Biomedical subjects

W Hohenberger

Publications and source records attributed to W Hohenberger.

At least 73 records · Page 4Linked to original sources

PubMed2002

[Immune tolerance and active suppression in oncology. Immunological principles and therapeutic options].

In view of the fact that conventional therapies continue to yield unsatisfactory results, a therapy based on tumor immunology is of increasing interest. The results of some clinical immunotherapy studies have shown that the mechanism of tolerance induced by tumors is of critical importance. There are several mechanisms to be recognized by the tumor, such asanergy, immunosuppressive cytokines, immunodeviation and dysfunction of the T-lymphocytes. The so-called tumor escape mechanisms, which often refer to molecules that contribute to the recognition of antigens and activation of specific T cells, also lead to immunological tolerance. Immunotherapies based on gene-modified tumor cells, peptide-pulsed antigen presenting cells (APC) or antibody therapies to activate immune cells, have a fairly reasonable chance of being successful if immunological tolerance can be understood and influenced. Time will show if combining all sorts of immunotherapy that are based on different strategies, can induce tumor rejection more efficiently. In the scope of multimodal therapy concepts, immunotherapy only seems to be reasonable if the immunological tolerance that was induced by tumors can be overcome. Immunological markers are of crucial importance, not only for the therapy but also for the diagnosis and prognosis of cancer patients.

Adjuvants, Immunologic↗

PubMed2002

[D3 versus D2 dissection in stomach carcinoma. A case-control study of postoperative morbidity, survival and early oncologic outcome].

INTRODUCTION: In western countries, the benefit of the Japanese extended D3 lymph node dissection in gastric cancer patients who have been operated on in curative intent has not been proven and higher rates of side effects are expected. The present matched-pair study retrospectively compared the new D3 method (1995-1999) with the historic D2 dissection (1982-1995). METHODS: Two 1:1 matched-pair populations were created: (1) regarding intra- and postoperative course, morbidity and mortality, 2 x 67 patients stratified to "age", "gender", "surgical procedure", "splenectomy" and "extended resections"; and (2) regarding early oncologic outcome, 2 x 32 patients additionally stratified to "UICC-stage" and "Laurén-classification". The D3 dissection was performed according to the Japanese method without routine pancreaticosplenectomy. RESULTS: D3 dissection harvested significantly (P = 0.004) more lymph nodes per patient: 56.4 vs. 46.8. Postoperative mortality was 3% (n = 2) in both groups, the overall complication rate of 30% (D3) vs. 25% (D2) was equivalent (P = 0.678) and the rate of surgical complications was identical (21%). Non-surgical complications of 21% after D3 dissection were not significantly elevated (vs. 10%; P = 0.143). Operative time [289 min (D3) vs. 218 min (D2); P = 0.0001] and postoperative stay [17.4 days (D3) vs. 14.5 days (D2); P = 0.003] were significantly longer after the extended procedure. The were no statistically significant differences between 2-year overall survival, locoregional-, distant- and overall recurrence-free survival. CONCLUSIONS: Compared to the D2 method, D3 dissection is feasible without disadvantages in the patients. However, D3 dissection cannot routinely be recommended because--possibly due to the short follow-up period and the small number of patients so far observed--an oncologic benefit could not be shown.

Adult↗

PubMed2002

DNA microarrays: a new diagnostic tool and its implications in colorectal cancer.

Effective treatment of colorectal cancer requires early detection and diagnostic and prognostic accuracy in characterizing patients of various risk groups. The development of DNA microarray makes it possible to analyze thousands of genes in a single tissue sample in one experiment and to characterize the biological behavior of colorectal cancer cells. Different cluster algorithms have been used to analyze large datasets on gene expression data, and initial results show significant differences between colorectal cancer and normal colon tissue. Although more than 6000 genes have been analyzed between colorectal cancer and normal tissue, different expression levels have been found in only 100-500 transcripts depending on the cluster algorithm. Most transcripts belong to genes involved in cell growth regulation, differentiation of cells, ribosomal proteins or metalloproteinase. A future goal in microarray technology will be the development of clustered gene chips which characterize each tumor type specifically and focus on gene expression that specifies cell identity.

Biomarkers, Tumor↗

PubMed2002

Small bowel resection in the rat: the effect upon bone and mineral metabolism.

