哈尼梯田景观地表水营养物质的时空变化

云南哈尼梯田是一种山地农业景观,不仅具有良好的水土保持功能,而且有极高的美学价值.本文对元阳县全福庄小流域地表水的氮、磷营养物质进行了采样和分析.结果表明:梯田田水中总氮(TN)和总磷(TP)的含量及其变幅的空间分异都是春季高;梯田区河沟水中TN和TP含量都是夏季高,而含量变幅的空间分异则随采样时间的不同而有差异;森林区河沟水TN和TP含量均是夏季高,但其变幅的空间分异两者有较大差别;从小流域整体看,景观中营养物质较为贫乏,并存在营养物质含量随季节(时间)的变化而不同.营养物质含量变幅在空间上则表现出梯田田水>梯田区河沟水>森林区河沟水的特点,显示梯田景观中地表水营养物质具有复杂的时空变化特征.     

The potential for interaction of hydrochlorothiazide with garlic in rats

The present study was undertaken to determine the pharmacokinetic and pharmacodynamic interaction of hydrochlorothiazide (HCTZ) with garlic homogenate (GH), in rats. The influence of garlic on pharmacokinetics of HCTZ was studied by HPLC method, while pharmacodynamic interaction was studied using diuretic activity, ECG and BP changes and isoproterenol (ISO) induced myocardial injury. HCTZ was given orally at 10 mg/kg and GH was administered at three different doses of 125, 250 and 500 mg/kg, p.o. The CK-MB, LDH, SOD, catalase and histopathological studies were carried out. The administration of HCTZ in GH pretreated rats found to decrease the QRS duration, RR interval, QT segment, systolic blood pressure, heart rate, serum potassium level, serum LDH and serum CK-MB activities significantly. The diuretic effect of HCTZ was significantly increased in presence of GH; however, kaliuresis was significantly reduced in presence of GH 250 mg/kg. Histopathological studies of heart tissue reveal the protective effect of GH 250 mg/kg in presence or absence of HCTZ during ISO stress to myocardium. The pharmacokinetic studies show that GH increases the bioavailability and half-life, along with decrease in clearance and elimination rate of HCTZ when administered orally. It was concluded that careful addition of garlic in moderate doses might result in beneficial effect during treatment of hypertension in patients with myocardial stress as garlic causes substantial fall in excretion of potassium when compared to HCTZ alone treatment in rats. This could be important in reducing the dose of HCTZ to achieve enhanced therapeutic effect with minimal adverse effect.     

蒜鳞片薄壁细胞衰败过程中类外连丝的形成及其共质传输能力的调节（简报）

在植物生长发育过程中,由于局部组织（细胞）的衰退或脱落．存活细胞与衰亡（或脱落）细胞分界壁上的胞间连丝衍变为类外连丝结构。这已先后在小麦胚胎发育、幼胚分化、蒜鳞茎休眠进程中以及玉米根冠组织中得到了论证。前文已曾报道．在玉米根冠细胞生长脱落进程中,脱落细胞与相邻细胞间胞间连丝有被拉伸、断裂形成类外连丝的结构变化．并经药理学试验表明。肌动蛋白和肌球蛋白共同参与了类外连丝通透性的调节。     

Effects of garlic extract consumption on plasma and erythrocyte antioxidant parameters in atherosclerotic patients

Effects of ingesting garlic extract on plasma and erythrocyte antioxidant parameters of atherosclerotic patients were investigated in this study. Eleven patients with atherosclerosis participated in the study. They ingested a dose of 1 ml/kg body weight of garlic extract daily for 6 months (study period). Before and after this period, fasting blood samples were obtained, and oxidant (malondialdehyde, MDA and xanthine oxidase, XO) and antioxidant (superoxide dismutase, SOD and glutathione peroxidase, GSH-Px) parameters were studied in plasma and erythrocytes obtained from the patients. Blood samples obtained from 11 healthy subjects served as the controls. Plasma XO activity and MDA levels were higher, but plasma and erythrocyte GSH-Px activities were lower, in patients with atherosclerosis relative to those of the control group. Our results showed that ingestion of garlic extract leads to significantly lowered plasma and erythrocyte MDA levels in the patients even in the absence of changes in antioxidant enzyme activities. Our results also demonstrated the presence of oxidant stress in blood samples from patients with atherosclerosis, but ingesting garlic extract prevented oxidation reactions by eliminating this oxidant stress. Thus, it is possible that reduced peroxidation processes may play a part in some of the beneficial effects of garlic in atherosclerotic diseases.     

