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Biomedical subjects

E Reiter

Publications and source records attributed to E Reiter.

At least 37 records · Page 2Linked to original sources
PubMed1999

Anaplastic squamous cell carcinoma (SCC) in a patient with chronic cutaneous graft-versus-host disease (GVHD).

We describe an allogeneic bone marrow (BM) recipient who developed aggressive, metastasizing squamous cell cancer (SCC) of the skin, and discuss possible risk factors in the development of this secondary solid tumor. The patient had been treated with cyclosporine (CsA), methyl-prednisolone and thalidomide for 3 years because of extensive de novo chronic cutaneous GVHD occurring 1 year after BMT. Ten years after BMT a locally invasive and metastasizing SCC occurred on the patient's neck, and diagnosis was confirmed by H&E histopathology and cytokeratin-immunohistochemistry. Analysis of genomic DNA did not reveal p53 mutations nor were HPV sequences detectable. Risk factors included conditioning for BMT with total body irradiation (TBI) and cyclophosphamide (Cy), immunosuppressive treatment for GVHD, and extensive exposure to UV radiation before and after BMT. Despite surgery and adjuvant chemotherapy with 5-fluorouracil (5-FU) the patient died 1 year after the diagnosis of SCC.

Adult↗
PubMed1999

Pneumatosis [correction of Pneumocystis] cystoides intestinalis with pneumoperitoneum and pneumoretroperitoneum in a patient with extensive chronic graft-versus-host disease.

Pneumatosis cystoides intestinalis is a rare finding of intramural gasfilled cysts in the bowel wall and sometimes free air in the abdomen. A few conditions are reported to cause this disease, one of them being immunosuppression. We describe a 50-year-old Caucasian male with extensive chronic graft-versus-host disease (GVHD) of the gut and skin who developed PCI with pneumoperitoneum and pneumoretroperitoneum. To our knowledge, this is the first report of PCI occurring in a patient with active chronic GVHD which resolved spontaneously.

Bone Marrow Transplantation↗
PubMed1999

Trichotomous noise-induced transitions.

A nonlinear one-dimensional process driven by a multiplicative exponentially correlated three-level Markovian noise (trichotomous noise) is considered. An explicit second-order linear ordinary differential equation for the stationary probability density distribution is obtained for the process. In the case of a linear process with an additive trichotomous noise the exact formula for the steady-state distribution is obtained. The well-known dichotomous noise can be regarded as a special case of the trichotomous noise. As a rule, the system variable has three specific values where the probability density distribution can be singular. For the case of the Hongler model the dependence of the behavior of the stationary probability density on the noise parameters is investigated in detail and illustrated by a phase diagram. Applications to the Gompertz and Verhulst models are also discussed.

Journal Article↗
PubMed1999

A novel gene overexpressed in the prostate of castrated rats: hormonal regulation, relationship to apoptosis and to acquired prostatic cell androgen independence.

We have identified a novel complementary DNA (cDNA) corresponding to a gene overexpressed in the rat ventral prostate after castration. This cDNA displays 89.4% identity with 453 bp of a mouse EST and 81.5% identity with 157 bp of a human EST and was named PARM-1 for prostatic androgen-repressed message-1. The complete cDNA is 1187 bp long and codes for a protein of 298 amino acids that contains four potential glycosylation sites and three half cystinyl residues. The PARM-1 gene was found to be expressed at quite low levels in most rat tissues including those of the urogenital tract. The kinetic of induction of PARM-1 gene in the prostate was highly correlated to the development of apoptosis in the whole organ. Supplementation of castrated animals with androgens reversed both the process of apoptosis and the overexpression of PARM-1 gene. Supplementation with estrogens did not result in an increase in the PARM-1 messenger RNA levels when compared with the castration alone. However, the treatment resulted in a more rapid return to intact levels in the castrated plus estrogen group. When apoptosis of testis and prostate was induced in vivo by hypophysectomy, it was found that PARM-1 was only overexpressed in the prostate. Therefore, PARM-1 seems to be regulated by androgens only in the prostate. Using in situ hybridization and immunohistological techniques, we have shown that PARM-1 gene product is found exclusively in the epithelial cells of involuting prostate. Analysis by flow cytometry of MAT LyLu epithelial cells transiently expressing PARM-1 protein did not allow us to demonstrate a direct effect of PARM-1 gene overexpression on the programmed death of the transfected cells. Treatment of MAT LyLu cells by transforming growth factor-beta induced apoptosis but had no effect on PARM-1 production. However PARM-1 protein has been detected by Western blotting in various cell lines such as MAT LyLu, MAT Lu, and PIF, which are androgen independent. This would suggest that PARM-1 gene product would be a marker for acquired androgen-independence of these tumor cells.