BACKGROUND AND AIMS: We analyzed bone and mineral metabolism after long-segment small bowel resection in the rat to detect functional and morphological alterations and to determine the development of osteopathy. METHODS: Twelve-week-old male Lewis rats were randomized into short (8-week) or long (16-week) follow-up groups. Sham operation, resection of the proximal third of the small bowel, resection of the distal third of the bowel and resection of the entire jejunum and ileum were carried out. Nineteen days before the end of the experiment the animals were transferred into a metabolic cage to analyze weight gain/loss, food intake, and fecal excretion/24 h. At the end of the experiment the animals were killed; blood samples and bowel and bone specimens were collected, length, weight, volume, density, mineral content, and fracturing energy were determined, and bone histology was examined. The calcium/phosphorus ratio, nonmineralized tissue content and the ratio fracturing energy/mean bone density were calculated. RESULTS: After 8 weeks there were significant differences to the control group in body weight, weight gain, food efficiency, femur length, weight, volume, mineral content, mineral density, fracturing energy per bone volume, and bone density but not in bone calcium or magnesium. After 16 weeks there were differences in body weight, weight gain, food efficiency, femur length, weight, volume, bone mineral content and density, bone minerals, and nonmineralized tissue but not in fracturing energy; the average values of all these parameters were lower in the resected groups, and lowest in the group after resection of the entire jejunum and ileum. Bone histology showed a reduction in trabecular bone mass after long-segment small bowel resection. CONCLUSIONS: Long-segment small bowel resection causes a significant loss of body weight despite of a comparable mean chow ingestion resulting in a significant decreased food efficiency. We conclude that there is no inverse relationship of bone calcium content and the fracture risk, and that there is no severe mineralization defect after long-segment small bowel resection.

Animals↗

PubMed2002

Testing a new staging system for cutaneous melanoma proposed by the American Joint Committee on Cancer.

The American Joint Committee on Cancer (AJCC) recently proposed a new staging system for cutaneous melanoma. We tested its practicability and its prognostic value was compared with the currently used TNM classification. The data of 1976 melanoma patients were used for the testing. 1218 patients (61.6%) could be assigned to the proposed pT classification, 136 patients (90.1%) with lymph node metastases and/or in-transit metastases to the proposed pN classification and all 14 patients with distant metastases to the proposed pM classification. Proposed pathological staging was possible for 971 patients (49%). The number of pT1 patients (399 versus 230) and stage I patients (544 versus 393) was distinctly higher in the proposed classification. In proposed stage II and III groups, subgroups with different prognosis could be identified. The new staging system includes more detailed information on clinical and pathohistological findings. Nevertheless, it is practicable and enables more patients with excellent prognosis to be identified.

Adolescent↗

PubMed2002

Accuracy and precision of bone mineral density and bone mineral content in excised rat humeri using fan beam dual-energy X-ray absorptiometry.

The aim of this study was the evaluation of fan beam dual-energy X-ray absorptiometry (DXA) for measuring bone mineral density (BMD) and bone mineral content (BMC) of isolated rat humeri. Defleshed rat humeri from male Lewis rats were examined with a Hologic QDR 4500 A (Hologic, Inc., Bedford, MA) high-resolution densitometer both in water and 0.9% saline solution. The small animal scan protocol with the regional high-resolution mode was used. BMC measured by DXA was compared with bone dry weight, ash weight, and bone calcium content. Furthermore, DXA BMD and BMC precision were determined. We also evaluated the effect of salinity of the water bath in which the bones were measured. Correlations (r(2)) of BMC, as determined by DXA with dry weight, ash weight, and bone calcium content, were 0.978, 0.988, and 0.890, respectively. DXA overestimated ash weight by 5%-9%. Precision errors for BMC (BMD) were 0.90% (0.76%) without and 1.3 (0.86) with repositioning. Changes in the salinity of the water bath had a significant influence on the DXA results: At the 0.9% physiological level, BMC (-4.4%) and area (-4.1%), but not BMD, values were significantly lower (p < 0.005) compared with measurements in tap water. Fan beam DXA is a highly accurate and precise technique for measuring BMC and BMD in excised small animal bones. A physiological saline concentration in the water bath had a significant impact on BMC and area, but not on BMD, and should therefore be strictly controlled to avoid an underestimation of BMC.

Absorptiometry, Photon↗

PubMed2002

Late locoregional recurrence in rectal carcinoma.

