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91.
Szczepan M. Biliński 《Chromosoma》1989,97(4):321-326
In the oocytes of Eomenacanthus stramineus accessory nuclei arise by budding from the nuclear envelope. It is suggested that microtubules and the thick layer of the nuclear lamina are involved in this process. Newly formed accessory nuclei contain aggregations of fibrillogranular material. These aggregations are slightly Feulgen positive, RNA negative and stain positively with the AgNOR method. During later developmental stages one dense, RNA-positive inclusion appears in each accessory nucleus. These inclusions consist of on Ag-NOR-positive cortical layer and an Ag-NOR-negative core. The function of accessory nuclei in the species investigated is discussed in the light of these results. 相似文献
92.
93.
Wojciech Uracz Jerzy Stachura Anna Pituch-Noworolska Tadeusz Popiela Antoni Czupryna Marek Zembala 《Cancer immunology, immunotherapy : CII》1988,27(2):171-176
Summary The expression of MHC class II determinants Ia.7 (detected by cross reactive mouse anti-Iak antibody) and HLA-DR on monocytes (MO) of gastric and colorectal cancer patients was examined. An increased proportion of MO bearing the Ia.7 determinant was found, while the number of MO expressing DR was not elevated. In gastric cancer patients the increased expression of the Ia.7 determinant was most pronounced in advanced cancer (stage IVA and IVB). The increased expression of this determinant was related to the presence of the tumour as the number of MO expressing Ia.7 decreased 6 months following surgical resection of the tumour. Further, the increased expression of Ia.7 on MO correlated with the tumour infiltration of the serosa. The Ia.7 determinants were mainly expressed on MO which also expressed the receptor for the Fc part of immunoglobulin. Immunostaining in cellular infiltrates surrounding the tumour revealed that Ia.7+ macrophages (MØ) were more numerous than in normal gastric mucosa and severe chronic gastritis and were mostly present in close proximity to tumour cells, while DR+ MØ were mainly localized within the stromal tissue of the tumour and their number was not increased in cancer infiltrates. These observations indicate that the Ia.7+ subpopulation of MØ may be involved in the anti-tumour response of the host. 相似文献
94.
Morphological and seed protein analyses of 26 species of the generaLolium, Festuca andVulpia confirmed their close systematic affinities. Six inflorescence characters readily differentiatedFestuca fromLolium. Protein similarities betweenFestuca of sect.Bovinae and cross-pollinated species ofLolium, coupled with cytogenetic and crossability data, substantiate that they should be united into one genus.Vulpia had phenetic similarities with sect.Scariosae, Montanae andOvinae ofFestuca. Lolium, Festuca, andVulpia are most likely derived from a common ancestral form which was close toFestuca pratensis andLolium perenne. 相似文献
95.
A B Slebodziński 《Acta physiologica Polonica》1988,39(5-6):364-379
Danowski et al. (1951) were probably the first who showed an increase of PBI in infants shortly after birth. Later a number of investigators presented further evidence on the increased thyroid gland function in newborns. This condition named "neonatal thyroid hyperactivity" [Fisher and Oddie, 1964] was described also in animals. The available data indicate that all the newborn mammals till now studied, independently of the maturation stage of development they reach at birth, display some features of thyroid hyperactivity, but in some it does not lead to hyperiodothyroninaemia. Interspecies differences coincide well with significance of the thyroid hormones for neonatal thermogenesis. There are few sequential studies of the three principal iodothyronines: T4, T3 and rT3 available at present. The most comprehensive data concern infants, newborn lambs and pigs. Immediately after birth, there is a sudden rise in serum thyroid hormone concentrations, with some species differences related to the degree of the increase and to the iodothyronines involved. The course of the postnatal hyperiodothyroninaemia is dependent on the maturation level reached at birth, food intake, and cooling relative to extrauterine environment. At least five main factors contribute to the immediate postnatal hyperiodothyroninaemia: 1) abrupt depletion of the preformed fetal hormonal iodine stores; 2) preferential T3 secretion; 3) increase in the T4 to T3 monodeiodination in the peripheral tissues; 4) a release of thyroid hormone content from peripheral reservoirs to plasma, and 5) action of other hormone(s) concomitantly released at birth. From the point of view of the thermal adaptability, the newborn mammals fall into two distinct groups: first, in which immediately after birth the metabolic rate decreases, and second, in which the metabolic rate increases, after cooling. Our understanding of the role and significance of hormonal factors involved in mechanisms of the postnatal thermogenesis is incomplete. However, some similarities in adaptation to cold in adults and in newborns seem to be relevant. Cold adaptation is accomplished by development of nonshivering thermogenesis (NST) depending on NA. The presence of brown adipose tissue (BAT) is essential for NA thermogenic action. According to the common opinion, based on data from laboratory animals and human baby, non-shivering thermogenesis, but not shivering, predominates in newborns. However, data from domestic animals indicate that shivering thermogenesis may be of comparable or greater thermogenic capacity than NST at birth. Besides, there are some newborns which have little or no BAT and associated NST.(ABSTRACT TRUNCATED AT 400 WORDS) 相似文献
96.
