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B Pedersen

Publications and source records attributed to B Pedersen.

At least 163 records · Page 9Linked to original sources
PubMed1987

The prognostic significance of cytological, histological and cytogenetic findings in refractory anaemia (RA) and RA with sideroblasts. A follow up study.

Two independent observers performed a double review of cytological and histological bone marrow material obtained at diagnosis and during follow up in 34 patients with the myelodysplastic syndrome (MDS), subtypes refractory anaemia (RA) and RA with ringed sideroblasts (RA-S) (26 and 8 patients, respectively). Average values were used for the analyses. Data obtained at diagnosis confirmed earlier observations that a worse prognosis was indicated by high blast cell counts (P less than 0.01), presence of blast foci and clonal cytogenetic abnormalities (P = 0.08). Data obtained during follow up, in addition, showed that an increased probability of progression to FAB-subtype RA with an excess of blasts was related to both the occurrence of blast foci (P less than 0.05) and the occurrence of new or additional clonal abnormalities (karyotype shift) (P less than 0.01). The relationship between parameters investigated at diagnosis, during follow up, and in the pooled material, points to RA-S being a separate entity having a better prognosis than RA, and further substantiates an earlier observed relationship between blast cell accumulation and the frequency of cytogenetically abnormal metaphases.

Adolescent↗
PubMed1987

13-cis retinoic acid treatment of myelodysplastic syndromes.

Of eight patients with primary myelodysplastic syndrome (MDS) treated with Roacutane (13-cis retinoic acid, Roche, Basel, (13-RA)) 20 mg/m2 for 6 weeks and an additional 100 mg/m2 for 4 weeks (3 patients), 4 responded either with a slight increase in peripheral blood neutrophil count or a decrease in myeloperoxidase deficient neutrophils. In agar cultures 2 patients showed a concurrent increase in growth of day 11 colonies and clusters. In 2 of the patients a decrease in the number of immature bone marrow cells positive for the myeloid antibody anti-My7 was observed. Only minor alterations were seen in natural killer cell activity. In 4 patients showing clonal chromosomal abnormalities before treatment a disappearance of minor clonal abnormalities during treatment was observed, and in 3 chromosomal abnormalities reappeared after cessation of therapy. Even though the overall impact of 13-RA on the hematopoietic system was minor, the increase in myeloperoxidase normal granulocytes in the blood and the decrease in My7 positive cells and in clonal chromosomal abnormalities warrants further interest in this agent as a treatment modality in MDS. The side effects, especially experienced by the patients receiving 100 mg/m2, were, in spite of symptomatic treatment, of such a degree that only low dose treatment (10-20 mg/m2) administered for prolonged periods of time (3-6 months) would seem recommendable.

Adult↗
PubMed1987

Specific minor chromosome deletions in myelodysplastic syndromes: clinical and morphologic correlations.

Thirty-four patients with myelodysplastic syndrome (MDS) subtypes refractory anemia (RA) and RA with ringed sideroblasts (RA-S) (26 and eight patients, respectively) were investigated for clinical and morphologic significance of the most frequently occurring minor chromosome deletions [del(17)(p12), del(8)(p22), del(2)(p24), and del(9)(p22)]. The occurrence of 17p- was statistically significantly related to a low initial bone marrow cellularity (p = 0.01) and severe granulocytopenia (p = 0.05). A diagnosis of RA was seen more frequently among patients with 17p-, also. 17p- alone was not related to progression to RA with an excess of blasts (RAEB). The occurrence of 8p- was statistically significantly related to a higher initial frequency of bone marrow myeloblasts (p = 0.05), but not to bone marrow cellularity or initial granulocytopenia. 8p- alone was not related to initial diagnosis, but a statistically significant relation to progression to RAEB was found (p = 0.05). 2p- was related to progression to RAEB, also (p = 0.02), but not to any of the other investigated parameters. No significant relations between the occurrence of 9p- and other parameters were demonstrated. The simultaneous occurrence of 17p- and 8p- was also statistically significantly related to progression to RAEB (p = 0.02). These relationships suggest that 17p- is involved in the development of bone marrow and peripheral blood granulocytopenia and that 8p-, and possibly 2p-, interferes with differentiation of primitive granulocyte precursors and, thus, play a part in the process leading to RAEB and acute myeloid leukemia.

Adolescent↗
PubMed1987

Vigabatrin: no microvacuoles in a human brain.

Vigabatrin (gamma-vinyl-GABA) has been shown to be an effective antiepileptic drug. However, clinical investigations have been hampered by the finding of intramyelin edema (microvacuoles) in rats and dogs. In an autopsy study of a 38-year-old woman with astrocytoma, treated with vigabatrin 80 mg/kg body weight per day for over 6 months and 125 mg/kg body weight per day for the last 2 months as add-on therapy because of drug-resistant epilepsy, we did not find any microvacuoles in the brain. So far microvacuoles have never been observed in primates, warranting continued investigations of this promising antiepileptic drug.

