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1.
Pericranial flaps are thin and, hence, their volumes are small. Therefore, their use for soft-tissue augmentation has not been popular. In this article, the author introduces a new concept: the use of a multifolded pericranial flap as a "plug" or a "pad" for localized contour defects. Eight patients were included in the study. In all cases, an anteriorly based pericranial flap was used, and the flap was folded on itself several times to increase its bulk. The results were satisfactory in all patients. The literature on the topic is reviewed, and the blood supply of pericranial flaps is discussed.  相似文献   

2.
Cell proliferation rate and 3H-thymidine labeling index of "young" (i. e. harvested in 3 days after subcultivation) cultured Chinese hamster cells (B11 dii-FAF28 line) have been determined in growth medium conditioned by the same cells for various periods of time during their growth and subsequent "stationary phase aging" (medium of different "age"). Cells were serially cultured in Eagle's medium with 10 % bovine serum. The experiment was conducted as follows. The "young" cells were seeded in Carrel's flasks (4500 cells/cm2) with fresh growth medium and placed at 37 degreesC. At definite time intervals, media from 3 randomly selected flasks were filtrated and stored in small glass flasks at 4 degreesC. The cells from all 3 flasks were collected by trypsin treatment and counted with hemocytometer. During the period of 26 day cultivation we collected a set of media of different "age" corresponding to certain points of the growth and "stationary phase aging" curve of the culture. Then, the "young" cells in fresh medium were seeded into tissue culture plates with cover slips placed into wells of the plates (26,600 cells/cm2) and grown at 37degreesC, 5 % CO2 for 2 h. At this point, the medium was replaced with media of different "age". 22 h later (i. e. on the first day after seeding) cell density was evaluated microscopically in all the wells. On the next day (i. e. in 2 days after seeding) 3H-thymidine was added to every well to final concentration 1.85 x 10(4) Bq/ml. After next 24 h (i. e. in 3 days after seeding) cell density was counted again, and the medium was removed. The cover slips were rinsed with Hank's solution and air-dried. Autoradiography was performed in standard manner by photoemulsion exposing for 5 days and subsequent developing in amidol developer. The relative number of nuclei with 10 and more "grains" was revealed microscopically. Based on the obtained results, two basic parameters were evaluated for every "age" medium: 1) cell proliferation activity index calculated as log2 (N3/N1), where N1 - cell density on the first day after seeding, and N3 - the same parameter on the third day after seeding; 2) cell labeling index calculated as percentage of cells with nuclei labeled by 3H-thymidine during incubation from 2nd to 3rd day of cultivation. These two indexes for cell growth in different "age" media appeared to be highly correlating (R = 0.85). Besides, it was found that the observed "age-related" diminishing of ability of the growth media of different "age" to stimulate proliferation of "young" cells cannot completely explain the "stationary phase aging" phenomenon (in particular, even for the "oldest" medium cell labeling index was 65 %). We conclude that the phenomenon is based on exactly intrinsic changes of cells, most likely on molecular level, though environmental effects cannot be entirely excluded. The authors are grateful to the Russian Basic Research Foundation for support (grants 03-04-49030 and 00-04-48049).  相似文献   

3.
"Aged" organophosphoryl conjugates of serine hydrolases differ from the corresponding "non-aged" conjugates in their striking resistance to nucleophilic reactivation. The refined X-ray structures of "aged" and "non-aged" organophosphoryl conjugates of gamma-chymotrypsin were compared in order to understand the molecular basis for this resistance of "aged" conjugates. "Aged" and "non-aged" crystalline organophosphoryl-gamma-chymotrypsin conjugates were obtained by prolonged soaking of native gamma-chymotrypsin crystals with appropriate organophosphates. Thus, a representative "non-aged" conjugate, diethylphosphoryl-gamma-chymotrypsin, was obtained by soaking native crystals with paraoxon (diethyl-p-nitrophenyl phosphate), and a closely related "aged" conjugate, monoisopropyl-gamma-chymotrypsin, was obtained by soaking with diisopropylphosphorofluoridate. In both crystalline conjugates, the refined structures clearly reveal a high occupancy of the active site by the appropriate organophosphoryl moiety within covalent bonding distance of Ser195 O gamma. Whereas in the "non-aged" conjugate both ethyl groups can be visualized clearly, in the putative "aged" conjugate, as expected, only one isopropyl group is present. There is virtually no difference between the "aged" and "non-aged" conjugates either with respect to the conformation of the polypeptide backbone as a whole or with respect to the positioning of the side-chains within the active site. In the "aged" conjugate, however, close proximity (2.6 A) of the negatively charged phosphate oxygen atom of the dealkylated organophosphoryl group to His57 N epsilon 2 indicates the presence of a salt bridge between these two moieties. In contrast, in the "non-aged" conjugate the DEP moiety retains its two alkyl groups; thus, lacking a negative oxygen atom, it does not enter into such a charge-charge interaction and its nearest oxygen atom is 3.6 A away from His57 N epsilon 2. It is suggested that steric constraints imposed by the salt bridge in the "aged" conjugate lie at the basis of its resistance to reactivation.  相似文献   

