Effects of growth conditions on the activities of superoxide dismutase and NADH-oxidase/NADH-peroxidase inStreptococcus lactis

An increase in the superoxide dismutase (SOD) activity inStreptococcus lactis was observed when the cells were grown at increased oxygen partial pressures or exposed to hyperbaric oxygen tensions. The NADH-oxidase/NADH-peroxidase activities inS. lactis increased in galactose-grown cells when cultivated in air compared with N₂/CO₂. This effect did not occur when glucose was the carbon source; however, an increase in the activities of these enzymes was observed in oxygen atmosphere. The correlation between SOD, NADH-oxidase/NADH-peroxidase, and the metabolic pathways involved is discussed. The effect of manganese on the SOD activity is also considered.     

Determination of betaxolol, a new beta-blocker, by gas chromatography mass spectrometry: application to pharmacokinetic studies

Betaxolol, a beta selective adrenoceptor antagonist recently approved for the treatment of hypertension, was determined by monitoring in chemical ionization mode with ammonia the [MH]+ ions of the trimethylsilyl derivatives of the drug and of its internal standard [2H5)betaxolol). Its pharmacokinetic profile obtained following administration of a 20 mg oral dose was characterized by a half-life of 22 h and a bioavailability of 85%. The main acid metabolite formed by elimination of the isopropylamino group may also be determined as the methyl TMS derivative but methylation with BF3-methanol should be used with caution since it may induce the opening of the cyclopropyl group. The routine electron capture determination procedure was compared to this mass spectrometric method and an excellent correlation was found (r = 0.9974). Both procedures have the same sensitivity (1 ng ml-1). Finally it was observed that under electron impact mode betaxolol trimethylsilyl side chain rearranged to lose TMS-O-CH=CH2; this elimination was confirmed by deuterium labelling studies.     

Cytologic observations on the effects of metallocene dichlorides on human fibroblasts cultivated in vitro

The effects of the organometallic cytostatic agents titanocene dichloride (TDC) and vanadocene dichloride (VDC) and of the inorganic cytostatic drug cis-diamminedichloroplatinum(II) (DDP) on the morphologic appearance of human embryonal fibroblasts cultivated as monolayers in vitro were analyzed by light and electron microscopy. All three substances induced similar structural changes which consisted of nuclear as well as cytoplasmic alterations. Many fibroblasts enlarged but the nuclear volume increased more extensively than that of the cytoplasm. The nuclear envelopes underwent invagination so that segmented nuclei were formed and the nucleoli increased in size and density. Within the cytoplasm there was evidence of conspicuous protein synthesis, characterized morphologically by an increase in the size and number of mitochondria, Golgi apparatuses and of cisternae of the rER. The phenomena observed are interpreted as indicating unbalanced cell growth characterized by a selective inhibition of DNA synthesis, coupled with progressive RNA and protein syntheses.     

Transplantation of a time-signal in honeybees

Summary It has been possible — by transplantation of brain tissue (i.e. mushroom-bodies) — to perform an interindividual transfer of a learned time-signal in honeybees. The information of the donor bees becomes determinative for the temporal activity pattern of the recipients about 3 to 4 days following transplantation.As seen from histological investigations done in parallel, the donor tissue is treated as a xenograft by the recipient's organism including disintegration and encapsulation processes. These observations give evidence for a humoral transfer of information.The results are discussed from the point of view of the analysis of the mechanism of time reception.Dedicated to Prof. Dr. H. Autrum on the occasion of his 70th birthdaySupported by the Akademie der Wissenschaften und der Literatur zu Mainz, the Stiftung Volkswagenwerk and the Deutsche ForschungsgemeinschaftAll observations done were individual per hand registrations. We want to give thanks to all people in the department who helped us to do the experiments.     

Exhaustive physical exercise and acid hydrolase activity in mouse skeletal muscle

Summary Adult, untrained NMRI mice were exhausted on a motor-driven treadmill by an intermittent-type running programme. Serial cryostate sections for the staining of NADH-tetrazolium reductase, -glucuronidase, -N-acetylglucosaminidase, and -glycerophosphatase activities and for making hematoxylin-eosin staining were cut from m. quadriceps femoris 1, 2, 3, 5, 7, and 15 days after physical exhaustion. A strong increase in the activities of -glucuronidase and -N-acetylglucosaminidase, was observed 7 days after exhaustion and the activity changes, which were similar for the both glycosidases, were more prominent in the highly oxidative red compared to less oxidative white fibres. Activity granules were more numerous in the perinuclear than the interfibrillar area of red fibres. Spots were arranged like longitudinal chains between myofibrils. Activity in connective tissue was usually observed only in animals exhausted 3–7 days earlier. Simultaneous activity in fibres exceeded that in connective tissue -Glycerophosphatase activity was not, by the method used, seen in histologically healthy or normal-looking fibres. in samples taken 2–5 days after exhaustion some degenerating and necrotic fibres were observed. Inflammatory reaction was also observed being at its strongest five days after loading when mononuclear cells were seen inside necrotic fibres. The number of regenerating muscle cells was most abundant 7 days after exhaustion. It is suggested that temporary hypoxia, which accompanies exhaustive physical exercise in skeletal muscle, upsets the energy metabolism and homeostasis of fibres and causes the observed histological and histochemical alterations, which posses features typical of both lethal and sublethal acute cell injury.     

