Effect of inhibition of MAO and COMT on intrarenal dopamine and serotonin and on renal function

The purpose of the present investigation was to study the effects of inhibition of monoamine oxidase (MAO) and/or catechol-O-methyltransferase (COMT), enzymes involved in the degradation of dopamine (DA) and serotonin (5-HT), on intrarenal DA and 5-HT, as reflected in the renal interstitial fluid (RIF) microdialysate and urine, and on renal function. Inhibition of MAO selectively increased RIF 5-HT from 3.16 +/- 0.38 to 8.03 +/- 1.83 pg/min (n = 7, P < 0.05), concomitant with decreases in mean arterial blood pressure and glomerular filtration rate (2.09 +/- 0. 18 to 1.57 +/- 0.22 ml/min, n = 7, P < 0.05). Inhibition of COMT significantly increased RIF DA (3.47 +/- 0.70 to 8.68 +/- 1.96 pg/min, n = 9, P < 0.05), urinary DA (2.00 +/- 0.16 to 2.76 +/- 0.26 ng/min, n = 9, P < 0.05), and absolute excretion of sodium (6.42 +/- 2.00 to 9.82 +/- 1.62 micromol/min, n = 10, P < 0.05). Combined inhibition of MAO and COMT significantly increased RIF DA, urinary DA, and urinary 5-HT, which was accompanied with increases in urine flow rate, and absolute (3.03 +/- 0.59 to 8.40 +/- 1.61 micromol/min, n = 9, P < 0.01) and fractional excretion of sodium. We conclude that inhibition of MAO selectively increases RIF 5-HT. COMT appears to be more important than MAO in the metabolism of intrarenal DA. Physiological increases in intrarenal DA/5-HT induced by inhibition of their degrading enzymes are accompanied with significant alterations of renal function.     

Effect of polyphenols on shoot and root growth and on seed germination

The effect of high concentrations of the simplest polyphenols on extension growth of maize (Zea mays L.) shoot ooleoptile segments, lettuce (Lactuca sativa L.) roots, and on radish (Raphanus sativus L.) seed germination, was studied. Quinone formation in the process of plant incubation in polyphenol solutions was proved. The data obtained are presumably explained by the important part that is played by the quinoid products of phenol oxidation in the ability ofo- andp-biatomic phenols to inhibit growth.     

Studies on the effects of insulin and acetylcholine on activation of glycogen synthase and on glycogenesis in hepatocytes

The addition of insulin (4.0 × 10^?11 M) or acetylcholine (10^?6 M) to isolated hepatocytes stimulated glycogen accumulation and this stimulation was more pronounced when the medium glucose was raised from 50 to 300 mg percent. Studies with [¹⁴C]-glucose showed a two-fold stimulation in glycogen synthesis by the addition of insulin (4.0 × 10^?11 M) or acetylcholine (10^?6 M). A sixteen percent increase in the activity of glycogen synthase was observed in cells incubated for 10 minutes with insulin (4.0 × 10^?11 M) or acetylcholine (10^?6 M), whereas at one hour incubation a 40 percent increase in activity was observed with the same concentration of insulin or acetylcholine. The effects of insulin and acetylcholine were not additive.     

乙醇与乙醛对心脏的影响及其可能机制的探讨

通过研究乙醇、乙醛对离体心脏和神经干的影响,探讨乙醇、乙醛对心脏作用的可能机制.用不同浓度的乙醇和乙醛处理牛蛙蛙心灌流标本和坐骨神经标本,用BL-420 系统对给药前后心脏的心率和振幅以及神经干最小刺激强度作记录.乙醇和乙醛可以引起神经兴奋性的改变从而影响神经冲动的传导,而且其影响具有明显的量效依赖关系,低浓度的乙醇和乙醛能使神经的兴奋性增加,高浓度则降低;乙醇对心脏的心率和振幅均有抑制作用,低浓度的乙醛对心脏心率和振幅有促进作用,高浓度的乙醛对心脏造成不可恢复的损伤.乙醇、乙醛对心脏的影响效果不同,但两者均可直接影响及通过神经而间接影响心脏的活动.     

