Dana Pfeiffer

Dana Pfeiffer
Simmons College · Graduate School of Social Work

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107
Publications
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1,329
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Publications

Publications (107)
Article
The epidermal growth factor (EGF) receptor and its various ligands (EGF, TGF-alpha, amphiregulin, heparin-binding (HB)-EGF, heregulin, betacellulin) seem to be involved in the growth regulation of intestinal mucosa and might be related to the development and progression of gastrointestinal tumors. However, few quantitative data investigating the im...
Article
The application of a quinoprotein glucose dehydrogenase modified thick-film sensor as label detector in a capillary immunoassay (CIA) for xenoestrogens is presented. The detection of the alkylphenols and their ethoxylates is based on the competition between the analyte and tracer molecules for the binding sites of anti-alkylphenol ethoxylate antibo...
Article
Full-text available
There is increasing evidence from animal experiments that mild hypothermia induced during or after cerebral ischemia might protect the immature brain from neuronal cell damage. However, the exact interrelation between the postischemic time delay and the degree of mild hypothermia by which to achieve neuroprotective effects on ischemic insults of di...
Article
Objective:There is increasing evidence from animal experiments that mild hypothermia induced during or after cerebral ischemia might protect the immature brain from neuronal cell damage. However, the exact interrelation between the postischemic time delay and the degree of mild hypothermia by which to achieve neuroprotective effects on ischemic ins...
Article
Full-text available
Asphyxia is one of the main causes of perinatal brain damage that can result in psychomotor deficits during later development. Recently lubeluzole, a new glutamate antagonist, was shown to improve clinical outcome considerably without any safety concerns in adults who had acute ischemic stroke. However, our preliminary experiments showed transient...
Article
Objective:Asphyxia is one of the main causes of perinatal brain damage that can result in psychomotor, deficits during later development, Recently lubeluzole, a new glutamate antagonist, was shown to improve clinical outcome considerably without any safety concerns in adults who had acute ischemic stroke. However, our preliminary experiments showed...
Article
Epidermal growth factor (EGF) and TGF-alpha play a central role in maintaining gastric mucosal integrity. Little is known about the regulative role of the four other widely expressed epidermal growth factor receptor ligands, heparin-binding EGF, amphiregulin, betacellulin and cripto in the gastric mucosa. Nineteen patients with Helicobacter pylori-...
Article
Full-text available
The aim of the present study was to clarify whether endotoxins [lipopolysaccharides (LPS)] have a toxic effect on fetal brain tissue after cerebral ischemia, while excluding their effect on the cardiovascular system. Experiments were therefore performed on hippocampal slices prepared from mature fetal guinea pigs. In particular, we studied the infl...
Article
Full-text available
Zusammenfassung In der vorliegenden Arbeit sollte die Bedeutung von Stickstoffmonoxid (NO) für den ischämiebedingten neuronalen Zelltod beim Feten unabhängig vom Herz-Kreislauf-System untersucht werden. Hierzu verwendeten wir ein hippokampales Gewebeschnittmodell. Als Marker für den neuronalen Zellschaden wählten wir die postischämische Beeinträcht...
Article
Full-text available
The role of the epidermal-growth-factor receptor (EGFR) in cervical cancer is controversial, due to technical difficulties in localizing or in quantifying EGFR by homogenate assays or immunohistochemistry. Our autoradiographic approach, in combination with morphometry, allowed cell-type-specific quantification of EGFR, leading to the following obse...
Article
Full-text available
Asphyxia is one of the major causes of perinatal brain damage and neuronal cell loss, which may result in psychomotor deficits during later development. It has been shown previously that the immature brain can be protected from ischemic injury by flunarizine, a class IV calcium antagonist. However, cardiovascular side-effects of flunarizine, when a...
Article
Full-text available
The role of the epidermal-growth-factor receptor (EGFR) in cervical cancer is controversial, due to technical difficulties in localizing or in quantifying EGFR by homogenate assays or immunohistochemistry. Our autoradiographic approach, in combination with morphometry, allowed cell-type-specific quantification of EGFR, leading to the following obse...
Article
Different amplification sensors based on the substrate recycling principle were investigated with respect to their applicability to catecholamine detection. In the bioelectrocatalytic approach, glassy carbon electrodes were modified by laccase or a PQQ-dependent glucose dehydrogenase. Substrate recycling occurs and the detection limit is in the low...
Article
The strength of a fuzzy expert system comes from its ability to handle imprecise, uncertain and vague information used by human experts while the power of neural networks lies in their learning, generalization and fault tolerance capabilities. There have already been many attempts to model and formulate fuzzy production rules (FPRs) by using neural...
