Search Results - (Author, Cooperation:G. Ayala)

2012-12-04

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Animals ; COUP Transcription Factor II/deficiency/genetics/*metabolism ; Cell Cycle Checkpoints ; Cell Line, Tumor ; *Cell Transformation, Neoplastic ; Disease Models, Animal ; Disease Progression ; Gene Deletion ; Humans ; Male ; Mice ; Neoplasm Metastasis ; PTEN Phosphohydrolase/deficiency/genetics ; Proportional Hazards Models ; Prostate/metabolism/pathology ; Prostatic Neoplasms/*metabolism/*pathology ; *Signal Transduction ; Smad4 Protein/deficiency/genetics/metabolism ; Transforming Growth Factor beta/*antagonists & inhibitors/metabolism

1471-4159

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Abstract— The effect of topical application of diethyl-α-fluoroglutarate on the primary response of cat cerebral cortex to thalamic stimulation was investigated, and samples of the involved tissue and of homologous contralateral control tissue were removed at appropriate times for biochemical analyses. Changes in electrocortical response were first noted 30–40 min after topical application of 10 μ1 (52.7 μmol) of the drug to the pericruciate gyrus. A rapid reduction in amplitude of the surface negative component of the primary response was observed initially, followed by amplitude reduction and rapid disappearance of the primary response throughout the cortical field within a few minutes after the change first observed at the surface. The effects were interpreted either as a direct action of the drug on the somadendritic membrane or an inhibition of the excitatory synaptic impingement.Analyses of the tissues removed at the time of maximum electrocortical response indicated profound metabolic changes, including depletion of energy reserves and several Krebs cycle intermediates. Large increases in tissue levels of glucose, glucose 6-phosphate, and pyruvate were found. Changes in amino acids comprised depletion of glutamate with increased tissue levels of aspartate, GABA, NH3, threonine, serine and alanine.Tissues were also removed at 10 min after topical application of the drug but before the advent of electrocortical changes. Decreased levels of glutamate were associated with a rise in tissue aspartate. Tissue levels of the other amino acids were unchanged. Glucose, glucose 6-phosphate and pyruvate levels were increased, lactate and ATP levels were unchanged, and P-creatine, α-KG and malate levels were reduced. We believe that the observed pattern of changes represents responses of the cerebral cortex to either a block in the synthesis of glutamate or in oxidation of pyruvate, with consequent interference with oxidative and energy metabolism and eventual depression of cortical electrical activity.

Electronic Resource

0003-9861

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Chemistry and Pharmacology

Physics

Electronic Resource

0005-2728

ATPase ; Cytochrome c oxidase ; Liposome ; Mitochondrial membrane ; Protein-lipid complex ; Succinic dehydrogenase

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Chemistry and Pharmacology

Medicine

Physics

Electronic Resource

0014-5793

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Chemistry and Pharmacology

Physics

Electronic Resource

1574-6968

Blackwell Publishing Journal Backfiles 1879-2005

Biology

To monitor changes along the entire Helicobacter pylori vacA gene we carried out full-length single-step PCR amplification in 21 gastritis and gastric cancer isolates. HindIII restriction analysis led us to detect a 〉400-bp internal insertion in vacA subsequently shown to be a direct 451-bp gene duplication. We found HindIII profiles for 16 genes that allowed their grouping into two restriction patterns that were related to theoretical profiles for previously sequenced Western genes. Comparisons with theoretical HindIII patterns for Japanese isolates appear suggestive of geographical H. pylori clonality. Full-length single-step PCR amplification seems suitable for quick restriction pattern assignment and detection of gene size changes.

Electronic Resource

1420-9071

Springer Online Journal Archives 1860-2000

Biology

Medicine

Summary Allotransplantation of fresh, 1 or 2 week cultured parathyroid glands from Wistar rats (AgB2) to Fischer rats (AgB1) resulted in prompt rejection of the transplant in the muscle site; whereas transplantation into the adrenal site offered slightly prolonged survival, suggesting that the latter is a privileged transplantation site.

Electronic Resource

1432-1017

Myelin membrane ; non-denaturing detergents ; lipids ; proteolipid protein ; Raman and infrared spectra

Springer Online Journal Archives 1860-2000

Biology

Physics

Abstract Raman and infrared spectroscopy have been simultaneously applied, for the first time, to the study of myelin membranes and their proteolipid protein (PLP) so as to obtain information on the secondary structure of proteins and the ordering of lipid chains. The vibrational spectra were recorded at physiological pH using a non-denaturing detergent (n-octyl-β-d-glucopyranoside) in phosphate buffer. Neither the buffer nor the detergent interfere spectroscopically with the amide bands from proteins. The spectra reveal that the predominant secondary structure in the polypeptide backbone in myelin is the helix. The proteolipid protein was found to be more disordered than the polypeptide arrangement of the myelin membrane, as deduced from the relative intensities and halfwidths of characteristic infrared amide I bands. β-form and turns are also present, the amount of these structures being higher in PLP. The study of the Raman spectra of vC-C and vC-H regions made it possible to obtain information on the lipid chain order.

Electronic Resource

1573-6873

computer simulations ; kinetic model ; LTD ; LTP ; retrograde messenger

Springer Online Journal Archives 1860-2000

Computer Science

Medicine

Physics

Abstract A computational model of long-term potentiation (LTP) and long-term depression (LTD) in the hippocampus is presented. The model assumes the existence of retrograde signals, is in good agreement with several experimental data on LTP, LTD, and their pharmacological manipulations, and shows how a simple kinetic scheme can capture the essential characteristics of the processes involved in LTP and LTD. We propose that LTP and LTD could be two different but conceptually similar processes, induced by the same class of retrograde signals, and maintained by two distinct mechanisms. An interpretation of a number of experiments in terms of the molecular processes involved in LTP and LTD induction and maintenance, and the roles of a retrograde signal are presented and discussed.

Electronic Resource

1573-1405

2D binary shape description ; stochastic mathematical morphology ; granulometry ; geometric covariogram ; shape matching

Springer Online Journal Archives 1860-2000

Computer Science

Abstract The subject of this paper is to propose and test a set of numerical descriptors of 2D binary planar shapes. Given a shape, A, the transformations of A with a given mathematical morphological operation and different structuring elements are considered. The measures of this family of transformed sets provide a numerical description of the original set A. These descriptors are very robust against noise and maintain a reasonable discriminatory power. The robustness against different levels of contour degradation is tested by simulation. Starting with a clean (without noise) set, Λ, it is assumed that the observed set, A, is a noisy version (with contour degradation) of Λ. The performance of the descriptors, when they are used to compare different shapes or shapes from a scene with models, is studied and compared with related descriptors based on the granulometric analysis of the original set, which are the closest previous alternative to our approach in the literature.

Electronic Resource