Candesartan Attenuates Ischemic Brain Edema and Protects the Blood–Brain Barrier Integrity from Ischemia/Reperfusion Injury in Rats

Background: Angiotensin II (Ang II) has an important role on cerebral microcirculation; however, its direct roles in terms of ischemic brain edema need to be clarified. This study evaluated the role of central Ang II by using candesartan, as an AT1 receptor blocker, in the brain edema formation and blood-brain barrier (BBB) disruption caused by ischemia/reperfusion (I/R) injuries in rat. Methods: Rats were exposed to 60-min middle cerebral artery (MCA) occlusion. Vehicle and non-hypotensive doses of candesartan (0.1 mg/kg) were administered one hour before ischemia. Neurological dysfunction scoring was evaluated following 24 h of reperfusion. Animals were then decapitated under deep anesthesia for the assessments of cerebral infarct size, edema formation, and BBB permeability. Results: The outcomes of 24 h reperfusion after 60-min MCA occlusion were severe neurological disability, massive BBB disruption (Evans blue extravasation = 12.5 ± 1.94 µg/g tissue), 4.02% edema, and cerebral infarction (317 ± 21 mm³). Candesartan at a dose of 0.1 mg/kg, without changing arterial blood pressure, improved neurological dysfunction scoring together with significant reductions in BBB disruption (54.9%), edema (59.2%), and cerebral infarction (54.9%). Conclusions: Inactivation of central AT1 receptors, if not accompanied with arterial hypotension, protected cerebral micro-vasculatures from damaging effects of acute stroke. Key Words: Blood–brain barrier, Brain edema, AT1 receptor, Candesartan     

Aged Garlic Extract Attenuates Cerebral Damage and Cyclooxygenase-2 Induction after Ischemia and Reperfusion in Rats

Different garlic products reduce the cerebral ischemic damage due to their antioxidant properties. In this work, we investigated the effect of aged garlic extract (AGE) on cyclooxygenase-2 (COX-2) protein levels and activity, and its role as a possible mechanism of neuroprotection in a cerebral ischemia model. Animals were subjected to 1 h of ischemia plus 24 h of reperfusion. AGE (1.2 ml/kg weight, i.p.) was administered at onset of reperfusion. To evaluate the damage induced by cerebral ischemia, the neurological deficit, the infarct area, and the histological alterations were measured. As an oxidative stress marker to deoxyribonucleic acid, 8-hydroxy-2-deoxyguanosine (8-OHdG) levels were determined. Finally, as inflammatory markers, TNFα levels and COX-2 protein levels and activity were measured. AGE treatment diminished the neurological alterations (61.6%), the infarct area (54.8%) and the histological damage (37.7%) induced by cerebral ischemia. AGE administration attenuated the increase in 8-OHdG levels (77.8%), in TNFα levels (76.6%), and in COX-2 protein levels (73.6%) and activity (30.7%) induced after 1 h of ischemia plus 24 h of reperfusion. These data suggest that the neuroprotective effect of AGE is associated not only to its antioxidant properties, but also with its capacity to diminish the increase in TNFα levels and COX-2 protein expression and activity. AGE may have the potential to attenuate the cerebral ischemia-induced inflammation.     

Effect of Combination Therapy Using Hypothermia and Granulocyte Colony-Stimulating Factor in a Rat Transient Middle Cerebral Artery Occlusion Model

