Tamás Bubán

Fever of unknown origin with seronegative spondyloarthropathy: an atypical manifestation of Whipple's disease

Many authors emphasise the diagnostic difficulties and point out the multifaceted nature of Whipples disease.1,2 Joint symptoms are present in 90% of all cases and may precede other disease manifestations by decades.3 We report here a case with fever of unknown origin accompanied by seronegative spondyloarthropathy with no typical gastrointestinal symptoms and initially negative upper panendoscopy. To confirm the diagnosis, the bacterial 16S ribosomal RNA sequence of Tropheryma whippelii was determined by polymerase chain reaction (PCR). A 58 year old white man had a 12 year history of intermittent arthralgias and seronegative polyarthritis. In 1993, monolateral stage II sacroiliitis was disclosed with no definite cause. Low dose methylprednisolone treatment was started, but there was no clinical improvement. In 1998 the patient became febrile, lost 10 kg of weight but had no gastrointestinal symptoms. He underwent an extensive examination, including radiological examinations of the chest and paranasal sinuses, abdominal sonography, echocardiography, abdominal computed tomography, upper panendoscopy, bone marrow biopsies, whole body gallium-67 citrate scan, multiple blood, stool, and urine cultures, as well as serological investigations for known …

Detection of mutations in the cDNA of the proliferation marker Ki-67 protein in four tumor cell lines

The Ki-67 protein has an essential role in cell proliferation. It is present in all dividing cells of normal and tumor tissues, but absent in resting cells. At present, no data are available about any alterations in the gene of this protein that could contribute to its altered structure and function, resulting in tumor development. We therefore searched for mutations in the Ki-67 gene (MKI67). cDNAs from four tumor cell lines derived from carcinoma of the cervix (HeLa), colon (CXF94, SW480), and lung (A549) were prepared. Defined parts of the cDNA were amplified by specific primers, cloned into pCRII-Blunt-TOPO vector, and replicated in Escherichia coli. The sequence of the amplified products were determined by automated fluorescence sequencing. Eight different mutations were characterized in the four cell lines tested. One is a deletion of a single base at position 1496 causing a truncated protein, the second is a A433T exchange is a silent mutation, and the remaining six mutations result in an amino acid change that might alter the conformation of the protein. Our results show that several mutations exist within the Ki-67 proteins cDNA in four tumor cell lines. These mutations might provide a genetic basis for tumor development.

Detection of internal tandem duplications in the FLT3 gene by different electrophoretic methods

Abstract Background: In acute myeloid leukemia (AML), the internal tandem duplication (ITD) in the juxtamembrane domain of the FLT3 (Fms-like tyrosine kinase 3) gene is one of the most frequent genetic alterations associated with poor prognosis. Methods: A complex evaluation of the analytical properties of the three most frequently used detection methods – PCR followed by agarose (AGE), polyacrylamide (PAGE) or capillary electrophoresis (CE) – was performed on 95 DNA samples obtained from 73 AML patients. Results: All the three methods verified the presence of a mutant allele in 20 samples from 18 patients. AGE and PAGE could detect the presence of 1%–2% mutant allele, while the detection limit of CE was 0.28%. However, acceptable reproducibility (inter-assay CV <25%) of the mutant allele rate determination was only achievable above 1.5% mutant/total allele rate. The reproducibility of the ITD size determination by CE was much better, but the ITD size calculated by PeakScanner or GeneScan analysis was 7% lower as compared to values obtained by DNA sequencing. The presence of multiple ITD was over-estimated by PAGE and AGE due to the formation of heteroduplexes. Conclusions: This study suggests the use of PCR+CE in the diagnostics and the follow-up of AML patients. The data further supports the importance of proper analytical evaluation of home-made molecular biological diagnostic tests.

A new mutation in Muir-Torre syndrome associated with familiar transmission of different gastrointestinal adenocarcinomas

Hereditary Nonpolyposis Colorectal Carcinoma (HNPCC) is the most frequent inherited disease which can lead to the development of tumors in the colon and other locations. Its genetic basis is related to the germline mutation of the Mismatch Repair (MMR) genes. Muir-Torre syndrome is considered one of the subtypes of this disease, in which the HNPCC tumor spectrum is frequently associated with sebaceous carcinoma of the skin or keratoacanthoma. A 57 years old male patient is presented with a mucinous carcinoma of the caecum and an adenocarcinoma of the pancreas head. A malignant sebaceous carcinoma was removed from his left neck area. His family history was significant for two cases of colon carcinoma, two cases of stomach cancer and a case of metacron endometrial and skin tumor as well. Both the colon carcinoma and the skin tumor proved to be microsatellite unstable. An Arg>Pro switch missense mutation was found in codon 265 of the hMLH1 gene. This error was found in 4 other members of his family. The detected genetic alteration was considered pathogenic and was not published yet in English literature. The significance of this particular case is the rare tumor association in a patient with Muir-Torre syndrome (MTS). In cases of sebaceous skin lesions, evaluation of family history is of utmost importance in the early detection of HNPCC and in the follow up care of family members with the particular mutation.