4.
BACKGROUND AND AIMS. Molecular authentication of Korean ginseng cultivars was investigated using the mitochondrial nicotinamide adenine dinucleotide (NADH) dehydrogenase subunit 7 (nad7) intron 3 region. MATERIALS AND METHODS. A mutation site specific to Panax ginseng "Gumpoong" and "Chungsun" cultivars was detected within the sequence data. Based on this mutation site and the "Gumpoong"-specific single nucleotide polymorphism site reported in 26S rDNA, two modified allele-specific primer pairs were designed and a multiplex amplification refractory mutation system (MARMS) was applied to identify "Gumpoong" and "Chungsun." RESULTS. The results showed that "Gumpoong" and "Chungsun" can be clearly discriminated from the other Korean ginseng cultivars by simultaneously identifying the haplotype of "Gumpoong" and the specific allele of "Chungsun" by applying the MARMS. CONCLUSION. This study, therefore, provides a simple and reliable method for simultaneous authentication of "Gumpoong" and "Chungsun" cultivars.  相似文献   

5.
6.
蕲州地区的蕲艾、青蒿、黄花蒿与茵陈的考订   总被引:3,自引:0,他引:3  
林有润  黄奏球   《广西植物》1983,(1):25-31
<正> 蕲州是我国中药材主要产地之一,是湖北省蕲春县的一个集镇,,是我国中医药大师李时珍的家乡。该地区生长的菊科蒿属植物Artemisia Linn。颇多,其中入药的有十余种,并在李时珍《本草纲目》中曾有记载。这里仅对该地区常见入药的蕲艾、青蒿、黄花蒿与茵陈结合《本草纲目》记载的材料作初步的考订。  相似文献   

7.
"Old" human erythrocytes showed a 21.2% decrease in cell surface area and a 2% decrease in the number of WGA receptor sites, but a 27% increase in the distribution density of the WGA (lectin) receptor site, when compared with "young" human erythrocytes. For a list of lectin abbreviations, see Materials and methods). Both "young" and "old" erythrocytes exhibited very weak binding activity for 125I-labeled PNA, but there was no difference in binding activity for PNA between "young" erythrocytes and "old" ones. Compared with "young" erythrocytes, decreases in the number and distribution density of receptor sites for five lectins including LPA, Con A, RCA-II, SBA and BPA on the cell surface were observed in aged erythrocytes. "Old" erythrocytes also showed a decrease in the number of PHA-E receptor sites, while the distribution density of the same receptor site remained unchanged. In view of these and other observations, it is thought that human erythrocyte aging is accompanied by elimination of some glycoconjugates which have affinity for six lectins, LPA, Con A, RCA-II, PHA-E, SBA and BPA, whereas no WGA receptor-containing glycoconjugates are released from erythrocyte membranes. Elimination of the glycoconjugates results in shrinkage of erythrocytes to reduce their cell surface areas.  相似文献   

8.
"Glyceel" has been considered for many years to be the best sealant for whole mounts of soil, plant-parasitic, freshwater, and marine nematodes. However, "Glyceel" has not been available since the mid 1980s when its production was halted. Currently available substitutes are inadequate. The original formula for "Glyceel" has been found in the literature and is given here with a method of preparation. "Glyceel" prepared in this way by the author has been used and appears to function well.  相似文献   

9.
A new HPLC method was set up for the simultaneous evaluation of the amount of uric acid and NADH produced by incubation of tissue fractions containing xanthine oxidase, from which the activity of both type "O" (oxidase) and type "D" (dehydrogenase) xanthine oxidase can be calculated. After incubation of the enzyme fraction and ethanol extraction, HPLC analysis is directly carried out. Sensitivity of the method is high enough for the evaluation of xanthine oxidase activity at the lowest reported tissue values. The reliability of the method was tested measuring the enzyme activity in rat heart and kidney extracts.  相似文献   