Amino Acid Sequence↗
PubMed1999

Involvement of G protein-coupled receptor kinases and arrestins in desensitization to follicle-stimulating hormone action.

FSH rapidly desensitizes the FSH-receptor (FSH-R) upon binding. Very little information is available concerning the regulatory proteins involved in this process. In the present study, we investigated whether G protein-coupled receptor kinases (GRKs) and arrestins have a role in FSH-R desensitization, using a mouse Ltk 7/12 cell line stably overexpressing the rat FSH-R as a model. We found that these cells, which express GRK2, GRK3, GRK5, and GRK6 as well as beta-arrestins 1 and 2 as detected by RT-PCR and by Western blotting, were rapidly desensitized in the presence of FSH. Overexpression of GRKs and/or beta-arrestins in Ltk 7/12 cells allowed us to demonstrate 1) that GRK2, -3, -5, -6a, and -6b inhibit the FSH-R-mediated signaling (from 71% to 96% of maximal inhibition depending on the kinase, P < 0.001); 2) that beta-arrestins 1 or 2 also decrease the FSH action when overexpressed (80% of maximal inhibition, P < 0.01) whereas dominant negative beta-arrestin 2 [319-418] potentiates it 8-fold (P < 0.001); 3) that beta-arrestins and GRKs (except GRK6a) exert additive inhibition on FSH-induced response; and 4) that FSH-R desensitization depends upon the endogenous expression of GRKs, since there is potentiation of the FSH response (2- to 3-fold, P < 0.05) with antisenses cDNAs for GRK2, -5, and -6, but not GRK3. Our results show that the desensitization of the FSH-induced response involves the GRK/arrestin system.

Animals↗
PubMed1998

Beta2 adrenergic receptors mediate cAMP, tissue-type plasminogen activator and transferrin production in rat Sertoli cells.

FSH is the main regulator of Sertoli cell function. Nevertheless, several other effectors such as catecholamines can also stimulate these cells through the adenylyl cyclase transduction pathway. However, the expression of beta adrenergic receptors in Sertoli cells is a subject of controversy. The aim of the present study was to determine if there are physiologically functional beta adrenergic receptors in Sertoli cells and to which subtype(s) they belong. In freshly isolated Sertoli cells, isoproterenol, a non selective beta-adrenergic agonist, was found to stimulate cAMP production and tissue-type plasminogen activator secretion. Specific transcripts for the beta1 and beta2, but not beta3, subtypes were detected by RT-PCR analysis. Beta2 transcripts were the form expressed predominantly in Sertoli cells. Binding experiments carried out on freshly isolated and on cytospined Sertoli cells indicated that in both conditions, [125I]iodocyanopindolol binding was inhibited by a non-selective and a 2 selective antagonist, whereas a beta1 selective antagonist had no effect. Scatchard analysis of beta2 specific inhibition revealed a dissociation constant of 0.3 nM and a receptor density of 14000 sites per cell. In freshly isolated Sertoli cells, we observed that cAMP and tissue-type plasminogen activator were stimulated by isoproterenol and a beta2 selective agonist, but not by beta1 or beta3 selective agonists. Accordingly, the isoproterenol-stimulated tissue-type plasminogen activator responses were abolished by the beta2 selective antagonist only. In cultured Sertoli cells, the trend was the same: tissue-type plasminogen activator and transferrin secretions were increased by isoproterenol and beta2 but not by beta1 or beta3 selective agonists. We conclude that freshly isolated Sertoli cells express beta2 adrenergic receptors which are functionally coupled to adenylyl cyclase and that these characteristics are preserved in cell culture. For the tested parameters, catecholamines and FSH effects were similar, but response magnitudes were systematically lower with beta agonists than with FSH. As norepinephrine is normally present in physiologically-relevant amounts in the interstitial fluid, it can be suspected to play a role in the regulation of Sertoli cell function.

