The geographic distribution of pubescence in the sea daisy, Borrichia aborescens, on Bahamian Islands

Borrichia aborescens (L.) DC. is a salt‐tolerant perennial herb that is common on small islands in the central Bahamas. Two morphotypes are present: one with densely pubescent leaves and one with glabrous leaves. I conducted surveys in three archipelagos to document the geographical distribution of pubescence in this species and to infer the underlying mechanisms. B. aborescens was also grown from seed in a greenhouse. The pubescent form of B. aborescens was relatively more abundant on small islands than on nearby large ‘mainland’ islands. In two of the three archipelagoes, pubescence increased with distance on small islands. The pubescent form was relatively more abundant on small islands exposed to the open ocean compared to small islands that were protected by mainland islands or reefs on all sides. On a large mainland island, the pubescent form decreased in relative abundance inland from the coast. B. aborescens cultivated in a greenhouse revealed the effect of a genetic factor on the expression of pubescence. The observed patterns of variation are consistent with a physiological explanation for the adaptive benefit of pubescence. Trichomes may prevent physical blockage of the stomata by accumulation of salt in areas near breaking waves and salt spray.     

NGF,BDNF and Arc mRNA Expression in the Hippocampus of Rats After Administration of Morphine

Morphine can influence immediate early genes (IEG) of activity-regulated cytoskeletal-associated protein (Arc) and brain-derived neurotrophic factor (BDNF) which are activated in response to physiological stimuli during learning, as well as the nerve growth factor (NGF) gene which increases the expression of several IEGs for memory formation. The purpose of the current study was first to evaluate the effect of acute (1-day) and subchronic (15-days) morphine administration on memory retrieval of rats and second to determine the hippocampal expression of NGF, BDNF and Arc genes as potential contributors in the observed effects in each setting. The effects of morphine (intraperitoneal, 10, 15 and 20 mg/kg) on memory function and gene expression were assessed using inhibitory avoidance test and real-time polymerase chain reaction, respectively. We found that a single dose of morphine at the highest dose of 20 mg/kg decreases the post-training step-through-latency, while repeated administration of the same dose for 15 successive days increases this indicator of memory retrieval. We did not detect a significant change in the hippocampal expression of Arc, BDNF or NGF genes after a single episode of morphine treatment. However, subchronic morphine administration (15 and 20 mg/kg) increased the expression of Arc and BDNF genes in a dose dependent manner. A higher mRNA expression for the NGF was observed at the higher dose of 20 mg/kg. We hypothesize that the subchronic effects were morphine-induced behavioral sensitization which may have been enhanced through increased hippocampal Arc expression.

     

The role of T-type calcium channels in morphine analgesia,development of antinociceptive tolerance and dependence to morphine,and morphine abstinence syndrome

Involvement of T-type voltage dependent Ca2+ channels (VDCCs) on morphine antinociception, in the development of tolerance and dependence to morphine, and naloxone-precipitated abstinence syndrome in morphine dependent mice was examined by using mibefradil, a T-type VDCCs blocker. Mice were rendered tolerant and dependent on morphine by subcutaneous (s.c.) implantation of a morphine pellet containing 75 mg of morphine base for 72 hr. The tail-flick test was used to assess the nociceptive threshold. Coadministration of acute mibefradil (10 mg/kg, i.p.) with morphine enhanced the antinociceptive effects of acute morphine. Repeated mibefradil administration (10 mg/kg, i.p., just before, 24 and 48 hr after morphine pellet implantation) completely blocked the development of tolerance to the antinociceptive effect of morphine and even by this effect reached supersensitivity to morphine. However, repeated mibefradil treatment did not alter the development of dependence to morphine assessed by the A(50) values of naloxone (s.c.) required to precipitate withdrawal jumping 72 hr after morphine pellet. But, acute mibefradil (10, 30, and 50 mg/kg, i.p.) dose dependently decreased the expression of morphine abstinence syndrome when given directly 30 min prior to naloxone (0,05 mg/kg, s.c.) 72 hr after morphine pellet. These results indicate a critical role of T-type VDCCs in morphine antinociception, the development of tolerance to the antinociceptive effects of morphine and in morphine abstinence syndrome.     

