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S Haas

Publications and source records attributed to S Haas.

At least 91 records · Page 5Linked to original sources
PubMed1998

MyEF-3, a developmentally controlled brain-derived nuclear protein which specifically interacts with myelin basic protein proximal regulatory sequences.

Myelin basic protein (MBP) gene contains the upstream regulatory sequence that confers cell type- and stage-specific transcription to MBP expression in oligodendrocytes during brain development. The MB1 regulatory motif located between -14 to -50 with respect to transcription start site binds to a brain derived nuclear protein and plays an important role in transcriptional activation of the MBP promoter in transfection assay. Here, we report the isolation of a recombinant cDNA clone, termed myelin expression factor-3, (MyEF-3) from a mouse brain expression library that encodes a novel protein which interacts with the MBP MB1 domain. Computer assisted evaluations of the MyEF-3 sequence revealed several interesting features including four sites for phosphorylation by casein kinase II, a transmembrane domain at the N-terminus, a nuclear localization signal and a Zinc finger domain at the carboxyl terminal. Results from Western and band shift assays indicate that MyEF-3 binds efficiently to double-stranded MB1 as well as the single-stranded non-coding strand of MB1. The use of short DNA fragments encompassing the nucleotide base substitutions across the MB1 domain in competition band shift assay revealed that the ten nucleotide sequence, 5'-GCCTGTCTTT-3' is important for binding of MyEF-3 to DNA. Results from Northern blot studies demonstrate that expression of MyEF-3 is restricted to brain and developmentally regulated during brain maturation. The biological importance of MyEF-3 in the cell type- and stage-specific expression of MBP during brain development is discussed.

Amino Acid Sequence↗
PubMed1998

Estimation of peritoneal mass transport by three-pore model in children.

BACKGROUND: Computerized modeling is increasingly used to optimize the efficacy of peritoneal dialysis (PD). The Personal Dialysis Capacity (PDC) test is a new tool to model PD efficacy based on the three-pore model of peritoneal mass transport. We sought to evaluate (i) whether the PDC test is applicable to children on chronic PD, and (ii) whether the physiological mass transport coefficients defined in the three pore model are dependent on age or body size in childhood. METHODS: A validation study was performed in 32 pediatric chronic PD patients. Twenty tests were performed using a standard CAPD regimen, and 22 tests using a simplified automated PD (APD) protocol. Test accuracy and precision were evaluated by comparison of predicted with measured 24-hour dialysate clearances of urea, creatinine, beta2-microglobulin and albumin and ultrafiltration rates. Long-term reproducibility was assessed in 16 patients by repeated clearance studies after a median time interval of 10 weeks. RESULTS: While daily clearances of urea and creatinine were predicted with good precision and accuracy with both test protocols (concordance correlation coefficients 0.90 to 0.98, mean difference predicted-calculated -0.6 to +0.6 ml/min/1.73 m2), ultrafiltration rates were predicted more closely by the APD (r = 0.97) than by the CAPD test (0.80). Middle and large molecule clearances were predicted less precisely in both test settings (r = 0.48 to 0.83). Re-test reproducibility was slightly lower than the predictive precision observed in the original test (r = 0.80 to 0.91). The calculated total peritoneal pore area increased in absolute terms, decreased with body size when standardized to weight, and was independent of body size when normalized to body surface area. The body size-normalized fluid reabsorption rate was slightly increased in young infants compared to older children or adults. CONCLUSIONS: The PDC test permits to model peritoneal solute and water transport with remarkable precision in children of all age groups. While the peritoneal pore area is a linear function of body surface area, fluid reabsorption appears to be slightly increased in young infants.

Adolescent↗
PubMed1998

Design and implementation of a patient classification system for rehabilitation nursing.

Development of a prototype patient classification (PCS) instrument designed specifically for rehabilitation patients is the focus of this article. The process of instrument development is discussed, as well as strategies used in implementing the PCS. These strategies include: staff education, management support, data collection, data analysis--including the development of supporting information systems, and ongoing use of the rehabilitation PCS. Changes engendered by implementation of the PCS also are discussed.

Chicago↗
PubMed1998

[Medical principles of thromboembolism prevention].

Since thromboembolic complications have been described to be one of the most frequent complications following surgery, a correct indication for prophylaxis is of great clinical importance. This requires comprehensive knowledge about the general thrombosis risk of various patient populations, experience in the assessment of the individual thrombosis risk, understanding of the mode of action of various prophylaxis modalities, and critical benefit/risk assessment when pharmacological agents are used. Patients with a moderate or high risk require medical prophylaxis with either unfractionated heparin, low molecular weight heparins, or oral anticoagulants unless there is too high a risk of bleeding. Mechanical methods such as physical exercise and early mobilisation of the patient remain the basic measurements which can be supplemented by graduated pressure stockings.

Adult↗
PubMed1997

Effect of glycoprotein IIb/IIIa antagonists on the HIT serum induced activation of platelets.

