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D Reinhardt

Publications and source records attributed to D Reinhardt.

At least 217 records · Page 12Linked to original sources

Interaction of liposomal and polycationic transfection complexes with pulmonary surfactant.

BACKGROUND: The delivery of genes to the airways holds promise for the treatment of lung diseases such as cystic fibrosis and asthma. Current non-viral gene delivery systems lack sufficient transfection efficiency. Pulmonary surfactant has been reported to be a barrier to gene transfer into the airways. Here we analyze the interaction of liposomal and polycationic transfection complexes with pulmonary surfactant. METHODS: The efficiency of non-viral transfection of cultured human airway epithelial cells (16HBE14o-), COS7 cells and porcine primary airway epithelial cells was studied in the presence of various surfactant preparations in order to model the conditions prevailing in the airways during transfection. RESULTS: The natural pulmonary surfactant, Alveofact, an extract from bovine lung lavage, was found to inhibit lipofection with lipofectAMINE for all cell lines investigated. Dendrimer meditated polyfection was unaffected for pulmonary cell lines and was weakly affected for COS7 cells. PEI-mediated polyfection was unaffected for all cell lines tested. The synthetic surfactant preparation Exosurf containing L-alpha-phosphatidylcholine-dipalmitoyl (DPPC) as the sole lipid ingredient had no statistically significant effect on polymer- and lipid-mediated transfection. The transfection efficiencies are related to structural changes in the DNA complexes as demonstrated by DNase-accessibility tests and fluorescence spectroscopy. In the presence of the phospholipid POPG, which is a constituent of Alveofact, DNA condensed in lipofectAMINE lipoplexes became accessible to DNaseI, while DNA condensed with PAMAM dendrimer or PEI was less accessible to DNase I as compared to lipoplexes. Consistently, the fluorescence of a DNA-intercalating dye increased after addition of Alveofact only in the case of lipoplexes. CONCLUSIONS: In contrast to lipofection, gene transfer with cationic polymers to airway epithelial cells is not inhibited by pulmonary surfactant in vitro. Depending on the surfactant concentration even an increase in polymermediated transfection can be seen. In conclusion, cationic polymers appear to be the more stable gene delivery systems for topical application into the airways.

Animals↗

Increase in band 3 density and aggregation in hereditary spherocytosis.

PURPOSE: Red cells in hereditary spherocytosis are characterized by a reduced surface area/volume ratio. The mechanisms leading to the loss of membrane material and subsequent elimination of the cells have still not been clarified. It was the aim of the present study to analyze band 3 distribution in the red cell membrane and its putative role in red cell elimination. METHODS/RESULTS: Immunogold histochemistry was performed to detect band 3 in red cell membranes. Band 3 density and distribution were visualized by electron microscopy. Unsplenectomized spherocytosis patients (n = 12) showed reduced band 3 density and aggregation compared to controls (n = 15) (density: 1.2 +/- 0.1 gold particles/microm circumference of red cell membrane vs 1.5 +/- 0.07 gold particles/microm, x +/- SEM; P < 0.05; aggregation: 0.26 +/- 0.02 aggregates/microm vs 0.3 +/- 0.02 aggregates/microm). By contrast, band 3 density and aggregation were increased in spherocytosis patients who had undergone splenectomy (density: 2.8 +/- 0.1 gold particles/microm vs 2.0 +/- 0.1 gold particles/microm; P < 0.05; aggregation: 1.5 +/- 0.1 aggregates/microm vs 0.5 +/- 0.03 aggregates/microm; P < 0.01). Artificial ageing of red cells from healthy controls (n = 6) led to a significant increase in band 3 aggregation (2.06 +/- 0.2 aggregates/microm vs 0.33 +/- 0.1 aggregates/microm; P(Wilcoxon) < 0.01) but no change in band 3 density. In hereditary spherocytosis (n = 6), both band 3 density and aggregation increased significantly after artificial ageing of the red cells. The elevated band 3 aggregation was associated with a stimulated erythrophagocytosis in vitro. CONCLUSION: Band 3 aggregation characterizes the red cells in hereditary spherocytosis. It may be the cause of selective splenic phagocytosis of both spherocytes and senescent erythrocytes.

