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21.
María Teresa Herrera Margarita Cacho M. Purificación Corchete Jorge Fernandez-Tarrago 《Plant Cell, Tissue and Organ Culture》1990,22(3):179-182
Shoot tips from seedlings of Digitalis thapsi L. were cultured on Murashige and Skoog's medium and the effect of various auxins (2,4-D, NAA and IAA) were analyzed alone or in combination with cytokinis (BA and kinetin). Shoot multiplication and direct rooting of the new shoots were obtained after four weeks of culture in MS medium without hormones, but callus formation and the appearance of abnormal phenotypes were frequent. The addition of auxins to the cultures prevented the formation of callus but not the appearance of variant phenotypes. Both drawbacks could be avoided by combination of NAA or IAA with BA or kinetin. The best results for shoot multiplication and direct rooting were obtained with 0.5 mg l-1 NAA and 0.1 or 0.5 mg l-1 kinetin.Abbreviations BA
6-benciladenine
- 2,4-D
2,4-dichlorophenoxyacetic acid
- IAA
indole-3-acetic acid
- Kin
kinetin
- NAA
naphtalene acetic acid
- MS
Murashige and Skoog 相似文献
22.
Lymphocyte subpopulations of regional lymph nodes in human colon and gastric adenocarcinomas 总被引:3,自引:0,他引:3
Beatriz Lores-Vazquez Margarita Pacheco-Carracedo Josefina Oliver-Morales Purificación Parada-Gonzalez F. Gambón-Deza 《Cancer immunology, immunotherapy : CII》1996,42(6):339-342
In order to study the host immune response to tumours, previous knowledge of the cellular composition of regional draining
lymph nodes is necessary. Enlarged regional lymph nodes are a common finding in colon and gastric adenocarcinomas. We have
studied the cellular composition of normal non-reactive and of regional draining lymph nodes of colon and gastric adenocarcinomas.
In normal non-reactive lymph nodes, T lymphocytes (CD2+, CD7+) constituted the largest fraction of the lymphoreticular cells. These lymphocytes were mainly CD4+, and there were more cells expressing the CD45RA isoform of the CD45 antigen than CD45RO. Reactive lymph nodes presented
a decreased proportion of CD4+ CD45RA+ cells and an increased number of B cells. Although most of the T cells in the reactive nodes were CD4+ CD45RO+, their proportion was similar to that found in normal non-reactive nodes. We studied the presence of the molecules CD28 and
CD80 involved in the processes of interaction and activation of T and B lymphocytes. The CD28 molecule was found in all the
T lymphocytes, while the CD80 molecule was weakly expressed on the B lymphocyte membrane.
Received: 4 January 1996 / Accepted: 28 May 1996 相似文献
23.
Roberto MacChiarelli Luca Bondioli Laura Censi Margarita Kristoff Hernaez Loretana Salvadei Alessandra Sperduti 《American journal of physical anthropology》1994,95(1):77-83
Little attention has been devoted to assessing the reproducibility of (paleo)pathological observations. Harris lines (HL) are among the markers most used to determine chronology of stresses suffered during growth. Nevertheless, their scoring entails remarkable methodological difficulty. Bone sections (S) and radiographs (R) of 29 adult tibiae of archeological provenance (medieval) were scored for HL by five observers. At regular intervals of time, each observer gave two independent counts on both series. Results show a) a substantial interobserver disagreement of HL estimates for both sectional and radiographic records, and b) a high level of intraobserver error. © 1994 Wiley-Liss, Inc. 相似文献
24.
Alicia Bravo José Miguel Hermoso Margarita Salas 《Molecular & general genetics : MGG》1994,245(5):529-536
Protein p6 of the Bacillus subtilis phage ø29 is essential for in vivo viral DNA replication. This protein activates the initiation of ø29 DNA replication in vitro by forming a multimeric nucleoprotein complex at the replication origins. The N-terminal region of protein p6 is involved in DNA binding, as shown by in vitro studies with p6 proteins altered by deletions or missense mutations. We report on the development of an in vivo functional assay for protein p6. This assay is based on the ability of protein p6-producing B. subtilis non-suppressor (su
–) cells to support growth of a ø29 sus6 mutant phage. We have used this trans-complementation assay to investigate the effect on in vivo viral DNA synthesis of missense mutations introduced into the protein p6 N-terminal region. The alteration of lysine to alanine at position 2 resulted in a partially functional protein, whereas the replacement of arginine by alanine at position 6 gave rise to an inactive protein. These results indicate that arginine at position 6 is critical for the in vivo activity of protein p6. Our complementation system provides a useful genetic approach for the identification of functionally important amino acids in protein p6. 相似文献
25.
