Search PubMed⌕ Search

Biomedical subjects

K Heinrich

Publications and source records attributed to K Heinrich.

At least 19 recordsLinked to original sources
PubMed2005

Application of stable carbon isotope analysis to the detection of 17beta-estradiol administration to cattle.

The use of anabolic agents in food producing animals is prohibited within the EU since 1988 (96/22/EC directive). The control of the illegal use of natural steroid hormones in cattle is still an exciting analytical challenge as far as no definitive method and non-ambiguous analytical criteria are available. The ability of gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS) to demonstrate the administration of 17beta-estradiol to bovine has been investigated in this paper. By comparison of 13C/12C isotopic ratio of main urinary estradiol metabolite, i.e. 17alpha-estradiol, with two endogenous reference compounds (ERCs), i.e. dehydroepiandrosterone (DHEA) and 5-androstene-3beta,17alpha-diol, the differentiation of estradiol metabolite origin, either endogenous or exogenous, has been proved to be achievable. After treatment, the delta(13)C(VPDB)-values of 17alpha-estradiol reached -27 per thousand to -29 per thousand, whereas delta13CVPDB-values of DHEA remained between -13 per thousand and -20 per thousand depending on the diet, maize and grass, respectively. A significant difference of delta13CVPDB between ERCs and 17alpha-estradiol was measurable over a period of 2 weeks after estradiol ester administration to the animal.

Androstenediol↗
PubMed2004

[Performance of the Candida mannan antigen detection in patients with fungemia].

For several years, the Platelia Candida mannan antigen enzyme immunoassay (Candida EIA) has been commercially available as a diagnostic test for invasive candidosis. We evaluated the Candida EIA with patients with proven fungemia caused by yeasts from which at least one serum sample was available. Fifty-nine patients with 121 serum samples were included in the study. Sixty-one different yeast strains were isolated from positive blood-cultures. The Candida EIA was positive (n = 35) or borderline positive (n = 8) in 43 of 59 patients with fungemia, resulting in an overall sensitivity of 73%. For the different yeast species, the following sensitivities were calculated: Candida albicans 30 of 39 (77%), Candida glabrata 7 of 11 (64%), Candida parapsilosis 1 of 3, Candida tropicalis 2 of 2, Candida kefyr 2 of 2, Candida lipolytica 0 of 1, Candida lusitaniae 1 of 1, Candida krusei 1 borderline positive of 1, Saccharomyces cerevisiae 1 of 1. In six patients the antigen levels over time were evaluable. In three cases the antigen was positive 3-4 days before the day the blood culture was drawn, in one case on the same day, and in two cases 2 and 5 days afterwards. In conclusion, the Candida EIA was suitable for the detection of fungemia due to the major facultatively pathogenic yeast species. The test was positive in about half of the patients before blood cultures became positive. In these cases, it contributed to an early diagnosis of invasive candidiasis.

Antigens, Fungal↗
PubMed2001

Coupling of endothelin receptors to the ERK/MAP kinase pathway. Roles of palmitoylation and G(alpha)q.

Endothelins are potent mitogens that stimulate extracellular signal-regulated kinases (ERK/MAP kinases) through their cognate G-protein-coupled receptors, ET(A) and ET(B). To address the role of post-translational ET receptor modifications such as acylation on ERK activation and to identify relevant downstream effectors coupling the ET receptor to the ERK signaling cascades we have constructed a panel of palmitoylation-deficient ET receptor mutants with differential G(alpha) protein binding capacity. Endothelin-1 stimulation of wild-type ET(A) or ET(B) induced a fivefold to sixfold increase in ERK in COS-7 and CHO cells whereas full-length nonpalmitoylated ET(A) and ET(B) mutants failed to stimulate ERK. A truncated ET(B) lacking the C-terminal tail domain including putative phosphorylation and arrestin binding site(s) but retaining the critical palmitoylation site(s) was still able to fully stimulate ERK activation. Using mutated ET receptors with selective G-protein-coupling we found that endothelin-induced stimulation of G(alpha)q, but not of G(alpha)i or G(alpha)s, is essential for endothelin-mediated ERK activation. Inhibition of protein kinases A and C or epidermal growth factor receptor kinase failed to prevent ET(A)- and ET(B)-mediated ERK activation whereas blockage of phospholipase C-beta completely abrogated endothelin-promoted ERK activation through ET(A) and ET(B) in recombinant COS-7 and native C6 cells. Complex formation of Ca2+ or inhibition of Src family tyrosine kinases prevented ET-1-induced ERK-2 activation in C6-cells. Our results indicate that endothelin-promoted ERK/MAPK activation criticially depends on palmitoylation but not on phosphorylation of ET receptors, and that the G(alpha)q/phospholipase C-beta/Ca2+/Src signaling cascade is necessary for efficient coupling of ET receptors to the ERK/MAPK pathway.