AIMS: Locoregional recurrence in rectal carcinoma usually occurs within the first five years of treatment. In recent years we have increasingly diagnosed patients with late locoregional recurrence more than 5 years after primary treatment. METHODS: The data of 978 patients with invasive stage I-III rectal carcinoma who underwent curative resection (R0) between 1978 and 1990 were analysed retrospectively. The median follow-up time was 10 years. RESULTS: The earliest locoregional recurrence was observed at 2 months, the latest at 148 months (extramural locoregional recurrence) after primary treatment. Within 1, 2 and 5 years 34, 64 and 91 per cent of all locoregional recurrences had been diagnosed. The 2-, 5- and 10-year locoregional recurrence rates of all patients increased from 11.3 to 16.7 to 18.8 per cent. The time lapse to diagnosis of locoregional recurrence was significantly influenced by the pN category (pN0: later), grading (low grade: later) and tumour cell dissemination (present: earlier). Locoregional recurrence was also diagnosed significantly earlier in patients undergoing regular follow-up. The curative reoperation rate was 22 per cent (n=37), being higher in patients with intramural locoregional recurrence (49 per cent), after primary anterior resection (32 per cent) and in the absence of distant metastases (29 per cent). CONCLUSION: Long-term follow-up beyond five years demonstrates increasing numbers of late locoregional recurrences.

Adult↗

PubMed2002

[Dysfunction of calcium metabolism following resection of the thyroid gland. An analysis of important risk factors].

PURPOSE: Dysfunction of the parathyroid glands is a typical complication following thyroid surgery. Risk factors for the development of postoperative symptomatic hypocalcemia were retrospectively analyzed. METHODS: 308 consecutive thyroid resections (women n = 236, men n = 72, mean age 53 years) performed in 1996 and 1997 were evaluated. Main diagnosis was non-toxic nodular goiter (n = 234, 76 %), 28 patients (9 %) had thyroid carcinoma. The most common operation performed was bilateral functional thyroid resection (n = 116, 38 %), the proportion of thyroidectomies was 14 % (n = 44). The patients with postoperative symptomatic hypocalcemia were followed for a median of 32 months. RESULTS: Clinical symptoms of hypocalcemia were observed in 18 patients (6 %) postoperatively. Three patients developed transient (n = 1) or permanent hypothyroidism (n = 2). In univariate analysis, the underlying thyroid disease, the method of operative therapy, removal, identification and autotransplantation of parathyroid glands, in multivariate analysis, thyroidectomy (relative risk 6.9) and removal of parathyroid glands (relative risk 23.9) were proved to be significant risk factors for the development of postoperative symptomatic hypocalcemia (p < 0.05). CONCLUSIONS: Patients with thyroidectomy, operation for thyroid carcinoma and intraoperative removal of parathyroid glands should be closely followed for postoperative hypocalcemia. Exact surgical technique provided, permanent hypoparathyroidism is rare, particularly if several parathyroid glands were identified intraoperatively and autotransplanted, if necessary.

Adolescent↗

PubMed2002

[Results of laryngeal nerve monitoring during thyroid operations--Studies and value for clinical practice].

Injuries of the laryngeal nerve still remain a source of morbidity for patients undergoing surgery for the thyroid gland. The incidence of permanent damage of the nerve varies from 0.5 % to 2.7 % depending on the series, but for special thyroid diseases like thyroid carcinoma or goiter recurrence the damage of the recurrent laryngeal nerve could be up to 25 %. For that reason several methods of monitoring the movement of the nerve while stimulation have been proposed. Such as inserting a needle into the vocal muscles or working with a surface laryngeal electrode that is attached above the cuff of the tube. For neither of those methods of nerve monitoring severe complications were described. The purchase costs for all the equipment are between 25.000 to 30.000 DM. All the published data regarding monitoring of the laryngeal nerve have been only observation studies with no control group and for that reason the results of the studies could not be obligatory statements. Furthermore not every nerve palsy has been identified by the monitoring of the laryngeal nerve, this method has a sensitivity of less than 70 %. Monitoring of the laryngeal nerve is a helpful clinical tool not only for training of surgeons but also during complicated thyroid surgery. Monitoring is especially useful for operations of thyroid carcinoma or revision procedures. But at the moment there is no randomised study available that shows any superiority of this new and expensive method over the standard therapy, therefore further studies are necessary. Until these studies exist the anatomical localisation of the nerve during surgical dissection is still the gold standard.

Humans↗

PubMed2002

A score card for upper GI endoscopy: Evaluation of interobserver variability in examiners with various levels of experience.

