Clinical evaluation of detomidine-butorphanol-guaifenesin-ketamine as short term TIVA in Spiti ponies

Veterinarians working under remote field conditions are routinely presented with variety of surgical interventions in equines like castrations, management of wound, traumatic and congenital hernias and musculoskeletal disorders thus necessitating the use of general anaesthesia for management of these conditions. The present study was carried out to evaluate and recommend the suitable short term anaesthetic technique for Spiti ponies under field conditions. Seven clinically healthy male Spiti ponies presented for castration were evaluated for short term Total Intravenous Anaesthesia (TIVA) using detomidine (0.02 mg kg(-1)), butorphanol (0.01 mg kg(-1)), 5% guaifenesin (20 mg kg(-1)) and ketamine (2.0 mg kg(-1)). The studies conducted were open label trials and all the animals received same treatment. After proper tetanus prophylaxis and preanesthetic fasting, detomidine was administered intravenously. Subsequently at head down position the animals received butorphanol intravenously. Thereafter, guaifenesin was administered intravenously. As soon as the signs of ataxia developed, the induction of surgical anaesthesia was achieved by intravenous administration of ketamine hydrochloride. The onset of sedation was observed in 2.43 +/- 0.53 min following detomidine administration and the animals were ataxic in 1.43 +/- 0.43 min after butorphanol and guaifenesin administration when ketamine was injected. The ponies were in surgical plane of anaesthesia within 2.28 +/- 0.42 min following ketamine administration. During recovery the limb/head movement and sternal recumbency were attained in 18.71 +/- 1.98 and 26.14 +/- 1.62 min, respectively whereas standing ataxia and normal gait were seen at 29.42 +/- 3.21 and 71.14 +/- 4.74 min, respectively. There was excellent to good muscle relaxation. The surgical anaesthesia remained for 22.57 +/- 1.48 min. The recovery was smooth. Moderate to good suppression of palpebral and corneal reflexes were observed immediately after induction and during anaesthesia. The analgesia was excellent. A highly significant (p < 0.01) to significant (p < 0.05) decrease in respiration rate was observed after induction, during anaesthesia and after recovery. The mean SpO2 value in equines of this group was 76.50 +/- 4.14 and 83.33 +/- 4.18% after induction and during anaesthesia, respectively. Some of the blood biochemical parameters like plasma alanine amino transferase (ALT), total proteins and glucose showed significant increase without clinical consequence. It was concluded that detomidine (0.02 mg kg(-1)), butorphanol (0.01 mg kg(-1)), guaifenesin 5% (20 mg kg(-1)) and ketamine (2.0 mg kg(-1)) combination can safely be used for short term total intravenous anaesthesia in equines under field conditions where the monitoring facilities are meager.     

Nephrotoxicity and oxidative stress of single large dose or two divided doses of gentamicin in rats

Gentamicin (GS) is a potent antimicrobial exhibiting concentration dependent bacterial killing. A high dose ofgentamicin (10 mg kg(-1)) is required to reach sufficient concentrations in specific fluids as cerebrospinal fluid and to be effective on antibiotics resistant bacteria as well as treatment of acute and dangerous illness. Using a rat model, the renal toxicity and oxidative stress of administering gentamicin (10 mg kg(-1) daily for 7 days) either in a single dose or divided into 2 doses was investigated. The safety of dose regimens was assessed through oxidant-antioxidant parameters as well as renal function tests. Typical renal damage and high oxidative stress were evident in the control group receiving 100 mg kg(-1) gentamicin daily for 7 days. This was verified by high serum urea, uric acid, creatinine as well as increase in the levels of oxidative stress biomarkers as malondialdehyde, NO, total antioxidant capacity and decrease in reduced glutathione level. At any of the used regimen, 10 mg kg(-1) gentamicin did not provide high compromise for renal functions nor significantly increased the oxidative stress and tissue damage. Based on microscopic lesions scores and biochemical analysis, there were no significant differences between single or two divided dosages of gentamicin at dose rate of 10 mg kg(-1) day(-1). Further studies are required for applications in other animals of human subjects.     

