Search PubMed⌕ Search

Biomedical subjects

M Neubauer

Publications and source records attributed to M Neubauer.

At least 19 recordsLinked to original sources
PubMed2000

Surgery for Graves' disease: total versus subtotal thyroidectomy-results of a prospective randomized trial.

The effect of surgery on Graves' orbitopathy (GO) is still controversial. Retrospective analyses of many authors (including our own group) demonstrated GO improvement after subtotal thyroid resection in up to 70% of operated patients, so the question arose whether total thyroidectomy could add anything to this pronounced positive effect on GO. We therefore performed a prospective randomized trial on 150 patients with Graves' disease (125 women, 25 men; mean thyroid volume 80.5 ml) comparing three surgical procedures (bilateral subtotal thyroid resection-total remnant < 4 ml; unilateral hemithyroidectomy with contralateral subtotal thyroid resection-remnant < 4 ml; total thyroidectomy) and their effect on postoperative GO changes, postoperative thyroid-stimulating hormone receptor (TSH-R) antibody titers, and postoperative complication rates. After a period of at least 6 months (6-36 months) GO had improved in 71% to 74% of all patients regardless of whether total or subtotal thyroidectomy was performed. TSH-R antibody titers showed no differences for the three surgical groups. Postoperative recurrent hyperthyroidism occurred in two patients with subtotal resections, and early postoperative hypoparathyroidism was more frequently detected in patients with total thyroidectomy than in those with subtotal thyroid resection (28% vs. 12%; p < 0.002). In respect to possible postoperative hypoparathyroidism and a lack of difference in postoperative GO changes, we do not advocate total thyroidectomy for patients with Graves' disease and Graves' orbitopathy but prefer radical subtotal thyroid resection with a remnant of less than 4 ml.

Adolescent↗
PubMed1998

Efficacy and toxicity of 2-Chlorodeoxyadenosine (Cladribine)--2 h infusion for 5 days--as first-line treatment for advanced low grade non-Hodgkin's lymphoma.

2-Chlorodeoxyadenosine (Cladribine) is a new purine analogue with high activity in pretreated low grade non-Hodgkin's lymphoma (NHL). To evaluate the efficacy of this drug in untreated patients with advanced NHL, we performed a prospective multicentre trial. Cladribine (0.12 mg/kg) was administered intravenously daily for 5 consecutive days in an out-patient setting. The treatment was repeated every 28 days for four cycles. Included were patients with a histological diagnosis of low grade NHL according to the Kiel classification and stage III or IV disease. Stage II patients were included when radiotherapy had failed. 55 patients were entered into the study. 50 patients were evaluable. The remission rate was 44/50 (88%; 95% confidence interval 82-100%), including complete remissions (CR) in 14 (28%) patients. Only 2 patients showed progression while on Cladribine treatment. The estimated overall survival, and time to treatment failure (TTF) were 85% and 51%, respectively, after a median observation time of 92 weeks. 11 (22%) patients showed grade 3 or 4 toxicity according to the WHO grading. Haematological toxicity was responsible for 86% of the overall toxicity and 100% of grade 3 and 4 toxicity. 7 patients (14%) had an infection, two of which were opportunistic. 12 (24%) patients did not experience any toxicity during the treatment. The results of this study clearly demonstrate the safety and considerable activity of this regimen. Cladribine is very effective even at lower doses than have been used so far.

Adult↗
PubMed1997

Molecular, biological, and preliminary structural analysis of recombinant bryodin 1, a ribosome-inactivating protein from the plant Bryonia dioica.

