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Biomedical subjects

A Hellmann

Publications and source records attributed to A Hellmann.

At least 73 records · Page 4Linked to original sources
PubMed1996

[Evaluation of treatment results in patients with polycythemia rubra vera].

The study was aimed to assess the efficacy of busulphan treatment in patients with polycythemia rubra vera (PRV). The group of 74 patients (mean age 60 years, range: 40-81) was studied, including 38 females, 36 males. The remission was achieved in all cases; the mean time of remission was 33 months (range 3-200), the mean busulphan dose necessary to reach the first PRV remission was 266 mg (range: 76-600). The associations between hemoglobin level, white blood cells, neurocytes, platelet counts at diagnosis and the mean cumulative busulphan dose necessary to obtain the first PRV remission as well as between above parameters and the mean duration of the first PRV remission was estimated. The mean duration of the first PRV remission was significantly (P < 0.03) longer in patients with neurocyte count below 9.6 G/l (9.6 x 10(3)/mm3) as compared to those with higher levels; except it, no relationship were noticed between above parameters. The results of the study confirmed that busulphan is an effective and safe drug for patients with PRV.

Adult↗
PubMed1995

Tubulin gene expression during growth and maturation of leaves with different developmental patterns.

Changes in the tubulin-protein and -poly(A) +RNA contents were monitored by means of Western and Northern blot analyses, respectively, during growth and maturation of leaves of a dicotyledonous (tobacco) and monocotyledonous (barley) plant. It was recently argued from immunofluorescence and preliminary biochemical data that the density of microtubular networks and concomitantly the tubulin content are distinctly reduced after cessation of cell growth in leaves [Jung et al., 1993]. The results presented now confirm and extend this view. There appeared to be clear differences between the monocot and the dicot: (1) the loss of tubulin during leaf development was much slower in the dicot than in the monocot leaves (within months instead of days); (2) the degree of loss was more dramatic in the monocot leaf and only very low threshold levels of tubulin were retained in fully differentiated tissues; and (3) the loss of tubulin in the monocot leaf tissue appeared to be correlated with the decrease in the mRNA content, whereas the high level of tubulin-RNA in fully differentiated or even almost senescent dicot leaves indicated a gene expression control at the posttranscriptional level. The comparatively rapid and very distinct tubulin-protein and -RNA disappearance during development of the monocot leaf tissues confirm at the molecular level that differentiation proceeds much faster and is much more determinative in these leaves, as was postulated from histological and physiological data.(ABSTRACT TRUNCATED AT 250 WORDS)

Blotting, Northern↗
PubMed1995

Chromosome aberrations, spontaneous SCE, and growth kinetics in PHA-stimulated lymphocytes of five cases with Sézary syndrome.

Cytogenetic studies of five patients with Sézary syndrome (SS) revealed clonal chromosome aberrations in all cases. In one patient, a del(8)(p21) was the sole abnormality, whereas the remaining cases had karyotypes with multiple chromosome changes. In three SS cases with hypodiploid chromosome numbers, structural rearrangements affecting regions 10q22-24 and 12p11-13, and aberrations leading to loss of material from 17p were found concurrently. Bands 14q11 and 14q32 were involved in structural rearrangements in one case each. Our results and review of 51 published previously SS cases that were analyzed with banding techniques indicate that the chromosomes most frequently involved in structural changes were chromosomes 1 and 2 (in 43% of cases), 6 (in 38%), 17 (in 34%), 14 (in 27%), 11 (in 25%), 13 (in 21%), and 9 (in 20%). In particular, the breakpoints tended to aggregate at 1p11, 1p36, 2p11-24, 6q, 9q, 11q, 13q11-14, 14q11, 14q32, and in the pericentric region of chromosome 17. The most common numerical change was loss of chromosome 10, detected in 32% of SS cases. In our studies of three SS cases, sister chromatid exchange frequencies were significantly higher in comparison to the normal control. Cell cycle kinetics analysis revealed that the cell cycle time in the malignant cells was significantly longer than in lymphocytes of normal individuals.

Adult↗
PubMed1995

[The level of erythropoietin in patients with anemia and myeloma multiplex treated with erythropoietin].

6 patients with anaemia associated with myeloma multiplex were treated with human recombinant erythropoietin (rHuEPO, Exprex*) at a dose of 150 units/kg s.c. three times a week for 12 weeks. A good response, defined as an increase of hemoglobin > 20 milligrams above the pretreatment level, was achieved in 4 patients. The erythropoietin serum concentration was measured four times in each patient: twice before commencing and twice after completing the treatment. In patients who responded to rHuEPO therapy the Epo serum concentration decreased whereas in non-responders increased.

Aged↗
PubMed1994

[Essential thrombocythemia--clinical course from personal material].

