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J Mayer

Publications and source records attributed to J Mayer.

At least 37 records · Page 2Linked to original sources
PubMed2004

RNA fingerprinting of microbial community in the rhizosphere soil of grain legumes.

Microbial structural and expression profiles of the rhizospheres of three legumes, faba beans, peas and white lupin, were compared by RNA-arbitrarily primed PCR technique. Two different primers, M13 reverse and 10-mer primers, were used in the amplification and products resolved on non-denaturing polyacrylamide gel. With both DNA and RNA profiles Lupinus and Pisum rhizospheres were more similar to each other than to Vicia rhizosphere. The RAP-PCR products were also dot blotted and probed for bacterial peptidase transcripts. Plant-dependent rhizosphere effect was evident by the marked absence of transcripts for bacterial neutral metallopeptidase in Lupinus rhizosphere. The results of dot blot were further confirmed by RT-PCR for the expression of bacterial neutral metallopeptidase in the three rhizospheres.

Bacteria↗
PubMed2004

[Current legal initiative to integrated care - effects of outpatient care in hospitals].

The strict separation of the out-patient and hospital-based health care delivery sectors in Germany leads to deficits in effectiveness and efficiency. Newly introduced legal initiatives to overcome this separation, namely "Ambulantes Operieren" (section 115 b SGB V), "Ambulante Behandlung durch Krankenhäuser" and Disease Management Programs (sections 116a-b SGB V) are described in detail in this article. Their impact on hospital-based health provision for out-patients is discussed. The aim of a better integration of different sectors with a better quality and a more efficient use of resources seems to be the target of these initiatives.

Delivery of Health Care, Integrated↗
PubMed2004

Second autologous transplantation for multiple myeloma patients relapsing after the first autograft -- a pilot study for the evaluation of experimental maintenance therapies. Report of the prospective non-randomized pilot study of the Czech Myeloma Group.

BACKGROUND: High-dose chemotherapy followed by autologous stem cell transplantation (AT) is accepted as first-line therapy for patients with multiple myeloma (MM), with very good tolerance and low mortality (2-3%). STUDY DESIGN: We tested repeated transplantation with different experimental maintenance therapies in patients with MM relapsing/progressing after first AT. Results were compared using intra-individual analyses, therefore inter-individual differences are excluded (T2 model). PATIENTS AND METHODS: Between January 1997 and January 2003, 32 patients with relapsing/progressing MM after first AT were included in the pilot study, median follow-up was 75.2 months. They received the following experimental therapies: IL-2-activated PBSC (10 pts), pamidronate (4 pts), thalidomide (15 pts), consolidation chemotherapy CED (3 pts). RESULTS: Sensitivity to C-VAD reinduction chemotherapy (4 cycles) was 50%, response to the second AT compared to the first was better in 7, the same in 16 and worse in 9 patients. Toxicity of the first and second transplantation was similar and usually did not exceed grade II (SWOG). Transplant-related mortality was 3% (1/32). Event-free survival after second AT (EFS II) is known in 22 patients; 7 have achieved prolongation of EFS II versus EFS I. In the whole group median EFS I was 15.7 months, median EFS II was 12.9 months, median overall survival (OS) was 79.1 months; 20/32 patients were alive at the time of analysis. CONCLUSIONS: Repeated AT is a feasible and successful strategy in treatment of relapsing MM; response to second AT and toxicity were acceptable and similar to the first AT in our assessment.

Adult↗
PubMed2004

[Molecular pathogenesis of chronic lymphocytic leukemia with emphasis on cell cycle regulation and apoptosis].

