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  • 1
    ISSN: 1432-0738
    Keywords: Benzene ; Hemoglobin ; Adducts ; S-Phenylcysteine ; Biological exposure index
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Benzene is metabolized to intermediates that bind to hemoglobin, forming adducts. These hemoglobin adducts may be usable as biomarkers of exposure. In this paper, we describe the development of a gas chromatography/mass spectroscopy assay for quantitating the binding of the benzene metabolite, benzene oxide, to cysteine groups in hemoglobin. We used this assay to study the hemoglobin adduct, S-phenylcysteine (SPC), in the blood of rats and mice exposed to benzene either by inhalation or by gavage. We were able to detect SPC in the hemoglobin of exposed rats and mice, to show the linearity of the exposure dose-response relationship, and to establish the sensitivity limits of this assay. For the same exposure regime, rats showed considerably higher levels of SPC than did mice. As yet, we have not been able to detect SPC in the globin of humans occupationally exposed to benzene. We attempted to determine whether the SPC found in hemoglobin originated from the metabolism of benzene within or outside of the red blood cell. We hypothesized that the greatest red blood cell metabolism would be associated with peripheral reticulocytes, which retain high metabolic capacity. After exposing rats to benzene, we isolated the red blood cells and used discontinuous Percoll gradients to fractionate them into age groups. No differences in SPC levels were found among any of the fractions, suggesting that the SPC found in globin originates from the metabolism of benzene to benzene oxide in a location external to the red blood cell. To our knowledge, this is the first demonstration of the nonenzymatic binding of the benzene metabolite, benzene oxide, to protein. The products of the interaction of benzene oxide with protein are particularly appealing as potential biomarkers. These adducts are stable both in vivo and during isolation, and because high background levels in unexposed individuals are unlikely, the presence of such adducts should be a specific indicator of exposure to benzene. If SPC can be detected in humans, the present assay, with some modification, may be amenable to routine monitoring of worker exposures to benzene.
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  • 2
    ISSN: 1432-1041
    Keywords: antiarrhythmic drugs ; lorcainide ; haemodynamic effects ; i.v. dose
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary The cardiovascular effects of a single i.v. dose (2 mg/kg over 5 min) of lorcainide were studied in 14 patients with heart disease. In the haemodynamic part of the study (6 patients), the aortic and pulmonary systolic, diastolic and mean pressures, left ventricular systolic and end-diastolic pressures, cardiac output and the rate of rise of left ventricular pressure were measured before and for 30 min after administration of the drug. Lorcainide produced a slight and short-lasting decrease in the aortic and pulmonary systolic pressures, and all other pressure values remained unchanged. The cardiac output and systemic vascular resistance were not altered by lorcainide. It consistently depressed the rate of rise of left ventricular pressure (maximum mean decrease 19%). In the angiographic part of the study (8 patients), the ejection fraction and the mean velocity of circumferential fiber shortening were measured before and 5 min after lorcainide. In all but one patient, lorcainide decreased the ejection fraction (mean decrease 11.6%), and the mean velocity of circumferential fiber shortening was uniformly diminished by lorcainide (mean decrease 29.7%). Thus, lorcainide moderately impaired myocardial performance in patients with normal and reduced left ventricular function without producing hypotensive side effects.
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Monatsschrift Kinderheilkunde 145 (1997), S. 1170-1172 
    ISSN: 1433-0474
    Keywords: Schlüsselwörter Zerkarien ; Badedermatitis ; Trichobilharzia ; Schistosomiasis ; Key words Cercariae ; Swimmer’s itch ; Trichobilharcia ; Schistosomiasis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary During a period of two weeks in hot dry midsummer 3 patients presented in our pediatric outpatient clinic after a bath in a small lake. They had an extremely itching, elevated exanthema mainly on their legs. The single efflorescence had a diameter of about 1–3 cm. There were no signs of infection or fever. The patients history, clinic and skin lesions made us think of swimmer’s itch caused by leeches (trematoda), cercariae of the trichobilharcia type. We prooved it serologically. Trichobilharcia scidati and trichobilharzia ocellata are certain avian schistosomatidae. In periods of dry and hot weather the number of cercariae raises in lakes. They penetrate the skin but cannot develop any further and cause as an allergic response a very itchy exanthema, which lasts for up to 20 days. Treatment is symptomatic and consists of antihistamine-gels. Discussion: Prevention of the disease is difficult. Reexposed persons could react stronger, therefore they should avoid swimming in those lakes.
    Notes: Zusammenfassung Während einer 2wöchigen sommerlichen Hitzeperiode stellten sich 3 Patienten nach einem Bad in einem Baggersee in unserer Ambulanz mit einem stark juckenden, beinbetonten und erhabenen Exanthem vor. Die einzelnen Effloreszenzen hatten einen Durchmesser von ca. 1–3 cm. Das Allgemeinbefinden war nicht beeinträchtigt. Aufgrund der Anamnese, der Klinik und des Verteilungsmusters der Effloreszenzen stellten wir die Verdachtsdiagnose einer Zerkariendermatitis, die serologisch betätigt wurde. Verursacher sind Trematoden, Zerkarien vom Typ der Trichobilharzia. In unseren Breiten handelt es sich um Trichobilharzia szidati und Trichobilharzia ocellata, die Erreger der Bilharziose bei Wasservögeln. In heißen Sommerperioden vermehren sich Zerkarien rasch in stehenden Gewässern. Sie dringen in die Haut ein und sterben in den oberen Hautschichten ab. Aufgrund allergischer Prozesse kommt es zu einem stark juckenden Exanthem, das gut auf lokale Antihistaminika anspricht und innerhalb von 20 Tagen folgenlos abheilt. Diskussion: Effektive Präventionsmaßnahmen gibt es nicht. Betroffene Personen sollten wegen der Gefahr einer verstärkten Reaktion bei Reexposition das Baden in den entsprechenden Seen meiden.