Ki-67 – new faces of an old player

The Ki-67 protein was isolated twenty-five years ago and has become the first histological marker of proliferating cells until now. This molecule with a unique structure possesses such fundamental biological functions that are essential for normal cell proliferation. Since the Ki-67 protein is present in every dividing cell (G1, S, G2/M phase) but is absent from the resting cells (G0 phase) it is very much suitable for identifying the proliferating fraction of cells. Thus, it provides essential information concerning the malignancy of a tumor and about the prediction of response to a certain therapy. Based on its important role in cell proliferation, the Ki-67 protein might also play a role in tumor genesis. In their present work the authors discuss the history and the properties of Ki-67, its role in cell cycle regulation and its prognostic importance in different malignant disorders.

Q48P mutation in the hMLH1 gene associated with Lynch syndrome in three Hungarian families

Lynch syndrome (Hereditary nonpolyposis colorectal cancer, HNPCC) is an inherited disease with variable phenotype causing the development of colon cancer and other malignancies. The basis of the disease is believed to be the mismatch repair gene mutations. Genetic screening has been performed among the patients who have undergone surgery for colon cancer at the University of Debrecen, Department of Surgery. Tumor samples of the screened patients were submitted to immunohistochemistry on hMLH1, hMSH2 and hMSH6 genes, microsatellite instability testing, followed by sequencing and multiple ligation dependent probe amplification. Three families were identified with the missense mutation c.143A>C (p.Q48P) of hMLH1 gene. In one of the families a segregation analysis of this particular variant was also accomplished. The segregation analysis revealed a clear correlation between the tumor cases and the occurrence of this mutation. However, none of the analyzed 100 healthy controls demonstrated the same aberration. There is only one published evidence in the literature about the presence of this rare variant in any population. The Gln to Pro switch in the ATPase domain, a conservative region of the hMLH1 gene, creates significant changes in the protein structure. These results indicate that this mutation is the abnormality responsible for the patients’ phenotype and it is feasible that this particular aberration occurs more frequently among Hungarian Lynch syndrome patients.

A hereditaer nonpolyposus colorectalis carcinoma szindrómás betegek szűrésének és szoros utánkövetésének fontossága egy családfa bemutatása kapcsán

INTRODUCTION Hereditary nonpolyposis colorectal carcinoma (HNPCC) is an autosomal dominant disease, which shows familial clustering. AIM We would like to emphasize the importance of monitoring the HNPCC syndrome patients by presenting a case of a proven MMR gene mutation carrier and her family tree encompassing 10 years. MATERIALS AND METHOD To screen a suspected HNPCC Hungarian family member we are taking thorough family histories. If the diagnosis of HNPCC was further supported by immunohistology and the microsatellite status, sequencing of the MMR genes was carried out. RESULTS A novel mutation in exon 6 of the hMSH2 gene leading to the deletion of two nucleotide pairs [c.969-970delTC] was detected in our patient. During the 10-year follow-up period of our patient new HNPCC-associated tumors have developed in several family members. Conslusion: Close surveillance of the patient and its family members at risk was effective, although it requires compliance from the subjects. Orv Hetil. 2017; 158(30): 1182-1187.Absztrakt: Bevezetes: A hereditaer nonpolyposus colorectalis carcinomara jellemző mutaciok (HNPCC) autoszomalis dominans oroklődesmenetet mutatnak. Leginkabb vastagbeldaganatok kialakulasaert felelősek. Celkitűzes: A HNPCC-szindromas betegek szűresenek es kovetesenek fontossagat szeretnenk hangsulyozni egy igazolt MMR-gen-mutaciot hordozo betegunk jelenlegi es 10 evvel korabbi csaladfajanak osszehasonlitasaval. Betegek es modszer: Hazankban előfordulo, HNPCC-re gyanus csaladok kiszűrese erdekeben alapos csaladi anamnezist veszunk fel. Amennyiben az immunhisztokemiai es mikroszatellitainstabilitas-vizsgalatok HNPCC-szindromara utalnak, elvegezzuk az MMR-genek szekvenalasat. Eredmenyek: Betegunknel egy, a hMSH2-gen 6. exon ket bazispart erintő deletioja (c.969–970delTC) igazolodott. Tizeves utankovetes soran betegunknel es rokonainal ujabb, a HNPCC-re jellemző tumorok jelentek meg. Kovetkeztetes: A veszelyeztetett csaladtagok kovetese soran a szekunder prevencio a jol egyuttműkodő betegeknel hatekony volt. ...