Adolescent↗

Hemoglobin F in myelodysplastic syndrome.

Reactivation of fetal hemoglobin synthesis in adulthood can be seen in hematological disorders affecting the erythropoietic system. The objective of the present study was to evaluate the incidence and prognostic significance of increased hemoglobin F in patients with myelodysplastic syndrome. Hemoglobin F concentrations and Ggamma/Ggamma + A gamma-globin chain ratios were determined in 26 patients with primary myelodysplastic syndrome. Median age of the patients was 65 years; all FAB subtypes were included. Increased hemoglobin F concentration of up to 20% of total hemoglobin (normal: below 2%) was seen in 16 patients; ten patients had normal values. There was a significant relation between hemoglobin F concentration and the course of disease, e.g., 12 of the 16 patients with elevated hemoglobin F survived at least 1 year after the examination, in contrast to only three of the ten patients with normal hemoglobin F (p < 0.025). All of six patients with hemoglobin F above 5% survived at least 1 year. There was no significant difference in the hemoglobin F concentration between patients with and without cytogenetic anomalies. The Ggamma/Ggamma + A gamma-globin chain ratio was slightly elevated in all patients, with a weak correlation to the degree of hemoglobin F elevation. The values were not of additional prognostic significance. The data of the present study suggest that the hemoglobin F concentration may be a prognostic parameter in myelodysplastic syndrome; increased hemoglobin F concentration may indicate a better prognosis.

Adolescent↗

[Improved treatment results in children with AML: Results of study AML-BFM 93].

BACKGROUND: In the multicenter trial AML-BFM 93 daunorubicin or idarubicin was randomly applied in all patients during induction in combination with cytarabine and etoposide. After induction all patients were stratified to the standard or high risk group. To improve outcome in high risk patients high dose cytarabine and mitoxantrone (HAM) was introduced. The placing of HAM as either the 2nd or 3rd therapy block was randomized to evaluate the efficacy and toxicity accordingly. PATIENTS AND METHODS: 471 children with de novo AML entered the trial AML-BFM 93 (161 standard risk, 310 high risk). RESULTS: Overall, 387 of 471 (82 %) patients achieved remission, 5-year survival, event free survival (EFS), and disease free survival were 60 % SE 3 %, 51 % SE 2 % and 62 % SE 3 %, respectively. Idarubicin-based induction resulted in a significantly better blast cell reduction in the bone marrow on day 15 (25 of 144=17 % patients with > 5 % blasts compared to 46 of 149=31 % patients after daunorubicin, pchi(2)=0.01). This was, however, mainly seen in high risk patients treated with idarubicin (19 % vs. 38 %, pchi(2)=0.007). Cardiotoxicity, WHO grade 1 - 3 shortening fraction reduction after induction occurred in 6 % patients in both arms. In the total group of patients probabilities of five years event-free survival and disease-free survival were similar for patients treated with daunorubicin or idarubicin. However, in patients presenting with more than 5 % blasts on day 15 there was a trend for a better outcome after treatment with idarubicin (p logrank 0.06). Outcome in high risk patients was superior in study 93 compared to study 87 (remission rate and 5-year pEFS in study AML-BFM 93 vs. study 87: 78 % vs. 68 %, p=0.007, and 44 % vs. 31 %, p logrank=0.01). The placing of HAM as the 2nd or 3rd therapy block was of minor importance. However, patients who received the daunorubicin treatment during induction benefited from early HAM. CONCLUSION: Compared to study AML-BFM 87 treatment results in study AML 93 improved significantly in high risk patients. This can partly be contributed to the better response on day 15 after idarubicin induction but is mainly due to the introduction of HAM.

Acute Disease↗

[Neuropsychological sequelae in children with AML treated with or without prophylactic CNS-irradiation].

