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Biomedical subjects

F Schneider

Publications and source records attributed to F Schneider.

At least 19 recordsLinked to original sources
PubMed2004

Simple DNA extraction method for dried blood spots and comparison of two PCR assays for diagnosis of vertical human immunodeficiency virus type 1 transmission in Rwanda.

Dried blood spots (DBS) on filter paper facilitate the collection, transport, and storage of blood samples for laboratory use. A rapid and simple DNA extraction procedure from DBS was developed and evaluated for the diagnosis of human immunodeficiency virus type 1 (HIV-1) infection in children by an in-house nested-PCR assay on three genome regions and by the Amplicor HIV-1 DNA prototype assay version 1.5 (Roche Molecular Systems). A total of 150 samples from children born to HIV-1-infected mothers were collected in Kigali, Rwanda, in parallel as DBS and as peripheral blood mononuclear cell (PBMC) pellets. The results obtained on DBS by the two PCR assays were compared to the results of nested PCR on PBMCs. Of 150 PBMC samples, 10 were positive, 117 were negative, and 23 were indeterminate for HIV-1 infection. In DNA extracted from filter papers and amplified by using the in-house nested PCR, 9 of these 10 positive samples (90%) were found to be positive, and 1 was found to be indeterminate (only the pol region could be amplified). All of the negative samples and all of the 23 indeterminate samples tested negative for HIV-1 infection. When we used the Amplicor DNA test on DBS, all of the 10 PBMC-positive samples were found to be positive and all of the 23 indeterminate samples were found to be negative. Of the PBMC-negative samples, 115 were found to be negative and 2 were found to be indeterminate. We conclude that this simple rapid DNA extraction method on DBS in combination with both detection methods gave a reliable molecular diagnosis of HIV-1 infection in children born to HIV-infected mothers.

Acquired Immunodeficiency Syndrome↗
PubMed2003

Dependence of film tension on the thickness of smectic films.

The film tension tau of free standing S(A) films has been measured for films with thicknesses between 2 and 150 layers. There is a clear increase of tau with the thickness for very thin films and a nonlinear slower increase for high thickness. The nonlinearity depends on the amount of liquid crystal accessible to the meniscus of the film during the drawing process. Several models are discussed that describe these effects.

Journal Article↗
PubMed2003

[Delirium increases morbidity and length of stay after vascular surgery operations. Results of a prospective study].

OBJECTIVE: We intended to analyze the influence of postoperative delirium on postoperative morbidity and length of hospital stay. PATIENTS AND METHOD: 153 patients undergoing elective arterial surgery were studied prospectively. Patients were examined postoperatively by a psychiatrist daily from days 1 to 7. Delirium was diagnosed according to standardised criteria (Diagnostic and Statistical Manual of Mental Disorders). The severity of delirium was quantified using the Delirium Rating Scale. We compared patients without delirium to those who developed postoperative delirium using univariate statistical analysis (t-test, chi (2) test, and Fisher's test). RESULTS: Sixty patients (39.2%) developed postoperative delirium. They removed catheters significantly more frequently than patients without delirium and had more catheter-related infections. Their length of stay in intensive care units was higher, as was their total postoperative length of stay in hospital. CONCLUSIONS: Patients who developed postoperative delirium have significantly more complications and increased postoperative length of stay in hospital and intensive care units.

Aged↗
PubMed2003

Atypical and typical neuroleptics in acute schizophrenia and related delusional disorders. Drug choice, switching and outcome under naturalistic treatment conditions.

Atypical neuroleptics have improved drug treatment in schizophrenia. However, their use varies greatly between countries and continents. Recent metaanalyses have deemphasized the range and magnitude of their superiority compared to typical neuroleptics. Aims of the present study were to contribute effectiveness data to this discussion. In 725 inpatients with ICD-10 diagnoses F20, 22-25 from four German psychiatric inpatient units acute neuroleptic treatment and outcome were analyzed under naturalistic conditions. Treatment strategies were stratified post hoc to answer the question, which proportion - and which kind - of patients are primarily given atypicals or typicals, for how long, at which rate and when the atypical/typical drugs are switched to typical/atypical drugs, and what the respective outcomes are. As the results demonstrate, atypicals were administered one time during inpatient treatment in nearly 48% of the patients, however as first choice drugs in only 15% of this population. Treatment change occurred in 28% after 5-6 weeks irrespective of the first drug choice. Outcome differences were, if at all, only modest and not systematically biased towards a single strategy. In conclusion, frequency of inpatient treatment with atypical neuroleptics corresponds to pharmaco-epidemiological data in Europe, but is still lower than in the US. Contrary to contemporary guideline recommendations atypical neuroleptics under routine inpatient treatment conditions were scarcely administered as first choice treatment, and acute clinical outcome is comparable to that under treatment with typical neuroleptics. Reasons and implications of these findings considering the methodological limitations are discussed.

