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1.
3-Aminoharman (3AH, 3-amino-1-methyl-9H-pyrido[3,4-b]indole), which has been reported as a novel substance with an antagonistic effect on induction of sister-chromatid exchange (SCE) by polycyclic mutagens in the presence of the metabolic activation system, was examined with a cultured human lymphoblastoid cell line, NL3, for its effect on SCE induction by direct-acting mutagens such as mitomycin C (MMC), nitrogen mustard N-oxide (NMO), methyl methanesulfonate (MMS), N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), 4-nitroquinoline 1-oxide (4NQO) and 3-hydroxyamino-1-methyl-5H-pyrido[4,3-b]indole (OH-Trp-P-2), and also by ultraviolet light (UV) irradiation. The results obtained on simultaneous treatment with 3AH and mutagens were as follows: (1) 3AH suppressed more than 50% of SCEs induced by MMC, NMO and OH-Trp-P-2; (2) 4NQO- and MNNG-induced SCEs were also suppressed by 3AH but to a lesser degree; (3) MMS-induced SCEs were not, however, altered by 3AH; and (4) the suppression of SCE by 3AH was dose-dependent. Treatment of cells with 3AH for 2 h immediately before MMC exposure suppressed SCE induction to a significant degree similar to the simultaneous treatment, but post-treatment with 3AH was much less effective. 3AH inhibited SCE induction by NMO when 3AH treatment was carried out either before or after NMO treatment, to an extent similar to the simultaneous treatment. Treatments with 3AH either before or after UV exposure did not change the UV-induced SCEs. Results with these direct-acting mutagens ruled out the relevance of metabolic activation as a necessary step for the antagonizing effect of 3AH. 相似文献
2.
近年来随着全球大都市的快速发展,热岛效应成为城市环境的严峻问题.人类活动日益增加的排热会显著改变城市热环境,从而加剧城市热岛效应的恶化.不同气候区、不同尺度的人为热排放特征不同,因此,其时空变化使人为热的计算变得复杂和不确定.本文通过对国内外人为热的不同计算方法结合实例进行综述,总结了其时空尺度、所需的基础数据及误差来源等,最后讨论了不同方法的优缺点并提出改良方向.建议人为热研究需要首先考虑时空尺度,并据此选择合适的计算方法以保障精度.人为热的计算有助于学者更好地理解研究区的排热状况,并通过合理的城市规划改善人居热环境. 相似文献
3.
《Animal : an international journal of animal bioscience》2016,10(4):607-615
The present study was conducted to determine the optimum age of Holstein dairy calves for an effective inclusion of alfalfa hay (AH) in starter feed on performance, apparent digestibility and feeding behavior. A total of 40 Holstein dairy calves (20 female and 20 male) were used in a completely randomized design in which calves were randomly assigned to one of four different dietary treatments including control (CON) calves fed starter feed without any forage and three treatments consisting of the same starter feed plus 15% chopped AH fed when calves were at the 2nd (AH2), 4th (AH4) or 6th (AH6) week of age. Calves were individually housed and bedded with sand that was replaced every other day. Feed and water were available ad libitum throughout the experiment. Calves were fed milk at 10% of birth BW twice daily until d 57. The study concluded when calves were 73 days old. Starter intake was recorded daily and BW was measured weekly. Data were analyzed as a complete randomized design by MIXED procedures of SAS. Results demonstrate that calves receiving AH treatments numerically consumed more starter feed (0.62 v. 0.78, 0.71 and 0.65 kg/day for CON, AH2, AH4 and AH6, respectively) and had greater average daily gain (ADG) compared with CON (0.48 v. 0.57, 0.49 and 0.49 kg/day for CON, AH2, AH4 and AH6), although the significant difference was observed only between AH2 and CON. Among AH treatments, calves in AH2 had better performance than AH6 in several cases including starter intake, ADG. No detectable differences were observed, however, in apparent dry matter, organic matter or CP digestibility among treatments. Ruminal pH and NH3 concentrations, measured on weeks 4, 6, 8 and 10, were lower for calves fed CON compared with other treatments, with ammonia concentrations decreasing over time. Calves in the AH treatments spent more time eating and ruminating compared with CON. Calves fed CON, however, spent more time on laying down compared with other treatments. Overall, results from the present study illustrated that inclusion of alfalfa in starter feed for calves at 2 weeks of age may improve feed intake, ADG and stimulate rumination in young Holstein dairy calves. Results, however, should be viewed with caution as the number of calves per treatment was small and large calf-to-calf variation may have affected the results reported. 相似文献
4.