10.
In this article is presented the result of the experiments on mice-hybrids F1(CBA x C57B1/6), which indicates the presence of the reaction of "ischemia/reperfusion" for stem cells of two "critical" cell renewal systems of organism (bone marrow and intestinal epithelium) during the irradiation under the conditions of hypoxic radioprotector application. The additional injection of the source of nitric oxide radicals-sodum nitroprusside (SNT) to the mice right after the irradiation under the conditions of hypoxic protection by serotonin, resulted the substantial increase of the survival rate of hematopoietic stem cells (registered by the methods of endogenous and exogenous colony forming in spleen) and stem cells of intestinal epithelium (registered by the method of intestinal "microcolonies"). The similar radioprotective effect was also registered during the test of survival rate of mice under tests of "bone marrow" and "intestinal" forms of radiation lethality that is evidence of the importance of the realization of phenomenon "ischemia/reperfusion" in the reaction of whole organism on the acute radiation injury. As SNP weakens the manifestation apoptosis and necrosis through competition with active forms of oxygen (AFO) during the period of "reperfusion" on basis of the found out phenomenon experimental model for studying mechanisms of stem cells damage in vivo induced by AFO and for the search of the modifiers weakening or strengthening such damage can be developed.  相似文献   

11.
This paper reports data on cytological peculiarities of neurons of two main zones of sexual dimorphism in brain amygdala (dorsomedial nucleus and anterior cortical nucleus). The main attention was paid to some characteristics of "dark" and "pale" cells found in the amygdaloid complex for the first time. It is supposed that the dark and pale cells are targets for gonadal steroids, whose cyclic changes in concentration in the blood difined their functional states. Though the ultrastructure of dark and pale cells of the amygdaloid complex is similar to that of neurosecretory cells of hypothalamus, there are necessary electron microscopic and cytochemical evidences.  相似文献   

12.
Experiments were carried out on immobilized cats to determine whether, among visual cortical neurons, besides the "scanners" described by the writers previously, which are responsible for a dynamic shift of preferred orientation, there exist also "timer" cells, which do not change the temporal parameters of their responses during rotation of a flashing stimulus. The existence of such cells is postulated on the basis of the previous hypothesis on the spatiotemporal principle of orientational coding. Of 76 neurons tested 27, i.e., 36%, were classed as "timers." They differed significantly from the "scanners" (64%) by the following properties: shorter latent periods, shorter time to the peak and duration of responses, more rapid rise of discharge frequently in the volley. The "timers" had less sharp orientational tuning and a low ratio between values of responses to presentation of preferred and worst stimuli (on account of a considerable increase in responses to unpreferred orientations). The set of preferred orientations of the "timers" was found to be highly selective and additional relative to the corresponding distribution for "scanners."The difference in frequency-temporal properties of responses and orientational tuning of the "timers" and "scanners" and their possible mutually complementary role in orientational coding at the visual cortical level are discussed.Institute of Higher Nervous Activity and Neurophysiology, Academy of Sciences of the USSR, Moscow. Translated from Neirofiziologiya, Vol. 17, No. 1, pp. 35–43, January–February, 1985.  相似文献   

13.
The distribution in the human genome of the largest family of mobile elements, the Alu sequences, has been investigated for the past 30 years, and the vast majority of Alu sequences were shown to have the highest density in GC-rich isochores. Ten years ago, it was discovered, however, that the small "youngest" (most recently transposed) Alu families had a strikingly different distribution compared with the "old" families. This raised the question as to how this change took place in evolution. We solved what was considered to be a "mystery" by 1) revisiting our previous results on the integration and stability of retroviral sequences, and 2) assessing the densities of acceptor sites TTTT/AA in isochore families. We could conclude 1) that the open state of chromatin structure plays a crucial role in allowing not only the initial integration of retroviral sequences but also that of the youngest Alu sequences, and 2) that the distribution of old Alus can be explained as due to Alu sequences being unstable in the GC-poor isochores but stable in the compositionally matching GC-rich isochores, again in line with what happens in the case of retroviral sequences.  相似文献   

14.
The influence of chronic stress on the ultrastructure of the myocardium and hypothalamus was studied in experiments on male rats with different levels of emotional-behavioral reactivity. "Emotional" rats manifested a pronounced increase in glycogen granules in myocytes and intercellular space, appearance of the areas of overcontraction of myofibrils, conglomerates of aggregated platelets in myocardial capillaries, and red cell egress from myocardial and hypothalamic capillaries. Alterations in the ultrastructure of the myocardium and hypothalamus in "nonemotional" rats were less marked and consisted in the appearance of the areas of overcontraction of myofibrils, enlargement of sarcoplasmic reticulum caverns, and in an increase in the lipid content in cardiomyocytes. The ultrastructural changes in the myocardium and hypothalamus of "emotional" and "nonemotional" rats indicate different reactivity of the animals and are likely to be accounted for by different levels of activation of their adrenergic systems.  相似文献   