BACKGROUND: In most European countries, training in GI endoscopy has largely been based on hands-on acquisition of experience in patients rather than on a structured training programme. With the development of training models systematic hands-on training in a variety of diagnostic and therapeutic endoscopy techniques was achieved. Little, however, is known about methods of objectively assessing trainees' performance. We therefore developed an assessment 'score card' for upper GI endoscopy and tested it in endoscopists with various levels of experience. The aim of the study was therefore to assess interobserver variations in the evaluation of trainees. METHODS: On the basis of textbook and expert opinions a consensus group of eight experienced endoscopists developed a score card for diagnostic upper GI endoscopy with biopsy. The score card includes an assessment of the single steps of the procedure as well as of the times needed to complete each step. This score card was then evaluated in a further conference including ten experts who blindly assessed videotapes of 15 endoscopists performing upper GI endoscopy in a training bio-simulation model (the 'Erlangen Endo-Trainer'). On the basis of their previous experience (i. e. the number of endoscopies performed) these 15 endoscopists were classified into four groups: very experienced, experienced, having some experience and inexperienced. Interobserver variability (IOV) was tested for the various score card parameters (Kendall's rank-correlation coefficient 0.0-0.5 poor, 0.5-1.0 good agreement). In addition, the correlation between the score card assessment and the examiners' experience levels was analysed. RESULTS: Despite poor IOV results for all the parameters tested (Kendall coefficient < 0.3), the assessment parameters correlated well when the examiners' different experience levels were taken into account (correlation coefficient 0.59-0.89, p < 0.05). The score card parameters were suitable for differentiating between the four groups of examiners with different levels of endoscopic experience. CONCLUSIONS: As expected with scores involving subjective assessment of performance, the variability between reviewers was substantial. Nevertheless, the assessment score was capable of distinguishing reliably between different experience levels in terms of a good individual observer consistency. The score card can therefore be used to document both training status and progress during endoscopy training courses using bio-simulation models, and this might be able to provide improved quality assurance in GI endoscopy training.

Animals↗

PubMed2002

[Palliative second-line treatment with oxaliplatin, gemcitabine and weekly high-dose 5-fluorouracil as 24-h infusion in patients with metastatic pancreatic adenocarcinoma].

The most commonly used treatment in the palliative first-line therapy of metastatic pancreatic adenocarcinoma is the Gemcitabine (Gem) monotherapy, while several combination therapies are currently being tested in clinical trials. With regard to pancreatic cancer, a palliative second-line therapy has not been established, yet. The four patients presented in this paper received a palliative second-line therapy with Oxaliplatin (L-OHP), Gem and high-dose 5-Fluorouracil (5-FU) as a 24-h infusion after a first-line therapy with Gem and weekly high-dose 5-FU as a 24-h infusion. During second-line therapy, four patients received 67 chemotherapy applications, which were well tolerated. As severe symptom of toxicity, thrombocytopenia (CTC toxicity grade 4) was observed in one patient. As a result of second-line therapy, stable disease (SD) with a significant decrease of CA 19 - 9 was achieved in three patients and partial remission (PR) in one patient. After palliative first- and second-line treatment the survival time of the patients was 9, 9, 15 and 20 months. Currently, a multicentre phase I study has been started aiming at an optimisation of the three-drug combination dosage.

Adenocarcinoma↗

PubMed2001

CC chemokine receptor 7-dependent and -independent pathways for lymphocyte homing: modulation by FTY720.

Cognate interaction of chemokine receptor CCR7 on lymphocytes with its ligands CCL19 and CCL21 expressed on high endothelial venules (HEVs) is essential for effective migration of T and B cells across HEVs into secondary lymphoid organs. Plt mice, which lack expression of CCL19 and CCL21-ser, both ligands for CCR7 on HEVs, as well as CCR7-deficient mice, have a defective cell migration and reduced homing of lymphocytes. FTY720, a novel immunosuppressant, causes a reduction of lymphocytes in peripheral blood and tissues and their sequestration into lymphoid tissues. In this study we demonstrate that FTY720 rescues the homing defect in both CCR7(-/-) mice and plt mice. After FTY720 treatment, the number of CD4(+) and CD8(+) T cells as well as B cells in peripheral blood is reduced while pertussis toxin-sensitive homing into peripheral lymph nodes, mesenteric lymph node, and Peyer's patches is increased. Immunohistology demonstrates that FTY720 enables these cells to enter lymphoid tissue through HEVs. Thus, our data suggest an alternative G-alpha(i)-dependent, CCR7-CCL19/CCL21-independent mechanism for lymphocyte homing through HEVs which is strongly augmented in the presence of FTY720.

