Jana Musilová

Boron-Doped Diamond Film Electrodes—New Tool for Voltammetric Determination of Organic Substances

This review with 194 references summarizes the recent progress in the development and applications of boron-doped diamond film electrodes in electroanalysis of organic compounds. It is based on the survey of 106 papers listed in a comprehensive table devoted to batch voltammetric and liquid flow amperometric methods using boron-doped diamond electrodes. The varieties in their construction, surface pre-treatment and electroanalytical methods used are discussed. Special attention is paid to miniaturized boron-doped diamond electrodes for in vitro/in vivo sensing, or electrochemical detection coupled to conventional or chip-based electrophoretic detection systems. Further, possibilities and limitations of surface modification are discussed.

Sister-chromatid exchanges and chromosal breakage in patients treated with cytostatics

The frequency of structural chromosomal rearrangements and sister-chromatid exchanges (SCEs) was investigated in short-term phytohemagglutininstimulated lymphocyte cultures by means of bromodeoxyuridine substitution and fluorescence plus Giemsa (FPG) staining technique. Both these parameters were significantly increased in patients treated with comparatively low doses of cyclophosphamide, busulphan and adriamycin. The increased SCE rate was proportional to the number of chromosome breaks, the ratio of SCE to breaks being about 100:1. The increase in the SCE number was maintained for several months after the termination of cytostatic therapy, when the conventional analysis of chromosome breaks yielded normal results. Normal SCE values were obtained in two patients treated with low doses of fluorouracil.

Chromosome study of 85 patients with myelodysplastic syndrome.

We studied bone marrow chromosomes in 85 consecutive patients with myelodysplastic syndrome (MDS). Fifty-seven (67%) had a clone with an abnormal karyotype at diagnosis. Eight had secondary MDS, all with abnormal karyotypes. The frequency of abnormal karyotypes in the primary MDS was 64.9%. During subsequent follow-up, five patients acquired chromosome abnormalities; thus, at the end of the study, 72.0% of patients had an abnormal karyotype. The most frequent chromosome abnormalities were 5q-, +8, -7, -5, and -22. Forty patients (i.e., 70% of those with an abnormal karyotype and 47% of the whole group) had one of the karyotype abnormalities associated with secondary MDS or acute nonlymphocytic leukemia; in other words, 5q- or -5, or -7. Of all patients, 21.1% progressed into ANLL. Unfavorable prognostic factors associated with the risk of evolution into ANLL and with shorter overall survival were the presence of greater than 5% of bone marrow blasts, major chromosome abnormalities, and monosomy 7.

Evolution of the karyotype and sex chromosome systems in basal clades of araneomorph spiders (Araneae: Araneomorphae).

Concepts of spider karyotype evolution are based mostly on advanced and most diversified clade, the entelegyne lineage of araneomorph spiders. Hence the typical spider karyotype is supposed to consist exclusively of acrocentric chromosomes including the multiple X chromosomes. However, our data show considerable diversity of chromosome morphology and sex chromosome systems in basal clades of araneomorphs. Karyotypes of basal araneomorphs consist of holocentric (superfamily Dysderoidea) or normal chromosomes with localized centromere. In males of basal araneomorphs the prophase of first meiotic division includes a long diffuse stage. Multiple X chromosomes are less common in basal clades. The sex chromosome system of many families includes a Y chromosome or nucleolus organizer region that occurs rarely in the entelegyne spiders. A derived X1X2Y system with an achiasmatic sex-chromosome pairing during meiosis was found in the families Drymusidae, Hypochilidae, Filistatidae, Sicariidae, and Pholcidae. This suggests a monophyletic origin of the families. In some lineages the X1X2Y system converted into an X0 system, as found in some pholcids, or into an XY system, which is typical for the family Diguetidae. The remarkable karyotype and sex chromosome system diversity allows us to distinguish four evolutionary lineages of basal araneomorphs and hypothesize about the ancestral karyotype of araneomorphs.

Deletion of 13q in two patients with retinoblastoma, one probably due to 13q- mosaicism in the mother

SummaryWe examined the peripheral blood chromosomes of eight patients with retinoblastoma. In two of them an interstitial deletion of 13q was found. The breakpoints were determined as follows: case 1, 13q12→21; case 2, 13q12→31. In both cases, band 13q14 was deleted. In case 2 the lymphocytes of the mother showed the identical interstitial 13q deletion in 3 of 100 mitoses, thus raising the possibility of maternal origin of the 13q deletion in a child. In one patient, retinoblastoma was unilateral; in the other, bilateral. Both patients were mentally retarded.