BACKGROUND: In study AML-BFM 87 the relapse rate was lower in patients receiving cranial irradiation (CRT). However, CRT has always been associated with adverse cognitive side effects. Therefore, the impact of CRT on neuropsychological function in children with AML was retrospectively evaluated. PATIENTS: We tested 53 children (30 boys, 23 girls) treated according to the AML-BFM-87 protocol (median age at diagnosis: 8.5 years, range 0.3 - 17.5; median time since diagnosis: 5.7 yrs, 3.8 - 10.7 yrs). To avoid any bias from additional therapy elements, patients with relapse or initial CNS involvement and transplanted patients were excluded (n=32). Our cohort was representative of the total group of 104 long term survivors of study AML-BFM 87. CNS prophylaxis consisted of ARA-C i.th., high dose ARA-C i. v. and either no CRT (n=15) or CRT (n=38) at a dose of 12 - 18 Gy depending on age. METHODS: Neuropsychological function was evaluated by psychological tests of attention and concentration (test d2 by Brickenkamp) and an intelligence test (Progressive Matrices by Raven). In addition, patients and their parents were interviewed about the occurrence of learning problems, subjective deficits in concentration and physical impairment. RESULTS: In the total group, no significant differences were seen between irradiated and non-irradiated patients regarding the psychological tests. However, the irradiated patients scored below the non-irradiated control group in test "d2" (concentration: 41st vs. 59th percentile). In the interview, irradiated patients tended to report more learning problems (lp) (10/36 vs. 1/14; p=0.15) and subjective deficits in concentration (con). In irradiated girls (con: 6/15 vs. 0/8; p=0.06; lp: 5/15 vs. 0/8; p=0.12) and younger patients (0 - 5 years at diagnosis; con: 7/12 vs. 2/9; p=0.18; lp 3/10 vs. 1/9; p=0.18) this trend was even more pronounced. CONCLUSION: Children with AML and CRT had no significant intellectual impairment in standardized tests when compared to non-irradiated patients. However, more irradiated patients reported learning problems and subjective concentration deficits.

Adolescent↗

[Minimal residual disease in acute myeloid leukemia in children--standardization and evaluation of immunophenotyping in the AML-BFM-98 study].

BACKGROUND: Minimal residual disease is a prognostic factor in AML. However, the impact on treatment stratification is not established. The AML-BFM 98 MRD study started in 1/2000 in order to evaluate, standardize and establish immunophenotyping in AML in children. METHODS: In a first phase the participating laboratories in Muenster, Goettingen, Vienna and Prague agreed on identical antibody-panels and standardized procedures of sample processing, analysis and data management. The consensus panel was evaluated and adapted to 3- and 4-color flowcytometry. The complete panel was applied to each follow-up sample in orderto minimize the risk offalse negative results due to the loss or shift of antigens during treatment, a known phenomenon in myeloid blasts. Between 1/2000 and 9/2001 165 of 198 protocol patients were analysed at diagnosis, in 149 children at least two follow-up samples were available. RESULTS: Three kinds of immunophenotypes could be defined. Asynchronous expression of stem cell and myeloid antigens i. e. CD34/CD117 combined with CD13/CD15 had a low specificity because precursors in regenerating or normal bone marrow expressed this pattern in 0.47 % (0.1 to 1.5 %). The aberrant co-expression of stem cell antigens and lymphatic antigens such as CD7 or CD2 showed a median level of specificity (0.07 % (0.04 to 0.19 %). Aberrant expression ofstem cell antigens combined with B-lymphatic (CD19, CD10) or NK-cell antigen (CD56) showed the best specificity. The maximal level in normal bone marrow was 0.05 %. Sensitivity of different immunophenotypes was evaluated by diluting known leukemic blasts in regenerating bone marrow. Minimal level of sensitivity was found to be at 10 (-3) to 5 x 10 (-4). According to these data highiy specific immunophenotypes could be detected in 33 %, median specificity was seen in 71 % and low specificity was seen in 88 % of the protocol patients. Two laboratories analyzed simultaneously 17 samples of children with AML from diagnosis and during therapy. A high correlation of blast quantification could be demonstrated (correlation r (2) = 0.98; blasts < 5 % r (2) = 0.91). In addition, two independent explorers quantified the raw data of 16 samples. All results correlated well (r (2) = 0.97; blasts < 5 % r (2) = 90.94). CONCLUSION: The prospective study phase, started 1/2002, aims to test the impact of MRD diagnostics as an independent prognostic factor in AML in children. This might facilitate future treatment stratification and consequently optimize outcome.