Effects of alpha 1 and alpha 2 activation of adrenergic receptors on aqueous humor dynamics 总被引:1,自引:0,他引:1
G C Chiou 《Life sciences》1983,32(15):1699-1704
Effects of phenylephrine (alpha 1-adrenergic agonist), prazosin (alpha 1-adrenergic antagonist), clonidine (alpha 2-adrenergic agonist), and yohimbine (alpha 2-adrenergic antagonist) on aqueous humor (AH) dynamics were studied with a cat eye model. Phenylephrine (130 microgram/ml) inhibited AH outflow (67% at 90 min. period) more than AH formation (26% at the same period) indicating the intraocular pressure (IOP) might be raised by the administration of phenylephrine. Prazosin (0.1 microgram/ml) produced effects opposite to those of phenylephrine (55% reduction of AH formation and 25% reduction of AH outflow at 3 hr. period) suggesting the alpha 1-adrenergic receptor is responsible for increases rather than decreases of IOP. Both clonidine (10 microgram/ml) and yohimbine (0.1-1.0 microgram/ml) inhibited AH formation (60% inhibition) more than AH outflow (no inhibition for clonidine and 40% inhibition for yohimbine) to lower IOP. The conventional theory of receptor antagonism does not seem to function at alpha 2-receptor sites. 相似文献
5.
Leukocytic pyrogen and sodium acetylsalicylate (ASA) were microinjected into the anterior hypothalamus (AH) of urethane anesthetized cats under thermoneutral conditions. The responses of single, identified thermoregulatory neurons in the AH to leukocytic pyrogen placed in the contralateral AH were examined initially. The attempt was then made to determine the effect of ASA on the activity of pyrogen challenged neurons when injected into the AH area opposite to that which received the pyrogen. Stereotaxically located AH units were defined as thermoregulatory by their response to body surface and hypothalamic thermal stimulation; both “thermopositive” (warm) and “thermonegative” (cold) types were studied. Administration of the leukocytic pyrogen was always followed by a change in the discharge rate of the distal thermoregulatory neurons. About half of the units were excited and half were depressed regardless of their thermoresponsive behavior. When ASA was injected after the pyrogen into the opposite AH area, it always altered the neuronal activity and the change was invariably in the direction of the unit's thermal response. The findings indicate that the antipyresis produced by ASA is not due to competition with leukocytic pyrogen for a common receptor site. 相似文献
6.
The effect of butyrate on glycolipid metabolism and morphological differentiation in the cell culture system of rat ascites hepatomas, AH 7974 of island-forming type and AH 7974F of free type, was studied. Both cell lines adhered to the substratum in the presence of 1 mM butyrate. In the case of AH 7974, the addition of butyrate induced a distinct morphological change but the other cell line showed no such conspicuous change. Butyrate-treated AH 7974 cells showed a 2 to 3-fold elevation of CMP-N-acetylneuraminic acid: lactosylceramide sialyltransferase activity to form N-acetylneuraminylgalactosylglucosylceramide (GM3). On the other hand, no enzyme activity could be detected in AH 7974F cells. Four glycosyltransferase activities involved in glycolipid synthesis, including sialyltransferase in AH 7974F cells, were reduced by butyrate. From these observations we concluded that sialyltransferase to form GM3, or TM3 itself, is prerequisite for the morphological alteration induced by butyrate. 相似文献
7.