Acute Disease↗
PubMed2003

[A puzzling circulatory failure after total hip replacement].

The diagnosis of acute circulatory failure in the postoperative course of hip replacement must concentrate on frequent complications, but rare complications requiring specific treatment must also be diagnosed. We report on the occurrence of a case of acute adrenal insufficiency subsequent to enoxaparin-induced type II thrombocytopenia. A delay was necessary to establish a correct diagnosis for two reasons: (1) an unusual clinical presentation and (2) an underevaluation of the medical risk during the preoperative visit. The evolution was nevertheless favorable after prescription of steroids that had to be prescribed chronically.

Acute Disease↗
PubMed2003

Technical refinements for validating functional MRI-based neuronavigation data by electrical stimulation during cortical language mapping.

Preoperative functional neuroimaging techniques represent an appealing method to localize language areas in tumor surgery, but their reliability still needs to be confirmed by accurate comparison with more invasive but validated mapping techniques like intraoperative electrical cortical stimulation. Two patients harboring a glioma involving speech areas underwent mapping of language function by preoperative functional magnetic resonance imaging (fMRI), whose results were integrated into the neuronavigation device, and by intraoperative electrical stimulation mapping (ESM). The utilization of neuronavigation allowed us to estimate the degree of spatial correspondence between language areas detected by the two techniques. Language areas identified by functional magnetic resonance imaging on the cerebral cortex exposed during surgery corresponded to those identified by invasive mapping in both patients. It was possible to achieve a gross total tumor removal while respecting language areas in both cases, with no permanent postoperative phasic aggravation. The concordance of results between pre- and intraoperative mapping techniques in our patients indicates that preoperative fMRI language mapping may prove useful when planning the resection of intracerebral lesions in language areas. However, accurate neurofunctional imaging protocols and image analysis are crucial to obtain a preoperative language mapping that is in agreement with ESM findings.

Brain Mapping↗
PubMed2003

Effect of long-term heat exposure on peripheral concentrations of heat shock protein 70 (Hsp70) and hormones in laying hens with different genotypes.

1. The effect of long-term, moderate heat stress (30 to 32 degrees C) on heat shock protein 70 (Hsp70) concentration in mononuclear blood cells and plasma concentrations of 3,5,3'-triiodothyronine (T3) and corticosterone in laying hens was investigated. 2. Three groups of 48 hens each (Ethopian line [Angete Melata, Na], New Hampshire [NH], F1 cross [Na x NH]) were divided into an experimental group (24 each) and a control group (24 each, ambient temperature 18 to 20 degrees C), respectively. All hens were kept in individual cages up to an age of 68 weeks and performance data were recorded. 3. Blood samples were taken from the wing vein of 12 hens from each group at weeks 22, 38, 51 and 65 (12 hens x 3 lines x 2 treatments). Mononuclear blood cells were isolated and Hsp70 concentrations were determined by Western Blot analysis with a monoclonal anti-Hsp70 antibody. T3 and corticosterone were measured with commercially available ELISA and RIA kits, respectively. 4. The moderate heat stress caused significantly increased Hsp70 levels compared with the control groups in weeks 51 and 65. However, the responses of the lines were not uniform at different ages. 5. In contrast, T3 levels were significantly decreased in stressed birds regardless of line and age. There was no effect of treatment and line on corticosterone levels during the experimental period. 6. Our results indicate that Hsp70 and T3 levels are affected by mild heat stress applied over a long period but are both involved in independent mechanisms of acquisition of thermotolerance. Further investigations are necessary to clarify whether the observed differences in Hsp70 response between the genotypes are indicators for differences in thermotolerance.

Animals↗
PubMed2003

[Development and repair of vessels from bone marrow stem cells in the adult: from biology to clinical practice].

