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A Bader

Publications and source records attributed to A Bader.

At least 19 recordsLinked to original sources
PubMed2006

The influence of medium composition and matrix on long-term cultivation of primary porcine and human hepatocytes.

The differentiated hepatocyte phenotype remains difficult to maintain in culture. The duration over which phenotypically stable hepatocytes can be cultured ranges from a couple of days to a few weeks. Shortcomings in medium formulation may be a factor in this lack of success. We have investigated effects of medium formulation on primary porcine and human hepatocyte cultures. We tested seven culture medium compositions (DMEM, ExCell 400, HepatoZYME-SFM, L-15 Leibovitz, SF-3, Waymouth, and Williams' E) and the effects of serum, fibronectin and biomatrix in a sandwich culture configuration. Albumin, urea, cholesterol, GOT, GPT, LDH and triglyceride concentrations were measured over 14 days. For both human and porcine cultures, the best results were obtained with SF-3 medium. Cells cultivated with Williams' E medium and FCS had good morphology and synthetic function during the first days of culture. However, continued addition of serum, was associated with a subsequent loss of differentiated phenotype. Addition of fibronectin was associated with improved function in cultures maintained in SF-3 medium whilst biomatrix had no effect. In contrast, addition of fibronectin did not influence cultures maintained in Williams' E medium, but cultures with biomatrix were associated with improved function at longer time points.

Animals↗
PubMed2006

New polyhydroxylated triterpenes and anti-inflammatory activity of Salvia hierosolymitana.

Salvia hierosolymitana (Lamiaceae) leaves were investigated for their topical anti-inflammatory properties following a bioassay-guided fractionation. The chloroform extract showed a strong inhibition of the Croton oil-induced ear oedema in mice, comparable to that of indomethacin. Phytochemical and pharmacological investigations of this extract led to the isolation of eight anti-inflammatory polyhydroxylated triterpenes of the ursane and oleanane series. Four of them are new compounds, whose structures were elucidated by NMR and mass spectroscopy as 3beta, 6alpha,23-trihydroxyurs-12,19(29)-dien-28-oic acid, 23-( TRANS-P-coumaroyloxy)-3beta, 6alpha,30-trihydroxyurs-12-en-28-oic acid, 2alpha,3beta-dihydroxyolean-28-oic acid and 24-nor-2alpha,3beta-dihydroxyolean-4(23),12-ene.

Animals↗
PubMed2006

Treatment of condylomata acuminata with pegylated interferon alfa-2b in HIV-infected patients.

BACKGROUND: Interferon in a variety of topical, interlesional, and parenteral preparations has been used for condylomata acuminata (CA) in HIV negative patients. - STUDY GOALS: This open trial was initiated to determine the safety and efficacy of a new formulation of interferon, pegylated interferon-alpha2b (PEG-IFN, PegIntron in the treatment of recalcitrant CA in patients with HIV infection. - STUDY DESIGN: 22 HIV-1 infected patients in virologic steady state with clinically demonstrable anogenital CA were enrolled in this study (treatment group, n=12; control group, n=10). Patients in the treatment group received 80 microg PEG-IFN s.c. once a week for 24 weeks. Follow-up period was 6 month. The effects were assessed by a clinical scoring system (complete response; major response; minor response; stable disease; progression of disease). - RESULTS: 2 patients did not finish the study because of side effects. PEG-IFN was well accepted and completed by ten patients. Four patients revealed complete response, four patients had major response and two had minor response after PEG-IFN. In the control group, all patients showed progression of CA during the 24 weeks of this study (p < 0.001). 7/10 patients of the treatment group and 8/10 patients of the control received HAART. - While the differences of CD4 cell counts between treatment group and control group were not significant (increase of the mean CD4 cell count in the treatment group was 31.5 (75.33 without patient 1 with leucopenia under ribavirine), in the control group 69.75 CD4 cells), the HIV RNA decline in the PEG-IFN group was impressive (0.74 log subset10). Biological side effects of PEG-IFN treatment included flu-like symptoms, fatigue, local reaction, leucopenia, and increase of AST. This result makes an educated guess that PEG-IFN enhances the benefit of HAART. - CONCLUSION: PEG-IFN is an effective and safe therapy option in HIV infected individuals with CA with concomitant positive effects on the suppression of HIV-1 replication and CD4 cell count. It might be considered as an alternative in patients that have failed to standard therapies of CA and - at the same time -could improve the benefit of HAART to a great extent. This last hypothesis needs further research.