Thoughts on the origin and nature of life and intelligence on earth

Believing, for good reasons, that our Universe engenders the occurrence of Life, it is probable that Life appeared more than once on young planet Earth. The universality of our genetic code indicates though, that only one line produced a population that was cellular, autopoietic, responsive intelligently (i.e., to its advantage) to its environment, and capable of reproduction. Its evolution took time during which other intermediate or incipient forms of life disappeared. Trying to retrace ab initio the preceding chemical evolution on our young planet, we may not repeat the chemistry which led to our line. One can argue that it may be profitable to attempt to construct artificial life forms using the kind of building blocks that we learned to know through studying the chemistry of our life. Independently, computers are being built, or are planned, which possess memory that can be used appropriately (intelligently), and which to some extent can repair and reproduce themselves. Such Life does not depend on our biochemistry. However, these machines do perform as yet only partly along the lines of our human intelligence which is guided by self-awareness and a sense of individual integrity, and are thereby not equipped to search for Understanding and Self-expression.     

Effects of diet on biomarkers of exposure and effects, and on oxidative damage

Modification of DNA is believed to be a key step in carcinogenesis, and therefore DNA adducts have been proposed as predictive biomarkers of human cancer. Smoked and grilled foods are important contributors of PAH-DNA adduct levels, while the consumption of flavonoids and other antioxidants seems to decrease the level of DNA adducts. The aim of this study was to assess the effect of each group of foods and of different dietary profiles on the DNA adducts levels and on oxidative damage to DNA. Occupationally exposed men were recruited in Czech Republic, Slovak Republic and Bulgaria. Non-occupationally exposed subjects were matched on age and gender to PAH-exposed workers. Three hundred and fifty-six subjects who completed the questionnaire for dietary information and had a measurement of DNA adduct levels and oxidative damage to DNA were included in this study. No food item seemed to be individually associated with markers of exposure or DNA damage. Total DNA adducts levels were significantly higher for subjects who had eaten, in the previous 24 h, smoked or fried food. A Principal Components Analysis was performed to identify groups of subjects with similar dietary profiles: no significant differences in biomarker levels were observed among the groups defined according to dietary profiles. In conclusion, this study did not show any significant association between diet and biomarkers of DNA damage, oxidative damage to DNA and chromosomal aberrations, neither when each food was considered separately, nor when the effect of different dietary profiles was tested. The recent consumption of smoked or fried food was associated with an increase in total DNA adducts levels.     

放牧对牧草光合作用、呼吸作用和氮、碳吸收与转运的影响

研究放牧对草地植物生理活动的影响,对于揭示草地放牧演替的生理机制有重要意义.大量研究表明,家畜放牧对牧草光合作用、呼吸作用以及C和N吸收与转运的影响,可以分为生理伤害和生理恢复2个阶段.放牧通过改变草地冠层结构影响牧草光合作用,净光合作用速率短期内迅速下降,随着叶面积指数增加又逐渐上升,呼吸作用有相似的变化趋势.牧草放牧后再生长所需的C和N最初主要来自根系和留茬中的贮藏物质,此后随着牧草生长恢复逐渐由同化作用供给,C代谢与土壤N水平负相关.放牧后牧草生理活动变化与牧草遗传特性、种间竞争、家畜放牧特征、非生物环境等因素密切相关.     

Effects of age and gender on success and death of mountaineers on Mount Everest

Increasing numbers of climbers are attempting Mount Everest, the highest mountain on Earth. We compiled interview data and computed the probabilities of summiting and of dying as a function of climber age and gender (2211 climbers, spring season) for the period of 1990-2005. Men and women had similar odds of summiting and of dying. However, climbers older than 40 years have reduced odds of summiting, and those older than 60 years have increased odds of dying, especially when descending from the summit. On Mount Everest, phenotypic selection appears blind to gender but favours young mountaineers.     

Implications of LCA and LCIA choices on interpretation of results and on decision support

The International Journal of Life Cycle Assessment -     

Effects of GA3 and IBA on rooting and on the sprouting of buds on stem cuttings of Ipomoea fistulosa

Both IBA and GA₃ enhance rooting, IBA being more effective particularlyat a concentration of 100 mg/liter as compared to 10 mg/liter.IBA decreases while GA₃ increases the sprouting of buds, withboth effects increasing with concentration. GA₃-caused promotionof rooting appears to be due to an increased synthesis of auxinand to an adequate supply of mobilized food materials. ¹ Present address: Department of Biology, University of Missouri,St. Louis, U.S.A. (Received January 26, 1972; )     

Effects of acidic fog on productivity of celery and lettuce and impact on incidence and severity of diseases

