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1.
Gerardo Argüello Enrique García-Hernández Mireya Sánchez Patricio Gariglio Luis Herrera-Estrella June Simpson 《The Plant journal : for cell and molecular biology》1992,2(3):301-309
Two protein factors binding to the regulatory region of the pea chlorophyl a/b binding protein gene AB80 have been identified. One of these factors is found only in green tissue but not in etiolated or root tissue. The second factor (denominated ABF-2) binds to a DNA sequence element that contains a direct heptamer repeat TCTCAAA. It was found that presence of both of the repeats is essential for binding. ABF-2 is present in both green and etiolated tissue and in roots and factors analogous to ABF-2 are present in several plant species. Computer analysis showed that the TCTCAAA motif is present in the regulatory region of several plant genes. 相似文献
2.
Dr. Alfonso Ruiz-Bravo María Jimenez-Valera Gerardo Alvarez de Cienfuegos Khalil Kouwatli Alberto Ramos-Cormenzana 《Current microbiology》1986,13(6):313-316
Twelve strains ofYersinia enterocolitica were examined for their ability to bind spontaneously to murine leukocytes. Each of eight HeLa cell invasive strains exhibited nonselective binding to peritoneal leukocytes, lymph node leukocytes, and thymocytes, whereas four noninvasive strains lacked binding properties. Like the HeLa cell invasion, the binding ofY. enterocolitica to leukocytes was much less efficient for bacteria grown at 37°C than for bacteria grown at 22°C. The binding properties were not influenced by the virulence plasmid that codes for Vwa+ phenotype. This leukocyte binding test is proposed as a simple assay for invasive properties ofY. enterocolitica. 相似文献
3.
Maria Claudia Gonzalez Deniselle Susana L. Gonzalez Gerardo G. Piroli Analia E. Lima Alejandro F. De Nicola 《Cellular and molecular neurobiology》1996,16(1):61-72
Summary 1. Wobbler mice suffer an autosomal recessive mutation producing severe motoneuron degeneration and dense astrogliosis, with
increased levels of glial fibrillary acidic protein (GFAP) in the spinal cord and brain stem. They have been considered animal
models of amyotrophic lateral sclerosis and infantile spinal muscular atrophy.
2. Using Wobbler mice and normal littermates, we investigated the effects of the membrane-active steroid Lazaroid U-74389F
on the number of GFAP-expressing astrocytes and glucocorticoid receptors (GR). Lazaroids are inhibitors of oxygen radical-induced
lipid peroxidation, and proved beneficial in cases of CNS injury and ischemia.
3. Four days after pellet implantation of U-74389F into Wobbler mice, hyperplasia and hypertophy of GFAP-expressing astrocytes
were apparent in the spinal cord ventral and dorsal horn, areas showing already intense astrogliosis in untreated Wobbler
mice. In control mice, U-74389F also produced astrocyte hyperplasia and hypertophy in the dorsal horn and hyperplasia in the
ventral-lateral funiculi of the cord.
4. Givenin vivo U-74389F did not change GR in spinal cord of Wobbler or control mice, in line with the concept that it is active in membranes
but does not bind to GR. Besides, U-74390F did not compete for [3H]dexamethasone binding when addedin vitro.
5. The results suggest that stimulation of proliferation and size of GFAP-expressing astrocytes by U-74389F may be a novel
mechanism of action of this compound. The Wobbler mouse may be a valuable animal model for further pharmacological testing
of glucocorticoid and nonglucocorticoid steroids in neurodegenerative diseases. 相似文献
4.
Ignacio García-De La Torre Mario Salazar-Páramo Gerardo Salmón-De La Torre 《Molecular biology reports》1996,23(3-4):153-157
Mixed connective tissue disease (MCTD) was described as a distinct clinical syndrome in 1972. Since then many cases have been reported in the literature worldwide. In this study we present our experience with a group of 17 Mexican patients with this syndrome, and we analyze their clinical and serological features, as well as the causes of death in these patients. The patients are Mexican mestizos living in Guadalajara and most of them have been followed-up at Hospital General de Occidente for a period of 1–10 years. The female/male ratio was 16:1, and their age ranged from 14–55 years with a mean of 29 years. The disease duration has ranged from 1–17 years, with a mean of 6 years. Among the clinical manifestations we have found a high frequency of lymphadenopathy when compared with published series (13/17 or 76%), and the laboratory findings in our patients included a very high polyclonal increase of gammaglobulins (93%), lymphopenia (76%), direct immunofluorescence speckled nuclear epidermal deposits in skin biopsies (75%) and positive rheumatoid factor (65%). Other clinical and serological features were similar to those reported in other series of patients with MCTD. Six of the 17 patients have died (35%), and in 3 of them (17.5%) the cause of death was due to an infectious disease that suddenly presented, and apparently was not related to a concomitant high dose of steroids or malnutrition in the patients. It seems that in addition to the already well known autoimmune abnormalities that occur in MCTD, there are other features like the presence of lymphadenopathy, the high polyclonal increase of gammaglobulins, and the lymphopenia, that reflect the profound disturbance of the immune system in this syndrome, possibly contributing to the sudden appearance of a severe infectious disease in some of our patients.Abbreviations ANA
antinuclear antibody
- CIE
counterimmunoelectrophoresis
- MCTD
mixed connective tissue disease
- PHA
passive hemagglutination
- PM
polymyositis
- RF
rheumatoid factor
- SLE
systemic lupus erythematosus
- SS
systemic sclerosis (SS) 相似文献
5.
Gerardo Argüello-Astorga Luis Herrera-Estrella Rafael Rivera-Bustamante 《Plant molecular biology》1994,26(2):553-556
Geminiviruses are plant pathogens that replicate by a rolling-circle mechanism, analogous to that used by several prokaryotic ssDNA replicons. Recent reports provide important progress in understanding the structure and functioning of replication origin from these viruses. We have used these data to propose models for the initiation of replication in dicot- and monocot-infecting geminiviruses. 相似文献
6.