Article
Expression of epidermal growth factor receptor (EGFR) was quantified by 2-color flow cytometry in cervical cancer (n = 73) and normal cervical epithelium (n = 11). EGFR was determined using a murine monoclonal EGFR antibody, and number of bound antibodies was quantified adding calibration beads with defined antigenic binding sites. Tumor cells were...
Article
Full-text available
Six different ligands of the epidermal-growth-factor receptor (EGFR) have been identified in the past. In some cervical squamous-cell carcinomas, an increased amount of proteins binding to the EGFR has been reported. In order to identify the mRNA of EGFR ligands (EGFRL), which might be over-expressed in cervical and endometrial cancers, we performe...
Conference Paper
Biosensors for about 140 different analytes have been described in the literature. Among them are low molecular weight substances (metabolites, drugs, nutrients, gases, metal ions, coenzymes, enzyme activators, and vitamins) as well as macromolecules (enzymes, lectins, nucleic acids, polymeric carbohydrates like starch, and cellulose), viruses, and...
Article
Full-text available
Six different ligands of the epidermal-growth-factor receptor (EGFR) have been identied in the past. In some cervical squamous-cell carcinomas, an increased amount of proteins binding to the EGFR has been reported. In order to identify the mRN A of EGFR ligands (EGFRL), which might be over-expressed in cervical and endometrial cancers, we performe...
Chapter
This chapter describes the enzyme based analytical systems. Biosensor research of the last few years resulted in an increasing number of sensor principles and detectable substances sensor devices often get stuck in the state of laboratory samples. There is a considerable expectation on biosensors, such as in the fields of environmental analytics or...
Article
Der epidermale Wachstumsfaktor (EGF) sowie der transformierende Wachstumsfaktor α (TGF α) wirken wachstumsstimulierend auf normale, ebenso wie maligne Zellen. In früheren Untersuchungen in Gewebshomogenaten konnten wir zeigen, daß Zervixkar-zinome mit hoher Expression des EGF-Rezeptors (EGF-R) eine schlechtere Prognose aufweisen, als Patientinnen m...
Article
The binding of the Epidermal Growth Factor (EGF) and the amount of EGF-like activity (EGF-A) was analysed in 75 cervical carcinomas and possible clinical implications were tested. EGF-A was significantly increased in patients with metastases to the pelvic and/or para-aortic lymph nodes. The EGF-receptor (EGF-R) capacity was inversely related to the...
Article
In 75 plattenepithelialen Zervixkarzinomgeweben wurde die Konzentration an EGF-Rezeptoren (= EGF-R) und die an den EGF-R bindende Aktivität (= EGF-A) mit Hilfe eines Scatchardplots bzw. eines Plazentamembranbindungsassays bestimmt und zu bekannten klinischen Prognoseparametern und zum tatsächlichen klinischen Verlauf korreliert. Es fand sich eine s...
Article
An amperometric lactate oxidase electrode has been designed for application to undiluted media by mathematical modelling, membrane screening and biochemical characterization. The lactate probe presented is characterized by a linear concentration range of 0·2–20 mmol 1−1 (sensitivity: 15 nA mmol−1 1) and a within-run imprecision below 4%. The respon...
Chapter
The paper demonstrates the development of an amperometric lactate oxidase electrode for the analysis of lactate in undiluted whole blood and serum without any preanalytics. There are included mathematical modelling, biochemical characterisation and analytical optimisation.
Article
In an attempt to clarify, whether the malignant potential of cervical cancer is age-dependent and whether this has changed in the last decade, we analysed the data from 1496 patients suffering from cervical cancer. The patients were treated between 1973 and 1988 at the second Universitäts-Frauenklinik, Lindwurmstrasse and at the Frauenklinik Grossh...
Article
Enzyme electrodes and optical immunosensors are at the leading edge of the biosensor field. The sensitivity of multi-enzyme electrodes is shifted to the subnanomolar concentration range. With monoenzyme sensors, several thousand samples per hour are measurable. Direct as well as enzyme-labelled immunosensors nowadays reach the sensitivity of immuno...
Chapter
The last 20 years have witnessed an alarming increase in the use of addictive drugs (including opiates), coincident with a more liberal view on sexuality. These contemporaneous events inevitably led to the popular association between drugs and sex which may well have contributed to the desire of many young people to “experience drugs”. On the other...
Chapter
Morphine and other opioids are known to affect the release of most anterior pituitary hormones. These actions are thought to be mediated by an interaction with hypothalamic factors which are secreted into the hypothalamo-pituitary circulation (for review see Illes 1989; Pfeiffer and Herz 1984; Millan and Herz 1985). The presence of at least three d...
