Biomedical subjects

S Dawiskiba

Publications and source records attributed to S Dawiskiba.

At least 19 recordsLinked to original sources

PubMed2001

Transhepatic intravascular ultrasound for evaluation of portal venous involvement in patients with cancer of the pancreatic head region.

The aim of this study was to evaluate the ability of intravascular ultrasound to diagnose tumor involvement of the portal and the superior mesenteric veins using the preoperative percutaneous, transhepatic approach, and to compare the findings with those made at concomitant direct portography, surgery, and histopathological examination. Ten patients with a preoperative diagnosis of a resectable tumor in the pancreatic head region were examined with percutaneous transhepatic portography (PTP) and intravascular ultrasound (IVUS). The surgeon's intraoperative evaluation and the histopathological examination in combination revealed tumor involvement of the portal or superior mesenteric veins in six of the ten patients. Percutaneous transhepatic portography suggested tumor involvement of the veins in six patients but two of the examinations were false positive and another two were false negative. Intravascular ultrasound showed signs of tumor involvement in eight patients. The examination was, however, false positive in two patients, but there were no false negatives. Complications of the percutaneous transhepatic procedure occurred in six patients including severe pain, bleeding, and related death. Percutaneous transhepatic IVUS of the portal vein may be a useful tool in the preoperative selection of the subgroup of patients with tumor of the pancreatic head region that could benefit from surgery. There is a need for technical improvement as well as studies with larger patient series to definitely decide the role of the technique.

Adult↗

PubMed2001

Extensive cytogenetic heterogeneity in a benign retroperitoneal schwannoma.

A benign retroperitoneal schwannoma from a patient without prior exposure to radiotherapy or chemotherapy was analyzed by chromosome banding after short-term culture. An extensive intratumor heterogeneity in the form of 29 karyotypically related as well as unrelated clones was found. The aberrant clones were diploid or near-diploid and displayed both numerical and structural changes. All chromosomes, except 11, 16, and 20, were affected. Numerical changes included trisomies X, 7, 9, 17, and 18, and monosomies 13 and 18. No clonal loss of chromosome 22, the most characteristic abnormality in schwannomas of other locations, was, however, detected. The structural aberrations resulted in a total of 58 chromosomal breakpoints, with chromosomes 18, 1, and 15 participating in rearrangements most frequently, followed by chromosomes 14, 2, and 22. A striking finding was the clonal involvement of 18p11 in eight rearrangements affecting different chromosomes, suggesting alteration of telomeric function. The molecular mechanisms underlying the observed massive polyclonality in the schwannoma, particularly the presence of cytogenetically unrelated clones, are unknown and probably heterogeneous.

Aged↗

PubMed2000

K-ras oncogene subtype mutations are associated with survival but not expression of p53, p16(INK4A), p21(WAF-1), cyclin D1, erbB-2 and erbB-3 in resected pancreatic ductal adenocarcinoma.

Previous studies of molecular prognostic markers following resection for exocrine pancreatic cancer have produced conflicting results. Our aim was to undertake a comprehensive analysis of potentially useful molecular markers in a large, multicentre patient population and to compare these markers with standard pathological prognostic variables. Formalin-fixed, paraffin-embedded specimens of pancreatic ductal adenocarcinoma were analysed from 157 patients [100 men and 57 women with a median (range) age of 60 (33-77) years] who had undergone pancreatectomy. Immunohistochemistry was used to detect expression of p16(INK4), p53, p21(WAF1), cyclin D1, erbB-2 and erbB-3. Mutations in codons 12 and 13 of the K-ras oncogene were detected by SSCP and sequencing following DNA extraction and amplification by PCR. The median (range) survival post-resection was 12.5 (3-83) months. Abnormalities of p16(INK4), p53, p21(WAF1), cyclin D1, erbB-2 and erbB-3 expression were found in 87%, 41%, 75%, 72%, 33% and 57% of cases, respectively. There was no significant correlation between expression of any of these markers and patient survival. K-ras mutations were found in 73 (75%) of 97 cases with amplifiable DNA. The presence of K-ras mutation alone did not correlate with survival, but there were significant differences in survival according to the type of K-ras mutation (p = 0.0007). Reduced survival was found in patients with GaT, cGT and GcT K-ras mutations compared to GtT, aGT and GaC mutations. In conclusion, survival was associated with type of K-ras mutation but not expression of p16(INK4), p53, p21(WAF1), cyclin D1, erbB-2 and erbB-3.