In spite of the fact that many papers dealing with the chronic lymphocytic leukemia include a sentence in Introduction, that the molecular pathology of the disease "is still largely unknown", the amount of accumulated information is impressive and enables to create the first models of the overall genesis of this "most frequent leukemia in the Western world". Since many studies have confirmed that B-CLL lymphocytes in peripheral blood are anchored in G0/G1-phase of the cell cycle, the recent general opinion is, that CLL is primarily caused by defects in apoptosis--lymphocytes are slowly accumulating, being not able to "die properly". However, it becomes evident, that in the microenvironment appropriate for the cell growth, i.e. in the bone marrow and lymph nodes, B-CLL lymphocytes proliferate and they are subsequently accumulated in peripheral blood. This review summarizes namely the knowledge about status and expression of key genes regulating apoptosis and cell cycle in B-CLL lymphocytes, including p53, ATM, MDM2, Bcl-2/Bax, caspase-3, CDK-inhibitor p27, cyclins D2 and D3. Relationship between some of these genes and the standard therapy is discussed and prospective therapeutic alternatives resulting from the new molecular-genetic findings are presented.

Apoptosis↗
PubMed2004

[Evaluation of the clinical effectivity and toxicity of the FDN regimen (fludarabin, mitoxantron, dexamethason) in patients with follicular lymphoma].

BACKGROUND: One of the perspective therapeutic possibilities in follicular lymphomas (FL) is the fludarabine-based regimen FND (fludarabine, mitoxantron, dexamethason). However serious signs of myelotoxicity and significant immunosuppression with appearance of the opportunistic infections were described after the fludarabine treatment. METHODS AND RESULTS: Follicular lymphoma patients with advanced disease grade I-II were treated with FND (6-8 cycles). The immunotoxicity was evaluated by measuring of immunoglobuline levels (IgA, IgG, IgM) and that of lymphocytes subpopulations (CD3+, CD4+, CD8+, CD20+, CD56+) in peripheral blood. The myelotoxicity was evaluated by cultures of progenitor cells (CFC and LTC-IC). Totally 34 patients (median age 55.5 years) were evaluated, the overall response was 72% (CR 61%, PR 11%, progression 28%). 73% patients of 11 after 6-8 FND show persisting CR (27% relapsed) with median follow-up about 15 months. The dominating toxicity was myelotoxicity. The leucopenia grade III-IV occurred in about 30% cycles. Because of toxicity it was necessary to reduce doses of FND in 10% cycles and this treatment had to be finished ahead of schedule in 29% patients. The significant immunotoxicity was found only in the decrease of whole lymphocyte population (p < 0.05) and of IgG level (p < 0.05). The decrease of lymphocyte subpopulations did not reach any statistical significance. The long-term myelotoxicity caused the decrease of LTC-IC that had a clinical correlation with the very difficult mobilization of PBSC. CONCLUSIONS: FND is efficient in treatment of follicular lymphoma. However myelotoxicity seems to be limiting. Myelotoxicity doesn't allow administering scheduled dose of FND in substantial amount of patients, long-term myelotoxicity complicates PBSC-mobilization. Lymphotoxicity is apparent, but seems not to be clinically important.

Adult↗
PubMed2003

[Basic ethical aspects of living organ donation].

A characteristic feature of transplanting organs from living donors is that not only patients in need for treatment but also healthy individuals are submitted to medical interventions. Ethical considerations in this field have to deal with the question of property attributes of the human body and conflicts with traditional medical principles. Altruistic organ donation, appreciated by Christianity as a sign of charity, is indeed contradictory to the classic maxim of medical ethics "primum nihil nocere, " meaning "first of all, do not harm." The autonomous choice of a potential donor has to be balanced thoroughly against his personal physical and psychological risks. Apart from organ donation with altruistic motives, commercial incentives or payment for organ donation, which are increasingly under discussion in many nations, need profound ethical reflection. Organ selling does not lead to long-term economic benefit for individual donors in developing countries and is associated with a decline in health. A market system of organ sales would foster exploitation of the poor, and it is substantially doubtful whether autonomy and self determination are valid under circumstances of poverty and coercion. Commodification of the human body risks viewing persons as marketable objects. The human body,however, is an integral element of an individual's personality and not a resource to be removed. It is therefore fundamental that the social good of altruism is preserved as the major principle in organ donation.

