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51.
Summary Guanethidine-induced sympathectomy in the rat during the neonatal period (injection of 20 g/g body weight every 48 h from day of birth until day 14) produces an absolute reduction in the number of sympathetic ganglion cells, but no significant alteration of body weight. Superior cervical ganglia show 79.8 % fewer cell bodies at 15 days and 92.3 % at 45 days; coeliac ganglia exhibit an 81.0 % reduction at 15 days and 89.6 % at 45 days in guanethidine-treated rats as compared to normal controls. The sympathetic ganglion cells that remain after treatment have an abnormal morphological appearance with distended mitochondria and depletion of endoplasmic reticulum. Sympathectomy produces a prolongation of the generation cycle time (Tc) as measured by the colchicine-induced mitotic arrest technique, and a decrease in labelling, mitotic, and migration indices. In addition, sympathectomy suppresses the amplitude of the circadian rhythm in mitotic activity. The general suppression of this activity in the intestinal epithelium is more pronounced in the jejunum and ileum than in the duodenum. Variation in the effectiveness of sympathectomy on the inhibition of intestinal cell proliferation may be related to segmental differences in cell proliferation, to segmental differences in innervation, and/or to segmental variation in the effectiveness of guanethidine.Supported by N.I.H. grant DE04557 to R.M.K. and N.I.H. grant 5-SO1-RR5373 to the University of Kansas Medical Center. The authors wish to acknowledge Charles A. Brownley, CIBA-Geigy, Summit New Jersey, U.S.A. for the gift of guanethidine-sulfate 相似文献
52.
J. del Mazo J. A. Abrisqueta Amalia Pérez-Castillo V. Aller M. Angeles Martín Lucas M. Luisa de Torres M. José Martín 《Human genetics》1978,44(1):105-108
Summary A new case of ring chromosome 4 in a 2-day-old female child with multiple malformations is described. By means of the GTG-banding technique, a karyotype 46,XX,r(4), (p16q35) was determined. The characteristics of the child's karyotype and the relationship with the structure of the chromosome, especially the location of the deletion that produces the syndrome, are compared with previous reports. 相似文献
53.
Two more "private" polymorphisms of Amerindian tribes: LDHb GUA-1 and ACP1 B GUA-1 in the Guaymi in Panama. 下载免费PDF全文
A survey of Guaymi Indians of Panama for the occurrence of genetic variants of 25 proteins of the erythrocytes and sera have revealed, in addition to seven well-known genetic polymorphisms, four rare variants and two "private polymorphisms," the latter involving erythrocyte acid phosphatase and lactate dehydrogenase. The significance of such private polymorphisms in tribal populations to the interpretation of rare variants in civilized populations is emphasized. 相似文献
54.
Two strains ofAspergillus flavus Linkex Fr. and two strains ofA. parasiticus Speare were cultured on crushed moist wheat (Triticum durum var. Pané no. 247) for aflatoxin production studies in correlation with morphological changes. The toxicogenic strains were adapted to the substratum by means of successive transfers at regular intervals (72 h.)The amount aflatoxins synthesized by the toxicogenic strains decreased gradually after succesive subculturing. The decrease was accompanied by marked morphological changes. One of the strains studied,A. flavus NRRL 3251, lost completly the capacity of aflatoxin synthesis after several subcultures, presenting at the same time strong morphological variations.A. flavus CBS 120.62 also lost its toxicogenicity after six subcultures. 相似文献
55.
Dr. Joseph Torres Jr. 《Cell and tissue research》1980,208(1):29-33
Summary A polytrophic ovariole of the queen honeybee, Apis mellifera, is composed of a linear series of increasingly mature egg chambers, each consisting of an oocyte, an interconnected cluster of nurse cells, and a covering layer of follicle cells. This study describes changes in the volume of each of these components, as a function of the position of the egg chamber in the ovariole. An oocyte increases in volume from approximately 8.9 × 103 m3 to approximately 9.6 × 106 m3 over an average series of 20 egg chambers. 相似文献
56.
57.
A birefringence technique is used to determine the average magnetic moments <μ> of magnetotactic bacteria in culture. Differences in <μ> are noted between live and dead bacteria, as well as between normal density and high density samples of live bacteria. 相似文献
58.
Characterization of immune type interferon (IFN gamma)-induced cytoplasmic protein kinase activity in mouse L cells 总被引:1,自引:0,他引:1
K Ohtsuki B A Torres H M Johnson 《Biochemical and biophysical research communications》1982,104(2):422-429
Mouse immune interferon (IFNγ) induced double-stranded RNA-independent protein kinase activity in the cytoplasmic fraction of mouse L cells as measured against a histone substrate. Chromatographic purification separated the activity into three distinct kinases of molecular weights of approximately 100K (kinase I), 70K (kinase II), and 70K (kinase III). Partially purified IFNγ was as effective as crude in inducing protein kinase activity. Induction was blocked by treatment of IFNγ with specific anti-IFNγ antibody or by treatment of the L cells with actinomycin D. Kinase II activity was different from that of kinases I and III in that it showed Ca-dependence in the absence of Mg2+, was inhibited in activity by the SH binding agent N-ethylmaleimide, and could use the cellular enzymes RNase A and hexokinase as substrates. The described protein kinases could play an important role in mediation of IFNγ effects, particularly where phosphorylated enzyme substrates were shown to have altered activity. 相似文献
59.
60.
Detection of salmonellas by DNA hybridization with a fluorescent alkaline phosphatase substrate. 总被引:2,自引:0,他引:2
R J Cano M J Torres R E Klem J C Palomares J Casadesus 《The Journal of applied bacteriology》1992,72(5):393-399
This study evaluates a DNA hybridization assay for salmonella with AttoPhos (JBL Scientific, San Luis Obispo, CA), a fluorescent substrate for alkaline phosphatase. The probe used (50 ng/ml) was a biotinylated 600 bp fragment consisting of a tandem repeat of an insertion sequence (IS200) found in most Salmonella spp. evaluated. The hybridization was carried out at 65 degrees C for 2 h without prior prehybridization and hybrids were detected by the addition of a streptavidin-alkaline phosphatase conjugate. Circles (5 mm) were cut from the membrane and placed in a cuvette containing 1 ml of 1 mmol/l AttoPhos. The reaction was evaluated after 30 min at 37 degrees C with a fluorometer with an excitation wavelength of 440 nm and an emission wavelength of 550 nm. The sensitivity of the probe was estimated to be 10,000 copies of target DNA or 5 x 10(-20) mol of DNA. All 74 salmonella strains tested reacted with the probe but none of the 98 heterologous species tested gave positive results. The results of this study indicate that our assay method, which employs a biotinylated tandem repeat of IS200 and AttoPhos, is a specific and highly sensitive quantitative method for the detection of salmonellas. 相似文献