Heparin-induced thrombocytopenia is an increasingly common side effect associated with heparin usage. In the more severe manifestation of the syndrome, patients can develop thrombosis; a 10% mortality is associated with heparin induced thrombocytopenia. To date, the therapeutic options for patients with heparin-induced thrombocytopenia are limited. Glycoprotein IIb/IIIa inhibitors have been shown to block platelet aggregation induced by a wide variety of agonists. The ability of antibody and synthetic small molecule inhibitors of glycoprotein IIb/IIIa to block in vitro activation and aggregation of platelets in response to heparin-induced thrombocytopenia positive serum/heparin was examined using flow cytometry, platelet aggregometry, and luminescence aggregometry. Abciximab, YM 337, and SR 121566A were each found to inhibit platelet microparticle formation and P-selectin expression in whole blood, in response to heparin-induced thrombocytopenia positive serum/heparin. In a platelet rich plasma system, the platelet aggregation response was inhibited by all three agents. The IC50 for inhibition of heparin-induced thrombocytopenia positive serum/heparin induced platelet aggregation by SR 121566A was 18 nM, a concentration which was 4 to 8 fold lower than that observed for collagen and arachidonic acid induced aggregation. Adenosine triphosphate release from activated platelets, as measured by luminescence aggregometry, was concentration-dependently inhibited by SR 121566A. These results suggest that glycoprotein Ilb/IIIa inhibitors may be beneficial in the management of heparin-induced thrombocytopenia and warrant further investigation.

Benzylamines↗
PubMed1997

Evidence for inhibition of MyEF-2 binding to MBP promoter by MEF-1/Pur alpha.

Myelin basic protein (MBP) is a major component of the myelin sheath whose production is developmentally controlled during myelinogenesis. Earlier studies have indicated that programmed expression of the MBP gene is regulated at the level of transcription. Evidently, the MB1 regulatory motif located between nucleotides -14 to -50 plays an important role in transcription of the MBP promoter in both in vivo systems. The MB1 element contains binding sites for the activator protein MEF-1/Pur alpha and the repressor protein MyEF-2. In this study we use bandshift assays with purified MEF-1/Pur alpha and MyEF-2 and demonstrate that binding of MyEF-2 to its target sequence is inhibited by MEF-1/Pur alpha. Under similar conditions, MyEF-2 enhances the association of MEF-1/Pur alpha with MB1 DNA. MEF-1/Pur alpha binds to MB1 in mono- and dimeric forms. Inclusion of MyEF-2 in the binding reaction increases the dimeric association of MEF-1/Pur alpha with the MB1 sequence. The use of MEF-1/Pur alpha variants in the bandshift assay suggests that two distinct regions of this protein may be involved in its binding to the MB1 sequences, and its ability to block MyEF-2 interaction with the MB1 sequence. Based on previous studies on the programmed expression of MEF-1/Pur alpha and MyEF-2 during myelination and the current findings on their interplay for binding to the MB1 motif, a model is proposed for their involvement in transcriptional regulation of the MBP gene during the course of brain development.

Adenosine Triphosphate↗
PubMed1997

A general role for c-Fos in cellular protection against DNA-damaging carcinogens and cytostatic drugs.

One of the earliest responses of cells upon exposure to DNA-damaging agents is the induction of c-fos. To elucidate the biological role of Fos expression, we analyzed cells deficient in c-Fos upon treatment with different DNA-damaging agents, including carcinogens and antineoplastic drugs. We show that cells lacking c-Fos are hypersensitive with regard to reproductive cell death, apoptosis, and chromosomal breakage after treatment with agents inducing methylation lesions, bulky adducts, or crosslinks in DNA. They were not significantly hypersensitive to ionizing radiation. The activities of various repair enzymes and glutathione S-transferase and the level of proliferating cell nuclear antigen were not altered in c-fos-/- fibroblasts. Furthermore, the cells were able to remove the main methylation lesions from DNA. c-Fos-deficient cells exhibited a more severe mutagen-induced block to DNA replication and were compromised in the abolition of replication blockage. The data provide compelling evidence that c-Fos/activator protein-1 plays a decisive and general role in cellular defense against genotoxic agents, which require DNA replication to induce chromosomal instability. They are consistent with the hypothesis that impaired recovery from DNA replication inhibition upon mutagen exposure is causally involved in c-fos-/- hypersensitivity.

4-Nitroquinoline-1-oxide↗
PubMed1997

Efficacy and safety of a low-molecular-weight heparin and standard unfractionated heparin for prophylaxis of postoperative venous thromboembolism: European multicenter trial.