Adrenergic beta-Agonists↗
PubMed1998

Subdural hygromas after bone marrow transplantation: results of a prospective study.

BACKGROUND: Subdural hygromas after bone marrow transplantation (BMT) have been occasionally found in patients with persisting headache and vomiting. We assessed the incidence of subdural hygromas after BMT and tried to define possible risk factors associated with this complication. METHODS: Fifty bone marrow graft recipients surviving more than 30 days were consecutively enrolled into a prospective study. Cranial CT scans were performed before and 30 days after BMT. Clinical data and symptoms were recorded daily during the first 30 days after BMT. In patients with subdural hygromas, a magnetic resonance imaging scan and monthly follow-up cranial computed tomography scans were performed until fluid collections had resolved completely. RESULTS: In 9 of the 50 patients (18%) who survived 30 days after transplantation, newly acquired subdural hygromas were found. Patients with hygromas suffered significantly longer and more severely from headache and vomiting (P=0.01). Application of intrathecal methotrexate and arterial hypertension occurred significantly more often in patients with hygromas (P=0.01). In a stepwise logistic regression model, arterial hypertension and intrathecal methotrexate application were the only independent risk factors for the development of hygromas. Monthly follow-up cranial computed tomography scans showed that all hygromas resolved completely after a median of 60 days after diagnosis (range: 30-120 days). CONCLUSIONS: Subdural hygromas are a frequent complication after BMT within the first 30 days after transplantation. They are reversible and disappear within 2-3 months. The need for routine application of intrathecal methotrexate in standard risk leukemia patients should be critically addressed. Furthermore, close monitoring of blood pressure and immediate antihypertensive therapy might contribute to avoid formation of subdural hygromas.

Adolescent↗
PubMed1998

Graft-versus-host disease following second syngeneic stem cell transplantation for relapsed chronic myeloid leukemia.

Allogeneic bone marrow transplantation is the only curative treatment for patients with Philadelphia chromosome-positive chronic myeloid leukemia (CML); however, recurrence of disease remains a major cause of treatment failure. A 26-year-old man with chronic myeloid leukemia who had a cytogenetic relapse 49 months after his first syngeneic bone marrow transplant (BMT) and hematologic relapse 23 months thereafter progressed to blast crisis despite treatment with IFN-alpha for 15 months. He underwent a second transplantation in early second blast crisis, 92 months after the first BMT with PBPC from his previous donor. Successful hematological reconstitution occurred. On day 50 after the second transplantation the patient developed a generalized rash, hepatomegaly, and cholestatic signs. Skin and liver biopsy revealed changes compatible with acute graft-versus-host disease (GVHD). Treatment with cyclosporin A (CSA) and prednisone was started, and the GVHD resolved. Fifteen months after PBPC transplantation he had a molecular relapse. Despite discontinuation of CSA, the patient progressed into blast crisis 7 months later. The occurrence of GVHD and disappearance of the BCR-ABL-positive clone suggest that a graft-versus-leukemia (GVL) effect may have been operative for 15 months in a patient given a second syngeneic BMT in blast crisis.

Adult↗
PubMed1998

Leukemia-free survival and mortality in patients with refractory or relapsed acute leukemia given marrow transplants from sibling and unrelated donors.

Between April 1982 and February 1997 39 patients (24 male, 15 female) with refractory acute leukemia and a median age of 31 years (19-51 years) received allogeneic marrow grafts from an HLA-identical sibling (n = 27), HLA-identical unrelated donor (MUD; n = 10) or 1-antigen mismatched unrelated donor (n = 2). Twenty-eight patients had acute myelogenous leukemia and 11 acute lymphoblastic leukemia. For conditioning most patients received total body irradiation combined with cyclophosphamide (n = 23) or etoposide (n = 7). For graft-versus-host disease prophylaxis patients received cyclosporin A (CsA) and methotrexate (MTX) (n = 20), MTX alone (n = 3), CsA and methylprednisone (n = 6), or CsA alone (n = 10), respectively. As of June 1997 probability of leukemia-free survival projected to 3 years after BMT was 14% for patients given sibling marrow grafts and 28% after MUD transplantation. Transplant-related mortality projected to 3 years was 32% after sibling and 37% after MUD marrow grafting. Although not significantly different, probability of relapse projected to 3 years after BMT was lower after MUD at 56% compared to 78% with sibling BMT. Thus, high-dose chemo/radiotherapy followed by allogeneic marrow infusion has a curative potential for patients with refractory leukemia and offers the chance of long-term disease-free survival for some patients.