Background: Stroke is the third leading cause of death. Hypothermia has been recognized as an effective method in reducing brain injury. In this study, we assessed the effects of granulocyte colony-stimulating factor (G-CSF) as a neuroprotective agent and mild hypothermia on mortality, behavioral function, infarct volume, and brain edema in Wistar rats. Methods: Forty male rats were used in five groups (eight rats in each group): control, hypothermy, G-CSF, combination hypothermy + CSF, and sham. Rats were anesthetized by injection of chloral hydrate (400 mg/kg) intraperitoneally. Transient cerebral ischemia was induced by 60-min intraluminal occlusion of left middle cerebral artery. Hypothermia, initiated at the time of reperfusion and G-CSF was started one hour after reperfusion at a dose of 15 mg/kg subcutaneously. The motor behavior was measured using Garcia’s index and animals were assigned for the assessments of infarction, brain swelling, and mortality rate. Results: The mortality was 38.46% (control group) and reduced in other groups. Neurological deficit score of control group (40.31 ± 1.56) was significantly lower than in treatment groups. The total cerebral infarct volume of treatment group was significantly lower than control group (43.96 ± 44.05 mm³). Treatment with hypothermy plus G-CSF (2.69 ± 0.24%) could significantly reduce brain swelling volume than other treatment groups. Conclusion: Our major finding is that mild hypothermic treatment plus G-CSF significantly reduced mortality rate and edema and improved neurological function. The results suggest that the combination of hypothermia and G-CSF is more effectively than other treatment groups being used alone. Key Words: Granulocyte colony-stimulating factor (G-CSF), Rats, Brain ischemia, Hypothermia     

Ω3 Supplementation and Intermittent Hypobaric Hypoxia Induce Cardioprotection Enhancing Antioxidant Mechanisms in Adult Rats

Intermittent hypobaric hypoxia (IH) is linked with oxidative stress, impairing cardiac function. However, early IH also activate cardio-protective mechanisms. Omega 3 fatty acids (Ω3) induce cardioprotection by reducing infarct size and reinforcing antioxidant defenses. The aim of this work was to determine the combined effects of IH and Ω3 on cardiac function; oxidative balance and inflammatory state. Twenty-eight rats were randomly divided into four groups: normobaric normoxia (N); N + Ω3 (0.3 g·kg⁻¹·day⁻¹); IH; and IH + Ω3. IH was induced by 4 intercalate periods of hypoxia (4 days)—normoxia (4 days) in a hypobaric chamber during 32 days. At the end of the exposure, hearts were mounted in a Langendorff system and subjected to 30 min of ischemia followed by 120 min of reperfusion. In addition, we determined HIF-1α and ATP levels, as well as oxidative stress by malondialdehyde and nitrotyrosine quantification. Further, the expression of the antioxidant enzymes superoxide dismutase, catalase, and glutathione peroxidase was determined. NF-kappaB and myeloperoxidase levels were assessed in the hearts. Relative to N hearts, IH improved left ventricular function (Left ventricular developed pressure: N; 21.8 ± 3.4 vs. IH; 42.8 ± 7.1 mmHg; p < 0.05); reduced oxidative stress (Malondialdehyde: N; 14.4 ± 1.8 vs. IH; 7.3 ± 2.1 μmol/mg prot.; p < 0.05); and increased antioxidant enzymes expression. Supplementation with Ω3 induces similar responses as IH group. Our findings suggest that both, IH and Ω3 in an independent manner, induce functional improvement by antioxidant and anti-inflammatory mechanisms, establishing cardio-protection.     

Role of endogenous vitamin E in renal ischemic preconditioning process: differences between male and female rats

Background: Antioxidants such as α-tocopherol (vitamin E) and β-carotene (vitamin A) play an important role in protective effect of repeated brief periods of ischemia, namely ischemic preconditioning (IPC). Values of these antioxidants were investigated and compared after induction of ischemia reperfusion (IR) and kidney IPC in both male and female rats. Methods: Forty eight Wistar rats were divided randomly into six groups of 8: groups A and B (male and female controls, respectively), group C (male IR or IR cases), group D (female IR cases) and groups E and F (male and female IPC cases, respectively). In groups C and D, ischemia was induced by clamping of left renal arteries for 45 min. In groups E and F, rats underwent four cycles of 4 min of arterial clamping and 11 min of de-clamping before final 45 min ischemia induction. Afterward, serum was collected to assess the blood urea nitrogen, creatinine and vitamins E and A values. Renal tissues were obtained for histological assessments. Results: α-tocopherol levels in male and female rats showed a significant increase in IPC compared with IR group (P<0.01) and also in female IPC compared with male IPC group. β-carotene levels had no significant variations. Histological evaluation showed that IR-induced renal injuries were less in female rats. Also, protective effects of IPC were more in female rats (P<0.01). Conclusions: Renal IPC reduced damages in both male and female rats, but tissue injuries in females were decreased much more along with the increase of endogenous vitamin E. Key Words: α-tocopherol, β-carotene, Antioxidant, Reperfusion, Ischemic preconditioning (IPC)     

