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991.
Judith Huerta-Bahena Rafael Villalobos-Molina J.Adolfo García-Sáinz 《Life sciences》1982,30(20):1757-1762
Cycloheximide, a widely used inhibitor of protein synthesis, stimulates glycogenolysis, gluconeogenesis and ureogenesis in isolated rat hepatocytes. The effects of cycloheximide were compared to those of norepinephrine. Both agents, cycloheximide and norepinephrine, produced slight increases in the levels of cyclic AMP (30% increases) which were blocked by propranolol. Interestingly, it was found that the metabolic actions of norepinephrine and cycloheximide (stimulation of glycogenolysis, gluconeogenesis and ureogenesis) were only slightly diminished by the β adrenergic antagonist propranolol but abolished by the selective α1 adrenergic antagonist prazosin. The ability of cycloheximide to inhibit protein synthesis was not affected by either prazosin or propranolol. It is concluded that the stimulation of glycogenolysis, gluconeogenesis and ureogenesis by cycloheximide in rat hepatocytes, is an effect of the antibiotic independent of its ability to inhibit protein synthesis and that is mediated through activation of α1 adrenoceptors. The adrenergic activity of cycloheximide should be considered when this drug is used as an inhibitor of protein synthesis. 相似文献
992.
Summary Gene hsrM (nonB) of Bacillus subtilis 168, causing non-permissiveness to phage SP10 (Saito et al. 1979) and reduced plating efficiency of unmodified phage 105, is responsible for non-permissiveness of B. subtilis 168 for phages 15 and PZA. Upon transformation to sporulation deficiency (allele spoOA) B. subtilis 168 becomes permissive for 15 and PZA and loses the ability to restrict 105. spoOA str-1 double transformants of B. subtilis 168, however, retain the restriction 168 and non-permissiveness for 15 and PZA phages, in spite of their Spo– phenotype. Therefore it appears that a functional product of the spoOA gene is required for expression of gene hsrM in wild-type bacteria, but is not essential in streptomycin-resistant bacteria. Phage genomes (PZA) were trapped in spores of the restriction deficient strain with much higher efficiency than in the wild-type. 相似文献
993.
From the aerial part of Teucrium chamaedrys a new neo-clerodane diterpenoid, dihydroteugin, has been isolated, besides the previously known diterpenoids teucrin A and teugin. The structure of dihydroteugin, (12S)-15,16-epoxy-2β,6β-dihydroxy-neo-cleroda-13(16), 14-diene-18,19:20,12-diolide, was established by chemical and spectroscopic means and by partial synthesis from teugin. 相似文献
994.
Assay of interferon and viral antibodies in the cerebrospinal fluid in clinical neurology and psychiatry 总被引:1,自引:0,他引:1
H Libíková S Breier M Kocisová J Pogády D Stünzner D Ujházyová 《Acta biologica et medica Germanica》1979,38(5-6):879-893
Cerebrospinal fluids (CSF) of 245 neurological and 194 psychiatric patients were tested for viral antibodies and interferon. Complement dependent neutralizing antibodies to Herpesvirus hominis 1 were found in the CSF of patients with encephalitis (50.6%), meningitis (35.4%), lesions of peripheral nerves (36.9%), sclerosis multiplex (41.2%), schizophrenia (31.9%), senile dementia (51.4%), mental retardation (11.1%), ethylism (43.5%). Neutralizing antibodies to tick-borne encephalitis virus were found in the CSF of 38% patients with encephalitis, in 14% meningitis, 11% lesions of peripheral nerves and also in 5.6--11.8% of psychiatric patients. In encephalitis, meningitis and in lesions of peripheral nerves were found in the CSF frequently plaque neutralizing antobidies to the tick-borne orbivirus Lipovník, complement-fixing antibodies to lymphocytic choriomeningitis virus and hemagglutination inhibiting antibodies to measles virus. In multiple sclerosis were detected CSF antibodies to measles virus (44%), Herpesvirus hominis 1 (41.2%) and Lipovník virus (52.6%). In neurological patients were observed CSF antibodies simultaneously to two or three viruses in 16.7 to 40.6%, while in psychiatric patients in zero to 4.6%. CSF interferon was found in psychiatric patients with an equal or even higher incidence (33.7 to 57.1%) than in the neurological patients (29.6--38.6%, in multiple sclerosis only 16.7%). Non-interferon virus inhibitors were excluded. The evaluation of the ratio of serum and CSF titers of viral antibodies and of interferon indicated local synthesis of both in the central nervous system -- with the exception of antibodies to Herpesvirus hominis 1 in CSF of some patients with very high titres in serum and probable lesions of the blood brain barrier. 相似文献
995.
