in situ Dotaz Zobrazit nápovědu
Stable telomere maintenance is essential for the indefinite cellular proliferation of germline and tumour cells. In most cases, telomere synthesis is performed by nucleoprotein enzyme complex of telomerase, that results in stabilisation of telomeres shortened to < or = 7 kb. Rarely, telomeres may be maintained via alternative (recombination-based) mechanism, which produces telomeres of heterogenous lengths (3-50 kb). Analysis of telomeres by in situ techniques, such as fluorescent in situ hybridisation (FISH) on metaphase spreads or on extended DNA fibres (fiber-FISH) and Primed in situ labelling (PRINS), enables to distinguish between these two mechanisms and to analyse individual telomeres in the given type of cells.
- MeSH
- DNA nádorová genetika MeSH
- DNA sondy MeSH
- genetické techniky * MeSH
- hybridizace in situ fluorescenční MeSH
- in situ značení DNA s primerem MeSH
- lidé MeSH
- telomery genetika patologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- anglický abstrakt MeSH
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
- Názvy látek
- DNA nádorová MeSH
- DNA sondy MeSH
I-FISH (fluorescence in situ hybridization on interphasic nuclei) represents a laboratory method linking morphological investigations (histological sections of formaldehyde fixed and paraffin embedded tissues) with molecular techniques (sequence specificity of nucleic acids bases for a certain locus). I-FISH is relatively undemanding for a laboratory workout, but offering a lot of important information about the investigated cells. Within a scope of pathology departments I-FISH is utilized mostly in diagnostics of neoplasms. I-FISH is helpful in detecting gene copy numbers (amplifications or deletions), and, importantly, in establishing copy numbers of individual chromosomes (polysomies or monosomies), chromosomal breaks and translocations. At present, I-FISH is used not only for diagnosis and estimation of prognosis, but also as a method to qualify a patient for a targeted biological therapy. Because demands on investigation of solid tumors keep raising I-FISH becomes a part of routine investigations. The aim of this paper is to summarize principles and the utility of I-FISH and to help the interested readers in finding a basic orientation in this laboratory method.
The diagnosis of bacterial agents of sepsis from blood cultures is crucial for the subsequent treatment of this condition. The aim of this study was to compare Gram stain, culture, and biochemical identification (conventional methods) and fluorescence in-situ hybridisation (FISH) that detects microorganisms from positive blood cultures using specific probes. Another aim was to evaluate the potential of this method for use in clinical practice. Altogether 71 samples of positive blood cultures were tested by FISH. Blood cultures were also processed in the conventional way using the BACTEC analyser. The bacteria recovered were inoculated on solid media and then identified biochemically. The results obtained by the conventional methods and HemoFISH were not 100% concordant. The sensitivity of HemoFISH was 90.1%. Very good results were achieved for staphylococci and enterobacteria. FISH identification failed in three cases because the hybridization probes were not able to bind to bacterial rRNA. The FISH bacterial identification is faster than the conventional methods, but should be confirmed by the latter.
- Klíčová slova
- sepsis - blood cultures - Gram stain - fluorescence in situ hybridization.,
- MeSH
- Bacteria * izolace a purifikace MeSH
- bakteriologické techniky metody MeSH
- hybridizace in situ fluorescenční * MeSH
- kultivační vyšetření krve * MeSH
- lidé MeSH
- senzitivita a specificita MeSH
- sepse * diagnóza mikrobiologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
During the last few years molecular biology methods expanded into human cytogenetics. This is in close connection with advanced technologies of DNA probes preparation and possibilities of their non-radioactive labelling by means of enzymatic incorporation of modified nucleotides as well as their hybridization with complementary DNA of chromosomes and interphase nuclei. FISH became a useful method in the clinical research. We present the short review of FISH methodologies and their applications for studies of translocation, deletions, amplifications and other chromosomal rearrangements in genetic and oncologic patients. The sensitivity of these methods is approximately 1-10 kb and therefore precise localization of genes on chromosomes is possible. Except gene mapping FISH can be used for comparative genomic mapping (CGH) and for identification of chromosomal changes of tumor cells.
- MeSH
- cytogenetika MeSH
- hybridizace in situ fluorescenční * metody MeSH
- lidé MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- anglický abstrakt MeSH
- časopisecké články MeSH
- přehledy MeSH
Various techniques are now available for wide genome screening of alterations in copy number, structure and expression of genes and DNA sequences. Molecular cytogenetics has special techniques of comparative genomic hybridization (CGH), spectral karyotyping (SKY) and multicolor FISH (mFISH). We present principles of these methods, their use in molecular cytogenetic examinations of patients. We quote our experience with mFISH for analyses of complex chromosomal rearrangements in neoplastic cells and identification of inborn supernumerary marker chromosome. Further, we also review the first experiences with multicolor high resolution banding of chromosome (mBAND). This method was used for analysis of bone marrow cells of patient with myelodysplastic syndrome and deletion of chromosome No. 5. With mBAND exact breakpoints were localized. Multicolor fluorescence methods mFISH and mBAND becones the new tools for more precise analyses of inborn and acquired numerical and structural chromosomal rearrangements.
