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Biomedical subjects

B Bauer

Publications and source records attributed to B Bauer.

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

A retrospective long-term analysis of the epidemiology and features of drug-induced headache.

Drug-induced headache is well known to result from the abuse of compounds taken for the treatment of primary headache. The features of drug-induced headache depend on various features including the availability of drugs, the regional health system, and psychogenic factors of the patients. We performed a retrospective study on a series of 257 consecutive German patients presenting with drug-induced headache during the period 1983-1996. Our aim study was to evaluate the demographic features, the frequency of various drugs used, in particular of ergotamine derivates, and changes in these features during the study period. The frequency of drug-induced headache among all headache patients was 8%, with a female preponderance of 81%. Drug-induced headache occurred in all age groups, predominantly in migraine patients (35%). The mean number of substances used was 2.7, mainly, acetaminophen (47.9%), ergotamine tartrate (45%), and combined analgesics (56%). We did not find a significant difference between the associations with ergotamine tartrate and dihydroergotamine, although the latter was taken less frequently. Comparing the early and late years of our study period, there were no changes in the frequency of drug-induced headache (8% versus 7%), although changes in the frequency of some drugs changed (barbiturates, ergotamine tartrate, and codeine intake decreased whereas nonsteroidal anti-inflationary drugs, combined analgesics, and sumatriptan intake increased). Our data suggest that changes in drug availability and the introduction of classification criteria and treatment recommendations did not have a major impact on the frequency of drug-induced headache.

Adult↗
PubMed1999

Convex hull test of the linear separability hypothesis in visual search.

Visual search for a colour target in distractors of two other colours is dramatically affected by the configuration of the colours in CIE (x, y) space. To a first approximation, search is difficult when a target's chromaticity falls directly between (i.e. is not linearly separable from) two distractor chromaticities, otherwise search is easy (D'Zmura [1991, Vision Research, 31, 951-966]; Bauer, Jolicoeur, & Cowan [1996a, Vision Research, 36, 1439-1466]; Bauer, Jolicoeur, & Cowan [1996b, Perception, 25, 1282-1294]). In this paper, we demonstrate that the linear separability effect transcends the two distractor case. Placing a target colour inside the convex hull defined by a set of distractors hindered search performance compared with a target placed outside the convex hull. This is true whether the target was linearly separable in chromaticity only (Experiments 1 and 2), or in a combination of luminance and chromaticity (Experiments 3 and 4).

Adult↗
PubMed1999

Physicians' decision-making in incompetent elderly patients: a comparative study between Austria, Germany (East, West), and Sweden.

In order to investigate to what extent various determinants in the decision-making process for the treatment of severely ill incompetent patients are influenced by cultural and sociopolitical factors, 540 physicians in Austria, Germany (East and West), and Sweden, countries representing different healthcare systems, were surveyed using a self-administered questionnaire. It provided three case vignettes with different levels of information about the patient's treatment wishes in case of incompetence in a life-threatening situation. We found a general trend to a lower level of treatment in line with the patient's wishes when the information provided was more detailed. Remarkably, a substantial number of doctors did not comply with the patient's wishes. Ethical concerns and patient's wishes appeared as the most important factors whereas religious beliefs of the physician and hospital costs scored lowest. Because of the variability of treatment decisions and the importance of various factors determining the decision-making, an advance directive may be a feasible way of reducing the number of conflicts in critical situations. We recommend that ethical issues of clinical practice should be emphasized in the medical curriculum and in the training of physicians.

Adult↗
PubMed1999

Improvement of cattle productivity through rapid alleviation of African animal trypanosomosis by integrated disease management practices in the agropastoral zone of Yalé, Burkina Faso.