Amino Acid Sequence↗
PubMed2001

An investigation into the acute nootropic effects of Hypericum perforatum L. (St. John's Wort) in healthy human volunteers.

Hypericum perforatum L. (St. John's Wort) is a complex herb that has been used for centuries for its putative medicinal properties, and has current therapeutic relevance as a treatment of mild to moderate depression. Recently, two studies in rodents have suggested that hypericum may also have memory-enhancing effects. It has a complex pharmacology, in that acute administration modulates numerous neurotransmitter systems that have previously been observed to either augment or impair a variety of memory processes in humans. This study aimed to examine whether acute administration of standardized hypericum extract could exert a nootropic effect in normal human subjects. The study employed a double-blind, crossover, repeated-measures design. Twelve healthy young subjects completed the Cognitive Drug Research (CDR) memory battery, following administration of placebo, 900 mg and 1800 mg hypericum (Blackmore's Hyperiforte). The findings suggested that hypericum does not have an acute nootropic effect in healthy humans at these doses. However, there was some evidence for an impairing effect on accuracy of numeric working memory and delayed picture recognition at the higher dose. This observed impairment could be due to a sensitivity of these specific tasks to modulation by neurotransmitters that have been noted to have memory-impairing effects (e.g. y-aminobutyric acid (GABA), serotonin).

Adolescent↗
PubMed2001

Early production of rhizopine in nodules induced by Sinorhizobium meliloti strain L5-30.

The rhizopine L-3-O-methyl-scyllo-inosamine (3-O-MSI) is metabolized by approximately 10% of the strains of Rhizobium leguminosarum by. viciae and Sinorhizobium meliloti. Rhizopine strains enjoy a substantial competitive advantage in nodulation, which is manifest before 14 days post-inoculation, implying that rhizopine is produced before this time. We were able to detect this compound in the roots of alfalfa (Medicago sativum L. cv. Hunter River) four days after germination (six days post-infection) with S. meliloti strain L5-30 by gas chromatography-mass spectrometry (GC-MS). At four days, nodules were not visible, and the concentration of rhizopine was extremely low, estimated at 67 pg/gfw (picograms/gram fresh weight). The amount increased gradually but remained low until 16 days, when there was a 50-fold increase from day four, by which time nodules were well established. This pattern of synthesis is consistent with previous studies indicating that rhizopine synthesis is regulated by nifA/ntrA regulatory genes, which are maximally expressed in bacteroids at the onset of nitrogen fixation. However, the low level of rhizopine synthesis must be responsible for the early effects on competition for nodulation. Production of rhizopine at this time most likely results from micro-aerobic induction of mos genes in free-living bacteria, either in the infection threads or in the rhizosphere.

Gas Chromatography-Mass Spectrometry↗
PubMed1999

Approaches to dendritic cell-based immunotherapy after peripheral blood stem cell transplantation.