Adult↗
PubMed2006

Biotransformation of cyclosporin in primary rat, porcine and human liver cell co-cultures.

The purpose of this study was to investigate the species-specific cyclosporin biotransformation in primary rat, human, and porcine liver cell cultures, and to investigate the suitability of a modified sandwich culture technique with non-purified liver cell co-cultures for drug metabolism studies. A sandwich culture was found to enhance hepatocellular metabolic activity and improve cellular morphology and ultrastructure. The cyclosporin metabolites AM9 and AM1 were formed in porcine and human liver cell sandwich co-cultures at levels corresponding to the respective in vivo situations. In contrast, metabolite profiles in rat hepatocytes were at variance with the in vivo situation. However, for all cell types, the overall metabolic activity was positively influenced by sandwich co-culture. The initial levels of albumin synthesis were higher in sandwich cultures than in those without matrix overlay. It is hypothesized that the sandwich culture system provides an improved microenvironment and is, therefore, an advantageous tool for in vitro studies of drug metabolism.

Animals↗
PubMed2005

FK506 enhances triptolide-induced down-regulation of cyclooxygenase-2, inducible nitric oxide synthase as well as their products PGE2 and NO in TNF-alpha-stimulated synovial fibroblasts from rheumatoid arthritic patients.

OBJECTIVE: To explore the effects of FK506 on the inhibition of cell proliferation and the expression of cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS) and their products PGE subset2 and NO in TNF-alpha-stimulated human rheumatoid arthritis synovial fibroblasts (RASF) treated with triptolide (TP), and to study the mechanisms involved when combining FK506 and TP in RA therapy. MATERIALS AND METHODS: RASF used in the experiments were obtained from the synovial tissue of patients with RA before being cultured. RASF were pretreated with FK506 (10 approximately 1000 nM) for 2 hours before being stimulated with TNF-alpha (20 ng/ml) in the presence or absence of TP (10 ng/ml) . RASF proliferation was determined by [3 supersetH]-TdR incorporation. Production of PGE subset2 and NO in culture supernatants of RASF was detected by competitive ELISA and enzymatic reduction of nitrate, respectively. Expressions of COX-2 and iNOS mRNA in RASF were analyzed by semi-quantitative RT-PCR. Expressions of COX-2 and iNOS protein were estimated by Western-blot and a cellular enzyme immunoassay. NFkappaB activity in whole-cell extract of treated RASF was also measured using an ELISA-based method. RESULTS: Neither FK506 nor TP at a lower concentration (10 ng/ml) affected TNF-alpha-induced COX-2 and iNOS expressions or PGE subset2 and NO productions in synovial cells. Combined treatment of FK506 and a lower concentration of TP (10 ng/ml) reduced both COX-2 and iNOS mRNA and protein expression, and correspondingly reduced PGE subset2 and NO produced by synovial fibroblasts. This effect was highly correlated with FK506 concentration (10 approximately 1000 nM). NFkappaB activity in TNF-alpha-stimulated synovial cells was suppressed more profoundly by FK506 plus TP (10 ng/ml) than by TP (10 ng/ml) alone. However, no change was observed regarding the inhibition of synovial cell proliferation after combined treatment of FK506 and TP. CONCLUSION: FK506 enhanced TP-mediated down-regulation of COX-2 and iNOS as well as their products PGE subset2 and NO in human TNF-alpha-stimulated RASF by more profoundly suppressing the activity of NFkappaB.

Arthritis, Rheumatoid↗
PubMed2005

Association of RANTES with the replication of severe acute respiratory syndrome coronavirus in THP-1 cells.

BACKGROUND: Severe acute respiratory syndrome (SARS) is a novel infectious disease which is characterized by an overaggressive immune response. Chemokines are important inflammatory mediators and regulate disease due to viral infection. In previous study, we found that SARS-CoV has the ability to replicate in mononuclear cells. In present work, we sought to characterize the replication of SARS-CoV at the presence of RANTES in THP-1 cells. METHODS: To determine whether RANTES play an role in the process of SARS, THP-1 cells were incubated with heat-inactivated SARS-CoV and ELISA was used to test RANTES levels in the supernatants; Then the effect of dexamethasone on the induced secretion was evaluated. Real-time PCR was used to investigate the effort of RANTES on the replication of SARS-CoV in vitro. Macrophages, induced by THP-1 cells, were used as cell model. FINDINGS: Inactive SARS-CoV could induce THP-1 cells secret RANTES and this increase effect could not be suppressed by DXM. RANTES itself could inhibit the replication of SARS-CoV in THP-1 cells when it was added into the culture before or at the same time with the virus; No inhibition effect was shown when RANTES were added into the culture after SARS-CoV infected the cells.