Altruism↗
PubMed2003

Mathematical model of peripheral blood stem cell harvest kinetics.

A mathematical model of peripheral blood stem cell harvests was developed, taking two new parameters R (number of recruited cells/minute) and E(f) (efficiency of collection) into consideration in addition to concentrations and collected amounts of cells. This model was tested on 241 harvest procedures in cancer patients (chemotherapy+G-CSF stimulation), donors of allogeneic PBSC, and platelet donors, using different collection procedures, with a Cobe Spectra Cell separator. The relationships between preapheresis concentrations, R, E(f) and harvested amounts of cells were complex, and different for different harvest procedures and populations of donors. However, invariably, recruitment played an important role and contributed significantly to the final harvest in all types of cells studied. For example, for the patient group, mean recruitment was 1.3 x 10(6) CD34+ cells/min and the amount of recruited cells corresponded to 65% of all collected cells. Recruitment was significantly influenced by pretreatment with chemo-therapy and/or radiotherapy. The mean recruitment values for the subgroups with limited, moderate, and extensive pretreatment were 1.65 x 10(6), 0.87 x 10(6), and 0.32 x 10(6) CD34+ cells released per minute, respectively. The finding of a quick and massive recruitment phenomenon may stimulate further research into hematopoiesis in order to maximize harvested cells.

Blood Component Removal↗
PubMed2003

Increased expression of fibroblast growth factor receptor 3 in CD34+ BCR-ABL+ cells from patients with chronic myeloid leukemia.

Previously, we showed that expression of myeloma-associated (proto)oncogene fibroblast growth factor receptor 3 (FGFR-3) is increased in white blood cells from patients with chronic myeloid leukemia (CML). The abnormal expression was returned back to the normal levels as soon as these patients reconstituted their hematopoiesis following transplantation of allogeneic peripheral blood stem cells. The aims of this study were: (1) to define population(s) of cells overexpressing FGFR-3, and (2) to determine the expression of FGFR-3 during the clinical course of the disease. We show that the vast majority of FGFR-3 transcripts as well as FGFR-3 protein arise from CD34+ BCR-ABL+ cells. Although increased levels of FGFR-3 were found in majority of late chronic phase patients treated with interferon alpha or hydroxyurea, the expression of FGFR-3 was always lowered following treatment with BCR-ABL tyrosine kinase inhibitor STI571. Compared to unstimulated cells, high levels of FGFR-3 were also identified in CD34+ cells from granulocyte colony-stimulating factor-mobilized blood stem cell harvests from healthy donors, suggesting a potential growth factor-dependent basis for elevated expression of FGFR-3 in CML. These findings have implications for the involvement of FGFR-3 in malignant hematopoiesis and depict FGFR-3 tyrosine kinase in CD34+ leukemic cells as a possible target for tyrosine kinase inhibitors.

Antigens, CD34↗
PubMed2003

[Hemophagocytic syndrome (case report and literature review)].

The haemophagocytic syndrome (HPS) is clinically characterized by fever, pancytopenia and hepatosplenomegaly. Usually it takes an acute course with a high mortality. The pathogenetic basis is inadequate activation of the immune system--in particular Th1-lymphocytes with subsequent overproduction of cytokines and extreme activation of macrophages with haemophagocytosis. The activated cells infiltrate organs, cause tissue damage and clinical manifestations of the syndrome. From the etiological aspect two forms exist: primary (familial) with autosomal recessive inheritance and the secondary form which forms a heterogeneous sub-group, caused as a rule by infection and/or a tumour. The prognosis seems somewhat more favourable in secondary forms. In treatment which is essentially the same for both forms, chemotherapy combined with immunosuppression proves useful, in more aggressive forms chemotherapy as used in the treatment of non-Hodgkin lymphomas. The only curative method is transplantation of haematopoietic stem cells which is also the treatment of first choice in the familial form of haemophagocytosis. In the submitted paper the authors present a review of contemporary knowledge on this treacherous and relatively rare entity. The haemopgagocytic syndrome should be always taken into account in the differential diagnosis of fever with an obscure etiology. The authors assume that the haemophagocytic syndrome is rarely considered in practice and therefore is usually inadequately diagnosed and thus not treated in time. In the conclusion the authors describe the case-records of a 26-year-old female patient with haemophagocytic syndrome which developed during pregnancy.

