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Biomedical subjects

R Arnold

Publications and source records attributed to R Arnold.

At least 37 records · Page 2Linked to original sources

Risk-adapted induction and consolidation therapy in adults with de novo AML aged </= 60 years: results of a prospective multicenter trial.

We treated 305 de novo acute myeloid leukemia (AML) patients aged </=60 years with risk-adapted therapy. Patients with CBF leukemias or normal karyotype and good response to induction I [</=5% bone marrow (BM) blasts on day 15] were considered standard risk (SR), all others as high risk (HR). Patients with t(15;17) were excluded. Chemotherapy comprised double induction followed by early consolidation. As late consolidation, SR patients received high-dose cytarabine/daunorubicin (AraC/DNR). SR patients with normal karyotype were allotransplanted from HLA-matched siblings. HR patients were allotransplanted or if no sibling donor was available autotransplanted with peripheral blood progenitor cells (PBSC) harvested after early consolidation. 89% of the SR and 60% of the HR patients achieved CR. The continuous complete remission (CCR) rate at 80 months (median follow-up: 48 months) was 48% for SR and 32% for HR. The CCR rate was 54% for t(8;21), 47% for normal karyotype, and 33% for inv(16) patients. In the HR group, the CCR rate did not differ significantly for patients with bad response to IVA-I, unfavorable karyotype, or both. Forty-five HR patients were autotransplanted (n=20) or allotransplanted (n=25). The probability of CCR was 44% for autotransplantation vs 33% for allotransplantation. In conclusion, our risk-adapted strategy produced encouraging results in SR patients. Early response to therapy is a strong prognostic factor that predicts the probability of CR and long-term outcome.

Adolescent↗

Pdcd4 inhibits growth of tumor cells by suppression of carbonic anhydrase type II.

To identify new genes that are upregulated during apoptosis we previously cloned rat pdcd4. While the role of pdcd4 is still unclear it seems to possess a tumor suppressor activity. Pdcd4 directly interacts with the RNA helicase eIF4A and inhibits protein synthesis by interfering with the assembly of the cap-dependent translation initiation complex. In the present study, we show that pdcd4 suppresses carbonic anhydrase type II protein expression in HEK293 and Bon-1 carcinoid cells. Since tumor cells require a high bicarbonate flux for their growth, carbonic anhydrase suppression results in growth inhibition. Similar to pdcd4, carbonic anhydrase inhibitor ethoxyzolamide reduces growth of several endocrine tumor cell lines. Thus, the translation inhibitor pdcd4 represses endocrine tumor cell growth by suppression of carbonic anhydase II. Furthermore, carbonic anhydrase inhibitors might represent promising tools for anti-endocrine tumor treatment.

Animals↗

MIPS: analysis and annotation of proteins from whole genomes.

The Munich Information Center for Protein Sequences (MIPS-GSF), Neuherberg, Germany, provides protein sequence-related information based on whole-genome analysis. The main focus of the work is directed toward the systematic organization of sequence-related attributes as gathered by a variety of algorithms, primary information from experimental data together with information compiled from the scientific literature. MIPS maintains automatically generated and manually annotated genome-specific databases, develops systematic classification schemes for the functional annotation of protein sequences and provides tools for the comprehensive analysis of protein sequences. This report updates the information on the yeast genome (CYGD), the Neurospora crassa genome (MNCDB), the database of complete cDNAs (German Human Genome Project, NGFN), the database of mammalian protein-protein interactions (MPPI), the database of FASTA homologies (SIMAP), and the interface for the fast retrieval of protein-associated information (QUIPOS). The Arabidopsis thaliana database, the rice database, the plant EST databases (MATDB, MOsDB, SPUTNIK), as well as the databases for the comprehensive set of genomes (PEDANT genomes) are described elsewhere in the 2003 and 2004 NAR database issues, respectively. All databases described, and the detailed descriptions of our projects can be accessed through the MIPS web server (http://mips.gsf.de).

Animals↗

The relative contribution of domains of quality of life to overall quality of life for different chronic diseases.

This study examined the contribution of the quality of life (QoL) domains physical, social and psychological functioning to the explanation of overall QoL. Various disorders may differentially affect QoL domains due to disease-specific factors and, consequently, the relationship between QoL domains and overall QoL may vary between diseases. We therefore studied this relationship for several diseases as well as the differential impact of these diseases on QoL. The present study had a cross-sectional design. We selected patients (aged 57 years and older) with one of the following eight chronic medical conditions: lung disorder, heart condition, hypertension, diabetes mellitus, back problems, rheumatoid arthritis, migraine, or dermatological disorders. The total group of respondents included 1457 patients and 1851 healthy subjects. Regression analyses showed that the domain of psychological functioning contributed to overall QoL for all disorders, whereas physical and social functioning contributed to overall QoL for some disorders. Differences were found between most patient groups and healthy subjects with respect to physical functioning; with respect to social and psychological functioning some groups differed from the healthy group. Explanations for the findings and implications for clinical practice are discussed.