Animals↗
PubMed2005

Tempromandibular joint (TMJ) response to intra-articular dexamethasone injection following mechanical arthropathy: a histological study in rats.

The purpose of this study was to evaluate as well as to compare the effect of intra-articular versus intra-peritoneal injection of dexamethasone on synovitis induced by trauma to the rat's TMJ. Twenty-seven male Wister rats were included in the present study. Induced forced condylar hypermobility achieved through opening the rat's mouth manually 10 times for 10 consecutive days. Rats were randomized into three groups (3 rats in the control group, and 24 rats in both experimental groups). Group I (control group): Rats of this group were left without any treatment after induction of synovitis. Group II: Rats were injected with a single dose of 1.2 mg/kg dexamethasone intra-articularly (after 10 days). Group III: Rats were injected with a single intra-peritoneal injection of 1.2 mg/kg dexamethasone (after 10 days). Control rats were sacrificed at 6 weeks, while rats in Groups II and III were sacrificed at 1 and 6 weeks after drug injection, then joints were dissected and processed for histological study. The condylar head of the rats injected with intra-articular dexamethasone showed resorption with active osteoclastic activity, although the drug was given only once. This might be an alarming sign of the severe adverse effect(s) of the local injection of dexamethasone.

Animals↗
PubMed2005

Precision of intracellular calcium spike timing in primary rat hepatocytes.

Extracellular stimuli are often encoded in the frequency, amplitude and duration of spikes in the intracellular concentration of calcium ([Ca2+]i). However, the timing of individual [Ca2+]i-spikes in relation to the dynamics of an extracellular stimulus is still an open question. To address this question, we use a systems biology approach combining experimental and theoretical methods. Using computer simulations, we predict that more naturalistic pulsed stimuli generate precisely-timed [Ca2+]i-spikes in contrast to the application of constant stimuli of the same dose. These computational results are confirmed experimentally in single primary rat hepatocytes upon alpha1-adrenergic stimulation. Hormonal signalling in analogy to neuronal signalling thus has the potential to make use of temporal coding on the level of single cells. The [Ca2+]i-signalling cascade provides a first example for increasing the information capacity of an intracellular regulatory signal beyond the known coding mechanisms of amplitude (AM) and frequency modulation (FM).

Algorithms↗
PubMed2005

UVA1 and UVB irradiated skin investigated by optical coherence tomography in vivo: a preliminary study.

In histological studies, it has frequently been demonstrated that ultraviolet (UV) exposure, in particular UVB, can induce significant thickening of the viable epidermis and/or stratum corneum. Since skin biopsy alters the original skin morphology and always requires an iatrogenic trauma, we aimed to introduce optical coherence tomography (OCT) in vivo for the investigation of changes of epidermal thickness (ET) following UVA1 and UVB irradiation. Twelve healthy subjects received daily 60 J/cm2 of UVA1 and 1.5 minimal erythema doses UVB on their upper back over 3 consecutive days. Twenty-four hours after the last irradiation, OCT assessments were performed on UV exposed and adjacent nonirradiated control sites. Data of ET as expressed by comparison of the averaged A-scans differed significantly between nonirradiated (94.2 +/- 15.7 microm), UVA1 (105.4 +/- 12.8 microm) and UVB (125.7 +/- 22.1 microm) exposed sites. In comparison to the nonirradiated sites, UVA1 exposed skin showed significant (P = 0.022) increase of ET of 11% and UVB exposed sites a significant (P < 0.001) increase of 25%. ET of UVA1 and UVB exposed skin sites differed significantly (P =0.005). Our results obtained from OCT in vivo measurements confirm data of previous histological studies indicating that not only erythemogenic doses of UVB, but also suberythemogenic doses of UVA1 may have a significant impact on ET. OCT appears to be a promising bioengineering technique for photobiological studies. However, further studies are needed to establish its measurement precision and validity, and to investigate in vivo spectral dependence on UV induced skin changes such as skin thickening.