Adult↗
PubMed2003

[Analysis of phenotypes and kinetics of CD34+ cells and lymphocytes in donors of hematopoietic stem cells for allogenic transplantation].

BACKGROUND: Amount of CD34+ cells is a critical parameter for quality assessment and successful engraftment of peripheral blood hematopoietic stem cells (PBSC) during the transplantation of haemopoisis. CD34+ cells are routinely analysed by immunophenotyping in PBSC and in peripheral blood during mobilization. Other leukocyte subpopulations are not usually assessed. METHODS AND RESULTS: The authors present results of immunophenotyping of subpopulations of CD34+ cells and leucocytes in samples from donors of PBSC for allogeneic transplantations, who were stimulated with the growth factor G-CSF at dose 16 micrograms/kg/day. The amount of CD34+ cells was not significantly different between days 4 and 5; however, there was a significant drop at day 6. CD34+90+ and CD34+61+ subpopulations reached their maximum at the day 4; partially differentiated CD34+ cells with co-expression of CD33, CD19, and CD7 reached maximum at the day 6. CD4+ Th-lymphocytes were concentrated in the grafts during leukapheresis, CD4/CD8 ratio in the grafts was increased to average 3.06. CONCLUSIONS: The knowledge of kinetics of CD34+ subpopulations, together with stem cell selection and ex vivo manipulation, may have an impact on the speed of engraftment or GvHD prevention in transplanted patients.

Antigens, CD34↗
PubMed2003

[Hereditary thrombocytopenia. Differential diagnosis of a case].

Hereditary thrombocytopenias are a heterogeneous group of extremely rare diseases characterized by a reduced number of blood platelets and by bleeding tendency of variable severity. Some of these diseases are exclusive to platelets, while in others the pathology extends to other cell types. Although rare, hereditary thrombocytopenias should be considered in the diagnosis. Hereditary thrombocytopenias have been classified into three groups depending on platelet volume. Hereditary thrombocytopenias with giant platelets form one of these groups. About fourteen clinical entities of inherited giant platelet disorders have been described. Bernard-Soulier syndrome, grey platelet syndrome and May-Hegglin anomaly are the most common giant platelet thrombocytopenias. May-Hegglin anomaly is condition characterized by the triad of thrombocytopenia, giant platelets, and pale-blue inclusions in leukocytes. May-Hegglin anomaly has an autosomal-dominant mode of inheritance. We described clinical and laboratory features of three adult women from one family with recently diagnosed May-Hegglin anomaly. Described cases are probably the first observed cases of May-Hegglin anomaly in the Czech lands.

Adolescent↗
PubMed2002

Reduced nephrotoxicity of conventional amphotericin B therapy after minimal nephroprotective measures: animal experiments and clinical study.

Amphotericin B (AmB)-treated rats develop severe polyuria, polydypsia, impairment of renal concentrating ability, and morphologic signs of tubular damage. However, renal insufficiency develops quickly only in animals in which water intake is restricted to the median volume drunk by rats of the control group. Therefore, vigorous hydration seems crucial for prevention of AmB-induced nephrotoxicity. In a clinical study, 61 patients with hematologic malignancies receiving AmB therapy were massively hydrated to ensure urine output of > or =4000 mL/day. Urine sodium, potassium, and magnesium were also measured, and all losses were supplemented (potassium as a 7.45% solution via central venous catheter). AmB-treated patients developed signs of renal tubular damage (increased fractional excretion of sodium and potassium) and required large amounts of ion supplementation. The serum ion concentration and creatinine clearance remained stable. No clinically significant renal damage developed to force premature cessation of AmB treatment.