Activities of Daily Living↗

Nonmyeloablative stem cell transplantation in metastatic renal cell carcinoma: delayed graft-versus-tumor effect is associated with chimerism conversion but transplantation has high toxicity.

Seven out of 29 patients with metastatic renal cell carcinoma (RCC) considered eligible for allogeneic stem cell transplantation underwent nonmyeloablative stem cell transplantation (NST) from HLA-identical donors. Conditioning comprised cyclophosphamide, fludarabine and antithymocyte globulin. Prolonged mixed chimerism (MC) after engraftment converted to complete donor chimerism (CC) after infusion of donor lymphocytes and/or graft-versus-host disease (GvHD) in six patients. Five patients developed severe GvHD. Two of seven patients had a delayed tumor response after conversion to CC. After a median follow-up of 10 months (4-24 months), 5/7 patients are alive, one in very good partial remission (PR), one with stable and three with progressive disease. One of the seven patients died from sepsis in PR and 1/7 died from rapid tumor progression after sustained MC. None of the 22 nontransplanted patients responded to further therapies. Survival after 1 year was 59% in transplanted and 66% in nontransplanted patients (n.s.). A pooled data analysis from the literature suggests a graft-versus-tumor effect after transplant in patients with metastatic RCC, which becomes effective after chimerism conversion. Available data demonstrate high nonrelapse mortality in these patients. NST in RCC still has to be regarded as an investigational approach requiring careful patients' selection and longer follow-up within clinical studies.

Adult↗

The rationale behind autologous autoimmune hematopoietic stem cell transplant conditioning regimens: concerns over the use of total-body irradiation in systemic sclerosis.

Hematopoietic stem cell transplantation (HSCT) is becoming an increasingly recognized indication for treatment of autoimmune diseases and severe immune-mediated disorders. However, multicenter registry data have demonstrated higher than anticipated early toxicity, approximately 10% for autoimmune diseases in general, and 20-27% for diffuse systemic sclerosis (scleroderma). If uncorrected, this high treatment-related mortality will hinder development of stem cell therapy for immune-mediated diseases. In order to develop safer regimens, we address some pitfalls and concepts involved in design and selection of conditioning regimens for autoimmune diseases in general, and because it is associated with the highest regimen-related toxicity, scleroderma in specific.

Autoimmune Diseases↗

Review article: the pathophysiology of gastro-oesophageal reflux disease - oesophageal manifestations.

The pathogenesis of gastro-oesophageal reflux disease (GERD) is multifactorial, involving transient lower oesophageal sphincter relaxations (TLESRs) as well as other lower oesophageal sphincter (LES) pressure abnormalities. GERD is associated with a decrease in LES pressure, which can be provoked by factors such as foods (fat, chocolate, etc.), alcohol, smoking and medications. These factors have also been shown to increase TLESRs. As a result, reflux of acid, bile, pepsin and pancreatic enzymes occurs, leading to oesophageal mucosal injury, which can potentially progress to oesophageal adenocarcinoma in a minority of patients with Barrett's metaplasia. In addition, duodenogastric contents can also contribute to oesophageal injury. Other factors contributing to the pathophysiology of GERD include hiatal hernia, poor oesophageal clearance, delayed gastric emptying and impaired mucosal defensive factors. Hiatal hernia has a permissive role in the pathogenesis of reflux oesophagitis by promoting LES dysfunction. Delayed gastric emptying, resulting in gastric distension, can significantly increase the rate of TLESRs, contributing to postprandial GER. The mucosal defensive factors have an important role in GERD. When excessive acid causes a breakdown in oesophageal epithelial defenses, epithelial resistance may be reduced. Nocturnal GERD is associated with prolonged acid exposure and proximal extent of acid contact, which elevates the risk for oesophageal damage and GERD-related complications. In sum, GERD is a complex problem caused by many factors that are exacerbated when the patient is in the supine position.

Esophageal Sphincter, Lower↗

Cocaine- and amphetamine-regulated transcript stimulates colonic motility via central CRF receptor activation and peripheral cholinergic pathways in fed, conscious rats.