Adult↗
PubMed2005

Bioartificial bone grafting: Tarsal joint fusion in a dog using a bioartificial composite bone graft consisting of beta-tricalciumphosphate and platelet rich plasma--a case report.

Grafting of large bone defects caused by trauma or tumor resection still remains a problem to solve. In experimental studies as well as in human dentistry, osteoconduction and biodegradation of the beta-tricalciumphosphate Cerasorb as well as osteoinductive capabilities of platelet rich plasma have been proven. In case of luxation of the right tarsal joint, including a compressive fracture of the forth tarsal bone, the recommended use of autologous cancellous bone to support osseous fusion was replaced by the use of a bioartificial bone graft. Biodegradation of the bone graft was proven clinically and radiographically. Complete osseous fusion of the intertarsal joint occurred. The use of the beta-tricalciumphosphate Cerasorb in combination with platelet rich plasma to support a partial arthrodesis of the tarsal joint in a dog did not impede the healing process but led to full recovery of the patient, indicating that this concept of bioartificial bone grafting could support bone healing.

Animals↗
PubMed2004

Impact of amphotericin B on the cytochrome P450 system in HIV-infected patients.

OBJECTIVE: To investigate whether cytochrome P450-dependent enzymes are influenced by amphotericin B (Am-B) during the treatment of Candida oesophagitis in HIV-infected patients. METHODS: Twelve HIV-infected, antiretroviral-naive patients (CDC/WHO stage C3) with Candida oesophagitits were enrolled into a prospective clinical trial. The patients were treated with Am-B (0.4 mg/kg body weight) for two weeks. At baseline and after Am-B therapy the clearance of antipyrine and its metabolites were investigated by high-performance liquid chromatography. In addition, the urinary excretion of 6-beta-hydroxycortisol and 17-hydroxycorticosteroids was assessed by means of a radioimmunoassay. RESULTS: The following significant changes were observed after Am-B treatment (P < 0.01): increase of antipyrine half-life (12.4 h vs 16.8 h) and the area under the plasma concentration-time curve (27.9 mg min/ml vs 38.1 mg min/ml); decrease of the total body clearance (61.2 ml/min vs 43.7 ml/min); decrease of the renal clearance of antipyrine metabolites - norantipyrine (7.45 ml/min vs 5.31 ml/min), 4-hydroxyantipyrine (15.4 ml/min vs 10.3 ml/min), hydroxymethylantipyrine (4.31 ml/min vs 3.65 ml/min); decrease of urinary 6-beta-hydroxycortisol excretion (453 microg/24h vs 298 microg/24h) and the ratio of 6-beta-hydroycortisol to 17-hydroxycorticosteroids (8.8% vs 6.4%). CONCLUSIONS: Our data indicate that Am-B therapy has an inhibitory effect on cytochrome P450-dependent enzymes in HIV-infected patients. These results are of particular significance for HIV-infected patients who are concomitantly treated with drugs that are predominantly metabolised in the liver. A careful drug monitoring system seems advisable, especially for proteinase inhibitor experienced HIV-1-infected subjects.

17-Hydroxycorticosteroids↗
PubMed2004

The decision to forgo antiretroviral therapy in people living with HIV compliance as paternalism or partnership?