Acetylglucosaminidase↗
PubMed2002

Structure of nanocrystalline anatase solved and refined from electron powder data.

Energy-filtered Debye-Scherrer electron powder data have been successfully employed to determine the structure of nanocrystalline anatase (TiO2). The performed structure analysis includes determining the unit cell, space group, solving the structure via direct methods from extracted intensities and refining the structure using the Rietveld technique. The refined structural parameters for space group I4(1)/amd are a = 3.872 (2), c = 9.616 (5) A with titanium at 0.5,0.75,0.375 and oxygen at 0.5,0.75,0.1618 (6). The obtained structure indicates low internal stress as judged from the almost regular geometry of the TiO6 building blocks. Striking resemblance with the anatase structure determined previously by Burdett, Hughbanks, Miller, Richardson & Smith [J. Am. Chem. Soc. (1987). 109, 3639-3646] from neutron diffraction on coarse-grained material gives strong support for the correctness of the structure determined here. The result of the present study shows that the methods originally developed for determining structures from X-ray powder data work equally well with data from electron powder diffraction. This may open the window for structural investigations on the vast number of nanocrystalline materials and thin films whose structures are difficult to determine by X-ray diffraction since they are frequently only available in small quantities.

Journal Article↗
PubMed2002

[Treatment of acute lymphoblastic leukemia in adults with seven-drug induction therapy and intensive consolidation with or without autologous stem cell transplantation followed by maintenance therapy. Experience of a single center].

BACKGROUND: During the last few years, improvement in prognosis of the adult acute lymphoblastic leukaemia (ALL) has been modest. The probability of leukemia-free survival is 20-40%. Philadelphia-chromosome positive (BCR-ABL positive) ALL has the worse prognosis. A single centre experience with treatment of ALL in adults is reported. METHODS AND RESULTS: Between April 1997 and July 2000, 15 consecutive patients with de novo adult ALL (7 T-lineage ALL, 7 B-lineage ALL, 1 null ALL) begin their treatment with the seven-drug induction regimen (in phase I, daunorubicin, vincristine, L-asparaginase, i.v., and prednisone, p.o.; in phase II, 6-mercaptopurine, p.o., cytosine arabinoside and cyclophosphamide, i.v.) and central nervous system (CNS) prophylaxis (methotrexate and CNS irradiation in patients without total body irradiation in conditioning regimen), with intensive consolidation (three times high-dose methotrexate and high-dose-cytarabine, i.v.), and with/out autologous peripheral blood stem cell transplantation (PBSCT) followed by maintenance chemotherapy (6-mercaptopurine and methotrexate, p.o.). Seven patients received autologous PBSCT. Median patient age was 30 years. Three patients were BCR-ABL positive at diagnosis. With median follow-up 14 month (range 0.1-46 month), seven (4 T-lineage ALL, 2 B-lineage ALL, 1 null ALL) out of 15 patients are alive in remission (four of them receiving autologous PBSCT). Causes of death were relapse (n = 3), chemotherapy related toxicity (n = 2), infection (n = 1), and acute myeloid leukaemia developed 10 months after autologous PBSCT (n = 1). All BCR-ABL positive patients died. CONCLUSIONS: Chemotherapy alone and autologous PBSCT with maintenance therapy may be curative for adult patients with ALL. We can recommend these treatment options for patients without risk factors in particular.

Adolescent↗
PubMed2002

Anatomical study of the blood supply of the coxal bone: radiological and clinical application.