Adolescent↗

[Liposomal daunorubicine combined with cytarabine in the treatment of relapsed/refractory acute myeloid leukemia in children].

BACKGROUND: First-line treatment in AML commonly included high cumulative doses of anthracyclines with an increasing risk of cardiotoxicity. Liposomal daunorubicin (L-DNR) is thought to be less cardiotoxic without impairment of efficacy. METHODS: The AML-BFM REZ 97 study included two reinduction blocks with L-DNR (2 x 60 mg/m (2) n = 38, since 2/1999 3 x 60 mg/m (2) n = 31) combined with cytarabine (500 mg/m (2) 4 d). Children who achieved a second blast clearance were allocated to allogeneic stem cell transplantation either from a matched related (MRD) or a matched unrelated donor (MUD). Lack of a donor justified haploidentical SCT in early relapse (1st remission < 1 year) and autologous SCT in late relapse. PATIENTS: Between 1/1997 and 9/2001, 69 children were enrolled in the AML-BFM 97 relapse study. The median duration of first remission was 0.9 years. Forty-one patients had a remission of less than one year, 28 of more than a year. RESULTS: 46 children (67 %) achieved a second remission, defined as clearance of blasts in bone marrow and at least a partial hematological reconstitution. Seventeen of these children are alive (12 of 25 children receiving allogeneic SCT (MFD/MUD); 1 of 8 children after haploidentical SCT; 1 of 4 patients after autologous SCT and 3 of 9 patients treated with chemotherapy only). Further three children without 2nd remission survived after MFD-SCT (n = 2) or chemotherapy (n = 1; follow-up 0.3 to 0.7 years). Duration of first remission remains a significant prognostic factor. The pharmacokinetic investigation showed a high overall AUC of 234.6 mg/l h at a dose of 60 mg/m (2), and a volume of distribution of 1.98 l/m (2), which is much lower in comparison to conventional Daunorubicin. Regarding toxicity, the combination of L-DNR and cytarabine followed by SCT was feasible in experienced centers, however, acute complications like infection or septicemia in aplasia, mucositis and GvHD were common. By contrast, no clinical relevant cardiotoxicity was seen so far, but definitive results in long-term cardiotoxicity await a longer follow-up. In conclusion, L-DNR/cytarabine treatment induced a 2nd remission in most of the children with relapsed or refractory AML. It has to be followed by allogeneic SCT which enables long-term survival.

Adolescent↗

[Analysis of causes of death during intensive chemotherapy according to treatment protocol AML-BFM 93].