Bryonia dioica (Cucurbitaceae family) produces at least two type I ribosome-inactivating proteins, bryodin 1 (BD1) and bryodin 2 (BD2). A cDNA sequence encoding BD1 was isolated from B. dioica leaf mRNA using degenerative oligonucleotides and codes for a 22 amino acid signal peptide followed by a protein of 267 residues. Expression of two recombinant BD1 (rBD1) forms in Escherichia coli yielded proteins of 267 (to the natural stop codon) and 247 amino acids (to the putative cleavage site yielding the mature protein) that had identical protein synthesis inhibition activity as compared to native BD1. The substitution of Lys for Glu at position 189 near the active site reduced the ability of rBD1 to inhibit protein synthesis by 10-fold. Toxicologic analysis showed that rBD1 was well tolerated in rodents with LD50 values of 40 mg/kg in mice and >25 mg/kg in rats. A crystal of mature rBD1 protein was used to collect X-ray diffraction data to 2.1 A resolution. The rBD1 crystal structure was solved and showed extensive homology with other type I RIPs and A chains of type II RIPs. The studies described here demonstrate that rBD1 retains full biologic activity and serve as a guide for using this potent, yet nontoxic, RIP in the construction of single-chain immunotoxin fusion proteins.

Amino Acid Sequence↗
PubMed1997

Identification of residues in CD6 which are critical for ligand binding.

CD6 is a member of the scavenger receptor cysteine rich protein superfamily (SRCRSF). This family includes many cell surface proteins whose three-dimensional structures and functions are presently not well understood. The extracellular region of CD6 includes 3 SRCR domains. The membrane proximal SRCR domain specifically binds the activated leukocyte cell adhesion molecule (ALCAM), a CD6 ligand belonging to the immunoglobulin superfamily. CD6-ALCAM interactions mediate immune cell adhesion and are implicated in T cell maturation and the regulation of T cell function. On the basis of SRCRSF sequence comparison, a mutagenesis analysis of the membrane proximal SRCR domain of CD6 (CD6D3) has been carried out. Fifteen mutants were characterized. Three CD6 residues were identified in a region of low sequence conservation which, when mutated, abolish ligand binding but not the binding to a panel of conformationally sensitive anti-CD6 mAbs. This study provides the first analysis of residues critical for ligand binding to a member of the SRCRSF.

Activated-Leukocyte Cell Adhesion Molecule↗
PubMed1997

Structure and chromosomal location of the human CD6 gene: detection of five human CD6 isoforms.

The CD6 protein has been shown to play important roles in T cell costimulation and adhesion. Recently, variably spliced isoforms of CD6 mRNA have been identified in both human and murine T cells. Here we report on the genomic organization of the human CD6 gene, its chromosomal localization, and the characterization of novel isoforms. Human CD6 is encoded by at least 13 exons. The amino terminal signal sequence, extracellular region, and transmembrane domain are encoded by seven exons, while the cytoplasmic domain of CD6 is encoded by six exons. Each of the three extracellular scavenger receptor cysteine-rich domains is encoded by a separate exon. Fluorescence in situ hybridization studies and screening of a chromosome-specific YAC (yeast artificial chromosome) library revealed that the gene encoding CD6 is located on chromosome 11 at 11q13 in close proximity to the gene encoding the related molecule CD5 and within 600 kb of CD20. Analysis of mRNA transcripts encoding CD6 isolated from mitogen-activated PBMC and from B cells obtained from patients with chronic lymphocytic leukemia revealed the presence of at least five different CD6 transcripts. These transcripts arise via variable splicing of exons encoding the cytoplasmic domain of CD6. The existence of these isoforms suggests that signaling through CD6 could be regulated via alternative splicing of cytoplasmic encoding exons.

Alternative Splicing↗
PubMed1997

Randomized open label phase III trial of CEOP/IMVP-Dexa alternating chemotherapy and filgrastim versus CEOP/IMVP-Dexa alternating chemotherapy for aggressive non-Hodgkin's lymphoma (NHL). A multicenter trial by the Austrian Working Group for Medical Tumor Therapy.