Investigations to identify the causes of high mortalities in cattle in the agropastoral zone (ZAP) of Yalé started in March 1993. African animal trypanosomosis (AAT) was found to be the major constraint, with incidence rates exceeding 30%, justifying a tsetse control programme, which started in March/ April 1994. The treatment of all cattle at bimonthly intervals with deltamethrin 1% pour on and the display of 1500 insecticide impregnated targets during the 6 months of the dry season each year helped to reduce the tsetse populations (Glossina tachinoides and G. morsitans submorsitans) by more than 90%. In less than 7 months, the incidence of AAT dropped below 5% and remained there throughout the intervention until June 1996, in spite of an increase to 3 months in the interval between the treatments. Mean PCV values increased significantly from 26.5-30.9%, before, to 30.7-36.3% during the intervention. The improvement in the overall health resulted in a resumption in fertility and milk production, allowing the sale of dairy products in Léo, thus creating a gross income of about $US3/day for the Fulani women.

Animals↗
PubMed1999

[Decisions and attitudes of nurses caring for severely ill elderly patients: a culture-comparing study].

Results of a comparative investigation in Swedish and German nurses are presented. Based on a case-vignette with three levels of available information about patient wishes the subjects were asked about their decisions. Generally, the Swedish nurses showed a tendency towards less aggressive treatment-options and to perform less frequent cardio-pulmonary resuscitation (CPR) against the patient written will compared with the Germans. The compliance with patient wishes among nurses from both countries was related with the valuation of the patient directive as a useful tool in their decision-making process. Furthermore, the "level of dementia" emerged as a significant predictor of the treatment decision in both groups. The results point to the necessity of continuous education and training of nurses aiming at the issues of ethical attitudes and coping with ethically problematic situations in the treatment of the elderly in order to improve patient autonomy.

Aged↗
PubMed1999

Photodynamic therapy utilising topical delta-aminolevulinic acid in non-melanoma skin malignancies of the eyelid and the periocular skin.

PURPOSE: Photodynamic therapy utilising delta-aminolevulinic acid-induced protoporphyrin IX photosensitisation, was evaluated as a treatment modality for nonmelanoma skin malignancies of the eyelids and the periocular skin. METHODS: Photodynamic therapy with laser light at 635 nm was performed in 13 patients with 19 basal cell carcinomas and one patient with 3 cutaneous T-cell lymphoma lesions. A topical application regimen was used and in median 3 treatment sessions were given to each lesion. RESULTS: A visually judged complete response was achieved in 42% (8/19) of the basal cell carcinomas and in 100% of the T-cell lymphoma lesions (3/3). Partial tumour response was seen in 42% (8/19) and no response in 16% (3/19) of the basal cell carcinomas. The median follow-up time was 12 months. No, or very little scarring and loss of cilia were induced by the treatment. CONCLUSION: Photodynamic therapy with delta-aminolevulinic acid can eradicate eye-close non-melanoma skin malignancies without compromising the function of the eyelids. Further development of the method is needed to reach the same cure rates as those of the conventional treatment modalities.

Administration, Topical↗
PubMed1999

Activated protein C resistance and anticoagulant proteins in young adults with central retinal vein occlusion.

BACKGROUND: Central retinal vein occlusion is a disease that is most common in old people, and often associated with atherosclerosis, hypertension, diabetes or glaucoma. Since these diseases are much less evident in young people, we wanted to investigate the prevalence of disorders in the most common anticoagulant proteins in a group of young patients with central retinal vein occlusion. METHODS: 37 consecutive patients younger than 50 years and with a history of central retinal vein occlusion, were analysed for deficiencies of natural inhibitors of coagulation (protein C, S, and antithrombin III), plasminogen, resistance to activated protein C, and the presence of anticardiolipin or lupus anticoagulants. RESULTS: Anticoagulant protein deficiencies were found in 4 patients (11%) and activated protein C resistance in 7 patients (19%). Anticardiolipin or lupus anticoagulants were not found in the patients. CONCLUSION: Activated protein C resistance and anticoagulant protein deficiencies seem to be important factors to the etiology to central retinal vein occlusion in young patients.

Activated Protein C Resistance↗
PubMed1999

Drug-induced headache: long-term results of stationary versus ambulatory withdrawal therapy.