Adult↗

PubMed2000

Operations for extrahepatic bile duct cancers: are the results really improving?

OBJECTIVE: To find out if our results for the treatment of extrahepatic bile duct cancer have improved we reviewed our latest patients as a comparison to a previously reported series from this department. DESIGN: Retrospective study. SETTING: Tertiary referral centre, Sweden. SUBJECTS: 102 patients who presented with extrahepatic bile duct cancer 1979-1995. MAIN OUTCOME MEASURES: Morbidity, mortality, and short and long term survival. RESULTS: 16 patients had various types of resection, which were radical in 14 according to the surgeon and in 10 according to the pathologist. One patient (6%) died in hospital, and 1 (44%) developed complications. 13 patients had other operations that did not involve resection, 23 had laparotomy alone, 61 had biliary drainage either by percutaneous transhepatic cholangiography (PTC) or endoscopy, and 10 had no active treatment. One patient of the 16 (6%) who had resections has survived for more than five years and another one is still alive after 40 months. CONCLUSION: Long term survival has not improved for patients with extrahepatic bile duct cancer in our hospital during the last decades.

Adult↗

PubMed1999

Molecular analyses of the 15q and 18q SMAD genes in pancreatic cancer.

SMAD4 (DPC4) is part of the TGFB signaling pathway and is frequently inactivated in pancreatic carcinomas. TGFB signals from the membrane to the nucleus via SMAD proteins. TGFB receptor activation results in SMAD2 and SMAD3 phosphorylation, which then form heteromeric complexes with SMAD4. Inhibitory SMADs, SMAD6 and SMAD7, can prevent TGFB signaling by interacting either with the receptor or with SMAD2 and SMAD3. The encoding sequences for these proteins are organized in two gene clusters, one at 18q21 (SMAD2, SMAD4, and SMAD7) and the other at 15q21-22 (SMAD3 and SMAD6). Losses of 15q and 18q material are frequent in pancreatic carcinomas, and in order to map the extent of 15q and 18q deletions and to investigate further the involvement of SMAD4 and the possible function of SMAD2 and SMAD3 as tumor suppressor genes in pancreatic carcinoma, we performed loss of heterozygosity studies as well as mutation and expression analyses of SMAD4, SMAD2, and SMAD3 in 13 low-passage cell lines from 12 pancreatic carcinoma patients. To investigate possible amplifications of SMAD6 and SMAD7, the genomic organization and the expression levels of these genes were analyzed. One tumor with homozygous loss of SMAD4 was detected, and mutations of this gene were found in four of the 12 carcinomas; no SMAD2 or SMAD3 inactivating genomic alterations were found. In none of the cases was transcriptional silencing seen. No genomic amplifications, mutations, or increased expression of SMAD6 and SMAD7 were detected. These results suggest that functional abrogation of SMAD2 or SMAD3 and increased expression of SMAD6 or SMAD7 are infrequent in pancreatic carcinomas and further stress the particular importance of SMAD4 inactivation in pancreatic carcinogenesis.

Aged↗

PubMed1999

Pancreatic biopsy: why? When? How?