Acetylcholinesterase Inhibitory Activity of Pigment Echinochrome A from Sea Urchin Scaphechinus mirabilis

Echinochrome A (EchA) is a dark-red pigment of the polyhydroxynaphthoquinone class isolated from sea urchin Scaphechinus mirabilis. Acetylcholinesterase (AChE) inhibitors are used in the treatment of various neuromuscular disorders, and are considered as strong therapeutic agents for the treatment of Alzheimer’s disease (AD). Although EchA is clinically used to treat ophthalmic diseases and limit infarct formation during ischemia/reperfusion injury, anti-AChE effect of EchA is still unknown. In this study, we investigated the anti-AChE effect of EchA in vitro. EchA and its exhausted form which lost anti-oxidant capacity did not show any significant cytotoxicy on the H9c2 and A7r5 cells. EchA inhibited AChE with an irreversible and uncompetitive mode. In addition, EchA showed reactive oxygen species scavenging activity, particularly with nitric oxide. These findings indicate new therapeutic potential for EchA in treating reduced acetylcholine-related diseases including AD and provide an insight into developing new AChE inhibitors.     

人参皂苷Rb3及Rb2组合物对大鼠实验性心肌梗死的保护作用

目的研究人参皂苷Rb,及Rb,组合物对大鼠急性心肌梗死的保护作用。方法采用大鼠结扎左冠状动脉前降支制备急性心肌梗死模型,计算急性心肌梗死24h后的心肌梗死面积（MIS）,测定血清肌酸磷酸激酶（CK）、乳酸脱氢酶（LDH）、天门冬氨酸氨基转换酶（AST）、超氧物歧化酶（SOD）及谷胱甘肽过氧化物酶（GSH—Px）活力,丙二醛（MAD）及一氧化氮（NO）含量。结果人参皂苷Rb,及Rb：组合物5、10、20mg／kg均可明显缩小急性心肌梗死大鼠的MIS,降低血清CK、LDH、AST活性及MAD含量,提高血清SOD、GSH—Px活性及NO含量。结论人参皂苷Rb,及Rb：组合物对大鼠急性心肌梗死具有明显保护作用,可能与其增强抗氧化酶活性,减少氧自由基对心肌的损伤等机制有关。     

Attenuation of Focal Cerebral Ischemic Injury Following Post-Ischemic Inhibition of Angiotensin Converting Enzyme (ACE) Activity in Normotensive Rat

Background

Central renin angiotensin system has an important role on the cerebral microcirculation and metabolism. Our previous work showed that inhibition of angiotensin converting enzyme () activity prior to induction of ischemia protected the brain from severe ischemia/reperfusion (I/R) injuries. This study evaluated the impacts of post-ischemic inhibition of , enalapril, on brain infarction in normotensive rats.

Methods

Rats were anesthetized with chloral hydrate (400 mg/kg). Focal cerebral ischemia was induced by 60-min intraluminal occlusion of right middle cerebral artery (MCA). Intraperitoneal injection of enalapril (0.03 or 0.1 mg/kg) was done after MCA reopening (reperfusion). Neurological deficit score (NDS) was evaluated after 24 h and the animals randomly assigned for the assessments of infarction, absolute brain water content (ABWC) and index of brain edema

Results

Severe impaired motor functions (NDS = 2.78 ± 0.28), massive infarction (cortex = 214 ± 19 mm³, striatum = 86 ± 5 mm³) and edema (ABWC = 83.1 ± 0.46%) were observed in non-treated ischemic rats. Non-hypotensive dose of enalapril (0.03 mg/kg) significantly reduced NDS (1.5 ± 0.22), infarction (cortex = 102 ± 16 mm³, striatum = 38 ± 5 mm³) and edema (ABWC = 80.9 ± 0.81%). Enalapril at dose of 0.1 mg/kg significantly lowered arterial pressure could not improve NDS (2.0 ± 0.45) and reduce infarction (cortex = 166 ± 26 mm³, striatum = 71 ± 11 mm³).