Spiradiclis quanzhouensis sp. nov. (Rubiaceae) from a limestone area in Guangxi,China

Spiradiclis quanzhouensis, a new species of Rubiaceae from northeastern Guangxi, China is described and illustrated. It is similar to S. umbelliformis, but can be distinguished by its rosulate habit, subglabrous stems, leaf blades that are pubescent on both surfaces, lanceolate purple‐pubescent stipules that are undivided or sometimes bifid in apical 1/3, an inflorescence with 2–4 flowers, lanceolate 4–5 mm long calyx lobes that are purple‐pubescent outside, a salveriform corolla that is light purple‐pubescent outside, a semi‐inferior ovary, and capsules that are light purple‐pubescent with persistent calyx lobes 5–6 mm, in fruit 2 × as long as capsule.     

Histamine release as the basis for morphine action on bile duct and sphincter of Oddi

We have investigated the mechanism by which morphine contracts hog bile duct and sphincter of Oddi. Morphine contraction is antagonized by naloxone, competitively on the sphincter, noncompetitively on the bile duct. Diphenhydramine at low concentration (3.4 X 10(-6)M) also antagonizes both actions of morphine. Histamine has a very potent contracting action on the sphincter and bile duct and this is antagonized by diphenhydramine. Burimamide only weakly antagonizes the actions of morphine or histamine. Compound 48/80 causes a pronounced contraction of sphincter and bile duct following which morphine effects are greatly attenuated. These results suggest that morphine-induced contraction of the sphincter of Oddi and bile duct is mediated by a two step reaction involving interaction with a specific opiate receptor leading to the release of histamine which combines with an H1 receptor to produce the effect.     

Effects of leaf pubescence in Salix borealis on host- plant choice and feeding behaviour of the leaf beetle, Melasoma lapponica

Density of leaf trichomes in Salix borealis affected both the choice of individual host plants and feeding behaviour of adults and last instar larvae of the willow feeding leaf beetle, Melasoma lapponica. Beetles clearly preferred shaved disks to unshaved ones taken from the same leaf; this preference was highest in leaves of the most pubescent plants. High leaf pubescence explained the low preference for willow clones from the high density site in among-site preference trials; shaving significantly increased the consumption of these pubescent willow clones. In no-choice experiments, the food consumption by both adults and last instar larvae decreased with an increase in leaf pubescence. The time budget of adults did not depend on leaf pubescence of the host plants, however adults compelled to feed on highly pubescent plants changed their feeding sites twice as often as on less pubescent willow clones. Larvae feeding on highly pubescent plants spend moving three times as much time as larvae feeding on less pubescent plants. Combined with our earlier observations on the increase in leaf pubescence in the year(s) following defoliation, these data suggest that leaf hairiness may have contributed to the delayed induced resistance in S. borealis by disturbing the feeding behaviour of M. lapponica.     

Effect of maturation on the relationship between physical performance and body size

The purpose of the study was to explore the effect of maturation on the body size-physical performance relationship. Based on our previous study that evaluated only muscle strength, we hypothesized that the physical performance tested on pubescent subjects would be related to body size at a higher rate than predicted by standard scaling theory applied on pre- and postpubescent subjects. Six age groups of highly selected and trained junior soccer players (N = 478; age 12-17 years) presumably including prepubescent, pubescent, and postpubescent subjects were evaluated. They were tested using various standard tests of maximum physical performance including muscle strength of 3 leg muscle groups, 2 jumps, sit-ups, hand and foot tapping, and agility. The results revealed a steeper increase of the tested performance with an increase in body size for the pubescent age than for the pre- and postpubescent age. The observed phenomenon was interpreted by different level of maturation of the subjects tested within the same pubescent age group. We conclude that maturation alters the effect of body size on various physical performances and, therefore, this phenomenon needs to be taken into account when interpreting the data from the physical performance tests applied on pubescent subjects.     