In addition to its role in hematopoiesis, bone marrow appears to be a reservoir of stem cells that can differentiate into components of vessel wall. Upon stimulation by factors such as tissue ischemia, bone marrow stem cells can enter into circulating blood, and incorporate into areas of vascular development. Animal models suggest that bone marrow is a cellular source for tissue repair and/or regeneration. Data from humans, and clinical trials using bone marrow stem cells for the treatment of chronic ischemia in limbs and myocardium, support the view that stem cells may represent a new tool for the treatment of ischemia.

Adult↗
PubMed2002

Fatal allergic vasculitis associated with celecoxib.

We report on the occurrence of a rare and as yet unforseeable adverse reaction to treatment with celecoxib, a cyclooxygenase-2 (COX-2) selective, non-steroidal, anti-inflammatory drug. A previously healthy adult suffered fatal acute multiple organ failure presumably after diffuse allergic vasculitis with diffuse necrotic purpura. Although no conclusive proof is available, such a reaction could have been triggered by at least one of two mechanisms: an allergic reaction linked to the chemical structure of celecoxib; or an interaction of the drug with synthesis of endothelial eiconasoids leading to an imbalance between vasoactive end products, resulting in widespread rise to local thrombosis.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2002

Role of operculoinsular cortices in human pain processing: converging evidence from PET, fMRI, dipole modeling, and intracerebral recordings of evoked potentials.

Insular and SII cortices have been consistently shown by PET, fMRI, EPs, and MEG techniques to be activated bilaterally by a nociceptive stimulation. The aim of the present study was to refer to, and to compare within a common stereotactic space, the nociceptive responses obtained in humans by (i) PET, (ii) fMRI, (iii) dipole modeling of scalp LEPs, and (iv) intracerebral recordings of LEPs. PET, fMRI, and scalp LEPs were obtained from normal subjects during thermal pain. Operculoinsular LEPs were obtained from 13 patients using deep brain electrodes implanted for presurgical evaluation of drug-resistant epilepsy. Whatever the technique, we obtained responses which were located bilaterally in the insular and SII cortices. In electrophysiological responses (LEPs) the SII insular contribution peaked between 150 and 250 ms poststimulus and corresponded to the earliest portions of the whole cerebral response. Group analysis of PET and fMRI data showed highly consistent responses contralateral to stimulation. On single-subject analysis, LEPs and fMRI activations were concentrated in relatively restricted volumes even though spatial sampling was quite different for both techniques. Despite our multimodal approach, however, it was not possible to separate insular from SII activities. Individual variations in the anatomy and function of SII and insular cortices may explain this limitation. This multimodal study provides, however, cross-validated spatial and temporal information on the pain-related processes occurring in the operculoinsular region, which thus appears as a major site for the early cortical pain encoding in the human brain.

Adult↗
PubMed2002

Administration of recombinant porcine somatotropin (rpST) changes hormone and metabolic status during early pregnancy.

The objective of this study was to examine the effects of somatotropin (ST) on porcine reproductive and metabolic statuses during early pregnancy. Four pregnant crossbred gilts received 6 mg of recombinant porcine somatotropin (rpST) daily from days 10 to 27 after artificial insemination while six pregnant gilts served as controls. Blood samples were taken on days 8, 10, 12, 14, 18, 22, and 27 prior to rpST injections (8:00 h) and subsequently at 9:00, 10:00, 12:00, 14:00, 16:00, 18:00, and 20:00 h. On all remaining days of treatment, samples were taken once daily before injections (8:00 h). The samples were assayed for the metabolic hormones: ST, insulin-like growth factor I (IGF-I), insulin, thyroxine (T(4)), triiodothyronine (T(3)), and cortisol; for metabolites: free fatty acids (FFA) and glucose; and for the reproductive hormones: luteinizing hormone (LH), progesterone, estradiol-17beta, estrone sulfate, and prostaglandin F(2alpha). Delivery of rpST daily induced a 20- to 40-fold increase in plasma ST concentrations. Moreover, repeated administration of rpST resulted in a continuous increase in plasma IGF-I concentration (P < 0.001), from 191.0 +/- 22.3-340.0 +/- 15.3 ng/mL 24 h after initial injection to 591.3 +/- 46.8 ng/mL after final injections. Mean serum insulin tended to be greater in rpST-treated gilts. Blood concentrations of T(4) were reduced (P < 0.05) from day 14 of gestation in treated gilts while T(3) concentrations remained unchanged. Concentrations of both glucose and FFA were greater (P < 0.01) and cortisol concentrations were unchanged in treated gilts. Changes in reproductive steroid hormones were minimally affected. Circulating progesterone (P = 0.078), and estradiol-17beta (P = 0.087) concentrations tended to be lower in treated animals. These data show that treatment of pregnant gilts with rpST during early gestation mainly impacts metabolic rather than reproductive status.