Drug-induced headache is a well-known complication of the treatment of primary headache disorders, and its successful management is only possible by withdrawal therapy. However, it is unknown whether ambulatory or stationary withdrawal is the therapy preferred. We conducted a prospective study on the outcome of stationary versus ambulatory withdrawal therapy in patients with drug-induced headache according to the International Headache Society criteria. Out of 257 patients with the diagnosis of drug-induced headache during the study period, 101 patients (41 after ambulatory and 60 after stationary withdrawal therapy) could be followed up for 5.9 +/- 4.0 years. The total relapse rate after successful withdrawal therapy was 20.8% (14.6% after ambulatory and 25.0% after stationary withdrawal therapy, p < 0.2). The main risk factors for a relapse were male sex (OR = 3.9, CI = 1.3-11.6), intake of combined analgesic drugs (OR = 3.8, CI = 1.4-10.3), administration of naturopathy (OR = 6.0, CI = 1.2-29.3), and a trend to tension-type headache as the primary headache disorder (OR = 1.9, CI = 0.6-53.0). Our data suggest that neither the method of withdrawal therapy nor the kind of analgesic and other antimigraine drugs has a major impact on the long-term result after successful withdrawal therapy. Patients with risk factors according to our findings should be informed and monitored regularly, and combined drugs should be avoided. Furthermore, our data suggest that there is a need for research on individual psychological and behavioral risk factors for relapse after successful withdrawal therapy in drug-induced headache.

Adult↗
PubMed1999

Novel membrane-targeted ERK1 and ERK2 chimeras which act as dominant negative, isotype-specific mitogen-activated protein kinase inhibitors of Ras-Raf-mediated transcriptional activation of c-fos in NIH 3T3 cells.

Expression of constructs encoding fusion proteins of ERK1 and ERK2 containing a C-terminal farnesylation motif (CAAX) is predominantly localized at the cell membrane and was activated by coexpression of constitutively active Ha-RasL61 and epidermal growth factor. Both fusion proteins significantly inhibit the transcriptional activation of a c-fos-chloramphenicol acetyltransferase reporter induced by RasL61, constitutively active MEK1, or constitutively active RafBXB. The corresponding SAAX chimeras or overexpression of the wild-type ERKs did not interfere with the transcriptional activation of c-fos. The inhibition of the Ras-mediated c-fos induction by ERK2-CAAX can in part be rescued by coexpression of a wild-type ERK2 but not by wild-type ERK1. We find that ERK1-CAAX acts in the same fashion, indicating that mitogen-activated protein kinase (MAPK)-CAAX chimeras interact in an isotype-specific manner. It is demonstrated that both ERK1-CAAX and ERK2-CAAX associate with the corresponding endogenous ERKs, which explains the isotype-specific inhibitory effects of the ERK-CAAX chimeras. Evidence is presented that expression of ERK-CAAX fusion proteins inhibits the nuclear translocation of the corresponding endogenous ERKs. Disruption of MAPK translocation by membrane targeting provides additional, independent proof that nuclear translocation of ERKs is essential for the transcriptional activation of c-fos.

3T3 Cells↗
PubMed1999

Antihypertensive profiles with ascending dose combinations of ramipril and felodipine ER.

The aim of the study was to identify the most appropriate dosage combination of ramipril and felodipine ER (an extended release tablet) for mild-to-moderate hypertension. Hypertensive patients (N = 507) with supinediastolic blood pressure (DBP) values between 100-115 mm Hg were included in a randomized, multicenter, double-blind study of 3x4 factorial design with a 2-4 week single-blind, placebo run-in and 6 week active treatment phase. The patients were randomized to 12 groups: placebo, ramipril (2.5, 5, 10 mg), felodipine ER (5, 10 mg), or ramipril-felodipine ER combinations (2.5/5 mg, 2.5/10 mg, 5/5 mg, 5/10 mg, 10/5 mg, 10/10 mg). Although the greatest reductions in blood pressure were observed with ramipril-felodipine ER (10/10 mg), consideration of the antihypertensive efficacy and safety factors suggest that the ramipril-felodipine ER (5/5 mg) combination has the best efficacy/tolerability ratio of the combinations tested. The incidence of adverse events with ramipril-felodipine ER combination therapy was similar to that with felodipine ER monotherapy, but peripheral edema, tachycardia and vasodilatation occurred less frequently with ramipril-felodipine ER (5/5 mg) combination than with felodipine ER monotherapy. The combination of ramipril-felodipine ER (5/5 mg) can be considered to be the most suitable option for hypertensive patients with an inadequate response to either of the monocomponents.