15.
T A Detlaf 《Ontogenez》1988,19(5):453-460
The use of the term "commitment" by different authors was compared and the term itself was compared with the term "determination". Different authors understand the term "commitment" in different ways. It is proposed to preserve the terms "competence", "determination" (labile and stable) and "differentiation" in studies of normal development at stages preceding the appearance of organ rudiments in order to facilitate the use of the knowledge acquired by experimental embryology and to decipher these concepts at the molecular level. The meaning of the term "commitment" should be made more precise when describing the experimental results and also when assessing the results obtained by various authors and published in numerous papers and reviews.  相似文献   

16.
The ultrastructural localization of succinate dehydrogenase (SDH) and lactate dehydrogenase (LDH) activity in "dark" and "light" neurons of the intact rat's frontal brain cortex has been studied. The enzymes' activity was detected with using potassium ferricyanide as artificial acceptor of electrons. In the "light" cells SDH activity is localized in the mitochondria and plasma membranes. LDH activity is localized in the mitochondria, plasma membranes and hyaloplasm. SDH and LDH activity was not found in the "dark" cells.  相似文献   

17.
A brief historical account on the origin and meaning of the word "allosteric" is presented. The word was coined in an attempt to qualify the chemical mechanism of the feedback inhibition of bacterial enzymes by regulatory ligands. The data lead to the proposal that, at variance with the classical mechanism of mutual exclusion by steric hindrance, the inhibition takes place through an "allosteric" interaction between "no overlapping", stereospecifically distinct, sites for substrate and feedback inhibitor, mediated by a discrete reversible alteration of the molecular structure of the protein.  相似文献   

18.
采用砂基培养法,研究了0、0.05和0.5 mg·L-1Zn2+(0.05 mg·L-1为对照,0.5 mg·L-1为锌过量,0 mg·L-1为锌缺乏)处理下“不知火”和“椪柑”叶片的一些生理指标及不同部位锌含量的变化。结果表明:1)缺锌处理的“不知火”叶绿体色素含量和叶面积均显著低于其对照和锌过量处理;锌过量处理的“椪柑”叶绿体色素含量和叶面积均显著低于对照。2) 3个锌浓度处理间,“不知火”叶片POD、“椪柑”叶片CAT活性无显著性差异,“不知火”叶片CAT、SOD活性随着锌浓度的升高而升高,锌缺乏处理下“椪柑”叶片POD、CAT、SOD活性均显著地高于“不知火”,而锌过量时“不知火”叶片SOD活性显著高于“椪柑”;锌胁迫下“不知火”和“椪柑”叶片MDA含量均显著高于对照,锌过量时“椪柑”叶片MDA含量显著高于“不知火”。3)2品种柑橘不同部位的锌含量随着锌处理浓度的升高而升高,在相同浓度的锌处理下“椪柑”叶锌含量显著高于其他部位及“不知火”叶锌含量,“不知火”上部叶锌含量显著高于其下部叶。  相似文献   

19.
Two-dimensional-electrophoretic analysis has been applied to non-neoplastic mammary epithelium from eight healthy women, tumor tissue from eight "diploid" mammary adenocarcinomas, and tumor tissue from eight "aneuploid" mammary adenocarcinomas. Compared with non-neoplastic mammary epithelium, a slight numerical net non-neoplastic mammary epithelium, a slight numerical net increase of the protein spots was detected in "diploid" tumors and a marked increase in "aneuploid" tumors. Two prominent spots were present in all 16 malignant tissues examined and absent in all eight non-neoplastic tissues (silver staining method). The results suggest that a difference in the composition of cellular proteins exists both between non-neoplastic mammary cells and malignant tumor cells, and between "diploid" and "aneuploid" tumors.  相似文献   

20.
The " A" - " Not A" method is a rating method with two categories. It is often treated as a discrimination method. Unlike forced choice procedures, the Thurstonian model for this method involves a choice criterion. In statistical tests, it is treated as a comparison of two proportions. In this paper, the power for hypothesis tests involving the monadic and replicated monadic " A" - " Not A" method is discussed. The power functions and the sample sizes needed for 80% power are given based on Thurstone's δ. Designs with equal and unequal allocations for A and A (Not A) samples are considered. The power of the method is also compared with that of four forced choice methods under the assumption that the perceptual variance is identical among methods. The comparison shows that, in general, the power for the five methods ranks from high to low: the 3-AFC, 2-AFC, " A" - " Not A", triangular and duo-trio. The comparison also shows that, based on the same number of panelists and/or the same sample size for the A and A samples for the methods, if the panelists are not too discrepant and the choice criterion in the " A" - " Not A" method is not too strict or too lax, the power of the " A" - " Not A" method is very close to that of the 2-AFC method.  相似文献   

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