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H Schütz

Publications and source records attributed to H Schütz.

At least 19 recordsLinked to original sources
PubMed2006

[SAR values of mobile phones. Safety evaluation and risk perception].

The specific absorption rate (SAR) is a prominent topic in the discussion about precautionary health protection. An experimental study investigated the effect of information about various SAR values (below the existing partial body limit value of 2 W/kg) on safety judgments of potential mobile phones users. It turns out that about 94% of the participants do not know the SAR value of their own mobile phone. SAR values below existing limits are not perceived as equally safe. Rather, the lower the SAR value, the higher the perceived safety. However, a majority of the participants does not consider these SAR values to be 100% safe, even if they are clearly below the existing limits. Explicitly indicating a precautionary limit value (referring to the Federal Office for Radiation Protection or to consumer organizations) does not change this safety evaluation. As expected, safety evaluation of the SAR values is also related to the perception of mobile phone risks. Those who are concerned about mobile phone communication give lower safety judgments than the unconcerned-independent of the level of the SAR values. Irrespective of that, our results suggest that establishing the SAR value as a criterion for mobile phones depends first of all on making it known to the public.

Adult↗
PubMed2006

Bioequivalence of a methylphenidate hydrochloride extended-release preparation: comparison of an intact capsule and an opened capsule sprinkled on applesauce.

OBJECTIVE: To assess bioequivalence between an intact capsule and the content of a capsule sprinkled on applesauce. MATERIALS: Medikinet retard 20 mg capsules were obtained from Medice (Iserlohn, Germany). METHODS: This was a single-center, completely randomized, open, 2-period, 2-sequence, balanced crossover study with a washout period of 1 week between administrations, in 12 healthy male and female subjects, aged 18-45 years. Blood samples were collected over 24 hours and methylphenidate plasma concentration-time data were used to calculate pharmacokinetic parameters for both administrations. The main parameters were (confirmatory) AUC0-tz (extent of BA), Cmax, tmax (rate of BA) and (descriptively) AUC0-infinity and t1/2. Equivalence was concluded if the 90% confidence interval (CI) for the ratio between test and reference was 0.80-1.25 (AUC0-tz). RESULTS: All 12 dosed subjects finished both treatment periods and were included in pharmacokinetic and safety analyses. 90% geometric confidence intervals for AUC0-tz and Cmax data were well within accepted bioequivalence limits. The study has shown that both treatment modes lead to similar pattern of absorption and elimination following single-dose administration in the fed state. The test treatment (content of capsule sprinkled over 15 ml applesauce) is bioequivalent to the reference treatment (intact capsule) in terms of extent and rate of absorption. CONCLUSION: Data collected from this study demonstrate that Medikinet retard capsules can be opened and the content sprinkled on a tablespoon of applesauce without influencing the rate and extent of bioavailability.

Adolescent↗
PubMed2004

[Risks of drug screening using immunoassays].

Now-a-days immunoassays are world wide used for the rapid screening of drugs. Despite the fact that they are a highly valuable tool for the test of legal and illicit drugs, there is a non-negligible risk of false positive and false negative findings and many pitfalls must be taken into account when using these tests in an uncritical manner and without valid confirmation procedures.

Cross Reactions↗
PubMed2004

Intraventricular cytarabine in a case of idiopathic hypertrophic pachymeningitis.

Idiopathic hypertrophic chronic pachymeningitis (IHCP) is characterised by inflammatory fibrotic thickening of the dura mater. Long term management is controversial. A 28 year old man with craniospinal IHCP and prominent lymphocytic meningitis is reported. Cerebrospinal fluid and histological examination suggested a CD4+ T cell driven process and B cell stimulation. After surgical, tuberculostatic, and immunosuppressive treatment failed to control the progressive meningeal hypertrophy, causing severe headache and neurological disability, the disease process eventually abated with intraventricular cytarabine treatment.

Adult↗
PubMed2001

Multiple homicides as a result of chloroform poisoning: case report and experimental study.

Two cases (involving five murder victims) of multiple homicide by inhalational chloroform intoxication are reported. In the discussion of the findings the valence of toxicological analyses is underlined with regard to the possibility of forcible external suffocation due to occlusion of the respiratory orifices by means of a chloroform-soaked soft covering. In addition storage experiments were performed at +4, +20 and -20 degrees C with cadaver blood mixed with chloroform. The optimal solution for avoiding volatile losses was stored in glass tubes with ground glass stoppers. In cases of unclear death in which involvement of volatile substances is suspected it is, therefore, advisable to preserve an additional blood sample at -20 degrees C in glass tubes that are only opened for the analysis of volatile substances.

Adolescent↗
PubMed2001

pH-Dependent dissolving nano- and microparticles for improved peroral delivery of a highly lipophilic compound in dogs.