Effect of GABA-ergic substances on the analgesic effect of morphine in rats]

The effect of GABA-ergic compounds on morphine-induced analgesia was studied to reveal probable interaction of GABA and opiates. As an index for morphine effect the reaction of vocalization in response to electrical stimulation of the rat tail was used. It was shown that thiosemicarbazide, the inhibitor of glutamate decarboxylase and bicuculline, GABA-ergic receptor blocking agent, which were proposed to be joined in a group of GABA-negative compounds, reduce and shorten the effect of morphine. Depakine, the inhibitor of alpha-ketoglutarate-GABA-transaminase, as well as GABA itself administered in high doses (GABA-positive actions) make morphine analgesia more pronounced and longer. Probable causes of the described interrelationship between GABA and opiates are discussed.     

大盘山蔷薇——浙江产蔷薇属一新变种

描述和图解了浙江蔷薇属的一新变种——大盘山蔷薇,与原变种小果蔷薇的区别在于托叶革质,宿存,具1脉,边缘有腺毛状齿,叶轴密被短柔毛,小叶柄被短柔毛。     

Effect of morphine on the sensitivity of cerebral cortical neurons to acetylcholine

Sensitivity of sensorimotor cortical neurons to microiontophoretically applied morphine and acetylcholine has been studied in the experiments on unanesthetized rabbits. The predominant reaction to morphine and acetylcholine was decrease and increase in the rate of neuronal impulse activity, respectively. There was no correlation in the responses to morphine and acetylcholine. Atropine failed to influence the morphine effect. When both drugs are simultaneously applied to neurons, morphine decreases both excitatory and inhibitory responses to acetylcholine. This effect of morphine may occur in the case when the drug is applied in doses which do not change spontaneous neuronal activity. On the contrary, excitatory effect of glutamic acid decreased only when morphine was applied in doses causing local anesthetic effect and decreasing background neuronal activity. It is suggested that morphine can exercise a modulating influence on choline receptors of cortical neurons.     

Effect of trichome density on soybean pod feeding by adult bean leaf beetles (Coleoptera: Chrysomelidae).

The role of soybean, Glycine max (L.) Merrill, pod trichomes on feeding by adult bean leaf beetles. Cerotoma trifurcata (Forster), was evaluated under laboratory and field conditions during 1997 and 1998. Three Clark isolines and 'Corsoy 79' were used to compare the feeding preference of the beetle on pods with different trichome densities. The three Clark isolines, including densely pubescent, sparsely pubescent, and glabrous, were isogenic except for trichome density. The trichome densities on the pods of Clark densely pubescent, Clark sparsely pubescent, and Corsoy 79 were significantly different. In no-choice tests, under both laboratory and field conditions, the feeding on pods of Clark densely pubescent was significantly lower than that on the other isolines. In the choice test of Corsoy 79 conducted in the laboratory and field, when the trichomes on one of the two pods were shaven off, the feeding on the shaven pods was significantly higher than that of the intact ones. In the choice test among Clark isolines under laboratory condition, the result was significant, with the lowest feeding on the densely pubescent pods. This study demonstrates that densely pubescent soybean has the potential to resist bean leaf beetle feeding on pods.     

Effects of yohimbine and naltrexone in counteraction of the morphine straub tail and the amphetamine-potentiated morphine straub tail in mice

The alpha-adrenergic blocking agent, yohimbine, prevented the production of the morphine Straub tail reaction in mice, although on a mg dose basis it was only about $\text{1}\text{400}$ as potent as the narcotic antagonist naltrexone by subcutaneous injection. Likewise, yohimbine prevented the potentiation of the morphine Straub tail reaction by amphetamine, being about $\text{1}\text{170}$ as active as naltrexone. Preliminary studies with another alpha-adrenergic blocking agent, phentolamine, indicated that it also inhibited the production of the Straub tail reaction by morphine, although it appeared to be somewhat weaker than yohimbine in this respect. These results suggest the involvement of alpha-adrenergic mechanisms in the production of the morphine Straub tail reaction and in the potentiation of the morphine Straub tail reaction by amphetamine.     