The effects of acidic fog on productivity of celery and lettuce were examined using a portable fogging apparatus to expose field plots to simulated fog episodes. Acidic solutions were formulated to simulate fog reported for southern California. Celery (Apium graveolens var. dulec cv. Bishop) and lettuce (Lactuca sativa cv. Mesa 659) were exposed in separate experiments once or twice each week during crop growth and maturation to 1 - to 2-h of fog at specific acidity levels between pH 1.6 and 3.8. Necrosis occurred as small, irregularly shaped white (celery) or brown (lettuce) lesions on the most exposed portions of the plants. Fog necrosis sufficient to reduce marketability of celery was evident after single exposures at pH 2.4. Although injury occurred on wrapper leaves of lettuce at acidity levels as high as pH 3.4, marketability was reduced from foliar necrosis only after exposure to acidity levels of pH 2.6 or lower. Repeated exposure of lettuce to acidity below pH 2.0 was necessary to reduce yield. The field experiments demonstrated that acidic fog influenced natural incidence of disease. At low pH fog exposure, celery had increased occurrence of basal stalk rot and lettuce exhibited increased bacterial soft rot. Indirect effects of acidic fog on host-pathogen relationships and subsequent crop marketability may be more important than the direct effects of acidic fog exposure on plant tissue.     

Effects of boron and limestone on cereal yields and on B and N concentration of plant tissue

Summary Rates of added B up to 1.8 kg/ha had no effect on grain yield, but at rates of 2.24 kg/ha and higher it decreased yield of both barley and wheat. Lime-stone applications up to 4000 kg/ha did not induce B deficiency at low levels of B or alleviate B toxicity at high B levels in the two crops. Liming increased barley yields where soil pH was less than 5.8 but gave no yield response when soil pH exceeded 5.8. In general, liming did not decrease the B concentration of boot stage tissue (b.s.t.) except in barley at 1.8 kg B/ha on Location 1, where liming to pH 6.3 and 6.6 decreased B in b.s.t. from 16.4 to 12.2 and 11.4 ppm. The applications of B generally increased the N concentration of wheat grain where yields decreased due to B toxicity. Contribution no. 360, Research Branch, Research Station, Charlottetown, Prince Edward Island, Canada, C1A 7M8. Contribution no. 360, Research Branch, Research Station, Charlottetown, Prince Edward Island, Canada, C1A 7M8.     

Effect of pH and phosphate on soluble soil aluminium and on growth and composition of kikuyu grass

Summary Kikuyu (Pennisetum clandestinium Hochst) grew relatively poorly on the Wollongbar krasnozem at soil pH values below 4.36. At these low pH values dry matter yields were increased by raising the pH or by application of high rates of phosphate. Both treatments decreased the concentration of soluble soil-Al on which the concentration of Al in tops was linearly dependent (r=0.95). The inverse relationship found between plant growth and Al concentration, when present in excess of ∼1.5 μg/g soil and ∼90 μg/g tops, is suggestive of Al toxicity. However, at Al concentrations causing severe yield reductions, the Ca concentration in kikuyu tops was approaching deficiency levels. The Al-Ca antagonism was further demonstrated by the reduction in Ca-uptake caused by increased concentrations of soluble soil-Al under constant conditions of exchangeable Ca and of pH. The yield-reducing effects of Al toxicity per se and Al-induced Ca deficiency are therefore confounded.     

Studies on growth and metabolism of Oenococcus oeni on sugars and sugar mixtures

AIMS: To study the effect of sugars and sugar mixtures on the growth kinetics of Oenococcus oeni NCIMB 11648 in batch culture with the aim of producing a high cell productivity system for starter cultures. METHODS AND RESULTS: The growth of O. oeni was investigated on single sugars (glucose, fructose or sucrose) and their mixtures (glucose-fructose, glucose-sucrose or fructose-sucrose). Better growth was obtained on sugar mixtures compared with growth on a single sugar. The production system of O. oeni biomass was investigated in batch culture with or without pH control with respect to kinetics, specific growth rate and biomass yield. The effect of pH and substrate concentration on fermentation balances and ATP yield were determined. The optimal growth of O. oeni was achieved on the glucose-fructose mixture (9 g l(-1), 1 : 1) at pH 4.5 and 25 degrees C with pH control, with highest cell volumetric productivity (7.9 mg cell l(-1) h(-1)), biomass yield (0.041 g cell g(-1) sugar) and specific growth rate (0.066 h(-1)). CONCLUSIONS: The limitations to the growth of O. oeni were pH and inhibition by end product resulting in poor utilization of the medium with low cell yields. The cell productivity of the system can be improved by the appropriate use of mixed sugar growth medium. SIGNIFICANCE AND IMPACT OF THE STUDY: This study uniquely showed that appropriate sugar mixtures with the correct environmental conditions can significantly improve the productivity of O. oeni cultures.