Adult↗
PubMed1998

Structure determination of the Ras-binding domain of the Ral-specific guanine nucleotide exchange factor Rlf.

Ral-specific guanine nucleotide exchange factors RalGDS, Rgl, and Rlf have been suggested to function as intermediates between Ras and Ral pathways by being able to bind Ras proteins through their C-terminal Ras-binding domains (RBD). The RBDs of RalGDS and of the Ser/Thr kinase c-Raf-1 have been shown to have the same tertiary structure. In contrast to the RBDs of Raf and RalGDS, which bind either Ras or Rap with high affinity, Rlf-RBD has a similar affinity for both GTP-binding proteins. To be able to compare these RBDs on a structural level, we have solved the three-dimensional structure of Rlf-RBD by NMR spectroscopy. The overall tertiary structure of Rlf-RBD shows the betabetaalphabetabetaalphabeta-fold of the ubiquitin superfamily and is very similar to that of RalGDS-RBD. The binding interface of Rlf-RBD to Ras was mapped using chemical shift analysis and indicated a binding mode similar to that in the case of Rap.Raf-RBD. However, comparison of the putatively interacting regions revealed structural differences which are proposed to be responsible for the different substrate affinities of Rlf-, RalGDS-, and Raf-RBD.

Amino Acid Sequence↗
PubMed1998

Specific inhibition of phorbol ester-stimulated phospholipase D by Clostridium sordellii lethal toxin and Clostridium difficile toxin B-1470 in HEK-293 cells. Restoration by Ral GTPases.

Activation of m3 muscarinic acetylcholine receptor (mAChR), stably expressed in human embryonic kidney (HEK)-293 cells, leads to phospholipase D (PLD) stimulation, a process apparently involving Rho GTPases, as shown by studies with Clostridium botulinum C3 exoenzyme and Clostridium difficile toxin B (TcdB). Direct activation of protein kinase C (PKC) by phorbol esters, such as phorbol 12-myristate 13-acetate (PMA), also induces PLD stimulation, which is additive to the mAChR action and which is only poorly sensitive to inactivation of Rho proteins by TcdB. To study whether Ras-like GTPases are involved in PLD regulation, we studied the effects of the TcdB variant TcdB-1470 and Clostridium sordellii lethal toxin (TcsL), known to inactivate Rac and some members of the Ras protein family, on PLD activities. TcdB-1470 and TcsL did not affect basal PLD activity and PLD stimulation by mAChR or direct G protein activation. In contrast, PMA-induced PLD stimulation was inhibited by TcdB-1470 and TcsL in a time- and concentration-dependent manner, without alteration in immunologically detectable PKC isozyme levels. In membranes of HEK-293 cells pretreated with TcdB-1470 or TcsL, basal and stable GTP analog-stimulated PLD activities measured with exogenous phosphatidylcholine, in the presence or absence of phosphatidylinositol 4,5-bisphosphate, were not altered. In contrast, pretreatment with TcdB-1470 and TcsL, but not TcdB, strongly reduced PMA-stimulated PLD activity. The addition of recombinant Rac1, serving as glucosylation substrate for TcdB, TcsL, and TcdB-1470, did not restore PLD stimulation by PMA. Furthermore, PMA-stimulated PLD activity, suppressed by prior treatment with TcdB-1470 or TcsL, was not rescued by the addition of recombinant Ras (RasG12V) or Rap proteins, acting as glucosylation substrates for TcsL only (Ras) or TcdB-1470 and TcsL (Rap). In contrast, the addition of recombinant Ral proteins (RalA and RalB), glucosylation substrates for TscL and TcdB-1470, but not for TcdB, to membranes of TcdB-1470- or TcsL-treated cells fully restored PLD stimulation by PMA without altering the strict MgATP dependence of PMA-induced PLD stimulation. RalA-mediated restoration of PMA-stimulated PLD activity in membranes of TcsL-treated cells was not enhanced by coaddition of RasG12V. In conclusion, the data presented indicate that TcdB-1470 and TcsL selectively interfere with phorbol ester stimulation of PLD and suggest an essential role of Ral proteins in PKC signaling to PLD in HEK-293 cells.