Motor disorders and impaired electrical power of pallidal EEG improved by gallic acid in animal model of Parkinson's disease

The aim of this study was evaluation the effect of Gallic acid on movement disorders and pallidal electrical power in animal model of Parkinson's Disease (PD). PD is clinically characterized by development of motor disturbances, such as bradykinesia, resting tremors, rigidity and a later loss ofpostural reflexes. Oxidative stress is a hallmark factor where the oxidation of dopamine generates Reactive Oxygen Species (ROS) and an unbalanced production ROS induces neuronal damage, therefor leading the neuronal death. Gallic Acid (GA) and its derivatives are present in the plant kingdom and acts as a potent antioxidant. Wistar male rats divided into seven groups randomly with 8 in each. Animals in all groups except control received 8 microg/2 microL 6-hydroxydopamine dissolved in normal saline contains 0.01% ascorbate or vehicle in right Medial Forbrain Bundle (MFB) and a bipolar wire electrode was implanted in the left globus pallidus nucleus of all animals under stereotaxic surgery. Two weeks later PD was approved by contralateral rotation signs induced by apomorphine and then movements and electrical power of pallidal were evaluated. Motor functions and pallidal electrical power were impaired and GA could improve motor dysfunctions and gamma wave power in parkinsonian rats' significantly with higher dose of GA (200 mg kg(-1)). Present result showed that GA may act as a potent antioxidant and free radical scavenger to reverse motor disorders and pallidal gamma wave power after 6-OHDA neurotoxicity in brain.     

Vasorelaxation, induced by Dictyota pulchella (Dictyotaceae), a brown alga, is mediated via inhibition of calcium influx in rats

This study aimed to investigate the cardiovascular effects elicited by Dictyota pulchella, a brown alga, using in vivo and in vitro approaches. In normotensive conscious rats, CH(2)Cl(2)/MeOH Extract (CME, 5, 10, 20 and 40 mg/kg) from Dictyota pulchella produced dose-dependent hypotension (-4 ± 1; -8 ± 2; -53 ± 8 and -63 ± 3 mmHg) and bradycardia (-8 ± 6; -17 ± 11; -257 ± 36 and -285 ± 27 b.p.m.). In addition, CME and Hexane/EtOAc Phase (HEP) (0.01-300 μg/mL) from Dictyota pulchella induced a concentration-dependent relaxation in phenylephrine (Phe, 1 μM)-pre-contracted mesenteric artery rings. The vasorelaxant effect was not modified by the removal of the vascular endothelium or pre-incubation with KCl (20 mM), tetraethylammonium (TEA, 3 mM) or tromboxane A(2) agonist U-46619 (100 nM). Furthermore, CME and HEP reversed CaCl(2)-induced vascular contractions. These results suggest that both CME and HEP act on the voltage-operated calcium channel in order to produce vasorelaxation. In addition, CME induced vasodilatation after the vessels have been pre-contracted with L-type Ca(2+) channel agonist (Bay K 8644, 200 nM). Taken together, our data show that CME induces hypotension and bradycardia in vivo and that both CME and HEP induce endothelium-independent vasodilatation in vitro that seems to involve the inhibition of the Ca(2+) influx through blockade of voltage-operated calcium channels.     

Effect of hydroalcoholic extract of Lavandula officinalis on nicotine-induced convulsion in mice