Adrenal Glands↗
PubMed2002

Comparing mRNA levels of genes encoding leptin, leptin receptor, and lipoprotein lipase between dairy and beef cattle.

Body weight and fat mass vary distinctly between German Holstein (dairy cattle) and Charolais (beef cattle). The aim of this study was to determine whether the expression of the obese (Ob) gene and lipoprotein lipase (LPL) gene in fat tissues and expression of the long isoform leptin receptor (Ob-Rb) gene in the hypothalamus were different between these two cattle breeds. Body weight and the area of longissimus muscle cross-section of German Holstein were lower (P<0.001), while body fat content, as well as the omental and perirenal fat mass were higher (P<0.001), compared to Charolais. Plasma insulin and leptin levels between two cattle breeds were determined by radioimmunoassay. Compared to Charolais, plasma insulin concentrations were significantly higher (P<0.01), and plasma leptin levels were tended to be higher (P<0.1) in German Holstein. Ob mRNA levels in subcutaneous and perirenal fat depots, but not in the omental fat depot, were significantly higher (P<0.05) in German Holstein than in Charolais. LPL mRNA expression in the perirenal fat depot of German Holstein was greater in abundance than that of Charolais. No significantly different LPL mRNA levels were found in subcutaneous and omental fat depots, and Ob-Rb mRNA levels in the hypothalamus between these two cattle breeds (P<0.05). Both Ob and LPL expression was greater in perirenal and omental fat depots than in the subcutaneous fat depot (P<0.05). Data indicated that in bovine the Ob and LPL gene expression levels in perirenal fats are an important index that is associated with body fat content, while Ob-Rb in hypothalamus is not.

Adipose Tissue↗
PubMed2002

Characterization of a purified beta-fructofuranosidase from Bifidobacterium infantis ATCC 15697.

AIMS: To characterize the beta-fructofuranosidase of Bifidobacterium infantis ATCC 15697 and to compare it with other bacterial beta-fructofuranosidases. METHODS AND RESULTS: The beta-fructofuranosidase of B. infantis ATCC 15697 was purified 46.8 times over the crude extract by anion exchange chromatography, ultrafiltration and gel filtration. The sequence of 15 amino acid residues of the NH2 terminal was determined. This enzyme was a monomeric protein (Mr 70 kDa) with beta-fructofuranosidase and invertase activities. The isoelectric point was pH 4.3, the optimum pH 6.0 and pKas (4.5 and 7.2) of two active groups were obtained. The activities were inhibited by Hg2+ and p-chloromercuribenzoic acid (pCMB). The optimal temperature was 37 degrees C and activities were unstable at 55 degrees C. beta-fructofuranosidase activity was more efficient than that of invertase with Vm/Km ratios of 0.65 and 0.025 x 10-3 l min(-1) mg(-1), respectively. The enzyme catalyses the hydrolysis of fructo-oligosaccharides, sucrose and inulin at relative velocities of 100, 10 and 6, respectively. CONCLUSIONS: The enzyme of B. infantis ATCC 15697 is an exo-inulinase which has beta-fructofuranosidase and invertase activities. This protein was different from the beta-fructofuranosidase of another strain of B. infantis (B. infantis JCM no. 7007). SIGNIFICANCE AND IMPACT OF THE STUDY: A better knowledge of bacterial beta-fructofuranosidases, especially from bifidobacteria, has been gained.

Bifidobacterium↗
PubMed2002

[The "Barthel Index": alternative to expertising in compulsory care insurance?].

Measuring the level of care needed is difficult and since the introduction of nursing care insurance in Germany in 1995 the assessment method applied by the MDK (Medizinischer Dienst der Krankenversicherung) has repeatedly been criticised. The method is very costly and not broadly tested for its validity and reliability. The question arises whether similar results can be obtained by applying another instrument, like the Barthel Index (BI), which is easier to use and more reliable. In this article the authors show - based on a preliminary study in 1999 - that by using the Barthel Index a discriminance analysis will show identical results in 80 % of all cases. The authors regard this identical measurement of care needs, which is reached by scoring only ten items (BI) versus thirty (MDK's assessment method) and with a presumingly higher reliability, as a major progress and reason enough for further discussion and studies of the use of the Barthel Index for care needs assessment.