A randomized, double-blind multicenter trial was performed to compare the safety and efficacy of a new low-molecular-weight heparin (LMWH) (LU 47311, Clivarine) and standard unfractionated heparin for the prophylaxis of postoperative venous thromboembolism. Altogether 1351 patients scheduled to undergo abdominal surgery were included. Main outcome measures included the incidence of thromboembolic events (deep vein thrombosis, pulmonary embolism, or both) and bleeding complications, including wound hematoma. A total of 655 patients received 1750 anti-Xa IU of LMWH plus a placebo injection daily; 677 patients received 5000 IU of unfractionated heparin (UFH) twice a day. Both drugs were found to be equally effective, as 4.7% of patients in the LMWH group and 4.3% in the UFH group developed postoperative thromboembolic complications. However, the incidence of bleeding complications was significantly reduced in the LMWH group: 55 (8.3%) patients in the LMWH group and 80 (11.8%) in the UFH group developed bleeding complications, a relative risk (RR) of 0.70 (95% CI 0.51-0.97;p = 0.03); wound hematoma occurred in 29 (4.4%) of the LMWH group compared with 55 (7.7%) in those in the UFH group for an RR of 0.57 (95% CI 0.37-0.88;p = 0.01). This study confirmed that a very low dose of 1750 anti-Xa IU daily of this new LMWH is as effective as 10,000 IU of UFH for preventing postoperative deep vein thrombosis. At this dose its administration is associated with a significant reduction in the risk of bleeding including wound hematoma.

Adult↗
PubMed1997

Divalproex: a possible treatment alternative for demented, elderly aggressive patients.

Elderly, demented people often exhibit behavioral dyscontrol. Divalproex appears to be safe and effective in the management of this presentation. Twelve cases treated with divalproex all responded with improved emotional control. Patients became less verbally and physically disruptive and much more socially appropriate. Divalproex was well tolerated in this population with none of the subjects experiencing significant medicinal side effects. This uncontrolled report suggests that divalproex should be considered as a pharmacotherapy for aggressivity in cognitively impaired, elderly people.

Aged↗
PubMed1997

[Epilepsy].

Explore the source record for details and available documents.

Child↗
PubMed1997

Pharmacodynamic and safety results of PEG-Hirudin in healthy volunteers.

PEG-Hirudin, a chemically defined conjugate of recombinant hirudin and two molecules of polyethylene glycol (PEG)-5000 is a highly selective direct thrombin inhibitor with a significantly longer duration of action than non-conjugated recombinant hirudin permitting once daily subcutaneous administration. A series of placebo-controlled, randomized, Phase I clinical trials were conducted in 75 healthy volunteers to investigate the anticoagulant effects, safety and pharmacodynamics of PEG-Hirudin when administered intravenously as a bolus injection, infusion, and subcutaneously. After single i.v. injections of various doses of PEG-Hirudin (0.03-0.3 mg/kg) dose-dependent increases in anti-IIa activity and APTT were observed. Four hours after injection of 0.3 mg/kg, mean plasma concentration expressed in terms of anti-IIa activity was still 0.89 micrograms/ml, corresponding to a 1.8-fold prolongation of APTT. Continuous intravenous infusions of 0.01 and 0.02 mg/kg/h PEG-Hirudin resulted in maximum anti-IIa activities of 0.42 micrograms/ml and 0.77 micrograms/ml, respectively, at the end of a six-hour infusion period without having reached steady state at this time. After termination of the infusion, anticoagulant activity displayed an immediate exponential decrease. The anticoagulant activities of single subcutaneous doses of 0.05 to 0.6 mg/kg were studied in a further series of investigations and slow increases and prolonged durations of anti-IIa activity and APTT prolongation were found. Repeated, once daily subcutaneous administrations of 0.2 to 0.4 mg/kg for five days resulted in dose-dependent prolongations of APTT and increases in anti-IIa activity without completely reaching steady state conditions. In a further study, 0.3 mg/kg of PEG-Hirudin was given as an i.v. bolus injection followed by three repeated single daily s.c. injections. In this trial, the APTT was shorter than expected from previous studies; therefore, a direct comparison of various APTT reagents was made in the intravenous infusion trial. Of the APTT reagents tested, BioMérieux Silimat and IL-ellagic acid proved to be the most sensitive to PEG-Hirudin. The hirudin derivative PEG-Hirudin was tolerated very well without immuno-allergic side effects. In view of the significantly prolonged anticoagulant efficacy in comparison to non-conjugated r-hirudin, PEG-Hirudin is a promising compound especially for repeated once daily subcutaneous administration.

Adult↗
PubMed1997

[Calcium metabolism after thyroidectomy with modified radical neck dissection and parathyroid gland autotransplantation].

The issue of parathyroid autotransplantation in oncologic thyroid surgery is discussed controversially. In a series of 15 patients who underwent bilateral modified radical neck dissection for thyroid malignancy, parathyroid autotransplantation was carried out. Six months after surgery only one patient was hypoparathyroid, requiring permanent medication, thus autotransplantation is a safe procedure for the prevention of accidental hypoparathyroidism.

Adult↗