For final diagnosis of pancreatic cancer histologic or cytologic confirmation is needed. Tissue or cell material can be achieved by percutaneous puncture as part of the preoperative workup. During operation core-needle, incisional, and wedge biopsies or fine-needle aspiration cytology (FNAC) can be chosen. Sensitivity and diagnostic accuracy are high for both histologic and cytologic examinations, and false-positive results are exceptional, giving a specificity of 100% in most published series. The complication rate is low, also for knife biopsies in recent reports, provided biopsy of seemingly normal tissue is avoided. Percutaneous puncture is currently restricted to patients found to have advanced disease and who are not candidates for laparotomy. Microscopic confirmation is required in all patients in whom chemotherapy, radiotherapy, or both are planned. However, for attempted radical surgery per se, biopsy is not mandatory if the clinical suspicion of cancer is high and the surgical team has documented low postoperative mortality and morbidity rates.

Biopsy, Needle↗

PubMed1998

Cytogenetic analysis of pancreatic carcinomas: intratumor heterogeneity and nonrandom pattern of chromosome aberrations.

Twenty-nine nonendocrine pancreatic carcinomas (20 primary tumors and nine metastases) were studied by chromosome banding after short-term culture. Acquired clonal aberrations were found in 25 tumors and a detailed analysis of these revealed extensive cytogenetic intratumor heterogeneity. Apart from six carcinomas with one clone only, 19 tumors displayed from two to 58 clones, bringing the total number of clones to 230. Karyotypically related clones, signifying evolutionary variation, were found in 16 tumors, whereas unrelated clones were present in nine, the latter finding probably reflecting a distinct pathogenetic mechanism. The cytogenetic profile of pancreatic carcinoma was characterized by multiple numerical and structural changes. In total, more than 500 abnormal chromosomes, including rings, markers, homogeneously stained regions, and double minutes, altogether displaying 608 breakpoints, were detected. This complexity and heterogeneity notwithstanding, a nonrandom karyotypic pattern can be discerned in pancreatic cancer. Chromosomes 1, 3, 6, 7, 8, 11, 12, 17, and 19 and bands 1q12, 1q21, 3q11, 6p21, 6q21, 7q11, 7q22, 7q32, 11q13, 13cen, 14cen, 17q11, 17q21, and 19q13 were most frequently involved in structural rearrangements. A total of 19 recurrent unbalanced structural changes were identified, 11 of which were not reported previously: del(1)(q11), del(3)(p11), i(3)(q10), del(4)(q25), del(11)(p13), dup(11)(q13q23), i(12)(p10), der(13;15)(q10;q10), del(18)(q12), del(18)(q21), and i(19)(q10). The main karyotypic imbalances were entire-copy losses of chromosomes 18, Y, and 21, gains of chromosomes 7, 2, and 20, partial or whole-arm losses of 1p, 3p, 6q, 8p, 9p, 15q, 17p, 18q, 19p, and 20p, and partial or whole-arm gains of 1q, 3q, 5p, 6p, 7q, 8q, 11q, 12p, 17q, 19q, and 20q. In general, the karyotypic pattern of pancreatic carcinoma fits the multistep carcinogenesis concept. The observed cytogenetic heterogeneity appears to reflect a multitude of interchangeable but oncogenetically equivalent events, and the nonrandomness of the chromosomal alterations underscores the preferential pathways involved in tumor initiation and progression.

Abdominal Neoplasms↗

PubMed1998

Cytogenetic and FISH analyses of pancreatic carcinoma reveal breaks in 18q11 with consistent loss of 18q12-qter and frequent gain of 18p.

Chromosome 18 was analysed using a banding technique and fluorescence in situ hybridization (FISH) in 13 pancreatic carcinoma samples. The cytogenetic analysis revealed that chromosome 18 abnormalities were present in all cases and that several different rearrangements, such as translocations, deletions, dicentrics and ring chromosomes, were often found together. FISH mapping using 18q YAC probes showed that all tumours had lost at least one copy of 18q and that 18p was over-represented in 6 of the 13 cases. Furthermore, out of 13 identified deletion breakpoints on 18q, 11 were mapped to 18q11. The clustering of breaks close to the centromere indicates that loss of genes in bands 18q11 and 18q12, in addition to those located in 18q21, e.g. DPC4 and DCC, are important in the development of pancreatic tumours.