OBJECTIVE: The purpose of this study was to examine the self-reported reasons that people living with HIV (PLWH) provide to support their autonomous (i.e., against medical advice) decisions not to take, or to stop taking, highly active antiretroviral therapy (HAART). A further purpose of this study was to examine physicians' reactions to their patients' autonomous decisions and to examine physicians' conceptualization of compliance. DESIGN/METHODS: Semi structured interviews were conducted with 11 PLWH (5 male, 6 female) and their 8 HIV-care providers (4 male, 4 female). Interviews were analysed qualitatively using thematic coding. Patients also completed sociodemographic and medical information questionnaires. Interrater reliability was also calculated on patients' reasons supporting their decisions with coefficients ranging from .84 to 1.00 (all ps <.01). RESULTS: For all 11 patients, preservation of quality of life and critical attitudes toward allopathic medicine were identified as reasons supporting autonomous decisions to refuse HAART. In addition, 10 patients cited the prior experience of, or the anticipated fear of, side-effects as central to their decision. Nine patients articulated their preference for alternative medicine and five patients expressed moral objections as significant reasons underlying their decisions. Gender differences emerged in care providers' conceptualization of compliance. Female care providers tended to view compliance as a collaboration between patient and care provider whereas male physicians tended to view compliance more as the patients' capacity to adhere to the prescribed HAART-regimen. Physician response strategies to patients' autonomous decision to refuse HAART were characterized as coercive or not. Neither the physicians' conceptualization of compliance nor their response strategies were consistent with the patients' perspective. In contrast, the central component of the patients' decision making was the patients' subjective view of the benefit they would derive from HAART. CONCLUSIONS: The results of this study provide some initial evidence that health care providers integrate recommendations for HAART with patients concerns for their own quality of life and make these recommendations within the context of the patients' worldview. In addition, these results suggest that traditional views of compliance, that emphasize obedience to physician prescriptions, may be inadequate in this regard. Rather, these results suggest that a theory of compliance that is based upon collaboration between physician and patient will allow for a consideration of patients' subjective views, their worldview, and their health care beliefs.

Adult↗
PubMed2004

Ligand-gated channels in early mesencephalic neuronal precursors: immunocytochemical and electrophysiological analysis.

Neuronal precursors play an important role in potential regenerative therapeutic strategies in different neurodegenerative diseases, e.g. Parkinson's disease. To understand proliferation and differentiation of these cells in vitro and in vivo, it is important to characterize functional properties of neuronal precursors in detail. The aim of the present study was to analyse the electrophysiological characteristics of ligand-gated channels of neuronal precursors prepared from the rat ventral mesencephalon (VM) of embryonic stage 12.5 during their in vitro differentiation. For the experiments we used the patch-clamp technique in combination with a system for ultrafast solution exchange and immunocytochemistry. It could be shown that functional active AMPA-type glutamate as well as GABA(A) receptor channels are expressed at an early stage of neuronal development. In culture we observed excitatory as well as inhibitory postsynaptic currents (defined by their different kinetics) which correspond to the activation of AMPAergic and GABAergic receptor channels. Two populations of glutamate-activated currents could be differentiated by their different time course of desensitization whereas the time course of resensitization and deactivation was normally distributed in all cells. GABAergic currents could be blocked by bicuculline and their kinetics correspond to that of GABA(A) receptor channel currents. Summarizing the results, in the present study it was shown for the first time that neuronal embryonic precursors of the rat VM express both functional AMPA-type glutamate and functional GABA(A) receptor channels in vitro.

Animals↗
PubMed2003

[Do local nursing home inmates get appropriate medication?--comments on the quality of drug application in nursing homes].

BACKGROUND: Preparing prescribed drugs in unit dose systems for often multimorbid patients in nursing homes is a responsible and difficult task for the nursing personnel. The aim of this study was to increase the knowledge on the quality level of drug supply. METHOD: In a non-representative sample the local inspectorates for pharmacies in North Rhine-Westphalia compared the actually available drugs with the prescribed drugs documented in nursing homes. Participation was voluntary. RESULTS: In 50 % of the investigated nursing homes no medication error could be found. 30 percent of the observed cases showed only one error. In 20 percent the individual preparation of drugs in unit dose systems should be improved. Nursing homes with specific quality standards showed the least number of errors. Oral and not documented arrangements seem to be a common cause for avoidable errors.

Aged↗
PubMed2002

[Intersections of reconstructive surgery in the area of regenerative medicine].

Based on significant progress in biotechnology, "Regenerative Medicine" is evolving as a new discipline that could significantly change current therapeutic approaches. Medicine, stem cell biology, tissue engineering, nanotechnology, genomic research, material sciences, as well as system- and process-engineering come together to answer fundamental problems of human disease, including trauma and aging. The long-term goal is to create a profound knowledge of individualized therapy originating from nonbiological organ replacement, through hybridized systems, to fully biological implants and finally to human regenerative systems in vivo. Two model tissues, including heart valves and liver tissue are discussed in the context of in vivo and in vitro regeneration technologies. Extracellular matrix regulates tissue differentiation in at least three ways, including the biochemical composition of the matrix constituents, the 3-D organization or architecture, and via mechanical forces mediated to the cells by the matrix. The in vivo extracellular matrix constitutes a biopolymer which potentially plays a permissive role for tissue differentiation.

Animals↗