S.M. Teresa Hernndez-Sotomayor Marina Macías-Silva Magdalena PlebanÜski J. Adolfo García-Sinz 《Biochimica et Biophysica Acta (BBA)/Molecular Cell Research》1988,972(3)
In hepatocytes obtained from hypothyroid rats, phorbol myristate acetate (PMA) and vasopressin diminished the accumulation of cyclic AMP and the stimulation of ureagenesis induced by isoprenaline or glucagon without altering significantly the accumulation of cyclic AMP induced by forskolin. Pretreatment with PMA markedly reduced the stimulation of ureagenesis and the accumulation of cyclic AMP induced by isoprenaline or glucagon. In membranes from cells pretreated with PMA, the stimulation of adenylate cyclase induced by isoprenaline + GTP, glucagon + GTP or by Gpp[NH]p were clearly diminished as compared to the control, whereas forskolin-stimulated activity was not affected. The data indicate heterologous desensitization of adenylate cyclase. It was also observed that the homologous (García-Sáinz J.A. and Michel, B. (1987) Biochem. J. 246, 331–336) and this heterologous β-adrenergic desensitizations were additive. Pertussis toxin treatment markedly reduced the heterologous desensitization of adenylate cyclase but not the homologous β-adrenergic desensitization. It is concluded that the homologous and heterologous desensitizations involve different mechanisms. The homologous desensitization seems to occur at the receptor level, whereas the heterologous probably involves the guanine nucleotide-binding regulatory protein, Ns. 相似文献
97.
The germination of Amaranthus paniculatus seeds was inhibited by applying paclobutrazol, a specific inhibitor of gibberellin biosynthesis. This inhibition was markedly counteracted by gibberellin A3 (GA3), suggesting that endogenous gibberellins are required for germination in this species. The inhibitory effect of paclobutrazol was also overcome by ethephon (2-chloroethylphosphonic acid) or the precursor of ethylene biosynthesis, ACC (1-aminocyclopropane-l-carboxylic acid). Thus the physiological effect of gibberellin can be mimicked by ethylene released from ethephon or synthesised from exogenous ACC. It is suggested, that endogenous gibberellins are involved in germination of Amaranthus paniculatus seeds and that action of GA3 can be substituted by ethylene.Abbreviations ACC
1-aminocyclopropane-l-carboxylic acid
- AMO-1618
(2-isopropyl-5methyl-4-trimethylammoniumchloride)-phenyl-l-piperidinium-carboxylate
- ancymidol
-cyclopropyl--(4-methoxyphenyl)-5-pyrimidine methanol
- chloromequat chloride
(2-chloroethyl)trimethylammoniumchloride
- ethephon
2-chloroethylphosphonic acid
- GA
gibberellin A3
- paclobutrazol
(2RS, 3RS)-1-(4-chlorophenyl)-4,4-dimethyl-2-(1,2,4-triazol-lyl)pentan-3-ol
- Phosphon D
2,4,dichlorobenzyl-tributhylphosphoniumchloride
- tetcyclacis
5,(4-chlorophenyl)-3,4,5,9,10-pentaaza-tetracyclo)5,4,1,0,Z,6,08,11 dodeca-3,9-diene 相似文献
98.
Fusarium species infecting heads of Triticale and mycotoxins presence in infected kernels and chaff were studied during two seasons. The most important species observed on infected heads were in 1986F. avenaceum (39%),F. nivale (21%),F. culmorum (20%),F. graminearum (14%), and others (6%). In 1987 after long and snowy winterF. nivale dominated (64%), followed byF. avenaceum (24%),F. culmorum (6%), andF. graminearum (5%). The mycotoxins deoxynivalenol (DON) and 3-acetyl DON were present in all 11 subsamples of kernels from heads infected byF. culmorum and/orF. Graminearum (1.6–16.4 mg and 0.7–2.4mg/kg, respectively). Chaff from the same subsamples contained 9.9–33.2mg/kg of DON and 5.2–16.0mg/kg of 3-AcDON. Kernels with visibleFusarium-damage contained 2.4–31.2 mg/kg of DON and 1.2–6.0 mg/kg of 3-AcDON. Remaining part of kernels without symptoms of visibleFusarium-damage contained only DON in an amount of 0.9–5.9 mg/kg. 相似文献
99.
E L Gregoraszczuk A Wojtusiak A Rózańska 《Folia histochemica et cytobiologica / Polish Academy of Sciences, Polish Histochemical and Cytochemical Society》1988,26(4):193-202
The effect of PGF2 alpha and its analogues on progesterone, estradiol and androgen production in cow corpus luteum in vitro was investigated. The cells derived from cow corpora lutea (CL) and collected in the early and middle luteal phases of the oestrus cycle were cultured as monolayers. The inhibitory effect was not apparent during the first 48 hr of culture, but appeared after this time and persisted through the remainder of the culture period. The direct luteolytic influence of PGF2 alpha was observed in the cultured cells and showed that this compound can act independently of the blood supply. 相似文献
100.
E Wielgus-Serafińska G Nowaczyk-Dura M Kamiński 《Folia histochemica et cytobiologica / Polish Academy of Sciences, Polish Histochemical and Cytochemical Society》1988,26(1):11-18
Most of the biological processes in the living organisms of both animals and man are known to be of rhythmical nature. Variability of enzymatic activity in circadian cycle depends on many factors among other on age, sexual maturity, diet as well as medication. The results obtained in our studies indicate, that the activity changes of acid phosphatase and ATP-ase Mg++ dependent in the liver of all the examined age groups were of 24 hour circadian rythm. As to the acid phosphatase activity the results of this experiments showed that in circadian cycle in all examined age groups there is only one peak of elevated activity. ATP-ase Mg++ dependent showed two activity peaks appearing at the same hour both in 30 and 60 days old animals. It should be noticed that the activities of ATP-ase Mg++ dependent in 100 day old animals were two times higher than in 30 and 60 days old rats. 相似文献