High-dose chemotherapy with peripheral blood progenitor cell transplantation (PBPCT) is a potentially curative treatment option for patients with both hematological malignancies and solid tumors, including breast cancer. However, based on a number of clinical studies, there is strong evidence that minimal residual disease (MRD) persists after high-dose chemotherapy in a number of patients, which eventually results in disease recurrence. Therefore, several approaches to the treatment of MRD are currently being evaluated, including treatment with dendritic cell (DC)-based cancer vaccines. DCs, which play a crucial role with regard to the initiation of T-lymphocyte responses, can be generated ex vivo either from CD34+ hematopoietic progenitor cells or from blood monocytes. They can be pulsed in vitro with tumor-derived peptides or proteins, and then used as a professional antigen-presenting cell (APC) vaccine for the induction of antigen-specific T-lymphocytes in vivo. This paper summarizes our preclinical studies on the induction of primary HER-2/neu specific cytotoxic T-lymphocyte (CTL) responses using peptide-pulsed DC. As HER-2/neu is overexpressed on 30-40% of breast and ovarian cancer cells, this novel vaccination approach might be particularly applicable to advanced breast or ovarian cancer patients after high-dose chemotherapy and autologous PBPCT.

Antigens, CD↗
PubMed1998

Herpes simplex virus encephalitis: long-term comparative study of viral load and the expression of immunologic nitric oxide synthase in mouse brain tissue.

In the brain tissue of 21 mice infected with herpes simplex virus type 1 (HSV-1) strain F we determined the expression of immunologic nitric oxide synthase (iNOS) as a potential mediator of neuronal injury with a semiquantitative reverse transcription polymerase chain reaction. Viral burden in brain tissue was quantitated with a dilutional polymerase chain reaction assay. Viral burden and iNOS-expression peaked at day 7 following infection. Thereafter viral burden declined to a low baseline value at 6 months following infection, whereas iNOS-expression was still 4-fold increased compared to baseline levels. In experimental herpes simplex virus encephalitis iNOS, as one potent mediator of neuronal injury, is upregulated in the acute and chronic disease. In future, in addition to antiviral treatment, inhibitors of iNOS might offer new therapeutic strategies in herpes simplex virus encephalitis.

Animals↗
PubMed1996

An Experimental Test of the Rhizopine Concept in Rhizobium meliloti.

In some Rhizobium-legume symbioses, compounds known as rhizopines are synthesized by bacteroids and subsequently catabolized by free-living cells of the producing strain. It has been suggested than rhizopines act as proprietary growth substrates and enhance the competitive ability of the producing strain in its interactions with the diverse microbial community found within the rhizosphere. Wild-type, rhizopine-producing Rhizobium meliloti L5-30 and mutant L5-30 strains deficient for either rhizopine synthesis or catabolism were inoculated onto lucerne host plants in competition experiments. These experiments demonstrated that no apparent advantage resulted from the ability to synthesize a rhizopine, whereas the ability to catabolize rhizopine provided a clear advantage when an organism was in competition with a strain without this ability. The results suggest that when an organism is in competition with a catabolism-deficient mutant, the ability to catabolize rhizopine results in enhanced rates of nodulation. The results of the experiments were not consistent with the hypothesis that the sole role of rhizopines is to act as proprietary growth substrates for the free-living population of the producing strain.

Journal Article↗
PubMed1995

Fluoxetine in patients with major depressive disorder--a responder analysis.

Fluoxetine is a selective serotonin re-uptake inhibitor and thus being a specific antidepressant has its specific responder. In order to attempt a differential description of fluoxetine responders we collected data of 219 patients with major depressive disorder (MDD; DSM-III R) in an open multicenter (phase IV) study, which were further subclassified. According to the treatment plan, these patients were to be treated with 20 mg fluoxetine daily for a period of five weeks. CGI, HAMD, SDS, undesired side effects, laboratory and physiological variables were recorded at weekly intervals. Predictors for response were searched for by means of discriminatory analysis. The stability of the relations found was verified in two randomized halves of the data. It was found that those patients are probably good responders who at base-line have a high Covi anxiety score, but who according to Raskin score, self-assessment of depression (SDS), and CGI are not particularly severely depressed and show a relatively favorable therapeutic response in the first week of treatment.

