Browsing by Author "CAMPOS, EO"

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    ACETYLCHOLINESTERASE CHANGES IN HEARTS WITH SINUS RHYTHM AND ATRIAL-FIBRILLATION
    (1993) GONZALEZ, RA; CAMPOS, EO; KARMELIC, C; MORAN, S; INESTROSA, NC
    1. Clinical and experimental evidence suggest that changes in the autonomic tone play a role in the pathogenesis of atrial fibrillation.
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    BLOOD MARKERS IN ALZHEIMER-DISEASE - SUBNORMAL ACETYLCHOLINESTERASE AND BUTYRYLCHOLINESTERASE IN LYMPHOCYTES AND ERYTHROCYTES
    (ELSEVIER SCIENCE BV, 1994) INESTROSA, NC; ALARCON, R; ARRIAGADA, J; DONOSO, A; ALVAREZ, J; CAMPOS, EO
    In patients with the clinical diagnosis of Alzheimer disease (AD), we searched for systemic changes in components of the blood as a diagnostic tool. The acetylcholine-related enzymes acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) were measured in plasma, erythrocytes, platelets and lymphocytes. Results did not show a general effect; notwithstanding, specific cell types presented alterations either in AChE or BuChE but not in both enzymatic activities. In AD patients, AChE of lymphocytes was reduced by 60% compared with the age-matched controls. However, when patients were divided, the sporadic but not the familial subgroup exhibited a significant reduction. In erythrocytes the BuChE activity was reduced by 45% in sporadic AD. The molecular forms of the lymphocyte AChE were characterized by velocity sedimentation. Both globular forms were subnormal, more so the tetrameric G(4) AChE form than the G(2) form.
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    CHARACTERIZATION OF ACETYLCHOLINESTERASE FROM HUMAN HEART AURICLES - EVIDENCE FOR THE PRESENCE OF A G-FORM SENSITIVE TO PHOSPHATIDYLINOSITOL-SPECIFIC PHOSPHOLIPASE-C
    (1991) GONZALEZ, R; CAMPOS, EO; MORAN, S; INESTROSA, NC
    1. Acetylcholinesterase (AChE) is an important enzyme of the cholinergic system in mammals.
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    METAMORPHOSIS OF CONCHOLEPAS-CONCHOLEPAS (BRUGUIERE, 1789) INDUCED BY EXCESS POTASSIUM
    (1993) INESTROSA, NC; GONZALEZ, M; CAMPOS, EO
    Planktonic larvae of Concholepas concholepas Bruguiere underwent complete metamorphosis in response to excess K+. The effect was dose-dependent and optimal at approximately double the normal concentration of K+ in 0.45 um membrane-filtered seawater. Increasing concentration over 25 mM K+ produced a decline in survival, suggesting toxicity. Metamorphosis began with propodium attachment to the substratum and subsequent deciliation and destruction of the velum, followed by the emergence of cephalic tentacles from the larval shell margin. Velar loss, induced by K+, began with the detachment of large ciliated cells at the velar margin. Field-collected larvae, from different localities along the Chilean coast, presented a positive response to excess K+, and almost 80% of the larvae metamorphosed in 1 to 2 days. The induction of metamorphosis of Concholepas concholepas larvae by K+, provides a useful biotechnological tool for the cultivation of this socio-economically important marine resource of the southeastern Pacific Ocean.
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    METAMORPHOSIS OF LABORATORY-REARED LARVAE OF CONCHOLEPAS-CONCHOLEPAS (MOLLUSCA, GASTROPODA)
    (1994) CAMPOS, EO; PINTO, A; BUSTOS, E; RODRIGUEZ, SR; INESTROSA, NC
    Metamorphosis of laboratory-reared larvae of the gastropod Concholepas concholepas was observed under the influence of K+ ions. After 64 h of incubation at 10 degrees C, 58% of larvae metamorphosed in response to 20 mM K+ final concentration in seawater, 11 mM above ambient. No effect was observed at 15 mM K+. Likewise, larvae were unable to survive when exposed to 25 mM K+. Metamorphosed individuals of C. concholepas migrated to the water-air interface within 28 h of their metamorphosis. This study reports the first successful experiment on the induction of metamorphosis in laboratory-reared larvae of C. concholepas. The advantages of mass production of larvae with metamorphic capacity of this economically important resource, related to its eventual culture on a pilot scale are discussed.
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    MOLECULAR-CHANGES INDUCED BY METAMORPHOSIS IN LARVAE OF THE PROSOBRANCH CONCHOLEPAS-CONCHOLEPAS BRUGUIERE (MOLLUSCA, GASTROPODA, MURICIDAE)
    (1993) INESTROSA, NC; GONZALEZ, M; CAMPOS, EO
    Metamorphosis may be the most critical point in the life history of marine molluscs. Excess potassium was used to trigger the metamorphic process in competent larvae of the prosobranch Concholepas concholepas Bruguiere. The specific, irreversible stimulation of complex morphogenetic events by this exogenous factor was used to study some molecular changes that occur during metamorphosis. Results show that metamorphosis entails several molecular changes, including: (1) a modification in the pattern of protein synthesis measured by incorporation of [S-35]methionine to newly synthetized polypeptides, (2) an increase of [S-35]methionine incorporation in heparin-binding proteins or the induction of heparin-binding proteins (i.e. growth factors?), (3) a decrease (20 times) in the larval levels of the second messenger cyclic AMP, and (4) the appearance of a new form of the neurotransmitter-related enzyme, acetylcholinesterase (AChE). To our knowledge this is the first attempt to characterize some of the molecular changes that take place during molluscan metamorphosis.