Primary end point of this trial was to reduce neutropenic infections during the treatment of aggressive NHL with CEOP/IMVP-Dexa (cyclophosphamide, epirubicin, vincristine, prednisolone ifosfamide, methotrexate, VP-16, and dexamethasone). Further, we studied the influence of filgrastim on dose intensity of CEOP/IMVP-Dexa, on the rate of complete remissions, on the time to relapse, and on survival. Eighty-five patients with untreated large-cell NHL were randomized to one of two treatment arms; 74 patients were eligible. Thirty-eight patients in arm 1 were treated with CEOP/IMVP-Dexa chemotherapy and filgrastim, 36 in arm 2 with CEOP/IMVP-Dexa chemotherapy alone. In arm 1 filgrastim was self-injected by the patients at 5 micrograms/kg body wt. s.c. daily, except on the days when cytotoxic drugs were given. During treatment we did weekly complete blood counts. Median leukocyte counts were 10.91 x 10(9)/l and 5.46 x 10(9)/l in arm 1 and 2, respectively (p = 10(-6)). Median neutrophil counts were 7.7 x 10(9)/l in arm 1 and 2.72 x 10(9)/l in arm 2 (p < 10(-6)). Median neutrophil nadirs were 0.199 x 10(9)/l and 0.213 x 10(9)/l in arm 1 and 2, respectively (p = 0.09). Mean platelet nadirs were 95 and 152 x 10(9)/l (p = 0.000004) and mean hemoglobin nadirs 83.95 g/l and 92.78 g/l (p = 0.00558) in arm 1 and 2, respectively. Dose intensity of CEOP/IMVP-Dexa was 82.3% and 76.2% in arm 1 and 2, respectively (p = 0.041). Forty-two percent and 58% of patients experienced a febrile neutropenia in arm 1 and 2, respectively (not significant, NS). Median time to first neutropenic infection was in treatment week 11 and 6 in arm 1 and 2, respectively (NS). There was no significant difference in rate, duration, and kind of infection, duration of hospitalization, or antibiotic treatment. Seven toxic deaths occurred, all due to neutropenic infection, 6 and 1 in arm 1 and 2, respectively (p = 0.0732). Four of the six patients, who died of infection in arm 1 were older than 60 years. Complete remission rate was 83% and 66.7% in arm 1 and 2, respectively (NS). After a median observation time of 3 years there was no difference in time to relapse or survival. Filgrastim increases leukocyte and neutrophil counts and dose intensity, if used with CEOP/IMVP-Dexa chemotherapy in high-grade lymphomas. There was no significant effect on febrile neutropenia or infections. The more frequent fatal neutropenic infection rate in the filgrastim arm was not statistically significant. It is most appropriate to explain it by the patient's age in combination with the high dose intensity. The small increase in dose intensity had no effect on survival but probably decreased hemoglobin levels and platelet counts in arm 1. We were unable to show a benefit for filgrastim in combination with CEOP/IMVP-Dexa.

Adolescent↗
PubMed1997

Mutations of the CD40 ligand gene in 13 Japanese patients with X-linked hyper-IgM syndrome.

X-linked hyper-IgM syndrome (XHIM) is a rare primary immunodeficiency caused by a defective CD40 ligand. We identified mutations of the CD40 ligand gene in 13 unrelated Japanese XHIM patients. Of the four patients with missense mutations, one had a mutation within the transmembrane domain, and the three others had mutations affecting the TNF homology region of the extracellular domain. Two of the missense mutations resulted in the substitution of amino acids that are highly conserved in TNF family proteins. Three patients had nonsense mutations, all of which resulted in the truncation of the TNF homology domain of the CD40 ligand. Three patients had genomic DNA deletions of 2, 3 or 4 nucleotides, respectively. All of the deletions were flanked by direct repeat sequences, suggesting that these deletions were caused by slipped mispairing. Three patients had mutations within introns resulting in altered splicing, and multiple splicing products were found in one patient. Thus, each of the 13 Japanese patients had different mutations, 9 of them being novel mutations. These results indicate that mutations in XHIM are highly heterogeneous, although codon 140 seems to be a hot spot of the CD40 ligand gene since two additional point mutations were located at Trp 140, bringing the total numbers of mutations affecting codon 140 to six. In one XHIM family with a missense mutation, prenatal diagnosis was performed by single-strand conformation polymorphism analysis of genomic DNA of a male fetus.