Cytogenetic study of cancer cells in effusions

A cytogenetic study of 71 malignant effusions caused by different histopathologic types of cancer was performed by a direct technique. Abnormal metaphases were present in 50 effusions (70.4%); a detailed analysis of banded karyotypes was possible in 20 of these. Trisomies and monosomies were present in 18 of 20 cases. The most common trisomies were +19, +3, +5, +8, +9, +10, +16 and +22; the most frequent monosomies were -X, -2, -5, -7, and -21. Clonal structural abnormalities were identified in 18 of 20 cases. In most instances, they were extensive, and some chromosomes were involved in a nonrandom fashion. Chromosomes #1, #13, and #6 were the most frequently involved in these rearrangements. A common marker chromosome, t(7;9)(p11;q12), was observed in two patients with cancer of the endometrium. Double minutes (DMs) were present in two patients, and there was a homogeneously stained region (HSR) in one.

Multiple unrelated clones in myelodysplastic syndrome and in acute myeloid leukemia

We identified cytogenetically unrelated clones in the bone marrow of 12 of 240 patients with myelodysplastic syndrome (MDS) and in 3 of 232 patients with acute myeloid leukemia (AML). In addition, unrelated single-cell abnormalities were found in six MDS and two AML patients. The most commonly encountered abnormalities present in the unrelated clones in patients with refractory anemia (RA) were del(5q), +8, and -7. In blastic types of MDS and AML trisomy 8 was found in two of eight patients while in the remaining cases the chromosome abnormalities were diverse and nonspecific. The presence of the chromosomally unrelated clones, together with recent data on the early appearance of monoclonality provided by molecular biology studies, support the interpretation that aberrations such as +8 and del(5q) are actually secondary abnormalities that develop during tumor progression in a cell with a primary submicroscopic genomic rearrangement.

Induction of Sister Chromatid Exchanges by Mitomycin C in Lymphocytes of Young and Old Human Donors

The kinetics of cell proliferation and sister chromatid exchanges (SCE) were studied in blood lymphocytes treated by mitomycin C (MMC) in young and old human donors. In both the young and old donors MMC inhibited cell proliferation. Spontaneous SCE frequency was not age-dependent. In young donors, MMC induced a dose-related linear increase in SCE frequency. In old donors a significantly reduced SCE rate was induced by 80 ng/ml of MMC, suggesting an altered SCE response to mutagen. As SCE represent some form of DNA repair, the results can be interpreted as an indication of a defective DNA repair in aging human lymphocytes.

Karyotype at diagnosis, subsequent leukemic transformation and survival in myelodysplastic syndrome

240 patients with MDS studied cytogenetically at diagnosis between 1981 and 1990 were followed until death or until April 1992 to evaluate the prognostic significance of FAB classification, age and karyotype. 61 patients (25.4%) subsequently transformed into AML and 176 (73.3%) died during the follow-up period. Patients with blastic MDS types had a shorter survival and a higher probability of leukemic transformation. The younger age increased the probability of leukemic transformation, but was associated with a longer survival. The absence of analyzable mitoses was associated with a shorter survival. The complex chromosomal abnormalities at the initial evaluation identified a subgroup of patients with a high risk of a short survival and/or subsequent leukemia transformation. In refractory anemia the presence of complex chromosomal abnormalities was linked with a relative risk of 3.58 of leukemic transformation and shorter survival as compared with other cytogenetically defined groups.

Sequential cytogenetic study of patients after bone marrow transplantation

Thirty-one patients (19 males and 12 females; mean age 23.9 years, range 4-41 years) were treated with bone marrow transplantation (BMT) after intensive chemoradiotherapy. Their diagnoses were as follows: chronic myeloid leukemia (CML) in 13, acute myeloid leukemia (AML) in seven, acute lymphocytic leukemia (ALL) in six, myelodysplastic syndrome (MDS) in two, aplastic anemia (AA) in two, and Fanconi anemia (FA) in one. Allogeneic BMT was performed in 28 cases (17 donors were of like sex, 11 were of unlike sex), one patient received syngenic transplant, and one received transplant of cells obtained from an unrelated donor through a computerized international registry in London. Autologous BMT was performed in three patients. BM cells were analyzed cytogenetically at diagnosis, before and serially after BMT (three to nine times). Follow-up ranged from 2 to 55.5 months. Cytogenetic examination was a very useful method for monitoring posttransplantation course in patients with CML or in those who received BM cells of unlike sex. Results of concomitant cytogenetic examinations are reported in detail.