologically proven ductal adenocarcinoma of the pancreatic head were treated. Partial pancreaticoduodenectomy with regional lymphadenectomy was performed in 26 patients. In 46 patients lymphadenectomy was expanded to include extended retroperitoneal lymphatic and connective tissue clearance. Comparing these two groups and including only patients with R0 resections (n = 58) no significant differences in long-term survival could be shown. The following parameters were shown to have a significant or nearly significant influence on long-term survival: (1) stage of the disease: The 5-year survival of patients with stage I/II pancreatic head cancer was 63%, compared to 15% in patients with stage III/IV a + b of the disease (p = 0.0087). (2) Grading: The 1-year survival of patients with well or moderately differentiated tumors was 55%, compared to 0% for patients with poorly differentiated ductal adenocarcinoma (p = 0.0022). (3) N stage: The 5-year survival of patients in N0 stage was 46.9%, compared with 15% for N1 stage patients. The difference was not quite significant (p = 0.081). (4) Portal vein involvement: The 1-year survival was 0% in patients with R0 resections and histologically proven tumor infiltration of the portal vein, compared to 63% for patients with curative resections without portal vein involvement (p = 0.0063). In conclusion our data indicate that extensive retroperitoneal tissue clearance during pancreaticoduodenectomy for ductal pancreatic cancer does not improve survival compared to regional lymphadenectomy restricted to the right side of the mesenteric artery.

Aged↗
PubMed2000

Mould constituents in the middle ear, a hearing-aid complication.

During the placement of a mould for a hearing-aid by a hearing-aid dispenser, moulding material entered the middle ear through pre-existent perforations in the tympanic membrane in both ears. Besides hearing loss, there were no other symptoms. Surgical removal of the moulding material by tympanotomy was necessary, and was complicated by encirclement of the ossicles by the material. All the material could be removed and the hearing was saved. Recommendations for an improved procedure of mould-making are made including more detailed information of the otoscopic findings at the prescriptions for hearing-aid moulds.

Child↗
PubMed1999

Influence of lamotrigine on progression of early Huntington disease: a randomized clinical trial.

OBJECTIVE: To assess the efficacy of lamotrigine, a novel antiepileptic drug that inhibits glutamate release, to retard disease progression in Huntington disease (HD). BACKGROUND: Excitatory amino acids may cause selective neuronal death in HD, and lamotrigine may inhibit glutamate release in vivo. METHODS: A double-blinded, placebo-controlled study was conducted of 64 patients with motor signs of less than 5 years' duration who were randomly assigned to either placebo or lamotrigine and assessed at 0 (baseline), 12, 24, and 30 months. The primary response variable was total functional capacity (TFC) score. Secondary response variables included the quantified neurological examination and a set of cognitive and motor tests. Repeated fluorodeoxyglucose measurements of regional cerebral metabolism using PET also were included. RESULTS: Fifty-five patients (28 on lamotrigine, 27 on placebo) completed the study. Neither the primary response variable nor any of the secondary response variables differed significantly between the treatment groups. Both the lamotrigine and the placebo group deteriorated significantly on the TFC, in the lamotrigine group by 1.89 and the placebo group by 2.11 points. No effect of CAG size on the rate of deterioration could be detected. CONCLUSIONS: There was no clear evidence that lamotrigine retarded the progression of early Huntington disease over a period of 30 months. However, more patients on lamotrigine reported symptomatic improvement (53.6 versus 14.8%; p = 0.006), and a trend toward decreased chorea was evident in the treated group (p = 0.08). The study also identified various indices of disease progression, including motor tests and PET studies, that were sensitive to deterioration over time.

Adult↗
PubMed1999

Immunological escape mechanisms in pancreatic carcinoma.

Malignancies have developed several strategies to evade immune surveillance. We have investigated pancreatic cancer cell lines and pancreatic cancer surgical specimens to evaluate possibilities of tumor escape in the Fas system, and local immune suppression. Despite Fas expression the majority of cell lines was resistant to Fas-mediated apoptosis. The Fas-associated phosphatase-1 is a strong candidate to confer Fas resistance in pancreatic cancer cells. In addition, all investigated pancreatic cancer cell lines and cancer specimens expressed Fas ligand. Fas ligand was functional in cancer cell lines as shown by coculture assays of pancreatic cancer cell lines with Jurkat cells as targets. Additional local immune suppression was demonstrated by loss of T-cell receptor/CD3-zeta chain of pancreatic cancer infiltrating T-lymphocytes. We conclude that these tumor escape mechanisms may contribute to the poor prognosis of pancreatic cancer but also represent targets for new treatment modalities.

Adenocarcinoma↗
PubMed1999

A new method for the placement of brachytherapy probes in paranasal sinus and nasopharynx neoplasms.