Alternative Splicing↗
PubMed1997

Somatosensory evoked potentials modified by laser-induced lesions of the rat cortex.

The effect of focal application of laser energy on the modification of somatosensory evoked potentials (SEPs) was studied in sensory cortical fields of the rat. This article describes the methodological set-up for recording of SEPs and for determining location and size of the laser-induced lesion. The results show that both the size of the lesion of the somatosensory cortex, and the suppression and time of recovery of cortical SEPs varied depending on the laser energy dose. It remains to be analyzed by further experiments if the recovery of SEPs is due to a transient dysfunction of the somatosensory cortex or if it reflects cortical plasticity.

Animals↗
PubMed1996

Identification of a novel Drosophila melanogaster heat-shock gene, lethal(2)denticleless [l(2)dtl], coding for an 83-kDa protein.

In this study, we describe the identification of a novel Drosophila melanogaster (Dm) gene, l(2)dtl, characterized by elevated expression under heat-shock (HS) conditions. It encodes a protein of 83 kDa with no homology to known members of the HSP90 family and other proteins. Gene l(2)dtl is located on the right arm of the second chromosome at locus 59F5, close to the tumor suppressor gene l(2)tid, a homolog of the dnaJ encoding a chaperone strongly conserved in evolution. In the following, we present the sequence of l(2)dtl, the putative protein it encodes, and its molecular localization in a closely interspaced gene cluster consisting of at least four nested genes spanning an approximately 10-kb genomic interval. Furthermore, we present the temporal expression of l(2)dtl in the wild type under normal and HS conditions, and describe the isolation and the phenotype of eight embryonic lethal l(2)dtl mutants.

Amino Acid Sequence↗
PubMed1996

Cyclin G1 and cyclin G2 comprise a new family of cyclins with contrasting tissue-specific and cell cycle-regulated expression.

We describe the isolation and characterization of cDNAs encoding full-length human and murine cyclin G1 and a novel human homologue of this cyclin designated cyclin G2. Cyclin G1 is expressed at high levels in skeletal muscle, ovary, and kidney. Following an initial up-regulation from early G1 to G1/S phase, cyclin G1 mRNA is constitutively expressed throughout the cell cycle in T and B cell lines. In contrast, in stimulated peripheral T cells, cyclin G1 mRNA is maximal in early G1 phase and declines in cell cycle progression. Cyclin G1 levels parallel p53 expression in murine B lymphocytes; however, in several human Burkitt's lymphomas, murine lymphocytes treated with transforming growth factor-beta, early murine embryos, and several tissues of p53 null mice, cyclin G1 levels are either inverse of p53 levels or expressed independent of p53. The cyclin G1 homologue, cyclin G2, exhibits 60% nucleotide sequence identity and 53% amino acid sequence identity with cyclin G1, and like cyclin G1, exhibits closest sequence identity to the cyclin A family. Distinct from cyclin G1, the amino acid sequence for cyclin G2 shows a PEST-rich sequence and a potential Shc PTB binding site. Cyclin G2 mRNA is differentially expressed compared to cyclin G1, the highest transcript levels seen in cerebellum, thymus, spleen, prostate, and kidney. In contrast to the constitutive expression of cyclin G1 in lymphocytes, cyclin G2 mRNA appears to oscillate through the cell cycle with peak expression in late S phase.

Amino Acid Sequence↗
PubMed1996

CEOP-IMVP-Dexa in the treatment of aggressive lymphomas: an Austrian multicenter trial.