Aged↗

PubMed1998

Cytogenetic and fluorescence in situ hybridization analyses of chromosome 19 aberrations in pancreatic carcinomas: frequent loss of 19p13.3 and gain of 19q13.1-13.2.

Cytogenetic investigation of nine pancreatic carcinomas revealed structural rearrangements of chromosome 19 in eight cases, resulting in a high frequency of 19p losses and 19q gains. To characterize these imbalances further, we performed fluorescence in situ hybridization (FISH) analysis with 12 mapped and evenly distributed cosmids. The FISH study not only verified the cytogenetic findings but also disclosed additional chromosome 19 aberrations not detected by chromosome banding analysis. Seven carcinomas displayed 19p losses, always including 19p13.3, either through partial- or whole-arm deletions. Six cases showed gain of 19q, usually as one to two copies above the ploidy level. In one case, a high level of amplification in 19q13.1 was seen. The commonly overrepresented segment was 19q13.1-13.2. These results suggest that genes of importance in the development of pancreatic carcinomas are located in 19p13.3 and 19q13.1-13.2.

Aged↗

PubMed1997

Comparative genomic hybridization reveals frequent gains of 20q, 8q, 11q, 12p, and 17q, and losses of 18q, 9p, and 15q in pancreatic cancer.

Comparative genomic hybridization (CGH) was used to screen for genomic imbalances in 24 exocrine pancreatic carcinomas, including II low-passage cell lines (4-8 subcultures) and 13 uncultured samples. Aberrations were found in all cell lines and in seven of the 13 biopsies. The most frequent changes in the cell lines were gains of 20q (91%), 11q (64%), 17q (64%), 19q (64%), 8q, 12p, 14q, and 20p (55%), and losses of 18q (100%), 9p (91%), 15q(73%), 21q (64%), 3p (55%), and 13q (55%). High-levels gains (tumor to normal ratio over 1.5) were detected at 3q, 6p, 7q, 8q, 12p, 19q, and 20q. Among the tumor biopsies, overrepresentations of 7p and 8q were most common (31%), followed by 5p, 5q, 11p, 11q, 12p, and 18q (23%), whereas the most frequent losses involved 18p and 18q (31%) and 6q and 17p (23%). The genetic changes in nine samples obtained from metastatic lesions did not differ significantly from those in 15 primary carcinomas. Most of the gains and losses detected in this CGH study correspond well to those identified in previous cytogenetic and molecular genetic investigations of pancreatic carcinomas. However, frequent gain of 12p and loss of 15q have not been previously reported. Molecular genetic analyses of these chromosome arms are warranted, and may lead to the discovery of novel genes important in pancreatic carcinogenesis.

Aged↗

PubMed1997

Intravascular ultrasound for evaluation of portal venous involvement in pancreatic cancer.

The aim of this study was to evaluate the accuracy of intravascular ultrasound (IVUS) in diagnosing tumour involvement of the portal vein in patients with exocrine cancer of the head of the pancreas. Seven consecutive patients with a preoperative diagnosis of carcinoma, preoperatively deemed to be resectable, were examined with IVUS of the portal vein during surgery. The IVUS catheters were 6.2 F (2.0 mm) in diameter with a 20-MHz transducer and were introduced into the portal vasculature through the mesenteric superior vein. All patients had tumour extending to the portal vein as demonstrated at histopathological examinations in six cases and at surgical dissection in one case. The IVUS technique correctly identified all these patients, whereas five patients were incorrectly deemed at surgery not to have tumour involvement of the portal vein. These results indicate that IVUS is a very sensitive method for the evaluation of tumour involvement of the portal vein.

Aged↗

PubMed1995

Cytogenetically detected clonal heterogeneity in a duodenal adenocarcinoma.