Because of the tradition of using honey as an antimicrobial medicament, we investigated the effect of natural honey (NH) on Streptococcus mutans growth, viability, and biofilm formation compared to that of an artificial honey (AH). AH contained the sugars at the concentrations reported for NH. NH and AH concentrations were obtained by serial dilution with tryptic soy broth (TSB). Several concentrations of NH and AH were tested for inhibition of bacterial growth, viability, and biofilm formation after inoculation with S. mutans UA159 in 96-well microtiter plates to obtain absorbance and CFU values. Overall, NH supported significantly less (P < 0.05) bacterial growth than AH at 25 and 12.5% concentrations. At 50 and 25% concentrations, both honey groups provided significantly less bacterial growth and biofilm formation than the TSB control. For bacterial viability, the results for all honey concentrations except 50% NH were not significantly different from those for the TSB control. NH was able to decrease the maximum velocity of S. mutans growth compared to AH. In summary, NH demonstrated more inhibition of bacterial growth, viability, and biofilm formation than AH. This study highlights the potential antibacterial properties of NH and could suggest that the antimicrobial mechanism of NH is not solely due to its high sugar content. 相似文献
8.
We used a 3-arm randomized control trial to investigate whether abdominal hollowing (AH) home exercise using pocket-sized ultrasonography (US)—miruco (AH with miruco group)—was more effective than conventional AH home exercise using abdominal palpation and or also a wait-and-see approach (control group) to improve isolated control of the transversus abdominis (TrA) muscle during AH. We randomized 60 participants with low back pain into the three groups equally. Primary outcome measures for the US group were percentage of change in TrA thickness and excursion of the edge of the TrA fascia during AH when the thickness of the internal or external oblique muscles increased. Score on the Oswestry Disability Index (ODI) was a secondary outcome measure. The intervention period was 1 week, followed by 1 week without intervention. As a result, we found no statistically significant interaction effect (P > .05) in changes of the primary outcome measures from baseline for each follow-up period. The AH with miruco group had a statistically lower ODI (P = .036) than did the control group after the intervention. Results indicate a limited benefit for use of the miruco in AH home exercise to improve isolated control of the TrA muscle during AH. 相似文献
9.
本文旨在研究黑木耳粉代替部分膳食对模型小鼠预防营养性肥胖的作用功效。试验选择5周龄健康ICR雄性小鼠48只,随机分为正常对照组(CK)、高脂组(HFD)、阳性药物对照组(PD)和黑木耳粉添加组(AH)。连续饲喂9周,检测小鼠的各项生理生化指标。结果表明:与HFD组相比,AH组小鼠体重、附睾脂肪指数显著降低(P<0.05);Lee’s指数、血清葡萄糖(GLU)含量、甘油三酯(TG)含量和肝脏指数含量极显著降低(P<0.01),血清高密度脂蛋白胆固醇(HDL-C)和肝脏HDL-C含量极显著提高(P<0.01);染色结果观察到AH组小鼠肝脏中脂肪细胞减小,脂质含量降低;附睾脂肪体积减小,附睾细胞形状较规则。高通量测序分析发现,黑木耳粉干预有效改善了小鼠肠道中的变形菌门、螺杆菌属与拟杆菌属的相对丰度。研究结果表明黑木耳有显著预防小鼠营养性肥胖的功效,为黑木耳的开发利用提供依据。 相似文献
10.
Pterostilbene, a methoxylated analogue of resveratrol, is a natural compound primarily found in blueberries and several types of grapes. However, little is known about the effect of pterostilbene on the proliferation of hepatoma cells and its modes of actions. This study was undertaken to characterize its ability to suppress the proliferation of hepatoma AH109A cells and the possible mechanism(s) involved. Pterostilbene showed a significant and dose-dependent effect on the anti-proliferative activity against AH109A cells. Pterostilbene exerted little or no effect on the proliferation of rat L6 myoblasts and rat skin fibroblasts. Pterostilbene-loaded rat sera could significantly inhibit the proliferation of AH109A cells, which suggests that pterostilbene could be absorbed through gastrointestinal tract and retain its anti-proliferative activity. Pterostilbene arrested the cell cycle of AH109A cells at G0/G1 phase and reduced the protein expression of cyclin-dependent kinase 4 and cyclin-dependent kinase 6 dose-dependently. We also found that pterostilbene could significantly increase the intracellular peroxide level of AH109A cells, which may be involved in its anti-proliferative activity. 相似文献
11.
