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S Hsiao

Publications and source records attributed to S Hsiao.

At least 19 recordsLinked to original sources
PubMed1998

Use of fluorescein labelled antibody and fluorescence activated cell sorter for rapid identification of Mycobacterium species.

A fluorescein labelled antibody (Ab)/Fluorescence Activated Cell Sorter (FACS)-based assay was developed for detection of a wide range of mycobacterial species directly from bacterial culture and sputum specimens. The whole process could be completed within 3 hours and had a high specificity and sensitivity for cultured bacteria. The method was also shown to be applicable for direct identification from clinical specimens. This study showed that pretesting of clinical specimens for mycobacteria to the genus level with an antibody to Mycobacterium species offers the routine clinical laboratory a single convenient test for the detection of tuberculous and nontuberculous mycobacteria. Depending on the availability of species-specific antibody, the identification of Mycobacterium to the species level can be achieved.

Antibodies, Bacterial↗
PubMed1996

Anticipatory contrast effect in rats: a new view with lick response analysis and the effect of dopamine blocking.

A negative anticipatory contrast effect (NACE) is manifested as a suppression of the effect of a reward stimulus to elicit consummatory or instrumental responses when a second more potent reward is presented right afterward. No well-supported theory explains the effect. We analyzed NACE with rats' licking responses to 3 solutions with varying reward value: 8% sucrose mixed with 0.008% quinine (A), 8% sucrose with 0.002% quinine (B), and 32% sucrose with 0.008% quinine (C). 3 groups (n = 4) of rats were given 2 solutions in succession, each 5 min with 15 s in between, for a total of 11 days: Group AA (control), A then A; Group AB, A then B; Group AC, A then C. On days 13 to 16, and 12 and 17, pimozide (0.4 mg/kg, i.p.), and the vehicle solution were injected, respectively. Results show that the licking of A was a function of what solution to follow: In AC, the total number of licks, the short interlick interval (SILI), and the number of licks per s during the initial contact were less than AA. In AB, only SILI was less. Licking of A was initially low but increased over days, except for AC. The failure of AC to increase the licking was attributed to a "retroactive overshadowing" effect of a more potent stimulus C blocking stimulus A to form a reward learning, thus preventing its rewarding property to be fully manifested. It may also be due to stimulus A becoming a "signal" for incoming reward, thus degrading its own rewarding function. The shorter SILI in AB and AC suggested a reward devaluation; however, devaluation alone did not predict the consummatory response. Pimozide reduced licking number overall without altering the relative reward property or SILI suggesting that NACE was not a dopamine-mediated motivated choosing behavior.

Animals↗
PubMed1995

Analysis of nocifensive behavior induced in rats by CO2 laser pulse stimulation.

To characterize nocifensive behavior, a laser beam was applied to the hind footpad of nonanesthetized and unrestrained rats and the reaction pattern was analyzed. Fifty-four rats were divided into nine groups of six animals, and each group was given one of nine combinations of laser stimuli: intensity of 4, 8 or 12 W and duration of 10, 30, or 50 ms. A single pulse was applied to a 0.13 cm2 area of right or left footpad and the trial was repeated 20 times with 3 min between trials. The behavior was videotaped and reviewed for a period of 2 min following each stimulation. It seemed to consist of eight discrete responses, and each response was scored for whether it occurred and for its summed duration per trial. The component responses and the behavior as a whole were characterized by their sensitivity in terms of the level of energy required to attain 50% of the maximum response, and their linear or quadratic trends with increasing stimulus energy. The most sensitive index of pain stimulation was the composite score, followed by foot jumping, foot elevation, body movements, licking, and then foot movements. As stimulus energy increased, rats exhibited a greater number of different responses and a greater frequency of each component response. The results suggest that a pool of hierarchically organized responses in the nocifensive motor system are recruited partially or wholly by nociceptive stimuli of varying intensity.

Animals↗
PubMed1995

Raclopride reduces sucrose preference in rats.