A primary duodenal adenocarcinoma, a tumor type for which no previous chromosome data existed, was cytogenetically analyzed after short-term culture. The main tumor mass was localized in the pancreatic head, but the histopathologic examination revealed its duodenal origin. A total of six abnormal, karyotypically unrelated, clones were identified. The largest exhibited clonal evolution and consisted of two subclones with massively rearranged karyotypes in the hypodiploid and hypotetraploid range. Chromosome imbalances brought about by these complex changes were gain of 1q, losses of chromosomes 6 and 9, and total or partial losses of 1p, 3p, 3q, 9p, 10p, 17p, 17q, 18q, 20p, and 20q. The remaining five smaller clones had 1-2 numerical or balanced structural chromosome aberrations. The present study thus revealed yet another epithelial tumor type characterized by karyotypically unrelated clones. For this as for other tumors, the pathogenetic significance of such cytogenetic polyclonality remains uncertain.

Adenocarcinoma↗

PubMed1995

Massive cytogenetic heterogeneity in a pancreatic carcinoma: fifty-four karyotypically unrelated clones.

Chromosome analysis after short-term culture revealed remarkable cytogenetic heterogeneity in a pancreatic carcinoma. The patient had no prior history of radio- or chemotherapy. A total of 54 aberrant, near-diploid, karyotypically unrelated clones were identified, three of which displayed clonal evolution. The abnormalities were unbalanced in 30% of the clones. From one to eight karyotypic anomalies per clone were found. Numerical changes were rare, whereas structural aberrations were numerous and diverse and included deletions, duplication, insertions, inversions, translocations, ring formation, and telomeric associations. All chromosomes except No. 15 were involved in structural rearrangements, chromosomes 1, 6, 7, 8, 11, and 12 being the most frequently affected. A similarly massive cytogenetic polyclonality has never been reported previously. Although the spectrum of epithelial neoplasms characterized by karyotypically unrelated clones is increasing, the pathogenetic role of this type of cytogenetic intratumor heterogeneity remains unknown.

Aged↗

PubMed1994

Karyotypic pattern of pancreatic adenocarcinomas correlates with survival and tumour grade.

The relationship between cytogenetic findings and clinicohistopathological parameters was assessed in 29 patients with pancreatic adenocarcinoma. Karyotypic analysis revealed normal karyotypes (N) in 8 carcinomas and abnormal karyotypes (A) in 21. Within the A group, 8 cases had simple chromosome abnormalities (As), i.e., only one numerical or structural aberration, whereas 13 had complex changes with multiple numerical and structural abnormalities (Ac). No significant differences between the N and A groups were detected in terms of tumour grade, clinical stage, type of surgery performed, tumour site or size or the patient's age and survival. A correlation analysis between groups As and Ac revealed a significant difference with regard to grade, poorly differentiated carcinomas being more frequent in the Ac group. Patients in the Ac group had also a significantly shorter survival time than those in the As group. None of the other potentially prognostic parameters, i.e., grade, tumour site, stage and type of surgery performed, correlated significantly with clinical outcome.

Adenocarcinoma↗

PubMed1992

Immunohistochemical characterization of endocrine cells in experimental exocrine pancreatic cancer in the Syrian golden hamster.

Fifty exocrine pancreatic adenocarcinomas and 57 benign tumors induced in Syrian hamsters by N-nitrosobis(2-oxopropyl)amine (BOP) were examined for the presence of argyrophil cells antiinsulin, -glucagon, -somatostatin, -pancreatic polypeptide (PP), -gastrin/CCK, -vasoactive intestinal polypeptide (VIP), and - neuron-specific enolase (NSE) reactive cells. Argyrophil - and antihormone-reactive cells were found in the normal pancreatic ducts and in the acini, as well as in hyperplastic and atypical ducts/ductules, tubular complexes, benign lesions, and in 80% of ductal adenocarcinomas. Insulin and antiNSE-reactive cells were the most common, followed in decreasing frequency by glucagon, somatostatin, and PP cells. Antigastrin-/CCK-and -VIP-reactive cells were found in two cases. Argyrophil cells were present in about 60% of the tumors with Grimelius staining and in 55% of those with Churukian-Schenk staining. Insulin cells were seen in ductal cancer that had grown into a lymph node and in the lymph node metastases of another cancer. A novel finding was the presence of argyrophil and insulin cells within the lumen of some malignant glandular structures. Coexistence of several peptide cells was found in 52% of the cancers. The presence of argyrophil and hormone-producing cells in induced pancreatic ductal/ductular lesions further strengthens the existence of a close developmental relationship between exocrine and endocrine cells of the pancreas.