Conclusion

Post-ischemic ACE inhibition in the normotensive rats without affecting arterial pressure protects the brain from reperfusion injuries; however, this beneficial action is masked by hypotension. Key Words: Angiotensin converting enzyme (ACE) inhibitors, Enalapril, Brain edema, Cerebral infarction     

振源胶囊对急性心肌梗死犬心肌氧代谢的影响

目的研究振源胶囊对急性心肌梗死犬心肌氧代谢的影响。方法采用犬结扎左冠状动脉前降支6小时造成急性心肌梗死模型,同时十二指肠给药进行治疗,以CORNIHG 178型血气分析仪测定动、静脉血氧含量,观察心肌氧代谢变化。结果振源胶囊10、20mg/kg可使急性心肌梗死6小时犬心肌氧利用率及心肌耗氧量明显降低(P<0.05或P<0.01),对心肌耗氧指数无明显影响(P>0.05)。结论振源胶囊可通过降低心肌耗氧及降低心肌氧利用率发挥抗急性心肌缺血作用。     

Microwave irradiation effects on the structure,viscosity, thermal properties and lubricity of soybean oil

Soybean oil is a highly valuable agricultural commodity for the United States. To further add value to soybean oil, chemical and physical modifications, as well as additives, have been extensively used to change the oil characteristics and properties, broadening the potential industrial applications. Heat treatments such as heat-bodying have been implemented to change soybean oil properties, but no research has studied the effects of microwave-irradiation on soybean oil structure and properties.Soybean oil (SBO) was heat-bodied (HB) or microwave-irradiated (MI). HB and MI (200–250 °C for 20–60 min) oil had similar Gardner bubble viscosity (B–C range). SBO that was HB or MI had increased viscosity compared with untreated SBO. ¹H NMR analysis showed no oxidation occurred for all treatments. However, HB and MI oil formed a cyclic ring structure with polymerization that most likely contributed to the increased viscosity. Pour point decreased from −9 °C for the untreated SBO, −15 °C for the HB, and −18 °C for the MI despite viscosity increases. Pour point anomaly is likely due to triacylglyceride cyclic ring formation. Pressurized DSC analysis showed higher oxidative stability for HB oil with even higher stability for MI oil. Compared with untreated SBO, HB and MI oil increased friction coefficient and decreased film percentage, whereas MI oil tended to leave larger wear scratches on the ball and disk during friction measurements. MI oil improved SBO cold-flow behavior, but reduced its potential as a lubricant.     

Neuronal Cell Reconstruction with Umbilical Cord Blood Cells in the Brain Hypoxia-Ischemia

Background: Brain hypoxia-ischemia is a human neonatal injury that is considered a candidate for stem cell therapy. Methods: The possible therapeutic potential of human umbilical cord blood (HUCB) stem cells was evaluated in 14-day-old rats subjected to the right common carotid occlusion, a model of neonatal brain hypoxia-ischemia. Seven days after hypoxia-ischemia, rats received either saline solution or 4 × 10⁵ HUCB cells i.v. Rats in control group did not receive any injection. After two weeks, rats were assessed using two motor tests. Subsequently, rats were scarified for histological and immunohistochemical analyses. Results: Our immunohistochemical findings demonstrated selective migration of the injected HUCB cells to the ischemic area as well as reduction in infarct volume. Seven days after surgery, we found significant recovery in the behavioral performance in the test group (12.7 +/- 0.3) compared to the sham group (10.0 +/-0.05), a trend which continued to day 14 (15.3 ± 0.3 vs. 11.9 ± 0.5, P<0.05). Postural and motor asymmetries at days 7 and 14 in the test group showed a significant decrease in the percentage of right turns in comparison to the sham group (75% and 59% vs. 97% and 96%, P<0.05). Conclusion: The results show the potential of HUCB stem cells in reduction of neurologic deficits associated with neonatal hypoxia-ischemia. Key Words: Hypoxia-Ischemia, Nerve cell, Umbilical Cord Blood     