Epilepsy an important CNS (central nervous system) problem that about 1% of world's population suffer of it. The aim of study was to evaluate of anticonvulsant effect of hydroalcoholic extract of Lavandula officinalis. In this study, anticonvulsant activity of the hydroalcoholic extract of Lavandula officinalis (L. officinalis) was studied against chemoconvulsant-induced seizures in male mice. Lavandula officinalis (100, 200, 400, 600 and 800 mg kg(-1)), diazepam (0.15 mg kg(-1)) and normal saline (10 mL kg(-1)) were injected intraperitoneally, respectively in different groups of mice, 30 min before nicotine (5 mg kg(-) i.p.). The onset time intensity and duration of convulsions and the percentage of death were recorded. Also the time-response (0, 15, 30, 45, 60 min before nicotine injection) for most effective dose of plant extract (600 mg kg(-1)) was investigated. The results showed that hydroalcoholic extract of Lavandula officinalis had anticonvulsant effect. The most effective dose of plant extract was 600 mg kg(-1). In time-response study for the most effective dose of extract (600 mg kg(-1)), the onset, duration and intensity of convulsion significantly (p < 0.05) increased, decreased and decreased, respectively for all tested times. The best response observed in 30, 45 and 60 min. The results showed significant anticonvulsant effect for hydroalcoholic extract of Lavandula.     

The study of antinociceptive effect of hydroalcoholic extract of Teucrium oliverianum (a plant used in southern Iranian traditional medicine) in rat by formalin test

Objective: Antinociceptive and anti-inflammatory activities of hydroalcoholic extract of Teucrium Oliverianum were investigated by formalin test model. This study was conducted in on the male Wistar rats, weighting 150-180 g. The animals were divided into seven groups (n = 7) and received 200, 400, 600 and 800 mg kg(-1) of hydroalcoholic extract of teucrium oliverianum intraperitoneally, respectively. Negative control group received normal saline (5 mL kg(-1)) and the positive control groups received 2.5 mg kg(-1) morphine and 300 mg kg(-1) aspirin, intraperitoneally respectively. The results showed that all doses of extract have significant analgesic effect (p < 0.05) in all studies times in comparison with negative control. The best result achieved with 600 mg kg(-1) of extract. The result revealed that the analgesic effect of the extract (600 mg kg(-1)) \was less than aspirin (300 mg kg(-1)) on the second phase of pain and less than morphine (2.5 mg kg(-1)) in both phases of the pain, more than aspirin in first phase of pain. One group of animals was treated with naloxone (1 mg kg(-1), i.p.) and suitable dose of extract (600 mg kg(-1), i.p.). Also, Naloxone inhibited analgesic effect of alcoholic extract of Teucrium Oliverianum. It can be concluded that the alcoholic extract of Teucrium oliverianum may exert its effect through opioid receptors, stimulating GABAergic system or promotes the release of endogenous opipeptides or decreasing free radicals.     

Bovine liver abscesses pus and the status of some important minerals

This research was conducted to determine selenium, copper, zinc, iron, calcium, phosphorous and magnesium concentration in the pus of cow liver abscess. The liver has a large reserve of function and approximately three-quarters of its parenchyma must be rendered inactive before clinical signs of hepatic dysfunction appear. Local suppurative infections of the liver cause significant losses in feedlot and grain-fed cattle because of the frequency ofrumenitis in those cattle leading to hepatic abscess formation. Also we know some minerals that can alter and uphold the specific immunity. At the presence of adequate amount of zinc, the formation of hepatic abscess may reduce. For this reason and to determine the mineral concentration in pus, the present study was designed on 40 slaughtered cattle with liver abscess in Shahrekord district. For measuring the minerals concentration, Potentiometric Stripping Analyzer (PSA), atomic absorption spectrometry were used. Results showed that the concentration of Se, Zn, Fe, Cu, Ca, P and Mg in pus were 0.551A+/-0.046 (mg kg(-1)), 6.41A+/-2.32 (mg kg(-1)), 18.18A+/-14.03 (mg kg(-1)), 6.63A+/-4.83 (mg kg(-1)), 221.8A+/-85.82 (mg kg(-1)), 0.85A+/-0.32 (g kg(-1)) and 40.64A+/-21.72 (mg kg(-1)), respectively. The concentration of mentioned minerals in liver parenchyma's were determined 1.06A+/-0.15 (mg kg(-1)), 82.91A+/-32.22 (mg kg(-1)), 62.29A+/-22.12 (mg kg(-1)), 39.22A+/-28.17 (mg kg(-1)), 0.12A+/-0.04 (g kg(-1)), 1.81A+/-0.56 (g kg(-1)) and 0.15A+/-0.07 (g kg(-1)), respectively. For determining the correlation between mineral concentration in pus and liver parenchyma, Pearson correlation was used at The level of p<0.05. The correlation between pus Fe and Cu and also Ca and Se were significantly positive (pvalue = 0.000228, r = +0.871) and negative (pvalue = 0.0305, r = -0.623), respectively. In liver parenchyma the correlation between Zn and Ca (pvalue = 0.0487, r = 0.535) and also Fe and Cu (pvalue = 0.0317, r = +0.596) were significantly positive.     