BACKGROUND: During intensive chemotherapy for AML, more than 10% of patients die because of treatment complications but not because of progression of their underlying disease. In order to improve supportive care and to decrease mortality, we analysed the causes of death and their relationship to the cycles of chemotherapy in children undergoing treatment for AML according to the study AML-BFM 93. RESULTS: Thirty-five (7.4%) of a total of 471 patients treated according to protocol AML-BFM 93 died before or within the first 6 weeks after diagnosis (early death). Fourty-nine patients (10%) did not achieve remission, and 18 (4 %) died of therapy-related complications after having achieved remission. In comparison to earlier AML-BFM studies, early mortality was reduced from 13%, 12%, 9% (AML-BFM 78, 83, 87) to 7% (AML-BFM 93, p-trend = 0.03). In contrast, mortality of patients in complete continuous remission (CCR) did not change. Infectious complications, in particular due to bacterial and fungal pathogens, were the main cause of death. One patient died of arrhythmia associated with SIAD. After stem-cell transplantation in first remission, 7 of 51 patients died, mainly because of graft-versus-host-disease and/or infections. The incidence of infectious complications decreased with the number of chemotherapy cycles and was highest during induction therapy. Fatal complications occurred in one patient during maintenance therapy and in one patient thereafter; both patients were in CCR. Another 14 patients died during intensive therapy (before day 150) mostly with a low percentage of blasts, but no haematologic recovery. The cause of death in these children was mainly bacterial infection or invasive aspergillosis, but seldom progression of leukaemia. CONCLUSION: This analysis confirmed the high incidence of fatal infections in children with AML during chemotherapy-induced severe neutropenia. To increase overall survival in children undergoing therapy for AML, we propose (1) to improve the prophylactic and therapeutic measures for haemorrhage and infections, (2) to continue risk-adapted therapy and (3) to treat high-risk patients in specialised centres only.

Adolescent↗

Immunophenotype of Down syndrome acute myeloid leukemia and transient myeloproliferative disease differs significantly from other diseases with morphologically identical or similar blasts.

BACKGROUND AND OBJECTIVES: Children with Down Syndrome (DS) have a 20-40 fold increased risk of developing acute myeloid leukemia (AML), mainly of the megakaryoblastic subtype (AMKL). Approximately 10 % of newborns with DS show transient myeloproliferative disease (TMD) which normally resolves spontaneously. The blast cells of both entities show megakaryoblastic/erythroblastic features (M7/M6) and cannot be distinguished by morphological characteristics. DESIGN AND METHODS: Blast cells of 62 children were analyzed by four-color flow cytometry and dual color fluorescence microscopy. RESULTS: The immunophenotype of blast cells from children with TMD and DS-AMKL is characterized by the expression of CD33 (+)/CD13 (+/-)/CD38 (+)/CD117 (+)/CD34 (+/-)/CD7 (+)/CD56 (+/-)/CD36 (+)/CD71 (+)/CD42b (+)/CD4dim (+)/TPO-R (+)/EPO-R (-)/IL-3-Ralpha (+)/IL-6-Ralpha (-). Non-DS children with morphologically related diseases, i. e. myelodysplastic syndrome (MDS), juvenile myelomonocytic leukemia (JMML), or AML-M6 and AML-M7, did not show this expression profile. CD34 expression was observed in 93 % of TMD, but only 50 % of DS-AMKL patients. The blast cells of all TMD and DS-AMKL cases were positive for TPO-R and IL-3R, whereas EPO-R and IL-6R were absent. CONCLUSIONS: Immunophenotyping by the use of surface antigens and growth factor receptors is a useful tool to discriminate TMD and DS-AMKL from diseases with morphologically similar or identical blasts. The absence of EPO-R on the blast cells might be a sign of the high expression of the mutated -- and less active -- GATA1 in DS. The higher amount of CD34 co-expression in TMD may be interpreted to indicate that TMD is a slightly more immature disease than DS-AMKL.

Acute Disease↗

[The beta adrenergic system of lymphocytes in children with atopic dermatitis].

A defect in the beta-adrenergic system is considered to be one of the basal causes of atopic dermatitis (AD). The number and affinity (KD) of beta-receptors was determined in lymphocytes of 19 children with AD and of 17 controls using the radioligand 125JCYP to find out whether this hypothesis is relevant. In addition, the basal cAMP level was measured as well as the cAMP-accumulation after stimulation of the adenylcyclase (AC) via the beta-receptor with 10(-4) M isoprenaline (IPN) and after direct stimulation of AC with 10(-4) M forskolin. Receptor quality and receptor quantity were compared to the severity of AD. A statistically significant difference between AD and control children was not registered for the following parameters: receptor-density, affinity for 125ICYP, cAMP-accumulation after adenylcyclase stimulation via the beta-receptor with IPN or after direct stimulation with forskolin. The increase in cAMP after IPN or forskolin was in the same range for children suffering from AD as for controls. Only the basal cAMP was significantly lower. Three patients with very severe AD (greater than 20% body surface area) had a significantly reduced number of beta-receptors (603 +/- 123 BS/Ly) compared with the control group (1142 +/- 112 BS/Ly). A linear relation existed between age, receptor density and isoprenaline-mediated cAMP accumulation for both control children and those with AD. This age-dependent response of the beta-receptor seems to be specific as cAMP-accumulation after stimulation with forskolin was not age-related.