The aim of this work was to study the arterial blood supply of the coxal bone in order to optimize radiological embolization and to minimize the risk of postoperative osteonecrosis. Ten fresh cadavers were dissected after intra-arterial injection of colored resin. All the collateral vessels running to this bone were described and counted. On 25 dry bones, the vascular foramina were measured with the aid of a millimetric gauge and a vascular map was created. The posterior part of the ilium appears to be twice as well vascularized as the anterior part. Fractures of the posterior arch of the pelvis are theoretically more hemorrhagic. The presence of the iliolumbar artery in contact with the sacroiliac joint increases the risk with open book or shearing fractures. The artery of the ischium, a collateral of the pudendal artery, supplies the posterior and lateral parts of the acetabulum and the artery of the roof of the acetabulum, its superior and lateral parts. The branches of the anterior and posterior divisions of the obturator artery supply the superior part of the surroundings of the obturator foramen and the antero-inferior and postero-inferior parts of the acetabulum. The Kocher approach may injure the artery of the ischium. Letournel's extended lateral approach and Mears' triradiate approach may injure the artery of the ischium and the artery of the roof of the acetabulum. The risk of osteonecrosis appears to be theoretically increased if one adds an endopelvic approach. The anterior approach to the acetabulum appears to be that which theoretically leads to the least devascularization. The French version of this article is available in the form of electronic supplementary material and can be obtained by using the Springer Link server located at http://dx.doi.org/10.1007/s00276-002-0029-2.

Arteries↗
PubMed2002

Technique for PBSC harvesting in children of weight under 10 kg.

Peripheral blood stem cell (PBSC) harvesting in the smallest children (weight <10 kg) using separators is complicated by specific problems. The volume of the separation set exceeds 25% of the total blood volume and the vascular access is generally not sufficient. Therefore, a simple manual technique for PBSC harvesting was developed. Three children (6-9 kg), with newly diagnosed tumours were scheduled to be treated with three to six sequential courses of high-dose chemotherapy, each followed by PBSC support. PBSC harvests were started after mobilization using cyclophosphamide and G-CSF when the peripheral blood CD34+ cell count exceeded 50/microl. About 50 ml of blood was drawn from a venous catheter, injected into a transfer bag containing ACD-A, and centrifuged. The buffy coat obtained was pooled in a collection bag, remaining plasma and erythrocytes were immediately reinfused and a subsequent cycle started. From three to 13 cycles were performed in 1-3 days and 18.0-32.2 x 10(6) CD34+cells/kg were collected. We did not detect any bacterial contamination or any notable complications. Fifteen PBSC reinfusions have been performed to date, each with rapid engraftment taking between 7 and 13 days. Patients are in very good PR (18 months from diagnosis) or in CR (6 and 8 months). We can conclude that this procedure is feasible and safe.

Antigens, CD34↗
PubMed2002

Interleukin-2 activation of haematopoietic stem cells.

BACKGROUND: Recent findings concerning the role of immunity in the eradication of residual malignant disease after autologous haematopoietic stem cell transplantation have led to extensive studies of T-cell and natural killer (NK) mediated anti-tumour effects. Interleukin 2 (IL-2) activation of autologous bone marrow (BM) or peripheral blood stem cells (PBSC) before transplantation is one of the methods of adoptive cell therapy. METHODS: Autologous BM of patients with chronic myelogenous leukaemia (n = 11) and PBSC of patients with multiple myeloma (n = 14) were activated by IL-2 in laboratory conditions with the aim of evaluating the feasibility of this method, the activation of T and NK cells, recovery of active progenitor cells, microbial contamination, and reduction of malignant cell content. RESULTS: Samples of BM (mean 2.6 x 10(6) cells) and PBSC (mean 10.3 x 10(6) cells) were cultured in complete culture medium with IL-2 (6000 Ul/ml) for 24 h. The recovery of CD34+ cells and CFU-GM was 82.5% and 51.5%, respectively, for BM, and 85% and 86%, respectively, for PBSC (mean values). No purging effect was detected by flow cytometry and a small decline in malignant cell contamination was observed by quantitative PCR in BM samples. No microbial contamination occurred during the sample processing. CONCLUSIONS: The described in vitro activation of BM and peripheral blood stem cells using IL-2 was evaluated as a safe and reliable method suitable for clinical application.

Bone Marrow↗