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Biomedical subjects

J Cervenka

Publications and source records attributed to J Cervenka.

At least 91 records · Page 5Linked to original sources

Successful bone-marrow transplantation for infantile malignant osteopetrosis.

A five-month-old girl with autosomal-recessive osteopetrosis received a bone-marrow transplant from her five-year-old HLA-MLC-identical brother after preparation with cyclophosphamide and modified total-body irradiation. Engraftment was documented by chromosomal analysis. Anemia, thrombocytopenia, and leukoerythroblastosis corrected within 12 weeks of transplantation. Low serum calcium and elevated serum alkaline and acid phosphatase levels became normal. Serial x-ray studies revealed bony remodeling and new nonsclerotic bone formation. A pretransplantation bone biopsy revealed small marrow spaces, rare marrow elements, increased osteoclasts, and no bony resorption. After transplantation, osteoclasts were actively resorbing bone, and medullary cavities contained normal bone marrow. Fluorescent Y-body analysis after transplantation revealed donor (male) osteoclasts and recipient (female) osteoblasts. Monocyte bactericidal activity, markedly decreased before transplantation, became normal. Vision, hearing, growth, and development were progressively improving 16 months after transplantation. Allogeneic bone-marrow transplantation appears to be the treatment of choice in this fatal disorder.

Blood Bactericidal Activity↗

Pattern of chromosomal replication in synchronized lymphocytes. I. Evaluation and application of methotrexate block.

The BrdUrd-Hoechst 33258-Giemsa technique was employed to study patterns of chromosomal replication in human lymphocytes synchronized by Methotrexate (MTX). It is proposed that in the presence of MTX, a major portion of the cell population is blocked in an advanced stage of the S-phase and not in the G1/S border of the cell cycle. At this point, the replication of the chromosomal segments corresponding to the R-bands is terminated, and the replication of the G-bands and the inactive X-chromosomes is being initiated. The use of this method in the study of higher resolution patterns of chromosomal replications is proposed.

Cell Cycle↗

Results of screening for phenylalanine and other amino acid disturbances among pregnant women.

Blood specimens were collected from 15000 pregnant women during the first 3 months of their pregnancy and screened for amino acid disturbances by means of paper chromatography. A high incidence of disturbances in the phenylalanine metabolism was discovered: three cases of mild hyperphenylalaninaemia without phenylpyruvicaciduria (incidence 1:5000); two cases of mild hyperphenylalaninaemia with phenylpyruvicaciduria (incidence 1:7550); four cases of mild phenylketonuria (incidence 1:3750). Disturbances in the metabolism of other amino acids were found to be rare. Metabolic and genealogical findings in some detected families are briefly described.

Adult↗

Albinism in Nigeria with delineation of new recessive oculocutaneous type.

Seventy-nine Nigerian oculocutaneous albinos were investigated. Fifty-six had typical tyrosinase-positive albinism (TPA) and 23 had brown albinism (BA), a new oculocutaneous type. The TPA were characterized by localized but no generalized skin pigment, yellow hair, blue to brown irides, nystagmus, and reduced or absent retinal pigment. Localized skin pigment included freckles and lentigines. The iris and skin pigment were the result of the slow accumulation of pigment with age as both were found in older individuals. The most severe skin changes were premalignant keratoses and squamous cell carcinoma of the skin, and the skin malignancies were the major factor in limiting the lifespan for TPA. The BA were characterized by generalized light brown skin pigment, light brown hair, blue to brown irides, nystagmus, and reduced retinal pigment. There was little accumulation or change of pigment in the eyes or skin with age. The generalized light skin pigment was effective in reducing sensitivity to solar radiation and very few BA had premalignant keratoses. Pedigree analysis for BA suggested on autosomal recessive inheritance pattern.

Adolescent↗

Nosocomial spread of gentamicin-tobramycin resistance in hospital strains of Pseudomonas aeruginosa and Enterobacter sp. origin, development and transfer of R plasmids from pseudomonas to enterobacter.

In the Medical Centre of the University of Bratislava the period between 1975 and 1976 was studied with regard to a rather limited use of Gentamicin (GEN) which was then followed by a period of excessive administration thereof due to a change in the availability of the antibiotic. As a consequence, GEN-resistant (GENR) Pseudomonas appeared in two medical wards, which resistance however, was non-transmissible. A few month later, however, transfer of GENR was demonstrated as a co-transfer with other types of resistance. For the first time in 1979 strains of P. aeruginosa transferring GENR directly appeared as rather individual, dispersed strains. Later in 1979, clustered outbreaks of hospital infections caused by GENR Entrobacter sp. transferring GENR appeared as single as well as mixed infections. Interspecies transfer from P. aeruginosa to Enterobacteriaceae, and vice versa, was demonstrated in vitro. Identity or close similarity of enzyme patterns inactivating aminoglycoside antibiotics in P. aeruginosa and Enterobacter suggest that genes for GENR could be transposed from P. aeruginosa under the massive selective pressure of GEN.

Anti-Bacterial Agents↗

Cell line derived from a metastasis of a human testicular germ cell tumor.