Aneta Ivanova Margarita Velcheva Plamen Denchev Atanas Atanassov Henri A. Van Onckelen 《Physiologia plantarum》1994,92(1):85-89
Endogenous indole-3-acetic acid, abscisic acid and cytokinins (zeatin, zeatin riboside, N-isopentenyladenine and N-isopentenyladenosine) were evaluated in initial explants (leaves) of in vitro propagated plants of alfalfa ( Medicago falcata L.) lines varying in embryogenic capacity and during the somatic embryogenesis process. Fast embryo-genic induction was correlated with high IAA and low ABA levels in the initial explants. No significant differences were observed in the cytokinin contents. Our results suggest that a certain hormone balance is necessary to allow the expression of the embryogenic potential. The consistent stages of the direct somatic embryogenesis are also characterized by changes in hormonal levels. 相似文献
26.
27.
Margarita Ostrowski de Núñez 《Systematic parasitology》1993,24(3):191-199
The life-cycle of Ascocotyle (Phagicola) diminuta (Stunkard & Haviland, 1924) was reproduced experimentally, starting from cercariae from naturally infected Littoridina castellanosae and L. parchappei (Hydrobiidae) collected from artificial ponds in the Zoological Garden in Buenos Aires and from Los Ranchos stream, Buenos
Aires Province, respectively. Metacercariae were found encysted in the gills of experimentally exposed Cnesterodon decemmaculatus (Poecilidae) and of other naturally infected freshwater fishes. Adults were obtained experimentally in chicks and mice and
from a naturally infected egret, Egretta thula. A. (P.) angrense Travassos, 1916 was found parasitising the egret Ixobrychus involucris; it is considered a valid species and the morphological differences between it and A. (P.) diminuta were established. The “Phagicola-form” of the cercaria in the present life-cycle is also known in the genus Pygidiopsis. 相似文献
28.
Ramón Montes Margarita Bedmar Maria Sol Martin 《Applied psychophysiology and biofeedback》1993,18(2):67-77
The aim of the present study was to apply EMG biofeedback as an auxiliary to piano teaching techniques. We studied the changes in integrated electromyographic activity, using the abductor pollicis brevis functioning as an agonist during the teaching of identical selective movements of piano playing in two groups, one with EMG biofeedback and the other following traditional method of instruction. The analysis of variance revealed an increase in the peak amplitude and the relaxation rate values for the biofeedback group. These results have implications for the application of piano playing techniques and reveal EMG biofeedback as an aid in the teaching of thumb attack with the abductor pollicis brevis as agonist.We are grateful for the valuable assistance of Dr. Jaime Vila (Professor of Therapy and Behavioral Modification, Faculty of Psychology, Granada), the cooperation of students at the Juventudes Musicales Music School, Santa Fe and at the Victoria Eugenia Conservatoire, (Granada), the Statistical Analysis Centre of University of Filosofia y Letras de Granada; Professor Enrique Garcia Fernandez-Abasal (Complutense University) for the design of the interface and software. 相似文献
29.
30.
Dr. Georgy M. Gongadze Alla S. Kostyukova Margarita L. Miroshnichenko Elizaveta A. Bonch-Osmolovskaya 《Current microbiology》1993,27(1):5-9
Proteinaceous layers of theThermococcus stetteri cell envelope were investigated and found to consist of regularly arrayed subunits 18 nm in diameter. According to the results of sodium dodecyl sulfate-polyacrylamide gel electrophoresis, two major proteins were present. They were glycosylated and had molecular weights of 80,000 and 210,000. In addition to two external regular proteinaceous layers, cells ofT. stetteri were found to have internal regular layers tightly attached to the cytoplasmic membrane. In the region of flagella attachment to the cell, polar membrane-like structures were found in the cytoplasm. 相似文献