996.
The effect of light on carotene accumulation was studied by analyzing the -carotene content of 4--old mycelia continuously exposed to illumination of different intensities. The wild-type, mutants defective in phototropism, mutants defective in carotene regulation, and newpic mutants specifically defective for photocarotenogenesis were examined. The results indicate that photocarotenogenesis depends on a single sensory pathway which shares its earlier steps (governed by genesmadA andmadB) with the sensory pathway for phototropism. It shares its later steps (probably governed by genescarA andpicB) with one of the pathways for carotene regulation, and includes at least one specific step (governed by genepicA) not known to be involved in other responses. 相似文献
997.
The recent mathematical formalization of the concepts of matter and extrinsical energy, which are used for the relational
representation of biological systems, is employed in the analysis of the important experimental discoveries of Comorosanet al. related to low energy electromagnetic irradiations on enzyme substrates. By means of the present analysis one of the properties
inherent to the experimental phenomena is more precisely exposed, and theoretical developments corresponding to “energetical
evolutions” in a biological system (Leguizamón, 1976) may now have an experimental basis.
Important limitations are introduced for the validity of the commutativity and associativity of cartesian product of sets,
when they represent matter and its linked extrinsical energy. In connection with this last aspect, new important knowledge
is obtained for the relational mathematical representation of biological systems. 相似文献
998.
Marie Kselíková Tomáš Mařík Bedřich Bíbr Jaroslav Lener 《Biological trace element research》1980,2(1):57-64
This study describes the interaction of molybdenum with blood components. Molybdenum-99 was added to blood, and after four
washings, 3% of the total radioactivity was found in red cells. More specifically, the radioactivity was determined to be
associated with the cell membrane.
Molybdenum-99 in the +VI form did not interact with the human erythrocyte membrane; however, Mo(V) forms did interact. Of
five different compounds, the highes uptake was observed with a brown Mo(V)-ascorbate complex generated from Mo(VI) and ascorbic
acid in the molar ratio 1∶20. A membrane suspension of Mo-ascorbate-treated human erythrocytes was prepared and the solubilized
proteins were separated on a polyacrylamide gel in the presence of sodium dodecyl sulfate (SDS). Molybdenum-99 binding to
spectrin was demonstrated, as well as some minor interactions with membrane hemoglobin and bands 6 and 8. 相似文献
999.
F. PospíšiL 《Biologia Plantarum》1980,22(3):161-166
The influence of phenolic and humic acids on the activity of glucose-6-phosphate-dehydrogenase in the roots of pea under aseptic
conditions has been investigated. It seems clear that vanillic and protocatechuic acids inhibit the enzyme activity in the
excised roots of pea, but their dry weight increases in relation to the control. Gallic acid stimulates the G-6-PD activity
in the roots of whole plants. The humic acids influence neither the enzyme activity nor the dry weight of pea seedlings after
short-term treatment. 相似文献
1000.
Dimethyl sulfoxide present in the agar medium at concentration 0.2 % (v/v) and lower does not inhibit cytokinin-induced betacyanin
synthesis in theAmaranthus caudatus seedlings. The activity of kinetin, N6-(Δ2-isopentenyl)adenine andtrans- zeatin is the same when these cytokinins are dissolved in either water or dimethyl sulfoxide and incorporated into the medium
after autoclaving. A simple method is described which allows the cytokinin activity of slightly water-soluble and thermolabile
compounds,e.g. aromatic urea and thiourea derivatives, to be determined in theAmaranthus bioassay. 相似文献