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Biomedical subjects

G Epple

Publications and source records attributed to G Epple.

At least 19 recordsLinked to original sources
PubMed2001

Zanthoxylum piperitum, an Asian spice, inhibits food intake in rats.

UNLABELLED: We investigated the effects of a total extract from Zanthoxylum piperitum fruit, of the volatile components of extract, and of a non-volatile fraction containing the major alkylamides of Zanthoxylum (NVA) on food intake in rats. In Experiment 1, three groups (A, B, C) of mildly food deprived rats were given one hour long feeding trials during which they were offered choices between an oat-bran wafer paired with vegetable oil and a wafer paired with a Zanthoxylum preparation in vegetable oil. Trials were divided into three blocks of two tests each. During Blocks 1 and 3, two wafers coated with vegetable oil were offered to establish baseline consumption. During Block 2, Group A was given choices between wafers coated with oil and wafers coated with total extract. Group B was offered oil coated wafers and wafers coated with the NVA fraction. Group C received two oil coated wafers. One was served on top of a screened dish containing a sample of total extract. In this manner, the rats were exposed to volatile compounds emanating from the extract but could not contact the extract. The second wafer was served on top of a screened sample of oil. RESULTS: In Blocks 1 and 3 trials, the rats fed indiscriminately from both wafers. During Block 2, total extract, the NVA fraction and the volatile compounds from extract all significantly reduced food consumption. In Experiment 2, habituation to the NVA fraction and to the volatile constituents of extract was examined in two additional groups (D, E), using the methods described above. Baseline consumption was tested in Blocks 1 and 3 by offering two oil coated wafers. During Block 2, group D was given 10 trials with oil coated and NVA-fraction coated wafers. Group E was given 10 trials with oil coated wafers paired with the volatile constituents of total extract and with those of oil. RESULTS: Both groups failed to habituate to the Zanthoxylum stimuli. Wafers treated with the NVA fraction and wafers paired with the volatile constituents of extract were avoided throughout the 10 test days.

Animals↗
PubMed1999

Ambient odors associated to failure influence cognitive performance in children.

We investigated whether odors can become conditioned to emotionally salient experiences such that when later encountered they influence performance consistent with a previously associated event. To test this hypothesis, 5-year-olds were given the experience of failure/frustration on a cognitive maze in a room scented with fragrance and later given another cognitively challenging test in a different room scented with either the same odor, a different odor, or no odor. Results revealed that subjects who performed the test in the presence of the same odor as the maze task did significantly worse than subjects in any other group. Performance in the different odor and the no odor groups were equivalent. Facial expressions and verbal remarks made during the maze task indicated a predominant display of negative affect. These findings show that odors can become conditioned to experiential states and when later encountered have directional influences on behavior.

Achievement↗
PubMed1998

Characterization of a novel acyl carrier protein, RkpF, encoded by an operon involved in capsular polysaccharide biosynthesis in Sinorhizobium meliloti.

Rhizobial capsular polysaccharides (RKPs) play an important role in the development of a nitrogen-fixing symbiosis with the plant host and in Sinorhizobium meliloti AK631 functional rkpABCDEF genes are required for the production of RKPs. After cloning the rkpF gene, we overexpressed and purified the derived protein product (RkpF) in Escherichia coli. Like acyl carrier protein (ACP), the RkpF protein can be labeled in vivo with radioactive beta-alanine added to the growth medium. If homogeneous RkpF protein is incubated with radiolabeled coenzyme A in the presence of purified holo-ACP synthase from E. coli, an in vitro transfer of 4'-phosphopantetheine to the RkpF protein can be observed. The conversion from apo-RkpF protein to holo-RkpF protein seems to go along with a major conformational change of the protein structure, because the holo-RkpF protein runs significantly faster on native polyacrylamide gel electrophoresis than the apo-RkpF protein. Electrospray mass spectrometric analysis reveals a mass of 9,585 for the apo-RkpF protein and a mass of 9,927 for the holo-RkpF protein. Our data show that RkpF is a novel ACP.

Acyl Carrier Protein↗
PubMed1997

Social memory in saddle-back tamarins (Saguinus fuscicollis).