Adolescent↗

The influence of methylphenidate on the sympathoadrenal reactivity in children diagnosed as hyperactive.

In order to investigate whether catecholamines play a role in the hyperkinetic child syndrome, we determined noradrenaline and adrenaline plasma levels before and after treatment with methylphenidate. The children were separated into drug responders and non-responders according to the efficacy of methylphenidate on behavioral symptoms. 21 children, 6-13 years of age, participated in this double-blind placebo controlled cross-over study. Conners' questionnaire was used to estimate the extent of the hyperactivity and to assess the drug response. Blood samples were drawn under resting and exercise conditions and plasma catecholamine concentrations determined as an indication of the amine release rate and the reactivity of the sympathoadrenal system. The results may be summarized: The postexercise noradrenaline levels of untreated hyperkinetic children were slightly, but not significantly higher than those of an age-matched control group. After 3-4 weeks of stimulant medication the noradrenaline release induced by physical exercise was significantly lower than after placebo. 12 out of 21 children showed an alleviation of their symptoms during methyl- phenidate therapy and thus could be assumed as drug-responders. When children were separated into drug-responders and non-responders according to the degree of the clinical improvement, both groups showed the same catecholamine release in response to exercise. Methylphenidate reduced the noradrenaline release in 9 out of 11 children in the responder group and in 7 out of 9 children in the non-responder group. In conclusion, catecholamines may be involved in the hyperkinetic child syndrome, but because of the heterogenity of this syndrome the depression of the plasma catecholamines as observed under methylphenidate could not differentiate between drug-responders and non-responders.

Adolescent↗

[Lupus erythematodesus profundus].

A 4 year old boy with lupus panniculitis since the third month is presented. Typical discoid lupus erythematosus lesions were also present. There were no signs of systemic involvement. Lupus panniculitis is an uncommon subtype of cutaneous lupus erythematosus. Our case is very unusual as the lesions developed already 3 month after birth. Clinical manifestation, therapy and histopathology of lupus panniculitis are discussed.

Adipose Tissue↗

[Value of the basophil stimulation test in the diagnosis of juvenile bronchial asthma].

The diagnostic value of histamine liberation from basophil granulocytes (BST) was investigated in asthmatic children with house dust, house dust mite or moulds allergy. BST corresponded at about 80% to skin prick test (PRICK) and radio-allergo-sorbens test (RAST) in 178 patients. The relevance of the results of BST, PRICK and RAST for the asthmatic symptoms was proved by bronchial provocation in 77 children. BST corresponded clearly better to the inhalation test than PRICK and RAST. Correspondence of BST in house dust mite allergy amounted to 94%, in house dust allergy to 100%, and in moulds allergy to 77%. Overall correspondence of BST was 92%. Even when RAST and PRICK showed different results correspondence of BST attained 91%. In cases with identical results of BST, PRICK and RAST the bronchial provocation test corresponded in 98%. It is concluded, that if history fits to BST, RAST and PRICK bronchial provocation is no longer essential for the diagnosis of relevant allergens in perennial childhood asthma. This seems to hold also in cases of house dust or house dust mite allergy, where the result of PRICK or RAST is different. Especially in childhood the use of BST in the diagnostic procedure provides the following advantages: risks of bronchial provocation and the necessary hospitalisation can be avoided, cooperation of the patient is not needed, and costs can be reduced.

Allergens↗