Pelagia noctiluca (Scyphozoa) Crude Venom Injection Elicits Oxidative Stress and Inflammatory Response in Rats

Cnidarian toxins represent a rich source of biologically active compounds. Since they may act via oxidative stress events, the aim of the present study was to verify whether crude venom, extracted from the jellyfish Pelagia noctiluca, elicits inflammation and oxidative stress processes, known to be mediated by Reactive Oxygen Species (ROS) production, in rats. In a first set of experiments, the animals were injected with crude venom (at three different doses 6, 30 and 60 µg/kg, suspended in saline solution, i.v.) to test the mortality and possible blood pressure changes. In a second set of experiments, to confirm that Pelagia noctiluca crude venom enhances ROS formation and may contribute to the pathophysiology of inflammation, crude venom-injected animals (30 µg/kg) were also treated with tempol, a powerful antioxidant (100 mg/kg i.p., 30 and 60 min after crude venom). Administration of tempol after crude venom challenge, caused a significant reduction of each parameter related to inflammation. The potential effect of Pelagia noctiluca crude venom in the systemic inflammation process has been here demonstrated, adding novel information about its biological activity.     

Infection and decontamination of citrus canker-inoculated leaf surfaces

Citrus canker (Xanthomonas citri subsp. citri, Xcc) is now considered endemic in Florida and continues to spread. Various surfaces, including plant material, personnel and equipment can become contaminated. Decontamination is practiced in both disease-endemic and disease-free areas to reduce the risk of bacterial spread by man or machinery. We used grapefruit leaf surfaces to explore the efficacy of a commonly used personnel sprayer system applying a quaternary amine decontaminant. In three experiments, plants in flush (leaves ¾ expanded) were inoculated (∼10⁵ CFU ml⁻¹). Immediately after inoculation, plants were passed through the sprayers 0, 1, 2, 3, or 6 times. Leaves were sampled at 0.5, 10 and 20 min after decontamination and tested for viable Xcc by dilution plating. There was a large and rapid decline in the quantity of live bacteria with one pass through the decontamination sprayer (>80% decrease in CFU ml⁻¹), and multiple sprays (2-6) resulted in up to 100% mortality of surface Xcc. Presumably more thorough coverage with multiple sprays killed remnant bacteria, although the first spray invariably caused the highest proportion of population mortality. The effect of the decontaminant spray was immediate (within 0.5 min only 3-11% of surface bacteria survived, and by 20 min <1-3% survived). Based on these results, use of a personnel sprayer with a quaternary amine compound is highly effective for reducing surface inoculum. A single spray kills a high proportion of the population, but multiple sprays increase mortality of Xcc. All the Xcc-inoculated plants subsequently developed symptoms of citrus canker. No significant difference in incidence or severity of grapefruit leaf infection was detected among decontamination treatments or compared to the untreated control. This finding indicates that infection occurred at, or very soon after, inoculation, and that Xcc was in protected sites inside the leaf before exposure to the decontaminant spray.     

Control of Botrytis cinerea,Alternaria alternata and Pyrenochaeta lycopersici on tomato with whey compost-tea applications

Compost teas are fermented extracts of composted materials that are used to control plant diseases. A compost extractor in liquid phase, with forced air blowing system and assembled using farmer facilities, was used to produce “on farm” aerated compost teas (CTs) from five types of compost, in a 14-day fermentation cycle. Solid feed stocks, including one biowaste compost and four composted tomato residues, were extracted in water (waCTs) and whey (whCTs), separately. The ten teas showed high biological control ability, both in vitro and in vivo, against three tomato pathogens: Alternaria alternata, Botrytis cinerea and Pyrenochaeta lycopersici. In in vitro trials, the suppressive ability of raw CTs was lost with sterilization, suggesting an antibiotic-like antagonism effect due to active microorganisms in suspension. Direct application of teas on tomato plants significantly reduced disease symptoms caused by tested pathogens. In vivo suppressiveness was more significant using the liquid phase fermentation (whey or water) than the compost. Whey could be considered a viable extractant for suppressive compost-tea production, although further dilution in dechlorinated water at a ratio of at least 1:5 proved a necessary method to avoid occurrence of root or foliar phytotoxicity, probably due to high salt concentrations and sub-acid pH of the relative teas.     