Chapter
Beim Zervixkarzinom sind die Verläufe trotz gleicher klinischer Ausgangskriterien wie Tumorstadium, Lymphknotenbefall, histologischem Differenzierungsgrad, Therapie und Höhe des Tumormarkers oft verschieden. Mit den bislang verfügbaren diagnostischen Kriterien läßt sich die Diskrepanz der Verläufe und des Therapieerfolgs nicht ausreichend erklären....
Chapter
Dem aus der Tradition der gynäkologischen Onkologie entstandenen Versuch, operative und strahlentherapeutische Therapiebemühungen kompetetiv gegenüber zu stellen, ist die Entwicklung einer Nomenklatur für die Stadien des Zervixkarzinoms zu danken, welche sich am Tastbefund orientiert. Die hinlänglich bekannte, notorisch unzuverlässige Stadieneintei...
Article
Frühstadien beim Ovarialkarzinom werden auch heute noch zum größten Teil als Zufallsbefund anläßlich einer Laparotomie aus anderen Gründen diagnostiziert. Mehr als 70% der Frauen mit Ovarialkarzinom stellen sich erst im bereits fortgeschrittenen Stadium in der Klinik vor. In der vorliegenden Studie wurde der Frage nachgegangen, inwieweit die präope...
Article
The clinical implications of the epidermal growth factor (EGF) and its receptor (EGF-R) were studied in 52 squamous cell carcinomas of the uterine cervix. In comparison to 40 biopsies of the normal cervix EGF-R capacity was significantly increased in the carcinomas, while the affinity was unchanged. The amount of EGF-like substances extracted from...
Article
The sensitivity, measuring range and lifetime of enzyme electrodes using glucose oxidase sandwiched between dialysis membranes or alternatively in a polyurethane layer directly on the surface of a platinum electrode are compared. The GOD modified electrode exhibits the highest sensitivity. However, the signal depends strongly on the stirring rate....
Article
Biosensors are obtaining an increasing significance for analytical purposes as well as for on-line monitoring and control in biotechnological processes [1]. In the special field of food industry enzyme and microbial biosensors are suited. With enzyme sensors one can analyse in mostly high specific reactions many substances – microbial sensors norma...
Article
The metabolic fate of the isomeric catecholestrogens 4-hydroxyestradiol (4-OHE2) and 2-hydroxyestradiol (2-OHE2) was studied to elucidate possible differences in their metabolism as an explanation for their different bioactivities. Healthy young men (n = 3 each) were infused (90 min) with 4-OHE2 (60 micrograms/h) or 2-OHE2 (100 micrograms/h). The m...
Article
The involvement of μ- and κ-opiate receptors in the regulation of LH and prolactin secretion was investigated in long-term ovariectomized rats using selective opiate receptor agonists and antagonists. The μ-agonists morphine and [ d -Ala ² ,MePhe ⁴ ,Gly ⁵ -ol]-enkephalin (DAGO) suppressed LH levels in a dose-related manner. The benzomorphane (−)-5,...
Article
It is the aim of this work to elucidate the influence of the immobilization technique on laccase activity in the oxidation of different substrates by air oxygen. The activity of the laccase immobilized in the film was assessed in terms of the indicator-electrode currents measured at different potentials (0. 0, 0. 6, and -0. 6 V) in the presence of...
Article
In an attempt to define pharmacological probes with which to test the role of catechol oestrogen formation in the central nervous system, five oestrogens (oestradiol-17β, oestradiol-17α, 4-fluoro-oestradiol, 2-fluoro-oestradiol and moxestrol (11β-methoxy-17α-ethynyloestradiol) were studied for binding to oestrogen receptors and conversion to catech...
Article
The role of catechol oestrogen formation in the mechanism by which circulating oestrogens facilitate gonadotrophin release and female sexual behaviour was explored in adult female rats. The effects of oestradiol-17β were compared with those of a group of oestrogens with either a reduced affinity for oestrogen receptors (oestradiol-17α) or a reduced...
Article
The electrode involves a layer of co-immobilized glucose oxidase and laccase in a gelatin membrane placed over a modified oxygen electrode. Hexacyanoferrate(III) is added to the samples to oxidize reductive interferents such as ascorbic acid, and the hexacyanoferrate(II) formed is re-oxidized by a laccase-catalyzed reaction. Ascorbic acid is comple...
Article
The in vitro release of LHRH from hypothalami of adult male rats (intact, 5-day castrates, 5-day castrates replaced with various doses of testosterone) was measured under basal conditions and after the addition of KCl, the opiate antagonist naloxone or the opiate agonist DAGO to the perifusion medium. Hypothalami from all treatment groups responded...
Article
The control of ACTH secretion by opiates seems to involve stimulatory and inhibitory pathways, since opiate agonists and antagonists are capable of releasing ACTH in conscious rats. To elucidate the role of different opiate receptors in the control of ACTH release, rats were treated with receptor-selective opiate agonists and antagonists. The mu-op...