Aim
To determine whether novobiocin resistance strategy could be used to attenuate a virulent Aeromonas hydrophila AH11P strain and to characterize the growth and pathogenic differences between the novobiocin‐resistant strain and its virulent parent strain AH11P.Methods and Results
A novobiocin‐resistant strain AH11NOVO was obtained from a virulent Aer. hydrophila strain AH11P through selection of resistance to novobiocin. AH11NOVO was found to be avirulent to channel catfish (Ictalurus punctatus), whereas AH11P was virulent. When AH11NOVO vaccinated channel catfish were challenged with AH11P at 14 days postvaccination, relative per cent of survival of vaccinated fish was 100%. The cell proliferation rate of AH11NOVO was found to be significantly (P < 0·05) less than that of AH11P. In vitro motility assay revealed that AH11NOVO was nonmotile, whereas AH11P was motile. AH11NOVO had significantly (P < 0·05) lower in vitro chemotactic response to catfish mucus than that of AH11P. Although the ability of AH11NOVO to attach catfish gill cells was similar to that of AH11P, the ability of AH11NOVO to invade catfish gill cells was significantly (P < 0·05) lower than that of AH11P.Conclusions
The novobiocin‐resistant AH11NOVO is attenuated and different from its parent AH11P in pathogenicity.Significance and Impact of the Study
The significantly lower chemotactic response and invasion ability of AH11NOVO compared with that of its virulent parent strain AH11P might shed light on the pathogenesis of Aer. hydrophila. 相似文献12.
Syrian hamsters are photoperiodic and become sexually quiescent when exposed to short "winter-like" photoperiods. In short photoperiods, male hamsters display significantly higher levels of aggression than males housed in long photoperiods. Arginine-vasopressin (AVP) within the anterior hypothalamus (AH) has been reported to modulate aggression in hamsters housed in long photoperiods. Previous studies have shown that AVP can facilitate aggression and its effects appear to be mediated by AVP V(1a) receptors (V(1a)R). In the present study, we investigated whether the increased levels of aggression observed after exposure to short photoperiod were the result of an increased responsiveness to AVP within the AH. Injections of AVP into the AH significantly increased aggression in hamsters housed in a long photoperiod, but had no effect in hamsters housed in a short photoperiod. In addition, injection of a V(1a)R antagonist into the AH significantly inhibited aggression in hamsters housed in long photoperiod, but had no effect in hamsters housed in a short photoperiod. These findings indicate that AVP within the AH increases aggression in hamsters housed in long photoperiods, but not in hamsters housed in short photoperiods. 相似文献
13.
Yutaka Miura Miyako Ariga Maiko Miyauchi Katsuhiko Arai Kazumi Yagasaki 《Cytotechnology》2003,43(1-3):27-32
Rat ascites hepatoma cell line of AH109A proved to be divided into two subpopulations with different invasive and metastatic potentials, when cultured in the medium containing allogeneic rat sera. One population adheres to the culture dish, actively extending pseudopodia, and the other remains in a floating state. Utilizing this character, we have separated these two populations. After three successive separation steps, adhesive AH109A cells and floating AH109A cells were obtained. Adhesive AH109A cells proliferated more rapidly and invaded more actively than did floating AH109A cells. Adhesive AH109A cells metastasized mainly to lung, while floating AH109A cells to mesentery, when intravenously injected into tail veins. Histological studies revealed that adhesive AH109A cells showed lymphatic metastases to lung. These results suggest that the two populations separated from parental AH109A cells provide good models for the study of tumor invasion and tissue-specific metastasis and that adhesive AH109A cells can be used for the creation of lymphatic metastasis model of rats. 相似文献
14.