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  • 4
    ISSN: 1432-2145
    Keywords: Key words Arabidopsis thaliana ; Megasporogenesis ; Megagametogenesis ; Mitosis-meiosis switch
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract  In this paper, we describe a novel plant mutant affected exclusively in the female mitosis-meiosis switch. The major effect of the swi1 mutation in Arabidopsis thaliana L. is to delay megasporogenesis events by inserting additional mitotic divisions of the mega- sporocyte. As a result of this delay, megagametogenesis is also affected. The absence of cellular polarity in the megasporocytes was also observed. Ovule ontogenesis is not affected by the mutation. The swi1 mutant is particularly interesting for studying sporophyt-gametophyte interactions. The swi1 mutation, obtained from a T-DNA tagging experiment, is monogenic recessive and mapped on chromosome five, at 16 cM from the yellow inflorescence marker.
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    World journal of urology 10 (1992), S. 149-153 
    ISSN: 1433-8726
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Despite its limitations, CT scanning is of significant value in evaluating the lower urinary tract and pelvis. Its major role in imaging the ureter involves the confirmation or further characterization of causes of obstruction or deviation of the ureter by tumor masses or vascular abnormalities. It is also useful in the evaluation of radiolucent filling defects found at urography and can help to delineate extraluminal extension of disease. The major role played by CT in evaluation of the bladder and prostate gland involves the staging of malignancy, especially in assessing of lymphadenopathy and distant metastases, in suggesting tumor involvement in adjacent tissue, and evaluating secondary complications such as renal obstruction. CT is also helpful in evaluating some nonneoplastic conditions of the bladder and prostate gland, particularly inflammatory lesions and continent urinary diversion.
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  • 6
    ISSN: 1420-908X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Diamine oxidase activity and imidazoleacetic acid formation in the foetal and maternal guinea pig liver during gestation were examined. DAO activity and IMAA formation in the foetal liver increased continuously, while maternal enzyme activity and ImAA formation in the second half of pregnancy simultaneously decreased. The roles of GABA and ImAA are discussed.
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Monatshefte für Chemie 99 (1968), S. 2142-2152 
    ISSN: 1434-4475
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Abstract The rate of reaction of Ag2S with atomic hydrogen has been measured at temperatures between 250° and 350°C. Definite sulphur activities in the Ag2S during the reduction were obtained using the galvanic solid state cell Pt/Ag/AgJ/Ag2S/Pt. It was found that the reduction is of first order with respect to the atomic hydrogen concentration and does not depend on the activity of the sulphur in silver sulphide. A mechanism for the reaction is proposed in such a way that the hydrogen atom from the gaseous phase interacts with an adsorbed hydrogen atom and sulphur on the silver sulphide surface.
    Notes: Zusammenfassung Die Kinetik der Reduktion von Ag2S durch atomaren Wasserstoff zwischen 250 und 350°C wird untersucht. In der Silbersulfidprobe, die eine Elektrode der galvanischen Festkörperkette Pt/Ag/AgJ/Ag2S/Pt bildet, können während der Reduktion definierte Schwefelaktivitäten eingestellt werden. Die Reduktion verläuft nach 1. Ordnung bezüglich der Wasserstoffatomkonzentration und ist von der Schwefelaktivität im Ag2S unabhängig. Zur Deutung des Ablaufs der Reaktion wird angenommen, daß ein adsorbiertes Wasserstoffatom und ein Wasserstoffatom aus der Gasphase mit Schwefel an der Silbersulfidoberfläche reagieren.
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  • 8
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Using the ( $$\vec d$$ ,3He) reactions on90Zr and144Sm at 52 MeV spins of deeply-bound hole states have been measured for the first time. In contrast to neutron pick-up reactions the shell model strength is exhausted which enables us to derive the 1f and 1g spin-orbit splitting.
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  • 9
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Angular distributions of differential cross sections and vector analyzing powers were measured forl=0, 1 and 2 transitions induced by the $$^{26} Mg\left( {\overrightarrow d ,\tau } \right)^{25} Na$$ reaction at 52 MeV. The following spins and parities of final states in25Na were deduced:J π =1/2+ (1.069 MeV), 3/2+ (2.202 MeV), 5/2+ (2.914 MeV), 1/2− (3.995 MeV) and 3/2− (5.190, 5.690, 6.549 and 7.603 MeV). The DWBA analysis of proton and neutron pick-up spectra obtained from a parallel measurement of the26Mg(d, τ)25Na and26Mg(d, t)25Mg reactions allows the identification ofT=3/2 analog states in25Mg. Interpretation in terms of the Nilsson model of energies and spectroscopic factors of the first 1/2− and 3/2− hole states observed in proton pick-up reactions from even 1d 5/2- shell nuclei indicates a close correspondence of the final state deformations with those of the first excited 2+ states in the target nuclei.
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  • 10
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Polarized deuteron beams may be obtained from metastable atomic beams by quenching three of the six hyperfinestructure levels. Using a field distribution which crosses zero on the beam axis the occupation numbers of the hyperfinestructure levels may be changed by a nonadiabatic process. The special conditions for this magnetic field are discussed by comparing the corresponding Larmor frequency of the metastable atoms with the angular frequency of the magnetic field vector. Experimental investigations were carried out for field gradients between 1.9 and 5.4 Oe/cm and for superposed homogeneous transverse fields of up to 6 Oe. With deuterons a tensorpolarization ofP 33=−0.70±0.01 was obtained at a negative ion beam current of 42 nA.
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