Adenocarcinoma↗

PubMed1989

Diffuse pigmented villonodular synovitis of the temporomandibular joint diagnosed by fine-needle aspiration cytology.

Diffuse pigmented villonodular synovitis is a rare tumor in the temporomandibular joint region. This article deals with a 32-yr-old male who suffered from pain and swelling in the right temporomandibular joint region associated with restricted mouth opening. Computed tomography showed a tumor lateral to the temporomandibular joint. Arthrography revealed a displaced temporomandibular joint disk. Fine-needle aspiration cytology showed characteristic cellular changes, including rounded or oval cells with abundant cytoplasm and intracytoplasmatic hemosiderin deposits and numerous multinucleated giant cells without nuclear atypia. A benign mesenchymal lesion suggestive for pigmented villonodular synovitis was diagnosed and later verified at histologic examination. Fine-needle aspiration cytology seems to be useful for this diagnosis.

Adult↗

PubMed1985

Sequential studies on the development of nitrosamine-induced pancreatic carcinoma in the Syrian golden hamster.

An attempt was made to define the importance of accumulated carcinogen dose and of induction-time on the development of pancreatic tumors after administration of N-nitrosobis(2-hydroxypropyl)amine (BHP) to Syrian golden hamsters. The development and progression of ductal hyperplasia, the number of tumor-bearing animals, the number of cancer-bearing animals, the number of tumors per tumor-bearing animal, and the grade of histological differentiation were found to be related to the accumulated dose of the carcinogen given, as was survival-time. The duration of the period between the carcinogen administration and examination was another factor of importance for the same changes except for the grade of histological differentiation of cancers and for survival-time. Once ductal hyperplasia and tumor development had started, there were no signs of regression - but rather progression - even after cessation of carcinogen administration. It is concluded that the development (progression) of induced pancreatic cancer in the Syrian golden hamster is influenced by the accumulated carcinogen (BHP) dose and the duration of the experiment. The results emphasize the need for a strict standardization of the experimental design as well as for the histological evaluation when animal models are used for studies of the effect of factors or procedures with a possible influence on the rate of tumor development.

Animals↗

PubMed1984

Studies of the effect of cerulein administration on experimental pancreatic carcinogenesis.

The influence of the cholecystokinin analogue cerulein on induced pancreatic cancer in the Syrian golden hamster was investigated. Of hamsters given weekly subcutaneous injection of N-nitrosobis(2-hydroxypropyl)amine (BHP) in initial experiments 50% succumbed within 30 weeks when a dose of 125 mg BHP per kg body weight was used and within 25 weeks after the double dose. An induction time of at most 24 weeks was therefore used in the subsequent experiments. Administration of cerulein (2 micrograms twice daily for 5 days a week) for 18 or 22 weeks caused an increase of pancreatic wet weight by about 100% and of pancreatic protein content by 73% (18 weeks). BHP did not influence the pancreatic weight either in hamsters given cerulein or in those given saline injections. BHP (125 mg/kg) caused tumors in 44% of the animals after 18 weeks and in 73% after 22 weeks. When BHP was given in a dose of 250 mg/kg, 100% of the animals had pancreatic tumors after 22 weeks. At neither dose and neither time interval did cerulein influence the number of tumor-bearing animals, number of cancer-bearing animals, or number of tumors per tumor-bearing animal or cancers per cancer-bearing animal. No morphological differences were found within the lesions of animals given only BHP as compared with those given cerulein in addition. All lesions were of ductal appearance. The distribution of tumors was also similar irrespective of the treatment given. The results show that cerulein does not influence experimental pancreatic carcinogenesis in the Syrian golden hamster, possibly reflecting that cerulein and BHP primarily act on different target cells.

Animals↗