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J Bajer

Publications and source records attributed to J Bajer.

At least 19 recordsLinked to original sources
PubMed1995

First report of t(8;21)(q22;q22) in a case of de novo acute monoblastic leukemia.

Here we describe the case of a 30-year-old man with a diagnosis of de novo acute monoblastic leukemia (FAB M5a), whose karyotype analysis revealed the presence of the translocation (8;21)(q22;q22) as the sole chromosome anomaly. In spite of the rather good prognosis patients suffering from acute leukemia and carrying this translocation are supposed to have, our patient had a very poor outcome, including an early relapse resistant to any treatment and meningeal localization. Death occurred within 5 months from diagnosis. To our knowledge this is the first report of t(8;21)(q22;q22) in de novo acute monoblastic leukemia.

Adult↗
PubMed1995

Trisomy 4 as the sole karyotypic anomaly in acute biphenotypic leukemia with B lineage markers and in acute minimally differentiated myeloid leukemia (M0).

Trisomy 4 is a recently defined chromosomal aberration in acute leukemia. The first reports suggested that this cytogenetic anomaly belongs to the M4 leukemia subtype of the FAB classification, but recent reports have described this alteration in a wider spectrum of leukemia subtypes. Here we report two cases of trisomy 4 as the sole chromosome anomaly: one was observed in a patient with acute biphenotypic leukemia with B-lineage markers and the second in a patient diagnosed with acute minimally differentiated myeloid leukemia (M0) with myelodysplastic features. To our knowledge these are, respectively, the first and second reports of trisomy 4 as the sole chromosomal anomaly in these leukemia subtypes.

Acute Disease↗
PubMed1993

Trisomy 4 in acute myeloblastic and acute lymphoblastic leukemia.

We report three cases of trisomy 4 in acute leukemia. This alteration was detected as the sole cytogenetic abnormality in a case of FAB M4 leukemia; it occurred in association with 5q deletion in a case of M1, and concomitant with Ph chromosome and trisomy 17 in a case of L2 leukemia. The latter case represents the fourth report of trisomy 4 in acute lymphoblastic leukemia.

Adult↗
PubMed1989

Catalase and glutathione peroxidase activity in cells with trisomy 21.

CuZnSOD is produced in overdose in cells with trisomy 21. This has been considered to be a cause of increased oxidative stress. In the present work we have studied the catalase and glutathione peroxidase activity in fibroblasts from 6, and blood cells from 30, subjects affected by Down syndrome. In the fibroblasts, catalase and glutathione peroxidase activities did not differ significantly from control cells. In platelets, lymphocytes, polymorphs and erythrocytes, no significant increase of catalase activity was found while glutathione peroxidase activity appeared significantly increased in platelets, polymorphs and erythrocytes but not in lymphocytes. These data seem to indicate that the increase of CuZnSOD in trisomy 21 cells does not affect the production of catalase. An increase, instead, of glutathione peroxidase has been detected in all blood cells, except in lymphocytes; this is a sign of a greater need for protection against the risk of lipoperoxidation. The fact that the enhancement of glutathione peroxidase activity could be assessed only in some types of cells examined suggests that the observed increase in those cells is probably a result of an additive effect of the overproduction of CuZnSOD due to gene dosage and the ordinarily higher content of oxygen radicals and peroxides.

Adolescent↗
PubMed1985

Coordinate expression of MnSOD and CuZnSOD in human fibroblasts.

The amount of manganese superoxide dismutase (MnSOD) and the activity of copper-zinc superoxide dismutase (CuZnSOD) have been studied in five karyotypically normal human fibroblast strains, using nuclear magnetic resonance (NMR) and polarographic methods. A significant correlation between the two enzyme activities, and a linear increase of MnSOD with the increase of CuZnSOD have been demonstrated. Both enzymes are present in nuclei, mitochondria, lysosome-microsome fraction and cytosol. These findings suggest that the two enzymes dismutate the O-2 cooperatively and that a common genetic control maintains the relative amounts of the two enzymes constant.

Adolescent↗
PubMed1985

Coordinate expression of Mn-containing superoxide dismutase and Cu,Zn-containing superoxide dismutase in human fibroblasts with trisomy 21.

The amount of Mn superoxide dismutase (MnSOD) and the activity of Cu,Zn-superoxide dismutase (CuZnSOD) have been studied in human fibroblasts of five subjects with trisomy 21 and five subjects with normal karyotype, using nuclear magnetic relaxation and polarographic methods. In the trisomic fibroblasts we have found a mean molar amount of MnSOD 25.4% lower than in the control, and an amount of CuZnSOD 54.7% higher. A positive significant correlation between the activities of both enzymes has been observed indicating that the two enzymes dismute the O2- cooperatively. However, the increase of MnSOD per unit of CuZnSOD appears significantly lower in the trisomic fibroblasts, an effect that is not due to a diminished inducibility of MnSOD. These findings suggest that the MnSOD and CuZnSOD genes interact to preserve the normal level of total SOD activity.

Adolescent↗