The article presents clinical course analysis of essential thrombocythemia in 17 patients aged 29-82. The diagnostic criteria were the same as described by Polycythemia Vera Study Group. Mean platelet level of diagnosis was 1680 x 10(9)/l. Haemorrhagic complications were observed in 42% of the patients, while thrombotic ones or embolisms in 35%. In two cases both types of complications occurred. Asymptomatic course of the disease was observed in 5 patients. The statistical analysis proved that the patients with platelet count between 900-1900 x 10(9)/l are in danger of developing thrombotic episodes and thus antiaggregation treatment should be considered. If platelet level exceeds 1900 x 10(9)/l the risk of haemorrhage increases, so antiaggregation treatment is contraindicated and thrombocytapheresis is advised instead. The patients was started on treatment when platelet count was above 1000 x 10(9)/l in asymptomatic cases or with lower platelet level in symptomatic ones. The treatment consisted of busulphan, hydroxyurea or interferon alpha (in one of the patients) until lowering platelet level below 600 x 10(9)/l.

Adult↗
PubMed1994

2-Chlorodeoxyadenosine treatment of patients with chronic lymphocytic leukaemia associated with autoimmune haemolysis.

7 patients with chronic lymphocytic leukaemia (CLL) associated with autoimmune haemolysis were treated with 2-chlorodeoxyadenosine (2-CdA) in 0.14 mg/kg/day 2 hour infusion for 5 consecutive days. 2 patients had concurrent immune thrombocytopenia. All patients received prior therapy and either failed or the continuation of prior therapy was contraindicated. The median follow up was 8 months. 5 patients responded: 2 patients experienced complete remission (for 3 months), 3 patients experienced partial remission; 2 patients did not respond. However the decrease of haemolysis was achieved in 6 patients. Therapy was well tolerated. Myelosupression associated with severe infections was the main toxicity. Our results show that 2-CdA may induce remission and resolution of haemolysis in some patients with CLL and concurrent autoimmune haemolytic anaemia.

Adult↗
PubMed1994

[Platelet defects in chronic myeloproliferative disorders].

Platelet abnormalities are common in patients with chronic myeloproliferative disorders. In this study we report abnormalities in platelets morphology and function in 45 patients with chronic myeloproliferative disorders: 15 with chronic myelogenous leukaemia (CML), 8 with polycythemia rubra vera (PRV), 20 with essential thrombocythemia, and 2 with myelofibrosis (ME). We investigated flow cytometric features of platelets as measured with Technicon H1 technology, VIZ, mean platelet volume (MPV), plateletocrit), platelet distribution width (PDW), and modal platelet volume (PLT Mode) Platelet aggregation in response to ADP, epinephrine and collagen was used as functional test. In patients with ET, PRV and MF we found a significant decrease in platelet volume (both MPV and PLT MODE). Decrease in platelet aggregation and secretion in response to ADP, epinephrine and collagen was the most frequent abnormality in platelets function and was observed in most of patients with thrombocythemia in chronic myeloproliferative disorders.

Adolescent↗
PubMed1994

[Interleukin-2 and its use in hemo-proliferative disorders].

Interleukin 2 (IL-2) is a cytokine which activates cytotoxic cells and stimulates T suppressor cells and may play a role in the treatment of neoplastic disorders. The majority of clinical trials were performed in renal carcinoma and melanoma. Recent studies showed that IL-2 may also play a role in the treatment of hemoproliferative disorders, but its effectiveness was shown mostly in eradication of minimal residual disease after aggressive chemotherapy and/or bone marrow transplantation.

Humans↗
PubMed1993

Noradrenaline depletion in patients with coronary artery disease before and after percutaneous transluminal coronary angioplasty with iodine-123 metaiodobenzylguanidine and single-photon emission tomography.

Iodine-123 metaiodobenzylguanidine (MIBG) is a noradrenaline analogue which can be used as a tracer to investigate the cardiac sympathetic nervous system. Regional ischaemia leads to noradrenaline depletion with functional denervation which can be demonstrated by reduced MIBG uptake. In order to evaluate the reversibility of ischaemia-associated damage to the sympathetic nervous system, neuronal scintigraphy with 123I-MIBG and myocardial rest and stress perfusion scintigraphy with technetium-99m sestamibi was performed in 16 patients with coronary artery disease before and 3-4 months after percutaneous transluminal coronary angioplasty (PTCA). Partial re-innervation occurred in five patients, the degree of stenosis of remaining lesions being estimated by repeat angiography to be below 40%. Unchanged MIBG defects could be confirmed in four patients with residual lesions of between 40% and 50%. Increased MIBG defects were shown in three patients with significant restenoses of more than 70%. In all patients the neuronal defects exceeded the ischaemia-induced or scar-associated perfusion defects. Three patients dropped out of this study: one for technical reasons, one due to emergency aortocoronary bypass surgery and one due to diabetic polyneuropathy. This investigation shows that the sympathetic nervous system is highly sensitive to ischaemia. Further studies need to be done to assess the conditions allowing re-innervation after PTCA.

3-Iodobenzylguanidine↗
PubMed1993

Interleukin 12 augments natural killer-cell mediated cytotoxicity in hairy cell leukemia.