Many neuropeptides participating in the hypothalamic control of feeding behaviour and satiety have been shown to be additionally involved in the autonomic control of gastrointestinal (GI) functions. Recently, the neuropeptide cocaine- and amphetamine-regulated transcript (CART) has been indicated to function as an anorectic substance in the brain. In the present study we examine the hypothesis that CART is involved in the modulation of GI motility. Colonic transit time was measured after peripheral and central injection of CART in fed and freely moving Sprague-Dawley rats. Intracerebroventricular injection of synthetic CART (55-102) (190 pmol and 1.9 nmol per 10 microL and saline controls) decreased the colonic transit time of conscious rats up to 46%. In contrast, i.p. injection of CART (55-102) (1.9 nmol and 19 nmol kg(-1) BW and saline controls) had no effect on colonic motility. Central administration of a CRF receptor antagonist (2.8 nmol) prior to central CART administration antagonized the CART-induced stimulation of colonic transit. Pretreatment with the peripherally acting cholinergic antagonist atropin methyl nitrate (0.1 mg kg(-1) i.p.) blocked the stimulatory CART effect on colonic motor function. The results suggest that CART acts in the central nervous system to modulate behavioural motor function via a central CRF receptor-dependent mechanism and peripheral cholinergic pathways.

Animals↗

Autologous stem cell transplantation in the treatment of systemic sclerosis: report from the EBMT/EULAR Registry.

OBJECTIVE: To analyse the durability of the responses after haematopoietic stem cell transplantation (HSCT) for severe systemic sclerosis (SSc) and determine whether the high transplant related mortality (TRM) improved with experience. This EBMT/EULAR report describes the longer outcome of patients originally described in addition to newly recruited cases. METHODS: Only patients with SSc, treated by HSCT in European phase I-II studies from 1996 up to 2002, with more than 6 months of follow up were included. Transplant regimens were according to the international consensus statements. Repeated evaluations analysed complete, partial, or non-response and the probability of disease progression and survival after HSCT (Kaplan-Meier). RESULTS: Given as median (range). Among 57 patients aged 40 (9.1-68.7) years the skin scores improved at 6 (n = 37 patients), 12 (n = 30), 24 (n = 19), and 36 (n = 10) months after HSCT (p<0.005). After 22.9 (4.5-81.1) months, partial (n = 32) or complete response (n = 14) was seen in 92% and non-response in 8% (n = 4) of 50 observed cases. 35% of the patients with initial partial (n = 13/32) or complete response (n = 3/14) relapsed within 10 (2.2-48.7) months after HSCT. The TRM was 8.7% (n = 5/57). Deaths related to progression accounted for 14% (n = 8/57) of the 23% (n = 13/57) total mortality rate. At 5 years, progression probability was 48% (95% CI 28 to 68) and the projected survival was 72% (95% CI 59 to 75). CONCLUSION: This EBMT/EULAR report showed that response in two thirds of the patients after HSCT was durable with an acceptable TRM. Based on these results prospective, randomised trials are proceeding.

Adolescent↗

Transarterial chemoembolization of advanced liver metastases of neuroendocrine tumors--a retrospective single-center analysis.

BACKGROUND: In neuroendocrine tumors, metastases are a negative prognostic factor for survival and quality of life. Transcatheter arterial chemoembolization (TACE) is thought to be an effective symptomatic and antiproliferative treatment in patients with otherwise progressive disease. METHODS: 62 chemoembolization procedures in 26 patients with progressive neuroendocrine tumors were reviewed. The underlying disease was carcinoid syndrome in 10, non-functional midgut tumor in 2, non-functional pancreatic tumor in 7, malignant insulinoma in 2 patients, non-functional tumor of the stomach in 1 and of unknown origin in 4 patients. Tumor burden of the liver was <25% in 3, 25-50% in 11, 50-75% in 6 and >75% in 6 patients. RESULTS: TACE was technically successful in 57 cases. Four patients developed minor and 5 major complications. The 30-day mortality rate was 7.7%. According to WHO criteria, 14 patients had no change in tumor burden, 2 had regression and 5 progress after chemoembolization. Patients with a tumor burden >75% of the liver did not benefit from TACE due to the development of major complications, whereas patients with low (<50%) tumor burden and high (>50%) lipiodol uptake showed a trend towards longer survival. Five-year survival time after diagnosis was 48%. Patients treated with octreotide and/or alpha-interferon had no benefit from chemoembolization with regard to their carcinoid syndrome. CONCLUSIONS: In this retrospective study, patients with low (<50%) tumor burden and high (>50%) lipiodol uptake responded better to TACE than end-stage patients.