Animals↗

PubMed2001

The prognostic inhomogeneity of colorectal carcinomas Stage III: a proposal for subdivision of Stage III.

BACKGROUND: The prognosis of patients with Stage III colorectal carcinoma seems to be inhomogeneous. Therefore a subdivision of Stage III was performed. METHODS: Data from 850 patients of the Erlangen Registry of Colo-Rectal Carcinomas and 603 patients of the Study Group Colo-Rectal Carcinoma (SGCRC) with Stage III colorectal carcinoma were analyzed. Three different subdivisions of Stage III were performed according to pT, pN, and pTpN. Observed 5-year survival rates for all possible substages were calculated according to Kaplan-Meier. To compare the predictive value of several possible substages, Brier-Score and receiver operator charcteristics (ROC) analysis were applied. RESULTS: The subdivision according to pT (pT1,2pN1,2 versus pT3 pN1,2 versus pT4 pN1,2) as well as the subdivision according to pN (any pT pN1 vs. any pT pN2) resulted in significant differences of observed 5-year survival rates. However, subdivision according to pT and pN (pT1,2 pN1 vs. pT3,4pN1 and pT1,2pN2 vs. pT3,4 pN2) was found to be superior. The three substages, IIIA, IIIB, and IIIC, identified 10%, 50%, and 40% of the patients with observed 5-year survival rates of 80%, 60%, and 30%, respectively. Using Brier-Score and ROC analysis an increase in predictive power was found, especially for the patients of the Erlangen Registry, but less clearly for SGCRC patients. CONCLUSION: Subdivision of Stage III colorectal carcinoma into three substages according to the pT and pN categories resulted in subgroups which differed significantly in prognosis. This may be important for comparing treatment results, especially in adjuvant treatment and patient care evaluation studies.

Adult↗

PubMed2001

High-risk groups of patients with Stage II colon carcinoma.

BACKGROUND: It is unclear whether patients with Stage II colon carcinoma should be offered adjuvant chemotherapy. Therefore, the authors analyzed the risk factors of these patients to identify high-risk subgroups who may benefit from such treatment. METHODS: The data from 305 patients with Stage II colon carcinoma documented in the Erlangen Registry of Colorectal Carcinoma were analyzed to identify risk factors for distant metastasis and disease-related survival. The patients were divided into two subgroups: those in a low-risk group and those in a high-risk group. The data were then compared with those from 306 patients with Stage II colon carcinoma from the German Study Group for Colorectal Carcinoma (SGCRC). RESULTS: Emergency presentation, a primary tumor site in the left colon, pT3 tumors with a depth of invasion of > 15 mm beyond the outer border of the muscularis propria, and pT4 lesions were identified as the major risk factors for Stage II colon carcinoma. On dividing patients into subgroups according to these risk factors, it was found that patients in the high-risk group had a significantly higher risk of distant metastases and a significantly lower disease-related survival rate compared with patients in the low-risk group. On analyzing the SGCRC data, the authors also found a significantly higher rate of distant metastases in the high-risk group, but the disease-related survival rate differed only marginally. CONCLUSIONS: Among patients with Stage II colon carcinoma, it is possible to identify a high-risk group of patients who may be candidates for adjuvant chemotherapy. Stratification by the risk factors emergency presentation, tumor site, depth of tumor invasion, and surgical department should be employed in further clinical studies.

Adult↗

PubMed2001

Palliation of a primary malignant melanoma of the distal esophagus by stent implantation. Report of a case.

BACKGROUND: A 55-year-old woman suffering from progressive dysphagia, retrosternal pain, and annoying foetor ex ore is described. Esophagogastroscopy showed a dark, necrotic tumor extending from 28 cm below the front teeth to the esophagogastric border, and biopsy showed it to be a primary malignant melanoma. The underlying progressive tumor stage with pericardial infiltration and intra-abdominal lymph node metastasis precluded the possibility of curative surgical treatment. METHODS: For palliation, we implanted a metal stent (Ultraflex, Microvasive, Boston Scientific Corporation, Watertown, MA, USA) in the distal esophagus to alleviate the dysphagia. RESULTS: Permanent recanalization of the tumor-obstructed esophagus by stent implantation alleviates symptoms, thereby significantly improving quality of life. Radiochemotherapy can be performed despite the presence of the stent. CONCLUSIONS: Surgery is the therapy of choice for resectable primary malignant melanoma of the esophagus. Endoscopic therapy should be considered for alleviating dysphagia if surgery is impossible.