PURPOSE: This trial evaluated the efficacy, toxicity, and practicability of a new intensive chemotherapy regimen in a multicenter setting of university and community hospitals. PATIENTS AND METHODS: We tested a hybrid protocol of two non-cross-resistant regimens, cyclophosphamide, epirubicin, vincristine, and prednisolone (CEOP) and ifosfamide, etoposide (VP-16), methotrexate, and dexamethasone (IMVP-Dexa) given every fourth week, three to six times according to response, in patients with untreated intermediate- and high-grade non-Hodgkin's lymphoma. Ten Austrian centers entered 81 patients onto this multicenter trial. Eleven patients were excluded. The median age was 55 years. Twenty-six of 70 patients had stage III or IV disease. The distribution among international risk categories low, intermediate-low, intermediate-high, and high was 20%, 34%, 23%, and 23%, respectively. RESULTS: Of 70 eligible patients, 56 (80%) had a complete remission and seven (10%) a partial remission. After a median observation time of 36 months, the estimated time to relapse and overall survival rates are 67% and 72%, respectively. Age and Karnofsky index were the only independent risk factors for survival. Toxicity was primarily hematologic, with a median granulocyte nadir of 0.56 x 10(9)/L. Sixty-seven percent of patients had infections; 25.7% were severe World Health Organization (WHO) grade III or IV. There were three treatment-related deaths. CONCLUSION: CEOP-IMVP-Dexa chemotherapy is safe and feasible on a groupwide basis even when used in community hospitals. Neutropenic infections are the major complications. A 72% 3-year survival rate in patients with intermediate- and high-grade non-Hodgkin's lymphoma warrants further studies. These data are the basis for a randomized trial to compare cyclophosphamide, doxorubicin, vincristine, and prednisolone (CHOP) with CEOP/IMVP-Dexa.

Adolescent↗
PubMed1995

Cloning, mapping, and characterization of activated leukocyte-cell adhesion molecule (ALCAM), a CD6 ligand.

Antibody-blocking studies have demonstrated the role of CD6 in thymocyte-thymic epithelial (TE) cell adhesion. Here we report that CD6 expressed by COS cells mediates adhesion to TE cells and that this interaction is specifically blocked with an anti-CD6 monoclonal antibody (mAb) or with a mAb (J4-81) that recognized a TE cell antigen. We isolated and expressed a cDNA clone encoding this antigen and show that COS cells transfected with this cDNA bind a CD6 immunoglobulin fusion protein (CD6-Rg). This antigen, which we named ALCAM (activated leukocyte-cell adhesion molecule) because of its expression on activated leukocytes, appears to be the human homologue of the chicken neural adhesion molecule BEN/SC-1/DM-GRASP. The gene was mapped to human chromosome 3q13.1-q13.2 by fluorescence in situ hybridization of cDNA probes to metaphase chromosomes. We prepared an ALCAM-Rg fusion protein and showed that it binds to COS cell transfectants expressing CD6, demonstrating that ALCAM is a CD6 ligand. The observations that ALCAM is also expressed by activated leukocytes and that both ALCAM and CD6 are expressed in the brain suggest that ALCAM-CD6 interactions may play a role in the binding of T and B cells to activated leukocytes, as well as in interactions between cells of the nervous system.

Activated-Leukocyte Cell Adhesion Molecule↗
PubMed1995

Effect of age and disease duration on parkinsonian motor scores under levodopa therapy.

One hundred and fifty patients suffering from Parkinson's disease were analysed for the expression of the motor symptoms during optimum response to levodopa therapy (subscale III of the Unified-Parkinson's Disease Rating Scale). Patients were grouped according to age (< or = 64, 65-74, > or = 75 years). Disease duration and daily levodopa dosage were similar in the three groups. Pooled residual scores for posture and gait impairment (PGI), tremor (T), rigidity (R) and distal motor impairment (DMI; hand and foot movements) increased with age (Kruskal-Wallis ANOVA). The parkinsonian scores were significantly higher than the scores of 150 age-matched normal controls (Mann-Whitney U test). The differences between the patients' scores and the scores of the age-matched controls increased with age. In spite of a significant increase in the daily levodopa dosage with disease duration (linear regression), PGI aggravated age-dependently, and DMI age-independently with symptom duration (Spearman rank correlation). In contrast, T and R did not increase with disease duration.

Adult↗