Discrimination between male former group members and unrelated males was tested in 13 males. During tests, each subject lived in a cage connected by tunnels to 2 cages, each housing a stimulus male. Subjects used the tunnels to approach and interact with both stimulus animals. Proximity to the stimulus males, aggressive and non-aggressive contacts and exchange of tongue flicks were recorded. aggressive contacts were rare. The subjects had significantly more non-aggressive contacts with former group members than with unrelated males but exchanged significantly more tongue flicks with unrelated animals. There was no difference in proximity to either class of stimulus male.

Aggression↗
PubMed1990

Copulatory behavior of adult tamarins (Saguinus fuscicollis) castrated as neonates or juveniles: effect of testosterone treatment.

The sexual interactions of Saguinus fuscicollis males castrated as neonates, at 37 days of age, or prepubertally with adult intact females were studied. Prepubertally castrated males were observed while receiving testosterone, and while being treated with saline. Males castrated neonatally or at 37 days of age were observed while receiving testosterone. Neonatal castrates had previously been studied without hormone treatment and therefore no control condition was included for these animals. Prepubertally castrated males showed Mounts, Mounts with Thrusts, and Sexual Tongue Flicking when treated with saline only. In three of the four males, all measures of sexual behavior increased with testosterone treatment. Neonatally castrated males had failed to display any mounting or thrusting without testosterone treatment during a previous study. During the present study, three of the four males did not respond to testosterone treatment with sexual behavior. The fourth male and one male castrated at 37 days of age displayed some sexual behavior. These results suggest that most neonatally castrated males are not able to respond to testosterone with the activation of copulatory behavior. The findings are consistent with the hypothesis that in callitrichids the sensitive period for behavioral differentiation is shifted into neonatal life. However, some neonatally castrated males show a weak response to testosterone. This may reflect an extended and perhaps partially prenatal period of sensitivity.

Animals↗
PubMed1985

Computerized pattern recognition: a new technique for the analysis of chemical communication.

Computerized pattern recognition techniques can be applied to the study of complex chemical communication systems. Analysis of high resolution gas chromatographic concentration patterns of the major volatile components of the scent marks of a South American primate, Saguinus fuscicollis, demonstrates that the concentration patterns can be used to predict the gender and subspecies of unknown donors.

Animals↗
PubMed1978

Reproductive and social behavior of marmosets with special reference to captive breeding.

The field studies reviewed above raise some doubts about the laboratory concept of the extended family as the basic social unit of the Callithricidae. As Dawson [6] suggests, wild groups might more closely approximate artificial laboratory groups. They probably consist of a dominant, monogamous breeding pair, its dependent offspring and separate hierarchies of subdominant males and females who stay associated with the group for various lengths of time. Some of these subdominants might be offspring or relatives of the breeding pair. As the field studies show, these groups are more or less open to immigrants coming from other groups. They possibly tolerate transient relatives more easily and for longer periods of time than nonrelated individuals. In spite of the relative tolerance of wild groups towards strange conspecifics, it appears most practical to maintain laboratory breeders as families and remove the offspring after they have participated in the care of their younger siblings. In this way their reproductive capacities can be utilized as soon as their parental behavior has developed adequately. Moreover, possible losses caused by keeping nonrelated adults of the same sex together are avoided. As pointed out above, some species are very aggressive towards strange adult conspecifics and some seem to defend territories in the wild. It seems advisable therefore to house them in cages which provide a certain degree of isolation from neighboring groups. We have found this to be more important in S. fuscicollis than in C. jacchus, particularly in densely populated colony rooms. We therefore house our animals in cages which allow no visual contact with any other group, and by doing so have reduced the general level of excitement in the colony room. We believe that aggressive displays between groups are responsible for a large amount of redirected aggression between mates and for some of the abortions we have seen in our colony. Moreover, Rothe's [28, 29] observation that the parturient female withdraws from her group and gives birth in relative isolation should be taken into consideration when designing breeding cages. Although not all individuals of all species might show this behavior [see 32] it seems to be widespread enough to be an important factor in breeding efficiency and might figure in some of the infanticides observed by us and other authors.

Aggression↗
PubMed1975

Parental behavior in Saguinus fuscicollis ssp. (Callithricidae).

Carrying and nursing of infants were recorded in 7 groups during the first 40 days postpartum. All members of all groups participated in carrying the infants. Dominant males tended to carry most frequently, followed by mothers and nonbreeding, mostly juvenile individuals. The role of early experience in caring for infants in the development of adequate parental behavior and rearing success is discussed.

Animals↗