Deglutition Disorders↗

PubMed2001

Arterialization of the portal vein in liver transplantation: a new microsurgical model in the rat.

BACKGROUND: A preexisting thrombosis of the portal vein and the deep splanchnic bed can make it extremely difficult to reestablish the portal blood flow in orthotopic liver transplantation in man. Complete arterialization of the liver transplant, including the donor portal vein, might be a viable therapeutic option. A new rat transplantation model is described, in which the liver is completely arterialized. METHODS: The outflow of the portal blood in the recipient was secured via a portocaval shunt. Hepatectomy was then performed and the liver transplant placed in orthotopic position. An interposed aortic segment was used for direct arterialization of the donor portal vein. RESULTS: The laboratory parameters determined in the serum at the end of the observation period of 28 days revealed normal functioning of the transplant. The histological examinations showed largely normal cellular architecture, with no signs of necrosis, but incipient fibrosis. CONCLUSIONS: Using this new surgical technique in the rat liver transplantation model, long-term morphological and functional changes in a completely arterialized liver graft, and the regenerative capability of liver tissue perfused in this way, can be investigated.

Anastomosis, Surgical↗

PubMed2001

Characterization of the phenotype and function of CD8(+), alpha / beta(+) NKT cells from tumor-bearing mice that show a natural killer cell activity and lyse multiple tumor targets.

Natural Killer (NK) T cells are a specialized T cell population that co-expresses receptors of the NK lineage with the alpha / beta TCR receptor and other T cell surface markers. Their functions, regulation and relationship to other cells in the immune system are not fully understood. This report demonstrates that tumor-bearing C57BL / 6 mice have a population of NKT cells that co-express CD8 and CD161 (NK1.1) surface markers. These cells are maintained in long-term culture with T helper 2 (Th2) cytokine interleukin-4 (IL-4), but produce large amounts of Th1 cytokine interferon-gamma (IFN-gamma) following activation. NK1.1(+)CD8(+) T cells show a potent NK-like cytotoxic activity against multiple tumor targets, and lysis is independent of major histocompatibility complex (MHC)-class I or non-classical MHC-class I molecules (Qa, TL). The NK1.1(+)CD8(+) T cells express Vbeta14 chain of the TCR. These NKT cells are not CD1d restricted, and their cytotoxic activity is CD1d independent. Therefore, they represent a unique subset of T cells with an unknown restriction element which produce large quantities of IFN-gamma following expansion with IL-4. Furthermore, their cytotoxic activity is enhanced by B7 co-stimulatory molecules present on tumor cells. CD161(+) T cells that are expanded in tumor-bearing hosts may function as a part of the innate immune system with potential role(s) in tumor surveillance.

Animals↗

PubMed2001

Mutation screening at the RNA level of the STK11/LKB1 gene in Peutz-Jeghers syndrome reveals complex splicing abnormalities and a novel mRNA isoform (STK11 c.597(insertion mark)598insIVS4).

This study was intended to evaluate a diagnostic reverse transcriptase polymerase chain reaction based protein-truncation test for the identification of germline mutations in the serine/threonine protein kinase 11 (STK11, also designated LKB1) gene in Peutz-Jeghers syndrome (PJS). Our data exemplify that the inactivation of STK11 can be due to unusual disturbances in splicing regulation which result in truncations of the protein. However, nonsense mediated mRNA decay must be blocked with puromycin to detect shortened STK11 gene products contained in the leucocytic mRNA pool of PJS patients. Interestingly, two mutations escaped from detection by exon sequencing techniques with usual flanking PCR primers, since alterations were located right in the middle of intronic sequences. We describe a compound heterozygous PJS patient who carried two different mutations in intron 1 on separate alleles. Each of the two mutations was transmitted individually to one of his two children. In the course of our RNA based analyses we detected high level expression of a novel STK11/LKB1 mRNA variant retaining intron 4 (STK11 c.597(insertion mark)598insIVS4) in various tissues. This mRNA isoform was initiated from an alternative transcription regulatory region as revealed by primer extension analyses even in cell lines with complete methylation of the normal promoter. As a consequence of novel mutational mechanisms identified we discuss the impact of RNA based strategies for the detection of germinal STK11 mutations in PJS.

AMP-Activated Protein Kinase Kinases↗