Adult↗
PubMed1986

Effect of vasoactive intestinal polypeptide (VIP) on steroidogenesis in women.

The VIPergic nervous system appears to be the major peptide-containing neuronal component in the female genital tract. Evidence has been put forward that exogenous VIP is able to stimulate progesterone secretion. In the present study the effect of human VIP (900 pmol/kg body weight per h i.v. during 30 min) on steroidogenesis in six female volunteers was investigated. The experiments were performed between the 6th and 14th day of their menstrual cycle, and peripheral venous blood was collected before, during and after infusion of VIP. The concentrations of VIP, oestradiol, progesterone, testosterone, androstenedione (AD), dihydrotestosterone (DHT), dehydroepiandrosterone sulphate (DHAS), sex hormone binding globulin (SHBG) and cortisol were measured. The infusion of VIP was accompanied by a 15% increase (P less than 0.05) in serum oestradiol concentrations, from a mean basal concentration of 0.58 nmol/l. The concentrations of testosterone and DHT also increased significantly. No effect of VIP on progesterone, AD, DHAS, SHBG or cortisol was observed. In the light of the presence of VIP in nerve fibres of the steroid producing tissue, this stimulatory effect of VIP might reflect a direct action on the ovary or the adrenal gland.

Adult↗
PubMed1986

Prognostic significance of some clinical, morphological and cytogenetic findings in refractory anaemia (RA) and RA with sideroblasts.

In 27 patients initially diagnosed as refractory anaemia (RA) or RA with sideroblasts (RA-S) according to the FAB-classification a number of clinical, morphological and cytogenetic parameters were correlated for prognostic significance. From these correlations it emerged that severe cytopenia is centrally positioned with regard to clinical course in RA and RA-S. Positive correlations were found to initial diagnosis, clonal cytogenetic abnormalities, progression to RA with an excess of blasts (RAEB) or acute myeloid leukaemia (AML), the percentage of bone marrow blast cells and prolonged half life for radioactively labeled iron. The degree of peripheral blood granulocytopenia, alone, was correlated to bone marrow hypoplasia. Moreover, the frequency of abnormal karyotypes was inversely correlated to bone marrow cellularity and proportional to the frequency of bone marrow blast cells. From these relationships it may be proposed that chromosome abnormalities are associated with prolonged blast cell generation times and inhibition of blast cell maturation resulting in reduced marrow cellularity and blast cell accumulation, and, in the peripheral blood, falling percentages of neutrophil granulocytes. With the blast cell accumulation the bone marrow cellularity again becomes hyperplastic and the preleukaemic condition is transformed into RAEB or AML.

Anemia, Refractory↗
PubMed1986

Specific minor chromosome deletions consistently occurring in myelodysplastic syndromes.

Forty-two patients with refractory anemia with or without sideroblasts have been investigated cytogenetically one to nine times (mean, 3) over a period of 1-36 months (mean, 16). The initial investigation showed numerical and/or major structural abnormalities [t(3;3), 5q-, -7, or 7q-, 11q-] in nine patients (21%). In addition, minimal terminal deletions were observed in 2p, 8p, 9p, 11p, 12p, 17p, 17q, 20q, and Xp. The detection of these deletions, which have not been reported earlier, was due to consistent application of the high resolution technique, G-banding without trypsin, and metaphase photography on large size negatives. Each deletion occurred as a clone on one or more occasions in 1-17 patients (mean, 7). One or other clonal minimal deletion was observed in 32 patients (76%). Preliminary indirect evidence indicates that alone or together with other factors the deletions promote leukemic transformation of refractory anemia.

Anemia, Refractory↗
PubMed1986

Myeloperoxidase-deficient polymorphonuclear leucocytes (VI): Relation to cytogenetic abnormalities in primary myelodysplastic syndromes.

Relations between cytogenetic status, FAB-classification and an abnormal subpopulation of myeloperoxidase (MPO)-deficient polymorphonuclears (PMN) in 45 patients with myelodysplastic syndrome (MDS) are reported. Clonal abnormalities were demonstrated in 85% of the patients, with a lower incidence in the RA+ group (refractory anaemia with ring sideroblasts) compared to the others (p = 0.004). In 12 patients a spontaneous progression in cytogenetic aberrations occurred and in 7 of these (60%) a simultaneous progression in FAB-subtype was seen. The appearance of MPO-deficient PMNs was observed in 6 of these patients (55%). A progression in FAB-subtype was noted in further 4 patients and 2 additional patients developed MPO-deficient PMNs. Only one sufficient cytogenetic investigation was available in these patients. Thus 100% of the fully studied patients showed progression in cytogenetic abnormalities when a progression in FAB-subtype or a development of MPO-deficient PMNs was seen. 3 (49%) of the 8 patients developing MPO-deficient PMNs too showed a progression in FAB-subtype. Although no significant correlation to specific categories of structural aberrations or abnormalities in specific chromosome pairs could be demonstrated, clonal cytogenetic aberrations seem to be involved when the disease progresses and when MPO-deficient PMN develop.

Chromosome Aberrations↗