Antinociceptive and anti-inflammatory activity of the ethanolic extract of Cymbidium aloifolium (L.)

The ethanol leaf extract of Cymbidium aloifolium (L.) was evaluated for its analgesic and antiinflammatory activities. The extract, at the dose of 200 and 400 mg kg(-1) body weight, exerted the analgesic activity by observing the number of abdominal contractions and anti-inflammatory activity against Carrageenin induced paw edema in mice by measuring the paw volume. The ethanolic extract of Cymbidium aloifolium (L.) showed statistically significant (p < 0.05) reduction of percentage of writhing of 33.57 and 61.31% at 200 and 400 mg kg(-1) oral dose, respectively, when compared to negative control. The Ethanolic plant extract also showed significant (p < 0.05) dose dependent reduction of mean increase of formation of paw edema. The results of the experiment and its statistical analysis showed that the ethanolic plant extract had shown significant (p < 0.05) dose dependent analgesic and anti-inflammatory activities when compared to the control.     

Toxicological screening of lyophilized extract of some Nigerian wild mushrooms in mice

Mushrooms are macrofungi widely consumed as food. However, many mushrooms rot away in the wild because of fear of toxicity. Therefore, lyophilized aqueous extracts of 6 mushroom species collected from Zaria, Nigeria and taxonomically identified as Chlorophyllum molybdites, Panaeolus subalteatus, Macrolepiota procera, Leucopaxillus albissmus, Hygrophoropsis aurantiacus and Pholiota aurea were screened for toxicity in mice. Lyophilized aqueous extract of each of these mushrooms was administered to three groups of 3 mice intraperitoneally (i.p.) at doses of 100, 1000 and 10, 000 mg kg(-1), respectively. Another group of three mice given distilled water served as control. The mice were examined for clinical signs of toxicity over a period of 72 h and pathological examinations conducted on dead animals. The severity of clinical signs, onset of death and pathological lesions were dose dependent. Death occurred within 10 min in all the mice dosed at 10,000 mg kg(-1) with the lyophilized extracts of all the mushrooms screened, with the exception of that of H. aurantiacus, which produced death 21-23 h post administration. This result showed that all the screened mushrooms, including the popular edible M. procera were found toxic. Therefore, since all the mushrooms screened were found toxic, it is recommended that extreme caution should be exercised in their consumption. Furthermore, in view of the regional differences in the toxicity of mushrooms, there is the need to screen more wild mushrooms found in Nigeria for toxicity. This will boost mushroom mycophagy, reduce poisoning incidence and reduce wastage of edible mushrooms in the wild.     

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     

百菌清在菜用大豆上残留动态及安全使用技术研究

对百菌清在菜用大豆上的残留消解动态进行田间试验,以及对其安全使用技术的进行示范试验。结果表明,百菌清在菜用大豆上残留消解动态均符合一级动力学方程,相关系数（｜r｜）=0．9837～0．9851（P〈0．01）,原始残留沉积量较高,消解速度快,消解系数（｜k｜）=0．32155±0．00215,半衰期（DT50）为2．1～2．2d,消解99％所需要的时间（T99）为4．2～14．4d。安全使用技术示范试验结果显示,按百菌清常规使用剂量及施药方法,施用1次或间隔7d连续施用2次,在末次施药后8d残留量〈5．0mg／kg,18d和20d的残留量均〈0．1mg／kg。对照GB2763—2005及日本、美国的MRL,其产品符合于我国或日本、美国和欧盟等国家或地区规定的质量安全要求。     