A new series of oxovanadium(IV) complexes of two aromatic acidhydrazides (BH and AH) have been reported. Of these two donors, AH is known to possess considerable in vitro antitubercular activity. At pH 2-4, oxometal complexes of the type [VO(BH/AH)2SO4].nH2O (n = 1, 0) and [VO(BH/AH)(C2O4)H2O].H2O (BH = C6H5CONHNH2 and AH = (2-NH2)C6H4.CO.NHNH2) were obtained. Reactions of [VO(BH/AH)(C2O4)H2O].H2O with a monodentate Lewis base lead to the isolation of metal-ligand complexes [VO(BH/AH)(C2O4)L].nH2O (L = NH3, n = 1, L = py, n = 2). Disposition of the bonding sites of donor molecules around the oxometal acceptor center and status of the metal-oxygen multiple bond have been established. A monomeric and distorted octahedral donor environment for the oxovanadium(IV) ion has been proposed on the basis of the electron paramagnetic resonance (EPR) spectra and magnetic susceptibility measurements. Antitubercular activities, in vitro, of the oxovanadium(IV) complexes of AH have also been evaluated towards tuberculosis mycobacteria such as Mycobacterium flae, Mycobacterium smegmatis and Mycobacterium H37Rv. 相似文献
15.
Effect of 2-(4-Phenylpiperidino)cyclohexanol on Acetylcholine Release and Subcellular Distribution in Rat Striatal Slices 总被引:8,自引:7,他引:1
These experiments measured the effect of 2-(4-phenylpiperidino)cyclohexanol (AH5183) on the release of acetylcholine (ACh) and its subcellular distribution in slices of rat striatum incubated in vitro. The AH5183, a drug that blocks the uptake of ACh by isolated synaptic vesicles, reduced the release of ACh from slices stimulated to release transmitter in response to K+ depolarization. Tissue stimulated in the presence of AH5183 contained more ACh in a nerve terminal cytoplasmic fraction than did tissue stimulated in the drug's absence, but stimulation in AH5183's presence reduced the amount of ACh measured in fractions containing synaptic vesicles. The depletion of ACh caused by stimulating tissue in the presence of AH5183 was more evident in the fraction of nerve terminal ACh occluded within synaptic vesicles as isolated by gradient centrifugation (fraction D) than it was in other nerve terminal occluded stores. It is concluded that the synaptic vesicles isolated as fraction D under the present experimental conditions likely contain releasable transmitter. The AH5183 also depressed the spontaneous release of ACh from incubated slices of striatum and this effect was evident in the presence or the absence of medium Ca2+. It is suggested that this effect might indicate that the process of spontaneous ACh release measured neurochemically results, in part, from an AH5183-sensitive carrier-mediated process. 相似文献
16.
To investigate the bioavailability and mode of action of theanine against cancer, we examined in vitro and ex vivo effects of theanine on invasion of a rat ascites hepatoma cell line of AH109A. Theanine dose-dependently inhibited the invasion
of AH109A cells across rat mesentery-derived mesothelial-cell (M-cell) monolayers without restraining AH109A cell proliferation
in vitro. Rat sera obtained after oral intubation of theanine also inhibited the invasion. A competitive N-methyl-D-aspartate (NMDA)
type glutamate receptor antagonist, (±) 2-amino-5-phosphonopentanoic acid (AP-5), dose-dependently counteracted the theanine-mediated
in vitro and ex vivo inhibition of AH109A invasion. A competitive non-NMDA type glutamate receptor antagonist, 6,7-dinitroquinoxaline 2,3-dione
(DNQX), did not affect this inhibition by theanine in vitro. These results suggest that the inhibition of AH109A invasion by theanine may be mediated by the NMDA receptor of AH109A.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
17.