Acute Disease↗
PubMed1998

Successful management of adult respiratory distress syndrome (ARDS) after high-dose chemotherapy and peripheral blood progenitor cell rescue by non-invasive ventilatory support.

A 34-year-old man suffering from Hodgkin's disease underwent high-dose chemotherapy (CBV) followed by transplantation of autologous peripheral blood stem cells. On day +6 after peripheral blood stem cell transplant (PBSCT) bacterial pneumonia developed. Along with rapid engraftment during stimulation with G-CSF adult respiratory distress syndrome (ARDS) developed within 4 days. High-flow CPAP (continuous positive airway pressure) ventilation via a sealed face-mask was initiated. The patient tolerated the sealed face-mask very well, and CPAP was continuously administered for 4 days, thus avoiding intubation. High-flow CPAP may offer a therapeutic alternative in selected patients with respiratory compromise after PBSCT.

Adult↗
PubMed1998

Bile duct adenocarcinoma mimicking veno-occlusive disease after autologous bone marrow transplantation for acute leukaemia.

A 52-year-old female underwent autologous BMT because of acute myeloid leukaemia FAB M4 in second remission. Since the patient had no HLA-identical sibling she received a purged autologous BM transplant. On day +5 she developed signs of a sepsis syndrome with fluid retention and was treated with broad-spectrum antibiotic therapy. However, her body weight remained high, ascites and an increase of total serum bilirubin and alkaline phosphatase developed. The icterus worsened to a total bilirubin level of 25 mg/100 ml. Sonographic and endoscopic imaging showed a dilated gall bladder but disclosed a post-hepatic cause for the icterus. A transjugular liver biopsy on day +71 revealed severe cholestasis and siderosis. The patient remained aplastic with constantly increased bilirubin levels. On day +73 septic shock syndrome occurred and the patient died of multiorgan failure 3 days later. At autopsy, a highly differentiated bile duct adenocarcinoma at the porta hepatis, so-called Klatskin tumour, was found, explaining the fatal course with intractable cholestasis.

Adenocarcinoma↗
PubMed1998

Gastrointestinal perforation early after peripheral blood stem cell transplantation for AL amyloidosis.

The morbidity and mortality of AL amyloidosis is caused by the deposition of Ig light chains as amyloid protein in vital organs. With conventional therapy median survival of patients with AL amyloidosis is 10-14 months. With high-dose chemotherapy clinical remissions of organ-specific disease have been reported. Here, we present a patient with high-risk AL amyloidosis who was given high-dose therapy and a peripheral blood stem cell transplant. Four days later she died of gastrointestinal perforation due to amyloid infiltrations.

Adult↗
PubMed1998

Rat G protein-coupled receptor kinase GRK4: identification, functional expression, and differential tissue distribution of two splice variants.

G protein-coupled receptor kinases (GRKs) specifically phosphorylate the agonist-occupied form of G protein-coupled receptors, leading to the homologous mode of desensitization. We report here on the cloning of complementary DNAs that encode two rat GRK4 variants. Rat GRK4A (575 amino acids) displays 76% identity with the long human GRK4 splice variant. Rat GRK4B (545 amino acids) delineates a new variant that is identical to GRK4A except for a 31-amino acid deletion in the N-terminal domain, corresponding to exon VI in the human GRK4 gene. GRKs4A and B are likely produced by alternative splicing from a single gene, the partial characterization of which revealed a structural organization similar to that of the human GRK4 gene. GRK4A messenger RNA (mRNA) is abundant only in testis. A combination of in situ hybridization and quantitative RT-PCR studies demonstrated that GRK4A mRNA level increases during testicular development and predominates in leptotene to late pachytene primary spermatocytes and round spermatids. GRK4B mRNA is poorly expressed in testis and most rat tissues but is heterogeneously distributed in the kidney, with 20-fold enrichment in the outer medulla. GRKs4A and B are both functional protein kinases, as demonstrated in a rhodopsin phosphorylation assay. The differential tissue distribution of GRKA4 and GRK4B suggests that individual GRK4 variants may serve distinct physiological functions.