Distinct RNA structural domains cooperate to maintain a specific cleavage site in the 3'-UTR of IGF-II mRNAs

The insulin-like growth factor II mRNAs are targets for site-specific endonucleolytic cleavage in the 3'-UTR, which results in a very stable 3' cleavage product of 1.8 kb, consisting of 3'-UTR sequences and a poly(A) tail. The 5' cleavage product contains the coding region and is rapidly degraded. Thus, cleavage is thought to provide an additional way to control IGF-II protein synthesis. We had established that cleavage requires two widely separated sequence elements (I and II) in the 3'-UTR that form a stable duplex of 83 nucleotides. The cleavage-site itself is located in an internal loop preceded by two stable stem-loop structures. Furthermore, in a study which was based on RNA folding algorithms, we have shown that there are specific sequence and structural requirements for the cleavage reaction. Here, the functions of the different structural domains in cleavage were assessed by deletion/mutational analyses, and biochemical structure probing assays were performed to characterize better the RNA structures formed and to verify the computer folding predictions. The data suggest that the stem-loop domain contributes to maintain a highly specific c leavage-site by preventing the formation of alternative structures in the cleavage-site domain. Involvement of the nucleotides in the cleavage-site loop itself in non-Watson-Crick interactions may be important for providing a specific recognition surface for an endoribonuclease activity.     

Pubescence,floral temperature and fecundity in species of Puya (Bromeliaceae) in the Ecuadorian Andes

Summary The effects of inflorescence pubescence on floral temperatures and fecundity were examined in four species of Puya in the Ecuadorian Andes. These species span an elevational range from 1,980–4,000 m and comparisons among these species showed that pubescence production increases significantly with elevation. Flower temperatures of glabrous or slightly pubescent species of Puya from lower elevations closely tracked air temperature, while those of the pubescent páramo species did not. Pubescence removal experiments on Puya hamata, a páramo species, demonstrated that pubescence is an effective insulator, maintaining elevated flower temperatures. In Puya clava-herculis (also a páramo species) elevated flower temperatures were associated with higher seed set. Thus, the greater production of inflorescence pubescence in páramo species of Puya may be an important factor contributing to reproductive success in these higher elevation species.     

The predatory mite Typhlodromalus aripo prefers green-mite induced plant odours from pubescent cassava varieties

It is well known that plant-inhabiting predators use herbivore-induced plant volatiles to locate herbivores being their prey. Much less known, however, is the phenomenon that genotypes of the same host plant species vary in the attractiveness of these induced chemical signals, whereas they also differ in characteristics that affect the predator’s foraging success, such as leaf pubescence. In a series of two-choice experiments (using a Y-tube olfactometer) we determined the preference of Typhlodromalus aripo for pubescent versus glabrous cassava cultivars infested with the cassava green mite Mononychellus tanajoa and also the preference for cultivars within each of the two groups. We found that when offered a choice between pubescent and glabrous cassava cultivars (either apex or leaves), T. aripo was significantly more attracted to pubescent cultivars. For each cultivar, M. tanajoa infested leaves and apices were equally attractive to T. aripo. There was however some variation in the response of T. aripo to M. tanajoa-infested plant parts within the group of pubescent cultivars, as well as within the group of glabrous cultivars. Our study confirms not only that T. aripo uses herbivore-induced plant volatiles to search for prey in cassava fields, but it also shows that it can discriminate between glabrous and pubescent cultivars and prefers the latter. This knowledge can be useful in selecting cultivars that are attractive and suitable to T. aripo, which, in turn, may promote biological control of the cassava green mite.