UNLABELLED: Urothelial carcinoma is a disease at high risk of recurrence after the initial therapy (70-80%) and with the tendency to progression accomplishing the recurrence (30%). Long lasting monitoring of patients with urothelial carcinoma is necessary. Cystoscopy and cytology are currently the primary modalities used to detect and monitor urothelial carcinoma. However, cytology has relatively poor sensitivity especially in well differentiated tumors. Cystoscopy is an invasive and relatively expensive method. Therefore, methods improving detection of urothelial carcinoma from urine specimens are employed. Uro Vysion (Vysis) fluorescence in situ hybridization (FISH) for improved detection of urothelial carcinoma was evaluated. MATERIALS AND METHODS: Bladder tumor progression is accompanied by increased chromosomal instability and aneuploidy of chromosomes 3, 7, 17 and loss of locus 9p21. A total of 124 patients were analyzed at Dpts. of Urology and Pathology, Faculty Hospital in Brno. Cytologically analyzed urine specimens were tested by FISH and simultaneously cystoscopy was employed including biopsy for histological examination. RESULTS: FISH analysis was positive in 35 cases, including 5 cases with negative biopsy and cytology. Negative FISH result was detected in 24 cases where the malignant status was determined. The sensitivity of FISH in our series was 58.9% and the specificity 88.1%. CONCLUSIONS: FISH is a relatively simple, speedy and non invasive diagnostic method. It detects the symptoms of malignity on the molecular level, which leads to earlier diagnosis and therapy and, hence, to potential extended survival. FISH makes it possible to take decision in cases of atypical or unclear cytological finding. The FISH method using the Uro Vysion kit appears as a prospective non invasive method capable of early UK detection, with a higher sensitivity than the standard cytology of urine.
- MeSH
- hybridizace in situ fluorescenční * MeSH
- lidé MeSH
- nádory močového měchýře diagnóza MeSH
- senzitivita a specificita MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- anglický abstrakt MeSH
- časopisecké články MeSH
- Klíčová slova
- LARYNX/neoplasms *,
- MeSH
- karcinom in situ * MeSH
- larynx * MeSH
- lidé MeSH
- nádory hrtanu * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
BACKGROUND: According to the literature approximately 50% of patients with Turner's syndrome have karyotype 45,X in every cell, the rest have two or more cell lines with mosaics of sex chromosomes. New methods have shown that the mosaicism is probably more frequent than expected from classical cytogenetics examinations. The aim of this study was to detect numerical changes of sex chromosomes in mitoses and interphase nuclei of cultivated peripheral lymphocytes of patients with Turner's syndrome by means of FISH, to compare the sensitivity of classical and molecular-cytogenetic methods and to estimate the values obtained in 10 control healthy females with karyotype 46,XX. METHODS AND RESULTS: 18 females with Turner's syndrome were examined. Karyotype 45,X was found by classical cytogenetics in all cells of 9 females. The 9 remaining patients had sex chromosome mosaicism of two or more clones. In all patients FISH confirmed the results of classical cytogenetic methods and in 6 patients (30%) it revealed other clones previously not detected. CONCLUSIONS: Higher sensitivity of FISH enables more precise detection of mosaicism of cell lines than classical cytogenetics and this technique is more suitable for examinations of patients with Turner' syndrome.
- MeSH
- chromozom X * MeSH
- dospělí MeSH
- hybridizace in situ fluorescenční * MeSH
- karyotypizace MeSH
- lidé MeSH
- mozaicismus * MeSH
- senzitivita a specificita MeSH
- Turnerův syndrom genetika MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- ženské pohlaví MeSH
- Publikační typ
- anglický abstrakt MeSH
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Klíčová slova
- CERVIX, UTERINE/neoplasms *,
- MeSH
- cervix uteri * MeSH
- karcinom in situ * MeSH
- lidé MeSH
- nádory * MeSH
- Check Tag
- lidé MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
The paper summarizes the latest knowledge of carcinoma in situ in testicular tissue. It discusses their morphological, cytogenetic and histochemical characteristic including diagnosis. It stresses the necessity of correct fixation of bioptic samples of the testes. It deals with the malignant character of the cells of carcinoma in situ and reported data supporting their invasive potencial. Further the paper shows the incidence of this finding in at-risk groups as well as clinical and pathological correlations.
- MeSH
- biopsie * MeSH
- karcinom in situ patologie MeSH
- lidé MeSH
- rizikové faktory MeSH
- testikulární nádory patologie MeSH
- testis patologie MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- anglický abstrakt MeSH
- časopisecké články MeSH