Amino Acid Sequence↗
PubMed1998

Experience with allogeneic and syngeneic blood stem cell transplantation in patients with hematological malignancies.

Between 1995 and 1997 twenty two patients with different hematological diseases ( CML n=10, AML n=6, ALL n=l, NHL n=3, SAA n=1,solid tumor n=1 ) and a median age of 37 (range, 20 to 55) years received unmanipulated peripheral blood stem cell (PBSC) transplants from HLA-identical sibling donors at our institution. Myeloablative chemotherapy consisted of cyclophosphamide (CY) and total body irradiation in 11, and chemotherapy alone in 11 patients. For graft-versus host-disease (GVHD) prophylaxis all patients were given cyclosporine A and methotrexate according to the Seattle protocol. PBSC were mobilized by granulocyte colony-stimulating factor (G-CSF) given at 10 microg/kg body weight (b.w.)/day for four days. Harvest of PBSC was started on day 5 and continued on day 6 if necessary. A median of 1 leukapheresis (range, 1 to 2) was performed and a median of 5.7 x 10(6) CD34+cells/kg b.w. (1.34 to 21.5) were obtained. Ten patients received G-CSF (5 microg/kg b.w.) starting on day one after PBSCT until neutrophil recovery. Absolute neutrophil counts >0.5 x 10(9)/L and ANC >1.0 x 10(9)/L were reached after a median of 13 (range 8 to 18) and 15 (range 9 to 19) days after PBSCT. Unsupported platelet counts >20 x 10(9)/L and 50 x 10(9)/L were reached after 17 (range 8 to 32) and 22 (range 13 to 40) days after PBSCT, respectively. Incidence of acute GVHD grade I to IV was 52%, extensive chronic GVHD occurred in 25% of patients. After a median observation time of 11 (range, 3 to 34) months twelve patients (55%) are alive and well. In summary, infusion of allogeneic PBSC after myeloablative therapy allows rapid and sustained hematologic reconstitution. Incidence of acute GVHD is not increased, for assessment of chronic GVHD longer observation times and larger patient numbers are required.

Adult↗
PubMed1998

Matched unrelated donor marrow transplantation in patients with advanced acute leukemia.

Patients with advanced acute leukemia (AL) have a poor prognosis with death due to disease or complications of therapy. High-dose chemoradiotherapy followed by allogeneic marrow transplantation (BMT) has been used to overcome resistance of the leukemic clone resulting in long-term survival of up to 20%. Due to lack of suitable related donors BMT from an HLA-compatible unrelated donor (MUD) has been increasingly applied in these patients during the last years. Between January 1991 and August 1997 twenty five patients with advanced acute myeloid (n=19) or lymphoid (n=6) leukemia, 11 males and 14 females, age 22 to 41 (median 32) years received MUD (n=22) or 1-antigen mismatched unrelated donor (n=3) grafts. In four patients an autologous BMT had been performed previously. For conditioning all patients were given total body irradiation containing regimens. Graft-versus-host disease (GVHD) prophylaxis consisted of cyclosporine (CSA) and methotrexate (n=24) or CSA and methylprednisone (n=1). In 23 patients (92%) class II region compatibility was assessed by DRB1, DRB3, DRB5, and DQB1 allele typing by hybridization of amplified DNA with ligation based typing. In 2 patients HLA-DR typing was performed by two colour fluorescence cytotoxicity test and mixed lymphocyte cultures. As of November 1997 10/25 patients (40%) are surviving leukemia-free after a median observation time of 17 (range, 3 to 38) months. Transplant-related mortality was an overall of 36% and 28% in patients receiving their first BMT. In 6/25 patients (24%) relapse occurred 2 to 26 months after BMT. Incidence of acute GVHD grade I to IV was 85%. The probability of relapse projected at 3 years was 35%. High-dose chemoradiotherapy followed by MUD marrow infusion has a curative potential for patients with advanced acute leukemia and offers the chance of long-term leukemia-free survival. Currently, up to 80% of patients with acute myelogenous leukemia (AML) and acute lymphoid leukemia (ALL) under the age of 50 years achieve complete hematological remission (CR) with conventional dose chemotherapy. However, in patients who are refractory to induction chemotherapy or relapse prognosis is still poor. There, high-dose chemoradiotherapy followed by allogeneic marrow infusion has been used to overcome resistance of the refractory leukemic clone and has resulted in long-term survival. For selected patients lacking a human leukocyte antigen (HLA) compatible family donor marrow transplantation (BMT) with a suitable unrelated marrow donor (MUD) has become a feasible and effective treatment. Here, we report our experience in patients with advanced acute leukemia given marrow grafts from unrelated donors.

