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1.
Braz. j. med. biol. res ; 52(9): e8935, 2019. graf
Article Dans Anglais | LILACS | ID: biblio-1019568

Résumé

The scientific publication landscape is changing quickly, with an enormous increase in options and models. Articles can be published in a complex variety of journals that differ in their presentation format (online-only or in-print), editorial organizations that maintain them (commercial and/or society-based), editorial handling (academic or professional editors), editorial board composition (academic or professional), payment options to cover editorial costs (open access or pay-to-read), indexation, visibility, branding, and other aspects. Additionally, online submissions of non-revised versions of manuscripts prior to seeking publication in a peer-reviewed journal (a practice known as pre-printing) are a growing trend in biological sciences. In this changing landscape, researchers in biochemistry and molecular biology must re-think their priorities in terms of scientific output dissemination. The evaluation processes and institutional funding for scientific publications should also be revised accordingly. This article presents the results of discussions within the Department of Biochemistry, University of São Paulo, on this subject.


Sujets)
Humains , Périodiques comme sujet/statistiques et données numériques , Édition/tendances , Recherche , Biochimie , Biologie moléculaire , Périodiques comme sujet/normes , Périodiques comme sujet/tendances , Brésil
2.
Braz. j. med. biol. res ; 31(6): 827-33, jun. 1998. tab
Article Dans Anglais | LILACS | ID: lil-210973

Résumé

Thiobarbituric acid reactant substances (TBARs) content, and the activities of glucose-6-phosphate dehydrogenase (G6PDh), citrate synthase (CS), Cu/Zn- and Mn-superoxide dismutase (SOD), catalase, and glutathione peroxidase (GPX) were measured in the lymphoid organs (thymus, spleen, and mesenteric lymph nodes (MLN)) and skeletal muscles (gastrocnemius and soleus) of adrenodemedullated (ADM) rats. The results were compared with those obtained for sham-operated rats. TBARs content was reduced by adrenodemedullation in the lymphoid organs (MLN (28 percent), thymus (40 percent) and spleen (42 percent)) and gastrocnemius muscle (67 percent). G6PDh activity was enhanced in the MLN (69 percent) and reduced in the spleen (28 percent) and soleus muscle (75 percent). CS activity was reduced in all tissues (MLN (75 percent), spleen (71 percent), gastrocnemius (61 percent) and soleus (43 percent)), except in the thymus which displayed an increment of 56 percent. Cu/Zn-SOD activity was increased in the MLN (126 percent), thymus (223 percent), spleen (80 percent) and gastrocnemius muscle (360 percent) and was reduced in the soleus muscle (31 percent). Mn-SOD activity was decreased in the MLN (67 percent) and spleen (26 percent) and increased in the thymus (142 percent), whereas catalase activity was reduced in the MLN (76 percent), thymus (54 percent) and soleus muscle (47 percent). It is particularly noteworthy that in ADM rats the activity of glutathione peroxidase was not detectable by the method used. These data are consistent with the possibility that epinephrine might play a role in the oxidative stress of the lymphoid organs. Whether this fact represents an important mechanism for the establishment of impaired immune function during stress remains to be elucidated


Sujets)
Animaux , Rats , Mâle , Médulla surrénale/chirurgie , Catalase/métabolisme , Glutathione peroxidase/métabolisme , Tissu lymphoïde/métabolisme , Muscles squelettiques/métabolisme , Superoxide dismutase/métabolisme , Substances réactives à l'acide thiobarbiturique/métabolisme , Catalase/analyse , Glutathione peroxidase/analyse , Noeuds lymphatiques/métabolisme , Mésentère/métabolisme , Rat Wistar , Rate/métabolisme , Superoxide dismutase/analyse , Substances réactives à l'acide thiobarbiturique/analyse , Thymus (glande)/métabolisme
3.
Braz. j. med. biol. res ; 29(7): 841-51, July 1996. ilus
Article Dans Anglais | LILACS | ID: lil-181496

Résumé

Highly reactive oxyradicals can be generated in vitro by iron-catalyzed aerobic oxidation of synthetic and naturally occuring substances capable of enolization in aqueous medium. Of biological interest are alfa-hydroxy- and alfa-aminocarbonyls such as carbohydrates, 5-aminolevulinic acid, and aminoacetone which tautomerize to the corresponding enediols and enolamines and yield oxyradicals initiated by electron transfer to dioxygen. Free radicals have been implicated in several normal and pathological processes. We briefly review our hypothesis of an in vivo prooxidant role of 5-aminolev-ulinic acid (ALA), the heme precursor accumulated in several porphyric disorders (e.g., lead poisoning, acute intermittent porphyria (AIP), tyrosinosis). Accordingly, i) ALA undergoes transition metal-catalyzed oxidation to give O-2, H2O2 and HO; ii) ALA induces iron release from ferritin, lipid peroxidation of cardiolipin-rich vesicles, single strand breaks in plasmid DNA, and guanosine oxidation in calf thymus DNA; iii) ALA causes Ca2+ -mediated rat liver mitochondria permeabilization; iv) rats chronically treated with ALA exhibit increased glycolytic metabolism; v) brain extracts of ALA-treated rats reveal increased levels of thiobarbituric acid reactive substances, direct chemiluminescence intensity, carbonyl proteins, ferritin, and "free iron"and gama-aminobutyric acid-receptor dissociation constant, and vi) patients with AIP and lead-exposed workers present augmented erythrocytic levels of the antioxidant enzymes superoxide dismutase and glutathione peroxidase. These data indicate the involvement of ALA-generated reactive species in the clinical manifestations (neuropathy, mental changes, muscle weakness, hepatoma) shared by the aforementioned inherited and acquired porphyric diseases.


Sujets)
Humains , Animaux , Rats , Acide amino-lévulinique/métabolisme , Espèces réactives de l'oxygène/métabolisme , Intoxication par le plomb/métabolisme , Stress oxydatif , Porphyrie aigüe intermittente/métabolisme , Acide amino-lévulinique/pharmacologie , Acide amino-lévulinique/urine , Calcium/métabolisme , Cerveau/effets des médicaments et des substances chimiques , Cerveau/métabolisme , Coeur , Altération de l'ADN , Espèces réactives de l'oxygène/pharmacologie , Foie , Foie/métabolisme , Hème/biosynthèse , Fer/métabolisme , Mitochondries/métabolisme , Peroxydation lipidique , Porphyries/métabolisme , Porphyries/urine , Protéines/métabolisme
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