DNA supercoiling and thermal regulation of unsaturated fatty acid synthesis in Bacillus subtilis 总被引:4,自引:1,他引:3
Roberto Grau Daniela Gardiol Gerardo Claudio Glikin Diego de Mendoza 《Molecular microbiology》1994,11(5):933-941
Bacillus subtilis growing at 37° C synthesizes, almost exclusively, saturated fatty acids. However, when a culture growing at 37°C is transferred to 20°C, the synthesis of unsaturated fatty acids is induced. The addition of the DNA gyrase inhibitor novobiocin specifically prevented the induction of unsaturated fatty acid synthesis at 20° C. Furthermore, it was determined that plasmid DNA isolated from cells growing at 20°C was significantly more negatively supercoiled than the equivalent DNA isolated from cells growing at 37°C. The overall results agree with the hypothesis that an increase in DNA supercoiling associated with a temperature downshift could regulate the unsaturated fatty acids synthesis in B. subtilis. 相似文献
7.
Gerardo D. Castro Christian J. Stamato Jos A. Castro 《Free radical biology & medicine》1994,16(6):693-701
The interaction between free radicals derived from the catalytic decomposition of carbon tetrachloride and tyrosine (the N-acetyl tyrosine ethyl ester, ATEE) under anaerobic and aerobic conditions was studied. The structure of the reaction products formed was desciphered by the GLC/MS analysis of their trimethylsilyl derivatives. Under anaerobic conditions the formation of the following products was found: (1) an unsaturated derivative of the amino acid; (2) the trimethylsilyl derivative of N-acetyl chloro tyrosine ethyl ester; (3) a hydroxyl adduct of ATEE ; (4) an ATEE adduct having a chlorine and a CCl3 group in the molecule (it is suggested that CCl3 is attached to the benzyl carbon and the chlorine located in the benzene ring); (5) an ATEE adduct having only a CCl3 group tentatively assigned to be located on the benzyl carbon; and (6) and (7) were found to be two isomers of an ATEE having one CCl3 on the aromatic ring. Under aerobic conditions the following reaction products were identified: Two products which were similar to those numbered (1) and (2) and formed anaerobically; (8) and (11) two isomeric dichlorinated adducts of ATEE; (9) and (10) two isomeric dichlorinated monohydroxylated derivatives of ATEE. Concerning the potential relevance of these findings, we consider that if similar interactions to those here reported occurred during CCl4 poisoning, the activity of enzymes having tyrosine in their active center might result in impairment. Further, enzymes operating on tyrosine moieties in proteins might be perturbed in their action if tyrosine groups were attacked by the free radicals arising from catalytic decomposition of CCl4 evidenced here. 相似文献
8.
Gerardo H. Vázquez Nin Ernestina Flores Olga M. Echeverría Hilde Merkert Rodolfo Wettstein Ricardo Benavente 《Chromosoma》1993,102(7):457-463
The distribution of DNA in synaptonemal complexes of rat and mouse spermatocytes, and of chick oocytes was investigated by immunogold electron microscopy. Except for a few specific sites, DNA was not immunolocalized in the space between lateral elements of the complex. Some labeled fibrils connecting the lateral elements with the central element were observed associated with recombination nodules or near them. However, other labeled fibrils in the space between lateral elements did not appear to present any relationship to recombination nodules. The immunocytochemical approaches used here confirmed the presence of significant amounts of DNA in the lateral elements as previously indicated by preferential DNA staining methods. Furthermore, our findings support the view that recombination nodules are the site of chiasma formation. 相似文献
9.
Estaras Matias Ortiz-Placin Candido Castillejo-Rufo Alba Fernandez-Bermejo Miguel Blanco Gerardo Mateos Jose M. Vara Daniel Gonzalez-Cordero Pedro L. Chamizo Sandra Lopez Diego Rojas Adela Jaen Isabel de Armas Noelia Salido Gines M. Iovanna Juan L. Santofimia-Castaño Patricia Gonzalez Antonio 《Journal of physiology and biochemistry》2023,79(1):235-249
Journal of Physiology and Biochemistry - We have investigated the effects of melatonin on major pathways related with cellular proliferation and energetic metabolism in pancreatic stellate cells.... 相似文献
10.
Gerardo A. Cordero Katie Birk Sara Ruane Stephen A. Dinkelacker Fredric J. Janzen 《Evolution & development》2023,25(2):153-169
Developing organisms are often exposed to fluctuating environments that destabilize tissue-scale processes and induce abnormal phenotypes. This might be common in species that lay eggs in the external environment and with little parental care, such as many reptiles. In turtles, morphological development has provided striking examples of abnormal phenotypic patterns, though the influence of the environment remains unclear. To this end, we compared fluctuating asymmetry, as a proxy for developmental instability, in turtle hatchlings incubated in controlled laboratory and unstable natural conditions. Wild and laboratory hatchlings featured similar proportions of supernumerary scales (scutes) on the dorsal shell (carapace). Such abnormal scutes likely elevated shape asymmetry, which was highest in natural nests. Moreover, we tested the hypothesis that hot and dry environments cause abnormal scute formation by subjecting eggs to a range of hydric and thermal laboratory incubation regimes. Shape asymmetry was similar in hatchlings incubated at five constant temperatures (26–30°C). A hot (30°C) and severely Dry substrate yielded smaller hatchlings but scutes were not overtly affected. Our study suggests that changing nest environments contribute to fluctuating asymmetry in egg-laying reptiles, while clarifying the conditions at which turtle shell development remains buffered from the external environment. 相似文献