Acute Disease↗
PubMed1998

Long term follow up after allogeneic stem cell transplantation for chronic myelogenous leukemia.

Between January 1983 and July 1997, 83 patients (35 female, 48 male) with a median age of 37 (19-57) years with chronic myelogenous leukemia (CML) were admitted for bone marrow transplantation (BMT) at the University hospital of Vienna. Fifty-six patients were in chronic phase, 17 in accelerated and 10 had blast crisis. Marrow donors were: HLA-identical siblings in 62 patients, 2-antigen mismatched related donor in 2, HLA-identical unrelated donors (MUD) in 17 and 1-antigen mismatched unrelated donor in 2 patients. The median time from diagnosis to BMT was 22 (2-91) months. Conditioning therapy consisted of cyclophosphamide (CY) and total body irradiation or CY and busulfan. For graft-versus-host disease (GVHD) prophylaxis methotrexate (MTX) alone, MTX and cyclosporine A (CSA), CSA alone or CSA and methylprednisone were given. Durable engraftment was documented in 75 of 77 patients (97%). As of July 31, 1997 48 patients are alive (58%), 36 (56%) after sibling transplantation with a median observation time of 77 months and 12 (63%) after MUD transplantation with a median observation time of 13 months. Overall survival for patients in chronic phase (CP) at time of BMT is 64%, 53% for patients in acceleration and 30% for patients in blast crisis (BC). Disease-free survival (DFS) after sibling BMT and unrelated donor transplantation is 53% and 58%, respectively. Ten patients (12%) experienced relapse of CML. Transplant-related mortality was 33% after sibling and 32% after MUD transplantation. Thus, sibling and unrelated donor BMT offer high cure rates with acceptable toxicity to patients with CML.

Adult↗
PubMed1997

Donor leukocyte infusion for leukemic relapse after allogeneic marrow transplantation: lack of residual donor hematopoiesis predicts aplasia.

We assessed the chimerism of CD34+ bone marrow cells before donor leukocyte infusion (DLI) on nine occasions in seven patients with leukemic relapse after allogeneic marrow transplantation. The patients suffered from acute lymphoblastic leukemia (n = 1), acute myeloid leukemia (n = 3), and chronic myeloid leukemia (CML; n = 3). Two patients received a second DLI because of disease progression after the first one. The origin of the CD34+ cells was determined by analyzing variable number of tandem repeats with polymerase chain reaction and, in sex-mismatched cases, by fluorescence in situ hybridization. Before DLI CD34+ cells were exclusively of donor origin in four patients. In another patient 41% of CD34+ cells were derived from the donor. No aplasia occurred in these patients after DLI, whereas in the two patients with exclusively recipient hematopoiesis severe aplasia lasting for 5 and 13 weeks necessitated hematopoietic stem cell support. One patient who had only 5% CD34+ donor cells before DLI recovered without stem cell support after 10 days. Two patients in relapse of CML showed a high percentage of BCR-ABL- CD34+ cells of recipient origin before DLI. These BCR-ABL- cells of recipient type did not prevent severe aplasia which indicates that the assessment of BCR-ABL+ hematopoiesis alone is insufficient for predicting aplasia. Our data indicate that in case of sufficient donor hematopoiesis before DLI no persistent aplasia will occur. Thus, evaluation of donor hematopoiesis allows prediction of aplasia after DLI and makes early therapeutic interventions possible.

Acute Disease↗