大蒜油不同给药途径对癌细胞周期移行过程的影响

本研究采用流式细胞光度术(FCM)分析癌灶局部及肌注大蒜油(GO)后,S180腹水癌细胞周期移行过程的变化。实验结果表明癌灶局部注射 GO 后,组方图上高倍体 DNA 峰值减少,癌细胞由 G_1期向 S 期运行受阻,S 期细胞显著减少,G_1期与 Go 期细胞积累。肌注 Go 对癌细胞周期影响远不如癌灶局部给药明显。Go 与 G_1期癌细胞积累的原因可能与 GO 对癌细胞周期活动选择性的抑制,或特异性杀伤 S 期或 G_2+M 期癌细胞有关。     

Cytochemieal Observation on Garlic Clove before and after Temperature-Modulated Break of Dormancy

Usually, garlic clove keeps itself in dormancy during summer months and tends to break their dormancy as the climate becomes cooler toward autumn. Prolonged storage of garlic clove under relatively high temperature is a good measure taken in practics to retain its dormancy and refrain from sprouting. In fact, if garlic is stored around 30 ℃, its dormancy can be extended to more than six months while its exposure to low temperature (4 ℃) for a short duration will eventualy break its dormancy. The Dormant release can be diagnosed in the upper epidermis by signs of nuclear disintegration and appearance of APase, ATPase and POase activities. The nuclei in dormant epidermal cells keep their characteristic round shape and in the central position of the cells which are devoid of the enzyme activities mentioned. In case the clove is kept in 30℃ over a year, partial disintegration of the cells evacuation of the constituents also take place, as clearly shown by numerous proteinaceous granules suspended in the interior and by “nuclear extrusion” across the intercellular boundary.     

Analysis of the genetic diversity of garlic (Allium sativum L.) germplasm by SRAP

Cluster analysis and principal component analysis were used to investigate the genetic diversity of 40 garlic germplasms analyzed with 23 sequence-related amplified polymorphism (SRAP) primer combinations. A total of 130 polymorphic loci were detected among these germplasms, with an average of 5.65 polymorphic loci per SRAP primer combination. The percentage of polymorphic loci was 69.1%, whereas the mean effective number of alleles, the mean Nei's gene diversity, and the mean Shannon's information index were 1.4446, 0.2788, and 0.4365, respectively. Cluster analysis revealed that the 40 germplasms could be divided into 3 groups. The results of principal component analysis were consistent with those of unweighted pair-group method with arithmetic averages (UPGMA) clustering analysis. The Shannon-Weaver information index ranged from 0.2419 to 0.4202, indicating that the garlic germplasms had high genetic diversity.     

S-Allylcysteine, a garlic-derived antioxidant, ameliorates quinolinic acid-induced neurotoxicity and oxidative damage in rats

Excitotoxicity elicited by overactivation of N-methyl-D-aspartate receptors is a well-known characteristic of quinolinic acid-induced neurotoxicity. However, since many experimental evidences suggest that the actions of quinolinic acid also involve reactive oxygen species formation and oxidative stress as major features of its pattern of toxicity, the use of antioxidants as experimental tools against the deleterious effects evoked by this neurotoxin becomes more relevant. In this work, we investigated the effect of a garlic-derived compound and well-characterized free radical scavenger, S-allylcysteine, on quinolinic acid-induced striatal neurotoxicity and oxidative damage. For this purpose, rats were administered S-allylcysteine (150, 300 or 450 mg/kg, i.p.) 30 min before a single striatal infusion of 1 microl of quinolinic acid (240 nmol). The lower dose (150 mg/kg) of S-allylcysteine resulted effective to prevent only the quinolinate-induced lipid peroxidation (P < 0.05), whereas the systemic administration of 300 mg/kg of this compound to rats decreased effectively the quinolinic acid-induced oxidative injury measured as striatal reactive oxygen species formation (P < 0.01) and lipid peroxidation (P < 0.05). S-Allylcysteine (300 mg/kg) also prevented the striatal decrease of copper/zinc-superoxide dismutase activity (P < 0.05) produced by quinolinate. In addition, S-allylcysteine, at the same dose tested, was able to reduce the quinolinic acid-induced neurotoxicity evaluated as circling behavior (P < 0.01) and striatal morphologic alterations. In summary, S-allylcysteine ameliorates the in vivo quinolinate striatal toxicity by a mechanism related to its ability to: (a) scavenge free radicals; (b) decrease oxidative stress; and (c) preserve the striatal activity of Cu,Zn-superoxide dismutase (Cu,Zn-SOD). This antioxidant effect seems to be responsible for the preservation of the morphological and functional integrity of the striatum.     

Effect of 900 MHz radiofrequency radiation on oxidative stress in rat brain and serum

The increasing use of mobile telephones raises the question of possible adverse effects of the electromagnetic fields (EMF) that these phones produce. In this study, we examined the oxidative stress in the brain tissue and serum of rats that resulted from exposure to a 900-MHz EMF at a whole body average specific absorption rate (SAR) of 1.08 W/kg for 1 h/day for 3 weeks. We also examined the antioxidant effect of garlic powder (500 mg/kg/day) given orally to EMF-exposed rats. We found that malondialdehyde (MDA) (p < 0.001) and advanced oxidation protein product (AOPP) (p < 0.05) increased in rat brain tissue exposed to the EMF and that garlic reduced these effects (p < 0.05). There was no significant difference in the nitric oxide (NO) levels in the brain. Paraoxonase (PON) was not detected in the brain. There was a significant increase in the levels of NO (p < 0.001) detected in the serum after EMF exposure, and garlic intake did not affect this increase in NO. Our results suggest that there is a significant increase in brain lipid and protein oxidation after electromagnetic radiation (EMR) exposure and that garlic has a protective effect against this oxidative stress.