Fucoxanthinol,Metabolite of Fucoxanthin,Improves Obesity-Induced Inflammation in Adipocyte Cells

Fucoxanthin (Fx) is a marine carotenoid found in edible brown seaweeds. We previously reported that dietary Fx metabolite into fucoxanthinol (FxOH), attenuates the weight gain of white adipose tissue of diabetic/obese KK-A^y mice. In this study, to evaluate anti-diabetic effects of Fx, we investigated improving the effect of insulin resistance on the diabetic model of KK-A^y mice. Furthermore, preventing the effect of FxOH on low-grade chronic inflammation related to oxidative stress was evaluated on 3T3-L1 adipocyte cells and a RAW264.7 macrophage cell co-culture system. A diet containing 0.1% Fx was fed to diabetic model KK-A^y mice for three weeks, then glucose tolerance was observed. Fx diet significantly improved glucose tolerance compared with the control diet group. In in vitro studies, FxOH showed suppressed tumor necrosis factor-α (TNF-α), and monocyte chemotactic protein-1 (MCP-1) mRNA expression and protein levels in a co-culture of adipocyte and macrophage cells. These findings suggest that Fx ameliorates glucose tolerance in the diabetic model mice. Furthermore, FxOH, a metabolite of Fx, suppresses low-grade chronic inflammation in adipocyte cells.     

Relationships between pathotypes and RAPDs, Gpi-allozyme patterns, mating types, and resistance to metalaxyl ofPhytophthora infestans in Canada in 1997

Relationships between pathotypes and other markers such as mating types, metalaxyl resistance, Gpi-allozyme and random amplified polymorphic DNA (RAPD) patterns, were investigated among 33 isolates ofPhytophthora infestans obtained from both potato and tomato across Canada in 1997. Pathogenicity testings, based on virulence against potato differentials carrying single-resistance genes and the size of lesions on leaves, revealed higher pathogenic diversity in 1997 than in the few past years, with more pathotypes and more race-complex isolates. A higher pathogenic diversity was observed within A2 (US-8) than within A1 (US-11) isolates. There was no correlation between the level of resistance to metalaxyl of an isolate and its pathogenicity. Nevertheless, when grouped into metalaxyl-sensitive (MS), -intermediate (MI), and -resistant (MR) classes, both average pathotype complexity and average lesion size were lowest for MS group. RAPD data revealed a good distinction between A1 (US-11) and A2 (US-8) mating type groups, and between isolates from British Columbia and those from other provinces. The detection in the last few years of both A1 and A2 mating types in Canada and the occurrence in 1997 of some isolates sharing different characteristics of both of these two groups suggest that sexual reproduction may have occurred locally.     

Evaluation of potato clones for severity of Verticillium wilt, yield and specific gravity in Maine

In 1994 and 1995, the effect of Verticillium wilt, caused byVerticillium dahliae andV. albo-atrum, on tuber yields, number and weight of U.S. No. 1 and B size tubers, and specific gravity was studied in northern Maine, an area with a short growing season. Seven clones (four resistant and three susceptible) were evaluated in a split-plot design with three replications. Clones were the whole-plot factor, and seed pieces in sub-plots were either uninoculated or inoculated with 50 ml of 4 × 10⁴ cfu/mlVerticillium spp. at planting. Individual plants were scored for Verticillium wilt symptoms before harvest on a 1= <3% wilt to 10= >97% wilt. Differences among clones for wilting and specific gravity were significant. The inoculation treatment had no effect on any of the tuber traits measured. However, there were significant clone x inoculation interactions for most tuber traits. Reductions in yield, weight and number of U.S. No. 1 potatoes, and specific gravity were greater in the Verticillium wilt susceptible clones than in the resistant clones. These results suggest that breeding clones with resistance toVerticillium spp. will reduce yield losses, while maintaining tuber size and specific gravity under disease pressure.     