Adolescent↗
PubMed1995

[Ignatius of Loyola--gifted or mentally ill?].

Subsequent to a severe injury and under the influence of religious reading, Loyola experienced a dramatic mental change in his spiritual values in the sense of a sublimation to an alternative knighthood. His behaviour patterns observed thereafter were determined by a totality of his attachment to God. Based on this certainty in his faith, which was free from any doubts, and on God, and with the background of fasting and praying, he had visionary and pseudo-hallucinatory experiences. As the founder of an order and head of the community of Jesuits, Ignatius of Loyola proved to be diplomatically highly talented. There is no evidence of any psychotic disease. Also, there is no probability of a personality disorder in the sense of a neurosis. The numerous unusual behaviour patterns of Ignatius cannot be interpreted as psychopathological symptoms. It is justified to call him a genius.

Famous Persons↗
PubMed1995

Randomized, double-blind, controlled trial of risperidone versus clozapine in patients with chronic schizophrenia.

This study compares the antipsychotic efficacy and the tolerability of risperidone and clozapine in patients with schizophrenia. Patients were randomized to double-blind treatment with risperidone, 4 mg (N = 20), risperidone, 8 mg (N = 19), or clozapine, 400 mg (N = 20), daily for 28 days. Efficacy was assessed by improvement of psychotic symptoms, measured on the Brief Psychiatric Rating Scale, and Clinical Global Impression. The tolerability was assessed by the Simpson and Angus scale for extrapyramidal side effects (EPS), the Association for Methodology and Documentation in Psychiatry (AMDP) scale for somatic side effects, spontaneous reports of adverse events, clinical laboratory assessments, and vital signs. All treatments reduced psychotic symptoms. The global tolerability was significantly better in the risperidone than in the clozapine-treated patients (p < 0.01). There were no differences between treatments on the AMDP scale. The most frequent spontaneously reported adverse effects were dizziness, fatigue, accommodation disturbance, and EPS in all treatment groups and increased salivation, mainly in the clozapine-treated patients. Although there were no changes in vital signs during risperidone treatment, clozapine was associated with a mean reduction in heart rate of 10 beats/minute. Risperidone tolerability at endpoint was classified as "very good" by 60 and 47% of patients treated with risperidone, 4 and 8 mg daily, respectively; the corresponding figure in clozapine-treated patients was 30%. The results suggest that risperidone is at least as effective as an antipsychotic as clozapine, providing a valuable new approach for the treatment of schizophrenia.

Adult↗
PubMed1995

["Snow" and "Walpurgisnacht". Hans Castorp's exemplary maturation crises in "Zauberberg"].

On the occasion of a rather incidental visit in the sanatorium "Berghof" at Davos, Hans Castorp, the--as to his primary personality--asthenic and low-profile protagonist of the "Zauberberg" is gradually getting caught up in the maelstrom of the there prevailing timelessness and irresponsibility, this being interrupted solely by two tapering to crisis episodes: his amouressness to Mme. Chauchat as an erotic crisis and by the visionary daydream during a snowstorm about the abilities of men as a cognitive, mental crisis. Both events are triggered by a pathoid irritability, following the maxim of Th. Mann that illness, decay and death as borderline experiences may be the presupposition for cognition and reversal. Both crises end without consequences--the "Zauberberg" is the negation of the novel of education and development in the narrower sense. The unsuccessfulness and undecidedness of Hans Castorp's existence culminate in the open end of the novel, regarding his surviving on the battle field, and is in strict contrast to Adrian Leverkühn's determined autoinfection with Lues with the aim of artistic perfection and the creative break-through of "Doctor Faustus". Hans Castorp's regression and self-fragmentation within the decadent-morbid atmosphere of the sanatorium lead to his storming into the battles of the First World War as a last and existential crisis; it is here where finally the individual and national fate are merging. Hans Castorp becomes the paradigma of the German pre-war bourgeoisie and its crisis-prone development.

Germany↗