Interleukin 12 (IL12, NKSF-natural killer stimulatory factor) was found to stimulate natural killer (NK) cell activity of hairy cell leukemia (HCL) patients. Two patients not responding to IL12 stimulation were also resistant to interferon alpha (IFN alpha)-mediated augmentation of NK activity. IL12 also enhanced slightly the interleukin 2 (IL2)-induced cytotoxicity of HCL patients, while IFN alpha reduced the stimulatory effect of IL2. These data suggest that interleukin 12 has NK modulatory properties in HCL leukemia patients, which may be different from those of IFN alpha.

Cytotoxicity, Immunologic↗
PubMed1993

Interleukin 2- and interferon alpha induced natural killer cell activity as a marker of progression in hairy cell leukemia.

Hairy cell leukemia (HCL), a rare B-cell chronic lymphoproliferative disorder, is often accompanied by immune abnormalities. A marked impairment of the natural killer cell-mediated cytotoxicity (NK activity) has been reported in most patients at diagnosis. In the present report a long-term follow-up study of NK activity of splenectomized HCL patients is recorded. Among patients who persisted with stable disease two groups, one with normal NK activity, and another with low NK activity, could be recognized. Patients with progressive stage were characterized by a low NK cytotoxic activity. In vitro tests showed that interferon alpha (IFN-alpha) and interleukin 2 (IL2) could increase the NK activity to normal levels only in HCL patients with stable disease, while in progressive HCL these cytokines showed a significantly decreased effect. These results indicate that cytokine-induced NK cytotoxicity appears to be a valuable parameter in assessing the stage of HCL.

Adult↗
PubMed1993

[Evaluation of treatment outcome in patients with idiopathic thrombocytopenia in the years 1980-1982].

Retrospective estimate was performed of the results of treatment of 67 patients aged from 18 to 80 years with diagnosed idiopathic thrombocytopenia, treated in the Haematological Outpatient Clinic in the years 1980-1992. In the treatment adrenocortical hormones (prednisone) were used in dose 1 mg/kg body weight daily for at least six weeks, and in cases refractory to treatment or disease recurrence the patients were referred for splenectomy or cytostatic immunosuppression was used. In highest per cent permanent remissions were achieved in the patients subjected to splenectomy as compared with other methods of treatment.

Adolescent↗
PubMed1993

[Katarjian's prognostic model in prognosing chronic myelogenous leukemia at diagnosis and after one year of disease duration].

We estimated survival time of 56 patients with chronic myelogenous leukemia retrospectively classified according to the model by Kantarjian. Moreover we analysed if there was a correlation between the first-year total dose of busulphan and the size of the spleen during the first year of treatment on the one hand and the patients' survival on the other and if the above factors could enhance the prognostic value of the model by Kantarjian. Although we found such a correlation our preliminary results suggest that the first-year total dose of busulphan and the spleen size do not enhance the prognostic value of the model by Kantarjian.

Adolescent↗
PubMed1992

[Molecular biology of chronic myeloid leukemia].

Chromosome Philadelphia (Ph) which originated from translocation 9;22 is an aberration connected with chronic myelogenous leukaemia (CML) and with part of the cases of acute lymphoblastic leukaemia (ALL). The analysis on the molecular level has shown that the rearrangement of ABL and BCR genes is the most important consequence of this translocation. The new hybrid gene translates the protein p210, which shows tyrosine phosphokinase activity. This protein could play an important role in the pathogenesis of CML. The investigations of BCR/ABL rearrangement on molecular level are an important tool for differential diagnosis of lymphoblastic crisis of CML and ALL and also are very valuable in detection of residual Ph positive cells in cytogenetic conversion of CML.

Chromosomes, Human, Pair 9↗
PubMed1991

Glutathione S-transferase activity of leukemic cells as a prognostic factor for response to chemotherapy in acute leukemias.

This paper presents an analysis of glutathione S-transferase (GST) activity of leukemic cells in 30 patients with acute leukemias and its predictive value for therapy. Blast cells were isolated from peripheral blood or bone marrow before induction therapy using Ficoll density gradient. GST activity was measured according to the spectrophotometric assay based on the use of 1-chloro-2,4-dinitrobenzene as a substrate. The results did not show any significant differences between activities of the enzyme within the different leukemia types according to the French-American-British (FAB) classification. The patients who achieved complete remission demonstrated the lowest value of enzyme activity. The highest enzyme activity was observed in those patients who achieved partial remission and the non-responsive patients presented a GST value within the median of these two groups. Two categories of patients were represented within the non-responsive treatment group. One was resistant to the conventional therapy and in the other death was caused by infectious or hemorrhagic complications. The mean GST activity in these two groups of patients differ greatly. These results suggest that low GST activity of leukemic cells could be a favourable prognostic factor whereas high GST values could help to find out the group of patients who should be further analysed prior to induction therapy.

Bone Marrow↗