RR01, a new highly lipophilic drug showing extremely low water solubility and poor oral bioavailability, has been incorporated into pH-dependent dissolving particles made of a poly(methacrylic acid-co-ethylacrylate) copolymer. The physicochemical properties of the particles were determined using laser-light-scattering techniques, scanning electron microscopy, high-performance liquid chromatography, and x-ray powder diffraction. Suspension of the free drug in a solution of hydroxypropylcellulose (reference formulation) and aqueous dispersions of pH-sensitive RR01-loaded nanoparticles or microparticles were administered orally to Beagle dogs according to a 2-block Latin square design (n = 6). Plasma samples were obtained over the course of 48 hours and analyzed by gas chromatography/mass spectrometry. The administration of the reference formulation resulted in a particularly high interindividual variability of pharmacokinetic parameters, with low exposure to compound RR01 (AUC0-48h of 6.5 microg x h/mL and coefficient of variation (CV) of 116%) and much higher Tmax, as compared to both pH-sensitive formulations. With respect to exposure and interindividual variability, nanoparticles were superior to microparticles (AUC0-48h of 27.1 microg x h/mL versus 17.7 microg x h/mL with CV of 19% and 40%, respectively), indicating that the particle size may play an important role in the absorption of compound RR01. The performance of pH-sensitive particles is attributed to their ability to release the drug selectively in the upper part of the intestine in a molecular or amorphous form. In conclusion, pH-dependent dissolving particles have a great potential as oral delivery systems for drugs with low water solubility and acceptable permeation properties.

Acrylic Resins↗
PubMed2000

Screening, identification and quantitation of benzodiazepines in serum by solid phase extraction on a cyanopropyl phase using high performance liquid chromatography and photodiode array detection.

A screening procedure for benzodiazepines in serum is presented. The compounds are extracted over a cyanopropyl phase followed by identification and determination via high performance liquid chromatography and photodiode array detection. Diazepam (CAS 439-14-5), flunitrazepam (CAS 1622-62-4), nordazepam (CAS 1088-11-5), oxazepam (CAS 604-75-1) and temazepam (CAS 846-50-4) are quantified. Retention data of 42 benzodiazepines and their metabolites as well as hydrolysis products are listed. This assay leads to an expansion of a known systematic toxicological analysis system to identify pharmaceuticals, drugs of abuse and pesticides.

Anti-Anxiety Agents↗
PubMed2000

Antibiotic prophylaxis in percutaneous endoscopic gastrostomy (PEG)--results from a prospective randomized multicenter trial.

OBJECTIVE: To determine the efficacy of antibiotic prophylaxis in percutaneous endoscopic gastrostomy (PEG) as a part of a standardized regimen. METHODS: An open prospective randomised multicenter study in 216 patients. 106 received ceftriaxone 1 g i.v. 30 min preinterventionally and 110 no study medication. A standardized protocol was followed for PEG preparation, insertion, and aftercare; all patients received a 15 French gastrostomy tube. Follow-up of local and systemic infection and clinical course was continued to postintervention day 10. An aggregate erythema and exudation score > 3 or the presence of pus was taken as indicative of peristomal infection. The pharmacoeconomics of antibiotic use were also examined. RESULTS: In no-prophylaxis patients, wound infection rates were 23.6% on day 4 and 24.5% on day 10 vs. 7.6% (p < 0.05) and 11.4% (p < 0.05), respectively, in prophylaxis patients. Results were disproportionally better in tumor patients in comparison with neurological patients. Patients systemic infection rates were 11.8% vs. 1.9% in noprophylaxis vs. prophylaxis (p < 0.05), and overall infection rates 36.3% vs. 13.3%, respectively (p < 0.05). Pneumonia was more frequent in patients with underlying neurological disease and reduced in the prophylaxis group. Antibiotic and application costs were similar in both groups (p = 0.400). CONCLUSIONS: Single-dose ceftriaxone 1 g is a effective prophylaxis against local and systemic infection after PEG and should be a part of a standard regimen.

Aged↗
PubMed1999

Risk communication for environmental health hazards.

Starting with the analysis of communication problems in the field of therapeutical and environmental risks the special requirements and challenges of communicating environmental health risks will be outlined. Important problems of this type of risk communication include: (1) The political context which imposes a new role structure upon the doctor and the people involved, (2) the special importance of credibility of scientific statements, given the limited understanding of health risks related to the environment, and (3) the strong emotional component and therefore the conflict-proneness of communication.

Communication↗
PubMed1998

High ethanol tolerance in young adults is associated with the low-activity variant of the promoter of the human serotonin transporter gene.