Antidiabetic activity evaluation of glimepiride and Nerium oleander extract on insulin, glucose levels and some liver enzymes activities in experimental diabetic rat model

The present study is aimed to assess the therapeutic potential of sulfonylurea drug glimepiride in comparison with Nerium oleander plant extract on insulin, glucose levels and some liver enzymes activities in streptozotocin-induced diabetic rats. Rats were rendered diabetic by intraperitoneal injection of a single dose of 50 mg kg(-1) body weight streptozotocin. Rats with serum glucose levels > 200 mg dL(-1) were subdivided into three sub-groups: the first sub-group were remained without treatment and considered as diabetics. The second and third subgroups were orally administered 0.1 mg kg(-1) body weight/day glimepiride and 250 mg kg(-1) body weight/day Nerium oleander, respectively for 4 weeks. Streptozotocin-induced diabetic rats showed hypoinsulinemia and hyperglycemia compared to controls. Strong negative correlation (r = -0.8) was found between serum insulin and glucose levels in diabetic rats. This correlation was +0.4 and -0.3 in glimepiride and Nerium olender-treated rats, respectively implying that glimepiride and plant extract improved insulin and glucose levels with the former was more efficient. The activities of serum aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase were significantly increased in streptozotocin-induced diabetic rats compared to controls. Treatment of diabetic rats with glimepiride or Nerium oleander extract also improved liver enzymes activities.     

六个杂交品种白胡椒精油香气成分GC-MS分析

采用GC-MS法,研究了以‘班尼约尔1号’和‘热引1号’胡椒为杂交亲本的6个杂交种白胡椒（‘PC003’、‘PC008’、‘PC009’、‘PC011’、‘PC033’、‘PC036’）精油的化学成分,其化学组成成分用总离子流色谱峰的峰面积归一化法定量分析。结果表明：6个杂交品种白胡椒精油中共检测出烯类、醇类、酯类、酚类等8大类77种化合物,含量较高的化学成分有石竹烯[(30.93±0.00)%~(53.81±0.01)%]、可巴烯[(0.83±0.00)%~(10.09±0.00)%]、δ-毕澄茄烯[(0.08±0.00)%~(7.64±0.01)%]、石竹烯氧化物[(0.10±0.00)%~(5.86±0.00)%]、α-红没药醇[(0.18±0.00)%~(5.51±0.01)%]、蛇麻烯[(0.55±0.01)%~(6.64±0.00)%]、异丙二醇[(2.56±0.00)%~(4.12±0.00)%]。不同杂交品种白胡椒精油中检测出的挥发性成分和总的百分含量都不同,部分品种间差异显著。研究结果为今后胡椒新品种选育和优异种质资源开发利用提供参考依据。     

The effect of curcumin (active substance of turmeric) on the acetic acid-induced visceral nociception in rats

In the present study, the effect of chronic oral administration of curcumin in the presence or absence of morphine and noloxone was investigated on the visceral nociception induced by acetic acid in rats. Intraperitoneal injection of acetic acid (1 mL, 2%) produced contractions in the abdominal musculature (writhes). The latency time to the beginning of the first writhe was measured and the total number of writhes in the 1 h after acetic acid injection was counted. The latency time to the beginning of the first writhe was significantly (p < 0.05) increased and the number of writhes was significantly (p < 0.05) decreased by curcumin (20 and 40 mg kg(-1) body weight). The same results were obtained after subcutaneous injection of morphine (1 mg kg(-1) b.wt.). Naloxone at the dose of 1 mg kg(-1) body weight had no effect on pain intensity. Curcumin significantly (p < 0.05) enhanced the effect of morphine on the visceral pain responses, however did not reverse the effect of naloxone. Present data suggest that in the acetic acid-induced visceral nociception of rats, curcumin may produce an antinociceptive effect and the endogenous analgesic opioid system is involved in the curcumin-induced antinociception.     