Adolescent↗
PubMed2002

[Fundamentals of functional magnetic resonance imaging in clinical psychology and psychiatry].

In the last few years, functional magnetic resonance imaging (fMRI) has become the preferred technique for brain mapping because of its superior spatial and temporal resolution. Other factors that have contributed to the popularity of this imaging method are the increasing availability of scanners and the technological advances made in data acquisition and analysis. This paper describes basic principles of fMRI essential to a comprehension of the capabilities of this complex technology. In particular, it focuses on blood oxygenation level dependent (BOLD) contrast, on the experimental procedures, as well as on possible imaging techniques and statistical analyses. Examples for studying brain-behavior-relationships come from research in the context of emotion in healthy subjects as well as in emotional dysfunctions in psychiatric patients.

Affective Symptoms↗
PubMed2002

Gonadotropin release in periovulatory heifers after GnRH analogs measured by two types of immunoassays.

This study on heifers (n = 27) compared the effects of a GnRH antagonist (Antarelix) and those of an agonist (Triptorelin) on gonadotropin release during the periovulatory period of the oestrous cycle. In three experiments (EXP I-III), an initial injection of GnRH analogs was given 48 h after a single PGF 2alpha pretreatment during the luteal phase, with a further five at 12 h intervals. A challenge by a GnRH agonist (Gonavet) was performed six hours after the last application of analogs. In EXP I (n = 9), heifers received six times 1.5 mg of Antarelix, 0.5 mg of Triptorelin, and mannitol (5%; control), respectively. In EXP II (n = 12), identical Antarelix and Triptorelin treatments were followed by a single injection of estradiol-17beta valerate (6 h after Gonavet). The dosage of Antarelix was increased to 5 mg for each injection in EXP III (n = 6). Measurement of LH in blood plasma frequently sampled was performed parallely by a competitive RIA method (EXP I + II) and by a sandwich-type electro-chemiluminescence-immunoassay (ECLIA) in EXP III. This non-isotopic technique was also used to additionally analyse FSH levels. Results of EXP I showed that the GnRH antagonist equally suppressed LH surges and ovulation. On the contrary, prior to suppression of LH levels due to down-regulation of pituitary GnRH receptors the agonist Triptorelin induced an initial increase in LH concentration which was followed by ovulation. In the control animals we observed endogenous LH surges as well as smaller elevations after the agonist (Gonavet) challenge. An increase was also observed in antagonist, but not in Triptorelin treated heifers. Pituitary GnRH receptors were not detectable in animals previously treated by the analogs, whereas concentrations between 2.2-21.0 fmol/mg protein were measured in controls. Results of EXP II confirmed the described effects of GnRH analogs. Additionally, it was shown that exogenous estradiol is able to release LH from the pituitary, although a previous treatment by a GnRH agonist had dropped the pulsatile gonadotropin secretion. Contrary to the LH pattern and despite elevated amounts of the antagonist, the mean concentration and pulse number of FSH were not influenced by the antagonist treatment (EXP III). These data confirmed that (a) the reversibly blocked pituitary function induced by a potent GnRH antagonist may be a useful tool to study gonadotropin-dependent final follicular growth as well as ovulation in cyclic heifers and (b) the novel non-isotopic ECLIA methods for the determination of FSH and LH provided practical alternatives to other immunoassay types.

Animals↗
PubMed2002

Fermentation of chicory fructo-oligosaccharides in mixtures of different degrees of polymerization by three strains of bifidobacteria.

We estimated and compared the action of three selected strains of bifidobacteria in a semi-synthetic medium for different degrees of polymerization of fructo-oligosaccharides contained in three commercial products derived from chicory inulin: Fibrulose F97 (shorter chains), Fibruline Instant (native chains), Fibruline LC (longer chains). Biomass and production of lactate and acetate were greater when the substrate contained mostly shorter chain fructo-oligosaccharides. Shorter chains were first to be consumed, and one strain could use longer chains. As the degree of polymerization increased, residual fructo-oligosaccharides increased after growth of the strains, and the rate of consumption of fructo-oligosaccharides decreased.

Acetates↗