3T3 Cells↗
PubMed1998

Cone b-wave implicit time as an early predictor of rubeosis in central retinal vein occlusion.

PURPOSE: To investigate the predictive value of the cone b-wave implicit time in the 30-Hz flicker electroretinogram for rubeosis in the acute phase of central retinal vein occlusion. METHODS: In a prospective study, 25 patients (25 eyes) with a central retinal vein occlusion of less than 14 days' duration were examined with electroretinography and followed up for a minimum of 18 months. RESULTS: The cone b-wave implicit time in the eyes that developed rubeosis (n = 11) was more than 37.1 milliseconds and in the eyes that did not develop rubeosis (n = 14), less than 37 milliseconds (P < .00001). CONCLUSION: The cone b-wave implicit time in the 30-Hz flicker electroretinogram is a good predictor of rubeosis at an early stage in eyes with central retinal vein occlusion.

Acute Disease↗
PubMed1998

Analysis of genomic rearrangement and subsequent gene deletion of the attenuated Orf virus strain D1701.

The orf virus (OV) strain D1701 belongs to the genetically heterogenous parapoxvirus (PPV) genus of the family Poxviridae. The attenuated OV D1701 has been licensed as a live vaccine against contagious ecthyma in sheep. Detailed knowledge on the genetic structure and organization of this PPV vaccine strain is an important prerequisite to reveal possible genetic mechanisms of PPV attenuation. The present study demonstrates a genomic map of the approximately 158 kbp DNA of OV D1701 established by hybridization studies of cloned restriction fragments covering the complete viral genome. The results show an enlargement of the inverted terminal repeats (ITR) to up to 18 kbp due to recombination between nonhomologous sequences during cell culture adaptation. DNA sequencing of the region adjacent to the ITR junction revealed the absence of one open reading frame designated E2L. In contrast to a transposition-deletion variant of the New Zealand OV strain NZ2 (Fleming et al., 1995) the two genes E3L (a homologue of dUTPase) and G1L neighbouring E2L are retained in OV D1701. DNA and RNA analyses proved the presence of E2L gene in wild-type OV isolated directly from scab material. The data presented indicate that the E2L gene is nonessential for virus replication in vitro and in vivo, and may represent one important viral gene in determining virulence and pathogenesis of OV.

Amino Acid Sequence↗
PubMed1998

Fluorescein angiography versus ERG for predicting the prognosis in central retinal vein occlusion.

PURPOSE: It is not easy to predict which patients with a central retinal vein occlusion will develop rubeosis and which will not. We have compared two methods for doing so, fluorescein angiography and full-field electroretinogram (ERG). Our aim was to improve our possibilities for predicting rubeosis in patients with central vein occlusion. METHODS: 32 patients with a central retinal vein occlusion with a duration of less than 14 days were included in the study. Fluorescein angiography and ERG were performed in all patients. The fluorescein angiograms were studied by two independent examiners in a masked mode. The patients were then followed for at least one year. RESULTS: Development of rubeosis in patients with central retinal vein occlusion could be predicted by fluorescein angiography in 82% of the patients and with ERG in 94% of the patients. The non-ischemic central retinal vein occlusions were identified in 62% by fluorescein angiography and in 100% with ERG. Fluorescein angiography misjudged 9 patients 28%, whereas ERG only misjudged 1 patient, 3%. CONCLUSION: ERG seems to be a better method for predicting the prognosis in central retinal vein occlusion than fluorescein angiography.

Adult↗
PubMed1998

Raltitrexed (Tomudex): an alternative drug for patients with colorectal cancer and 5-fluorouracil associated cardiotoxicity.

Two patients with proven 5-fluorouracil (5-FU)-associated cardiotoxicity were treated with the specific thymidylate synthase inhibitor raltitrexed safely, without evidence of cardiotoxicity. Raltitrexed might be an alternative for patients with advanced colorectal cancer and 5-FU-associated cardiotoxicity. 5-FU cardiotoxicity is not due to the antineoplastic mechanisms via thymidilate synthase.

Adenocarcinoma↗