Persistence of metalaxyl and mancozeb on potato leaves and their residues in tubers

The persistence of fungicides on two commercial cultivars of potato was determined under field conditions at Punjab Agricultural University, Ludhiana, Punjab. Initial deposits of mancozeb on potato leaves were found to be 26.9 and 38.7 mg kg(-1), following application of ready mixture of fungicide metalaxyl 8% + mancozeb 64% (Ridomil MZ) at the rate of 1260 and 2520 g a.i. ha(-1), whereas metalaxyl residues were found to be 35.1 and 49.5 mg kg(-1), respectively. The residue level of mancozeb in potato leaves 15 days after application at single and double doze were 19.0 and 27.0 mg kg(-1) showing a loss of 29.6 and 30.3%, whereas the values for metalaxyl at single and double doze were 0.40 and 0.80 mg kg(-1) showing a loss of 98.9 and 98.4%, respectively. Residues of mancozeb and metalaxyl were not detected at 0.04 and 0.02 mg kg(-1) level in potato tubers at harvest (PHI = 53 days) at both the dosages, respectively. The persistence and dissipation of mancozeb with the application of Ridomil MZ followed similar trend as in Indofil M-45. The rate of fungicide dissipation increased with time after application in both the potato cultivars 'Kufri Chandramukhi' and 'Chipsona'. No significant difference was observed on initial deposit, persistence and dissipation of the two molecules between the two potato cultivars.     

超高效液相色谱法测定啶酰菌胺和咯菌腈在番茄与土壤中的残留

应用超高效液相色谱仪建立一种同时检测番茄和土壤中啶酰菌胺和咯菌腈残留的分析方法。样品经乙腈提取,乙二胺-N-丙基硅烷（PSA）吸附净化,以乙腈和水为流动相等度洗脱,采用可变波长紫外检测器检测,外标法定量分析。结果表明,啶酰菌胺和咯菌腈在0.05~1 μg/mL范围内呈现良好的线性关系,相关系数R ²均为0.999,方法的检出限均为0.01 mg/kg,定量限为0.1 mg/kg;在0.1~1 mg/kg范围内,添加回收率在82.8%~102.8%和86.5%~115.3%之间,相对标准偏差（RSD）在4.1%~8.7%和4.9%~9.1%之间。该方法简单可靠、重现性好,适用于番茄和土壤中啶酰菌胺和咯菌腈的残留检测。     

Evaluation the effects of dextromethorphan and midazolam on morphine induced tolerance and dependence in mice

The main aim of this study was to evaluate the effects of dextromethorphan and midazolam and their combination on morphine tolerance and dependence in mice. In the present study, different groups of mice were rendered randomly and received morphine (50 mg kg(-1), s.c.), morphine (50 mg kg(-1), s.c.) + Dextromethorphan (25, 50 and 75 mg kg(-1), i.p.), morphine (50 mg kg(-1), s.c.) + midazolam (0.5, 1 and 2 mg kg(-1), i.p.), morphine (50 mg kg(-1), s.c.) + [Dextromethorphan (25 mg kg(-1), i.p. ) + midazolam (0.5 mg kg(-1), i.p.)] once a day for four days. Tolerance was assessed by administration of morphine (9 mg kg(-1), i.p.) on fifth day. Withdrawal symptoms (markers for dependence) was assessed by administration of naloxone (4 mg kg(-1), i.p.) 2 h after co-administration of morphine with either Dextromethorphan or midazolam or their combination. Results showed that pretreatment with Dextromethorphan or midazolam decreased the degree of tolerance and withdrawal symptoms significantly. Additionally co-administration ofDextromethorphan and midazolam couldn't decreased the tolerance and dependence significantly. From these results it may concluded that Dextromethorphan and midazolam alone or in combination could prevent the development of morphine induced tolerance and dependence. These effects can be related to the N-Methyl-D-Aspartate (NMDA) receptor antagonist behavior of Dextromethorphan and GABA-receptor agonist property of midazolam.     