Central serotonergic neurotransmission has been implicated in the aetiology of ethanol tolerance and dependence. Cellular expression of the serotonin transporter and serotonin reuptake is modulated via a polymorphic, repetitive element in the 5'-flanking regulatory region of the serotonin transporter gene (5-HTTLPR). We report the association of the low-activity, short variant of the 5-HTTLPR with high ethanol tolerance among young adults in a case-control association study (n = 713). The low-activity 5-HTTLPR showed a significantly increased allele frequency (chi2 = 7.30; df = 2; P = 0.007) and genotype frequency among young adults (< or =26 years) with high ethanol tolerance homozygous for the short allele (chi2 = 7.58; df = 1; P = 0.02). The estimated odds ratio for the homozygous short variant compared to the homozygous long variant was 2.82 (95% CI 1.30-6.11). This indicates that the low-activity 5-HTTLPR may be involved in the neuronal mechanisms responsible for ethanol tolerance and dependence.

Adult↗
PubMed1998

Judgments of personal and environmental risks of consumer products--do they differ?

Many psychometric studies have investigated judgments concerning personal risks from technologies, activities or consumer products, but only a few studies have included judgments of risk to the environment. Thus, little is known about this aspect of environmental risk perception, and whether it differs from personal risk perception. This study investigates risk judgments for 30 consumer products of various types such as herbal remedies, mobile telephones, genetically engineered drugs, or garden pesticides. A survey was conducted in two German cities: Leipzig and West Berlin. In total, 408 subjects evaluated the consumer products with regard to personal and environmental risk (and other risk-related aspects) and whether they would recommend the product to others. The findings show statistically significant differences between the mean values of perceived personal risk and environmental risk for most products. Despite these differences, the rank order of mean personal risk and environmental risk judgments for the products is quite similar. However, separate analyses for each product reveal that correlations between perceived personal and environmental risk vary strongly across products. Multiple regression analyses with personal and environmental risk judgments as predictors and product recommendation as criterion, run separately for each consumer product, show that it is mainly the judgment of perceived personal risk that explains product recommendation. Perceived risk to the environment adds little explanatory power. The study also explores differences in judgments of personal and environmental risk with regard to two sociodemographic variables: location (former East Germany vs. West Germany) and gender. Differences in both types of risk judgments are found with regard to location but not for gender.

Adolescent↗
PubMed1997

Free energy of the binding of uridylic acid oligomers with double stranded poly(A) x poly(U).

The binding parameters (K, omega) and the free energy (DeltaG(0)) of triple helix formation have been estimated for complexes of oligo(U)(n) (n = 5, 7-10) with poly(A) . poly(U) on the basis of hypochromicity measurements. The data were treated according to the formula of McGhee and von Hippel [J. Mol. Biol. 86 (1974) 469] by a computer program ALAU [H. Schütz et al., Stud. Biophys. 104 (1984) 23] which takes absorbancies and total concentrations as input. In 1 mM cacodylate buffer pH 7.0 with 10 mM NaCl and 10 mM MgCl(2) at 5 degrees C the free energy of contiguous binding was found to be a linear function of the oligomer length with a slope of DeltaG(c,U)(0) = -0.72 (+/-0.03) kcal x mol(-1) per nucleotide. The mean cooperativity coefficient (omega) was 24.5 (+/- 5.6), and the corresponding free energy of interaction between the neighbouring oligonucleotides in the third strand was DeltaG(0(omega)) = -1.74 (+/-0.13) kcal x mol(-1).

Journal Article↗
PubMed1997

The goat mammary gland as a target organ for atrial natriuretic peptide.

Milk secretion represents a major route for electrolyte and water excretion in the dairy goat. The aims of this study were to investigate whether the mammary gland is a target site for atrial natriuretic peptide (ANP) in the goat and whether ANP affects mammary sodium and water secretion. Receptor autoradiography using 125I-ANP as radioligand revealed specific binding sites in the secretory tissue of the mammary gland. The radioligand was totally displaced by unlabelled ANP, but not by brain natriuretic peptide or the ANP fragment c-ANP4-23, indicative of ANP-A receptor preference. To elucidate the role of ANP in milk secretion, ANP (30 ng kg-1 min-1; 120 min) or 0.15 M NaCl (control) were administered in vivo. The ANP infusions caused haemoconcentration, but did not change milk flow or the concentrations of sodium, potassium, lactose, fat and protein in the milk. The results show that the mammary gland of the goat expresses ANP-specific binding sites, however, a physiological role of ANP in goat mammary gland function remains to be elucidated.

Animals↗
PubMed1997

Relative bioavailability of 3 different chlormezanone 200 mg preparations after single dose oral administration.