Effect of air humidity on spinability and transport capacity of canine airway secretions 总被引:2,自引:0,他引:2
The effect of varying the inspired air humidity on a rheological property (spinability) and transport capacity of airway mucus has been analyzed in 10 mongrel dogs. Tracheal mucus was collected in anesthetized dogs inspiring through an endotracheal tube the air of a climate chamber maintained at constant temperature (T degrees:20 degrees C). In one test, the dogs inspired air at an absolute humidity (AH) of 9 g water/m3 air directly through the endotracheal tube. In the other test, the dogs inspired through an artificial nose connected to the endotracheal tube giving a AH of 30 g water/m3 air. Tracheal mucus was collected at the external distal end of the endotracheal tube. The spinability (Sp) or thread-forming properties of mucus was measured. The relative mucociliary transport rate (TR) of mucus was analyzed on a frog palate epithelium preparation. The transport rate was significantly (p less than 0.01) lower (range: 0.59-0.80) when the AH of the inspired air was low in comparison to that obtained with high AH (range: 0.70-1.13). The variations in mucus Sp due to changing AH were positively and significantly correlated (r = 0.80, p less than 0.01) with the corresponding variations in TR. These results suggest that lowering the AH of air induces a decrease in the transport capacity which appears to be dependent on the change of spinability that occurs in the mucus. 相似文献
18.
Aqueous humor contains transforming growth factor-beta and a small (less than 3500 daltons) inhibitor of thymocyte proliferation 总被引:5,自引:0,他引:5
R D Granstein R Staszewski T L Knisely E Zeira R Nazareno M Latina D M Albert 《Journal of immunology (Baltimore, Md. : 1950)》1990,144(8):3021-3027
The anterior chamber of the eye is an immunologically privileged site in which allografts survive longer than at other body sites. In this regard, it is relevant that aqueous humor (AH) inhibits lymphocyte proliferation. In order to analyze AH for specific substances that inhibit thymocyte proliferation, samples of human AH, murine AH, and rhesus monkey AH were added to cultures of thymocytes stimulated by IL-1 or IL-2 in the presence of PHA. All samples of AH tested had potent inhibitory activity on thymocyte proliferation in this system. Inhibitory activity was lost by heating AH to 80 degrees C for 1 h. Dialysis of murine AH indicated that species smaller than 3500 Da were capable of mediating this activity; we have termed the factor(s) responsible for this "small inhibitory factor(s) of AH." Retentate, containing species larger than 3500 Da, retained inhibitory activity, but less than nondialyzed AH. Assays for PGE2 demonstrated that murine and human AH contained small quantities of PGE2. These quantities were insufficient to inhibit thymocyte proliferation in our assay system. Furthermore, AH from mice treatend with indomethacin had full inhibitory activity. Assays for transforming growth factor beta (TGF-beta) after acid activation demonstrated significant quantities of latent TGF-beta within human and murine AH which could be largely neutralized by antisera to TGF-beta. Active TGF-beta "activity" was also present without acid activation in samples of AH at a level approximately 20% that of latent TGF-beta. However, most of this "activity" could not be neutralized by antisera to TGF-beta. AH contains factors capable of limiting thymocyte proliferation. 相似文献
19.
A 1H NMR study of urocanic acid dissolved in water/dimethyl sulfoxide mixtures together with potentiometric determinations of its two successive acidities in the same solutions reveal that a proton is transferred from the imidazolium ring to the carboxylate group when the amount of dimethyl sulfoxide is increased. An analysis of the potentiometric data by means of the classical Hammett linear relationship allowed the four microscopic acidity constants to be determined. At 20 degrees C, there are equal fractions of the tautomeric species, i.e. urocanic acid (AH0) and its zwitterion (AH+-) in the mixture containing 34% dimethyl sulfoxide by weight (congruent to 0.1 in mole fraction), while 50% dimethyl sulfoxide by weight (congruent to 0.2 in mole fraction) is necessary to completely bias the equilibrium: AH+- in equilibrium AH0 toward the molecular form AH0. 相似文献
20.
Jie Xu Xingquan Zhao Yilong Wang Chunxue Wang Liping Liu Baoying Sun Anxin Wang Yongjun Wang 《PloS one》2013,8(6)