Adult↗

Dental treatment prior to stem cell transplantation and its influence on the posttransplantation outcome.

Patients who receive allogeneic stem cell transplantation (SCT) for hematological malignancies are at increased risk of developing oral complications. To reduce morbidity pretransplantation dental evaluation and treatment of all sources of potential infection have become standard of care for these patients. This study examined the effect of dental foci on the posttransplantation (post-SCT) outcome in two groups of patients who underwent allogeneic or autologous SCT: those who had no dental foci or completed dental treatment preoperatively (n=36) and those who underwent SCT without dental interventions (n=22). Statistical analysis showed no significant correlations between dental foci and infections, mucositis, and survival rate post-SCT. We therefore do not recommend a radical dental treatment pre-SCT.

Adult↗

Randomized, controlled trial with IFN-alpha combined with ribavirin with and without amantadine sulphate in non-responders with chronic hepatitis C.

BACKGROUND/AIMS: Efficacy and safety of interferon-alpha (IFN-alpha)/ribavirin retreatment with or without amantadine sulphate were evaluated in non-responders with chronic hepatitis C. METHODS: Two hundred twenty five consecutive non-responders to previous antiviral treatment(s) with IFN-alpha alone or in combination with ribavirin or amantadine were treated with IFN-alpha 2b 5 MU daily for 4 weeks, 5 MU tiw for 20 weeks, followed by 3 MU tiw for additional 24 weeks combined with ribavirin 1000-1200 mg/d. One hundred fifteen of 225 patients were randomized to receive amantadine sulphate 100 mg bid for 48 weeks. Treatment was discontinued in patients with detectable serum hepatitis C virus (HCV)-RNA at treatment week 24. RESULTS: An overall sustained virologic response with undectable serum HCV-RNA levels was observed in 49/225 patients (22%). Patients infected with HCV-genotype non-1 (P<0.001), low viremia (P=0.011) and only one previous antiviral treatment (P=0.032) were more likely to respond to antiviral retreatment. There was a trend towards higher sustained virologic response rates in patients receiving triple retreatment compared with those treated with IFN-alpha/ribavirin alone (25 versus 18%, P=0.172). CONCLUSIONS: The addition of amantadine was well tolerated and led to an improvement of sustained virologic responses compared with retreatment with IFN-alpha/ribavirin alone, in particular in patients with low baseline viremia.

Adult↗

Reduced intensity conditioning and prophylactic DLI can cure patients with high-risk acute leukaemias if complete donor chimerism can be achieved.

23 patients with ALL (n=9) and AML (n=14) underwent nonmyeloablative stem cell transplantation (NST) from an HLA-identical donor after conditioning with fludarabine (180 mg/m(2)), busulfan (8 mg/kg) and anti-T-lymphocyte globulin (40 mg/kg). After NST, 20/23 patients engrafted. Ten out of 14 patients with uncontrolled disease reached complete remission. A multiplex-PCR using short tandem repeats was used for chimerism analysis and detected mixed chimerism (MC) in 14/22 evaluable patients (64%) after NST. Prophylactic donor lymphocyte infusions (DLI) were given to 11/14 patients with MC; MC converted to complete donor chimerism (CC) in 6/11 patients within 2-6 weeks. All patients with persistent MC with or without DLI relapsed during further follow-up. MC predicted impending relapse 4-52 weeks before clinical diagnosis. Ten of 23 patients (43%) are alive 2-34 months after stem cell transplantation. 12 of 23 patients (52%), have died from leukaemia after NST. One out of 23 patients has died from severe sepsis. In conclusion, NST leads to stable engraftment and complete remission in patients with advanced acute leukaemias. NST can cure a substantial proportion of these patients, but the relapse rate is still high. Repeated chimerism analysis is a useful tool to detect recipient cells, especially in patients without molecular markers of disease and can be used to monitor immunomodulatory therapies. MC is unstable in these patients and predicts impending relapse. Prophylactic DLI can convert MC to CC, which seemed to lower relapse risk.

Adult↗

Stem cell therapy for autoimmune disease: overview of concepts from the Snowbird 2002 tolerance and tissue regeneration meeting.

Hematopoietic stem cell transplantation as a treatment for autoimmune disease began in 1996 and has subsequently spread worldwide. In Europe phase III trials have opened, while in America phase III trials are being designed and funded by the National Institutes of Health. On 6 June 2002, clinicians and scientists from around the world met at Snowbird, Utah to discuss the results and future directions of stem cell therapy for autoimmune diseases. What follows are general concepts from chairpersons of this meeting.

Autoimmune Diseases↗