茶氨酸对小鼠戊巴比妥钠镇静催眠的双向作用

采用自发活动仪和观察翻正反射消失与否研究茶氨酸对戊巴巴比妥钠诱导的镇静催眠作用。结果显示:单用茶氨酸能剂量依赖性地抑制正常小鼠的自发活动,其半数抑制量为0.8518g/kg;较小剂量(≤1.0g/kg)茶氨酸能加强戊巴比妥钠(5mg/kg)的抑制自发活动效应,而在2.0g/kg时则引起自发活动反跳性的增加,呈现"U"型改变;单用茶氨酸5.0g/kg并无催眠效应,但小于等于5.0g/kg时茶氨酸加强戊巴比妥钠(25mg/kg)的催眠作用,并呈明显的剂量依赖性。上述结果表明茶氨酸对戊巴比妥钠诱导的小鼠自发活动影响为双向改变("U"改变);茶氨酸对戊巴比妥钠(25mg/kg)的催眠效应呈剂量依赖性地加强作用,并未出现双向改变。     

Time-of-day dependence of neurological deficits induced by sodium nitroprusside in young mice

Sodium nitroprusside (SNP) is widely used in pharmacological studies as a potent vasodilator or a nitric oxide donor. SNP-induced ataxic effects were assessed in mice by the Joulou-Couvoisier test. Swiss albino mice of both genders, 2-8 weeks of age, were acclimated at least for 2 weeks to 12 h light (rest span)/12 h dark (activity span). In 2 and 4 week old mice, maxima of ataxia were found following intraperitoneal administration of a dose ranging from 3 to 3.6 mg.kg-1 SNP at ≈ 1 and 13 HALO (Hours After Light Onset). The sublethal toxicity was statistically dosing-time dependent (χ2 test: P < 0.005). No rhythm was validated in neurotoxicity by cosinor analyses. At the 8th week of post-natal development (PND), SNP-induced ataxia was greatest at ≈ 1 HALO (69% in males vs. 49% in females) and lowest at ≈ 13 HALO (21% in males vs. 11% in females) (χ2 test: P < 0.00001). Cosinor analysis also revealed no statistically significant rhythm in mice injected with 3 or 3.3 mg.kg-1. However, a significant circadian (τ = 24 h) rhythm was detected by adjusted cosinor in 3.6 mg.kg-1-treated mice (P < 0.004). In all studied groups, SNP-induced motor impairment (expressed in %) was lower during the dark than the light phase. Furthermore, there was a non-significant gender-related difference in SNP-induced neuronal toxicity with the males more sensitive than females at every studied PND. The ataxic effects were inversely proportional to the lag time from injection and to the age of animals (with P < 0.05 only between 2 and 8 week old mice). These data indicate that both the administration time and age of the animal significantly affect the neurotoxic effects of SNP.     

应用诊断施肥综合法(DRIS)对槟榔叶片进行营养诊断

应用诊断施肥综合法(DRIS)对低产园和高产园槟榔进行了叶片营养诊断。结果表明,相对于高产园,低产园元素间关系较不平衡。槟榔叶片N、P、K、Ca、Mg以及Fe、Mn、Cu、Zn的适宜含量分别为(20.53±0.67)、(1.90±0.01)、(13.30±0.46)、(7.14±0.57)、(3.68±0.41)g/kg及(109.50±4.16)、(112.50±9.02)、(6.07±0.64)、(31.23±0.15)mg/kg。低产园N、P、K、Ca、Mg、Fe、Mn、Cu、Zn元素DRIS诊断指数分别为-44.58、-1.60、-17.16、0.09、-31.94、52.78、31.03、23.12、-11.74,需求强度较大的元素为N、Mg、K,其次是Zn、P。