Eighteen male volunteers have been treated with 3 different oral formulations of chlormezanone according to a randomized 3-way change-over design. The test preparation was a tablet (Krewel), reference preparation 1 was a suspension (Krewel), and reference preparation 2 was a tablet (Muskel Trancopal, Sanofi Winthrop GmbH). All preparations contained 200 mg of chlormezanone. Divided in 3 periods the volunteers received single doses of the test and the 2 reference formulations, respectively. Blood samples have been drawn immediately prior to each administration and at 21 sampling points within 144 h after dosing. A wash-out period of 2 weeks was maintained between successive drug doses. Plasma concentrations of chlormezanone were determined by a validated reversed-phase HPLC method with UV detection, with a lower limit of quantification of 0.1 microgram/ml. The following mean values have been obtained for the test preparation: AUC0-infinity 121 micrograms x h/ml, Cmax of 2.9 micrograms/ml at 1.5 h, t1/2 38 h, after administration of the suspension: AUC0-infinity 111 micrograms x h/ml, Cmax 2.6 micrograms/ml, tmax 1.5 h, t1/2 40 h, and after administration of the reference tablet: AUC0-infinity 121 micrograms x h/ml, Cmax 3.0 micrograms/ml, tmax 1.6 h, t1/2 38 h. The test preparation shows a relative bioavailability of 109% compared to the suspension and has been proven to be bioequivalent to the reference tablet with regard to extent and rate of absorption.

Administration, Oral↗
PubMed1997

Relative bioavailability of different butamirate citrate preparations after single dose oral administration to 18 healthy volunteers.

Eighteen volunteers have been treated with different oral formulations of butamirate citrate according to 2 randomized 2-way crossover designs. In the first study (study I) the test preparation was a syrup (Demotussol Hustensirup, Demopharm), and the reference preparation was a syrup already marketed (Sinecod Sirup, Zyma SA). A test preparation (Demotussol Tabletten) was compared to a solution (Demotussol Hustentropfen) in the second study (study II). Within the 2 study periods the volunteers received single 45 mg doses of the test and the reference formulation, respectively. Blood samples have been drawn immediately prior to each administration and at 17 sampling points within 96 h after dosing. A wash-out period of 1 week was maintained between successive drug doses. The plasma concentration of one of the main metabolites, 2-phenylbutyric acid, was determined by a validated reversed-phase HPLC method with UV detection, with a lower limit of quantification of 50 ng/ml. The following mean values have been obtained in study I (syrup preparations) for the test: AUC0-infinity 46.9 micrograms x h/ml, Cmax of 1.77 micrograms/ml at 1.1 h, t1/2 28 h and after administration of the reference: AUC0-infinity 50.4 micrograms x h/ml, Cmax 1.86 micrograms/ml, tmax 1.5 h, t1/2 26 h. In study II the following mean values have been obtained for the test preparation (tablet): AUC0-infinity 54.7 micrograms x h/ml, Cmax of 1.88 micrograms/ml at 1.1 h, t1/2 27 h and for the reference (solution): AUC0-infinity 54.5 micrograms x h/ml, Cmax 1.94 micrograms/ml, tmax 1.1 h, t1/2 26 h. Both preparations have been proven to be bioequivalent to their corresponding references regarding extent and rate of absorption.

Administration, Oral↗
PubMed1997

[Risk perception and risk communication in environmental medicine].

Environmental medicine requires special communicative talents in order to inform about risks, to change risk-related behavior or to reassure people with excessive risk-related anxieties. We provide some guidance on how to accomplish these communication tasks. First, the results of psychological risk perception research are outlined, and the cognitive and affective factors, which determine laypeople's risk appraisal, are explained. Then, the basic problems of risk communication are described and the tasks and duties of medical risk communication are specified: How can risk information be indicated in an appropriate way? Which risk comparisons can be provided to enhance understanding? What are the advantages and drawbacks of risk comparisons? What criteria can be used to evaluate the quality of risk assessment studies? What are the Do's and Dont's of risk communication? And, how should anxieties about risks be approached?

Environmental Monitoring↗
PubMed1996

Different effects of nonintercalative antitumor drugs on DNA triple helix stability: SN-18071 promotes triple helix formation.

The interaction of the nonintercalating bisquaternary ammonium heterocyclic drugs SN-18071 and SN-6999 with a DNA triple helix has been studied using thermal denaturation and CD spectroscopy. Our data show, that both minor groove binders can bind to the triple helix of poly(dA).2poly(dT) under comparable ionic conditions, but they influence the stability of the triplex relative to the duplex structure of poly(dA).poly(dT) in a different manner. SN-18071, a ligand devoid of forming hydrogen bonds, can promote triplex formation and thermally stabilizes it up to 500 mM Na+ concentration. SN-6999 destabilizes the triplex to duplex equibilirium whereas it stabilizes the duplex. The binding constant of SN-18071 is found to be greater than that to the duplex. The stabilizing effect of SN-18071 is explained by electrostatic interactions of three ligand molecules with the three grooves of the triple stranded structure. From the experiments it is concluded that SN-6999 binds to the triplex minor groove thereby destabilizing the triplex similar as previously reported for netropsin.

Antineoplastic Agents↗