Fine structure of dense-cored vesicles in glomus cells of rat carotid body after fixation with permanganate or glutaraldehyde

Summary Glomus (Type I) cells of the carotid body of adult rats were studied electron microscopically after fixation with potassium permanganate or with glutaraldehyde and osmium tetroxide. Two permanganate fixation methods (using Krebs-Ringer-glucose, pH 7.0, or acetate buffer, pH 5.0) were compared. Numerous dense-cored vesicles were observed only in about one tenth of the glomus cells when neutral permanganate was used for fixation, although all glomus cells showed such vesicles after fixation with glutaraldehyde and osmium tetroxide. Numerous vesicles with a dense core were observed in about one third of the cells after fixation with acid potassium permanganate. With this fixation, small dense-cored vesicles similar to those in adrenergic nerve terminals were occasionally seen in the cytoplasm of glomus cells. It is tentatively concluded that the amine-storing vesicles of the carotid body are different from those in the small intensely fluorescent (SIF) cells and those in adrenergic nerve terminals.     

N-banding in polytene chromosomes of Chironomus and Drosophila

The N-banding patterns of the polytene chromosomes of Drosophila melanogaster, Chironomus melanotus, Ch. th. thummi and Ch. th. thummi x Ch. th. piger were studied. In Chironomus the polytene N-banding patterns correspond to the polytene puffing patterns. This is revealed by comparison of the puffing and N-banding patterns of identical chromosomes. Size and staining intensity of the N-bands reflect the size of the puffs as shown by puff induction. There is no evidence that the N-bands are also located in Chironomus heterochromatin or are restricted to the nucleolar organizer regions. In Drosophila the -heterochromatin is strongly N-positive, whereas the -heterochromatin, as well as the Chironomus heterochromatin is not N-banded. Contrary to Chironomus, the puffs in Drosophila polytene chromosomes do not give rise selectively to well stained N-bands. — The N-banding method is interpreted to stain specifically non-histone protein which is (1) accumulated in genetically active chromosome regions and (2) present in a specific type of heterochromatin (-heterochromatin of Drosophila).     

A peroxisomal glycolate oxidase in the algaMougeotia

Microbodies of the algaMougeotia were isolated in a linear sucrose gradient. The organelles, which moved to the density 1.24 g cm^–3, contained about 70% of the glycolate oxidase (EC 1.1.3.1) found in this alga. The enzyme oxidized glycolate, utilizing either oxygen or 2,6-dichlorophenolindophenol (DCPIP) as the electron acceptor. L-Lactate was an alternate substrate; almost no D-lactate was utilized. In the presence of O₂, a K_m of 415 M was determined for glycolate, whereas the K_m for L-lactate was about 5,000 M. In the presence of DCPIP, lower concentrations of glycolate and L-lactate were sufficient to obtain the highest rates of enzyme activity.Abbreviations DCPIP 2,6-dichlorophenolindophenol Supported by the Deutsche Forschungsgemeinschaft     

An automatic method for determination of urinary 3-methylhistidine: normal values.

A system for automatic analysis of urinary 3-methylhistidine is described, applying ion-exchange chromatography and using an automatic sample injector, a motoric selector valve, and a diode programmer, which controls the analytical system. The method permits a sampling rate of 22 samples/day. 3-Methylhistidine was completely separated from histidine in 37 min whereas 1-methylhistidine was eluted together with ammonia. The 3-methylhistidine concentration was linear up to 150 nmol/ml and no appreciable sample interaction was found at automatic sequential runs. The error, in a single determination based on duplicate samples, was 4.61% and, in duplicated determinations, 3.26%. The mean urinary 3-methylhistidine output was 299.4 ± 23.8 μmol/day in 12 healthy females and 545.5 ± 35.2 μmol/day in 12 healthy males. The 3-methylhistidine excretion was significantly higher in males than in females, when expressed as the absolute daily output or as the estimated ratio to body weight, body surface area, or creatinine.