A cell line, designated 833K-E, has been established from a metastasis of a human testicular germ cell tumor that consisted of four histological types of tumor cells. The 833K-E cells have morphological and ultrastructural characteristics of epithelial cells and a hyperdiploid karyotype indicative of their human male origin. The cells grow in agar cultures and produce in nude mice tumors which have the hstological features of embryonal carcinoma without differentiated elements. Many of the cells express a stage-specific mouse embryonic antigen, and low levels of the major histocompatibility antigens and beta 2-microglobulin also were detected on a large percentage of the cells. A lymphoblastoid cell line (833K-LC) established from the same tumor specimen expresses major histocompatibility antigens and beta 2-microglobulin but does not express the embryonic antigen.

Animals↗

Mutagenic activity of anticancer agent cis-dichlorodiammine platinum-II.

cis-Dichlorodiamminoplatinum-II (cis-DDP) has been widely used as an anticancer chemotherapeutic agent. The mutagenicity of cis-DDP was investigated in vitro and in vivo using sister-chromatid exchange analysis and the analysis of chromosomal aberrations. Parallel human lymphocyte cultures were incubated with and without the addition of BrdU at 4 concentrations of cis-DDP. Significant increases in SCE rate were observed at 0.25 micrograms/ml and higher, showing a clear dose-response relation between SCE rate and cis-DDP concentration. A significant increase in chromosome breakage and tetraradial figures was observed in BrdU free cultures treated with cis-DDP again showing a dose dependency. Analysis of the distribution of cells in the first, second and third division in cis-DDP treated cultures demonstrated the depressing effect of the drug on mitotic activity. In vivo analysis of SCE and chromosome aberrations in mouse showed that 13.85 mg/kg i.p. of cis-DDP produces significant increases in the rate of SCE and chromosome aberrations in bone-marrow cells.

Animals↗

Chromosome breaks and sister chromatid exchanges in albinos in Nigeria.

The prevalence of squamous cell carcinoma of the skin in albinos reaches approximately 90% in patients over 20 years of age in the vicinity of Enugu, Nigeria. Chromosome breaks and sister chromatid exchanges (SCE) were evaluated in tyrosinase-positive oculocutaneous albinos and pigmented controls of Ibo extraction who were life-long residents of Nigeria. No difference in the frequency of chromosomal breaks in 14 albinos compared to 6 pigmented controls, and no differences in the frequency of SCE in 9 albinos compared to 3 controls could be detected. Increased chromosomal abnormalities in lymphocytes do not appear to be assoicated with albinism or fulminating skin cancer present in albinos in the tropics.

Adolescent↗

Sister chromatid exchange in lymphocytes from patients with malignant lymphoma.

Sister chromatid exchange (SCE) frequencies were studied in differentially stained lymphocytes from 47 patients with malignant lymphoma. Thirteen patients were untreated when studied. The mean SCE frequency [+/- standard error (SE)] for these patients was 12.7 +/- 0.9 per mitosis. The mean score for 40 controls was 6.1 +/- 0.3. SCE mean scores were significantly higher in the untreated patients than in the controls (P less than 0.001). Seven patients were treated with radiotherapy alone. They demonstrated a mean SCE frequency (8.8 +/- 0.8) significantly lower (P less than 0.01) than that found in untreated patients. Eleven patients received cyclophosphamide within 4 weeks prior to study. They demonstrated a mean SCE frequency (14.3 +/- 1.3) significantly higher (P less than 0.05) than that found in patients who had received regimens that did not contain cyclophosphamide in the prior 4 weeks (11.1 +/- 1.3) or who had been off drugs for at least 8 weeks (10.1 +/- 0.8). Our data suggest that untreated patients with malignant lymphoma have elevated SCE frequencies, which may be further increased by certain chemotherapeutic agents.

Adolescent↗

Studies on the transformation of rat embryo cells of low passage by carcinogenic fluorenylhydroxamic acids and their acetate esters.

Rat embryo cells of low passage subjected to a single treatment with certain carcinogenic fluorenylhydroxamic acids and their respective acetate esters showed signs of transformation in vitro, such as changes in phenotype, growth in soft agar and agglutination with concanavalin A. In addition, certain changes in karyotype and loss of diploidy were observed. There was no evidence, either by electron microscopy or by assay of RNA-dependent DNA polymerase, for the presence of virus. None of these cell lines produced tumors after inoculation into the isologous host. The results of these study lead us to suggest that malignant transformation is a multistep process and that certain criteria of transformation of rat embryo cells are associated with the initial stage(s) in which the cells are transformed without being tumorigenic. The ultimate test for malignant transformation of rat embryo cells remains the production of tumors in a susceptible host after inoculation of treated cells.

Agglutination Tests↗

Sister chromatid exchange in patients with viral disease.

Sister chromatid exchange (SCE) frequencies were studied in differentially stained chromosomes from lymphocytes of 17 patients with viral disease. The mean SCE score for the patients was 8.7 +/- 2.9 standard deviations. SCE scores were significantly elevated in the patients compared with the controls (p less than 0.01); however, variability in SCE means was observed in the patients. SCE elevations were also present in long term cultured Epstein Barr virus positive human B lymphocytes.

B-Lymphocytes↗