PURPOSE: In afterloading therapy, the exact placement of the applicator is crucial for the result of radiotherapy. A deviation of few millimeters from the target leads to a significant reduction of radiation energy to the tumor. METHODS AND MATERIALS: We present a new method using a computer-assisted device for three-dimensional placing of afterloading probes based on CT scans that allows for the exact placement. RESULTS: Target points have been reached with an accuracy of 0.6 mm. Since 1991 we have used this technique for 24 clinical applications in 11 patients with recurrent neoplasms in the region of the paranasal sinuses and nasopharynx for palliative treatment. CONCLUSIONS: The presented method is a reliable and precise procedure for the positioning of afterloading probes, avoiding the inaccuracy of the traditional methods.

Adult↗
PubMed1999

Quality of life following radical surgical treatment of gastric carcinoma.

Quality of life (QOL) in patients with gastric cancer who underwent total gastrectomy has so far not been studied using the EORTC QLQ-C30 (Quality of Life Core Questionnaire of the European Organization for Research and Treatment of Cancer) as a standardized European QOL instrument. The aim of this study was to evaluate the effect of radical procedures such as extensive lymph node resection and combined resection of adjacent organs on patients' QOL. From 1992 to 1996, 152 patients underwent total gastrectomy. All patients alive on July 1, 1996 were included in the study (77/152). For assessing QOL, the EORTC QOL questionnaire QLQ-C30 version 2.0 and a validated gastric cancer module were sent home to the patients for self-completion. The response rate was 91%. It was possible to evaluate the questionnaires of 62 patients who had undergone resection with curative intent including 13 extended gastrectomies (21%). Of the 62 resections, 50 were combined with D2 lymphadenectomy (80.6%). The global health status was not negatively influenced by D2 lymphadenectomy and extended gastrectomy. Patients with splenectomy were more affected by treatment than patients without splenectomy. Radical gastrectomy combined with D2 lymphadenectomy is the treatment of choice for gastric cancer patients, concerning not just survival but QOL as well.

Aged↗
PubMed1999

Procalcitonin as a marker of severity in septic shock.

BACKGROUND/AIMS: Procalcitonin (PCT) was shown to be related to the severity of bacterial infection and is recommended as a new parameter of inflammation and infection. To evaluate the prognostic value in septic shock, PCT levels were repeatedly determined and compared with tumour necrosis factor-alpha (TNF-alpha)- and interleukin (IL)-6 bioactivity as well as with C-reactive protein (CRP) serum levels. PATIENTS: Twenty-four surgical patients with septic shock were included. Eight patients died within the study period of 14 days. METHODS: Serum levels of TNF-(WEHI 164) and IL-6 (B13-29 subclone 9) bioactivity, CRP and PCT were determined on days 1, 3, 5, 7, 10 and 14 following diagnosis of septic shock. RESULTS: Survivors and non-survivors were comparable in terms of age and severity of sepsis characterized by the APACHE II score and multiple-organ-failure score. Predominant causes of sepsis were peritonitis and necrotiszing pancreatitis. TNF levels increased in non-survivors with no significant difference to survivors. IL-6 bioactivity was increased on day 1 (P = 0.06) and remained elevated in non-survivors, in whom it was significant on day 7 (P<0.05). CRP was constantly elevated with no difference between the groups. In nonsurvivors PCT remained increased, while the course of survivors was characterized by decreased values which were significantly lower (P<0.05) at every time point compared with those patients who died. A significant correlation could be found on day 1 (P<0.05) and at the end of the observation period (P<0.01) when comparing PCT levels with the multiple-organ-failure score. CONCLUSIONS: PCT seems to be a more reliable prognostic parameter in septic shock than IL-6, while TNF and CRP did not show any difference between survivors and non-survivors. These data indicate that PCT may represent a valuable parameter not only in the diagnosis of sepsis but also in the clinical course of the disease.

APACHE↗
PubMed1999

Immunocytological detection of isolated tumour cells in the bone marrow of malignant melanoma patients: a new method for the detection of minimal residual disease.

AIMS: Immunocytologically detected isolated tumour cells indicate a poor prognosis. This has been shown in breast, gastrointestinal and lung cancer, and might thereby help to indicate adjuvant therapy. Immunocytology has been proved to be a reliable technique and enables a phenotypic tumour cell characterization. We find this technique superior to molecular biological techniques such as reverse transcriptase polymerase chain reaction RT-PCR. So far, immunocytological studies have not been performed in malignant melanoma patients and our study aimed to establish this approach in melanoma patients. METHODS: Twenty melanoma patients who underwent surgery for lymph-node metastasis using a radical lymphadenectomy were studied. Using the immunoperoxidase method, cytospins of bone marrow aspirates (1.5x10(6)cells per patient) were stained with the monoclonal antibody HMB-45. Nineteen patients who were surgically treated but did not suffer from malignant melanoma were included as a control group. RESULTS: Four of the 20 patients showed isolated tumour cells in the aspirate. Three of these patients had stage IV disease. One patient had a stage III tumour (1/7; 14.3%). One patient was classified as stage II and did not show tumour cells in the bone marrow. No staining cells were found in the control group (n=19). CONCLUSIONS: Our study demonstrates that the immunocytological approach can be used as a new technique to detect occult tumour cell dissemination in malignant melanoma patients and supports previous findings in carcinoma of the stomach, colon, pancreas and other tumours.

Adult↗