Heparanase and Syndecan-4 Are Involved in Low Molecular Weight Fucoidan-Induced Angiogenesis

Induction of angiogenesis is a potential treatment for chronic ischemia. Low molecular weight fucoidan (LMWF), the sulfated polysaccharide from brown seaweeds, has been shown to promote revascularization in a rat limb ischemia, increasing angiogenesis in vivo. We investigated the potential role of two heparan sulfate (HS) metabolism enzymes, exostosin-2 (EXT2) and heparanase (HPSE), and of two HS-membrane proteoglycans, syndecan-1 and -4 (SDC-1 and SDC-4), in LMWF induced angiogenesis. Our results showed that LMWF increases human vascular endothelial cell (HUVEC) migration and angiogenesis in vitro. We report that the expression and activity of the HS-degrading HPSE was increased after LMWF treatment. The phenotypic tests of LMWF-treated and EXT2- or HPSE-siRNA-transfected cells indicated that EXT2 or HPSE expression significantly affect the proangiogenic potential of LMWF. In addition, LMWF increased SDC-1, but decreased SDC-4 expressions. The effect of LMWF depends on SDC-4 expression. Silencing EXT2 or HPSE leads to an increased expression of SDC-4, providing the evidence that EXT2 and HPSE regulate the SDC-4 expression. Altogether, these data indicate that EXT2, HPSE, and SDC-4 are involved in the proangiogenic effects of LMWF, suggesting that the HS metabolism changes linked to LMWF-induced angiogenesis offer the opportunity for new therapeutic strategies of ischemic diseases.     

人参皂苷Rb3对实验性心肌缺血的保护作用

目的研究人参皂苷Rb3(G-Rb3)对实验性心肌缺血的保护作用,并与西洋参茎叶20S-原人参二醇皂苷(PQDS)进行比较。方法昆明种小鼠皮下注射异丙肾上腺素后放入盛有钠石灰的250ml广口瓶内,加盖密封后记录小鼠存活时间;Wistar大鼠舌下静脉注射垂体后叶素后观察心电图变化程度。结果 G-Rb320、40mg/kg及PQDS 50mg/kg对皮下注射异丙肾上腺素缩短小鼠在常压缺氧状态下的存活时间均具有明显对抗作用;G-Rb3 14、28mg/kg及PQDS 35mg/kg均可明显减轻垂体后叶素诱发的大鼠急性心肌缺血心电图(ST段抬高及T波高耸)变化程度。结论 G-Rb3对实验性心肌缺血具有明显保护作用,其作用强度与维拉帕米相当。     

Assessment of mating types and resistance to metalaxyl of Canadian populations ofPhytophthora infestans in 1997

The distribution of A1 and A2 mating types, and of metalaxyl-sensitive (MS), metalaxyl-intermediate (MI), and metalaxyl-resistant (MR) strains ofPhytophthora infestans, the causal pathogen of late blight, were determined in Canada in 1997. Potato plants or tubers and tomato plants or fruits, suspected to have late blight infection, were received from seven Canadian provinces in 1997, and were assessed for the presence ofP. infestans. Among 220 samples suspected to have late blight,P. infestans was recovered from 132 samples (60%) received from British Columbia (BC), Manitoba, New Brunswick, Prince Edward Island, and Quebec. From the 132 samples, 364 isolates were obtained and tested for their mating type and response to metalaxyl. Populations ofP. infestans within Canadian provinces were homogeneous for mating types, except within BC, where populations comprised both A1 and A2 mating types both within fields and sometimes within samples. The A2 mating type was found in all provinces where late blight was present. The A1 mating type was found only in Manitoba (1 isolate) and in BC (38 isolates). Unlike the old A1 isolates, those found in BC in 1997 were highly resistant to metalaxyl. These A1 isolates are even more resistant than A2 isolates. Based on assays with 10 ug.ml^?1 of metalaxyl, 14% of all tested isolates were MS, 69.8% were MI and 16.2% were MR. In addition, all provinces contained MS, MI, and MR isolates. No specific mating type or metalaxyl sensitivity level were specific to tomato or potato.