Dopaminergic D1 and D2 antagonists decrease the intake of sweet solutions during sham feeding. Because the decreased intake of 10% sucrose produced by the D1 and D2 antagonists has been demonstrated to occur in the absence of significant deficits in the initiation of ingestion, or of its motor performance, we investigated the hypothesis that raclopride decreases intake by lowering the reinforcing potency of the orosensory stimulation provided by sucrose during sham feeding. Rats were adapted to ingest two differently flavored 10% sucrose solutions for 5 min in one-bottle tests. The flavored solution that rats preferred was paired with pretreatment with a dose of raclopride (400 micrograms/kg, IP, 15 min) that produced a mean decrease of intake of 55%. The other flavored 10% sucrose solution was paired with vehicle (0.15 M NaCl) injections. After three or six pairings with raclopride or vehicle injection, two two-bottle preference tests were given without raclopride pretreatment. Preference for the flavored 10% sucrose solution previously paired with raclopride decreased significantly in both tests. We interpret this decreased preference as evidence that raclopride decreased the reinforcing potency of flavored 10% sucrose during one-bottle tests. This is consistent with our hypothesis and with the more general hypothesis of Wise that central dopaminergic mechanisms mediate the reinforcing effect of food.

Animals↗
PubMed1995

Complex response competition and dopamine blocking: choosing of high cost sucrose solution versus low cost water in rats.

The effect of DA blocking with pimozide on complex response competition involving coupling of cost and benefit was studied with a double-bottle test in lickometer: The competition occurred between two responses; licking of 2% sucrose solution requiring a high effort of standing up and licking of water requiring a low effort of crouching posture. Rats normally chose sucrose over water (76% with vehicle); however, pimozide (0, 0.25, 0.375 and 0.5 mg/kg) diminished licking of the sucrose solution dose-dependently (57% at 0.5 mg/kg) without affecting licking of water. Analysis of lick pattern suggested that this shift in choice was attributable not much to a potential effect of pimozide to hamper motor capability or to reduce rewarding impact of sucrose because (a) the difference in licking profile for sucrose and water remained intact, (b) rats remained fully capable of assuming the standing posture for sustained and efficient licking of sucrose, and (c) the integrity of licking pattern largely remained. Pimozide appeared to selectively affect the behavior that cost more but with higher reward; rats settled with behavior that cost less with lower reward. Rats became less motivated to invest effort for a better reward, a behavior pattern described as "indolent". A more complex view of incentive motivation including coupling of behavioral cost and benefit was presented as a theory to explain the DA mediation of reward-maintained behaviors.

Animals↗
PubMed1993

Additivity of taste-specific effects of sucrose and quinine: microstructural analysis of ingestive behavior in rats.

Effects of sweet and bitter tastes on ingestion were studied by timing licking responses. Twelve water-deprived rats were given 15-min access to sucrose (S) solutions (0.00%, 1.25%, 2.50%, and 5.00%) with and without quinine (0.01%) and to quinine (Q) solutions (0.00%, 0.0025%, 0.005%, and 0.01%) with and without sucrose (5.00%). Volume ingested and number of licks increased with S and decreased with Q. In response to S, the number of bursts increased, and interlick intervals lengthened. In response to Q, licks to ingest 1 ml of solution, burst number, and percentage of slow licks increased, and burst size decreased. When Q and S were mixed in the same solution, the pattern of ingestive responses manifested attributes of both tastes. Results suggest 2 separate, parallel systems that operate simultaneously to govern rats' licking behavior. One system expresses the effect of S on the pattern of ingestion and the other expresses the effects of Q.

Animals↗
PubMed1993

Sensitivity to dopamine blocking in rat licking behavior: function of taste stimuli, response difficulty, and response measures.

The behavioral circumstances determining the efficacy of DA blocking was studied by observing the effects of pimozide, tastes and effort required to ingest liquid on consummatory licking responses. The microstructure of ingestive behavior was obtained to delineate differential behavioral adjustments. Twelve water-deprived rats were trained to lick water, 2.00% sucrose, and 0.01% quinine from a spout located either at a down position of 7 cm above (low effort) or an up position of 24 cm above the floor (high effort). They were injected with pimozide (0.25 mg/kg, ip) or its vehicle and licking responses were observed. Results indicated that the pimozide effect was dependent on tastes and positions as well as the behavioral aspects observed. Pimozide affected ingestion of quinine in many ways, but did not affect that of sucrose solution. The position affected ingestion of quinine in more ways than that of sucrose solution. The taste effect of quinine was more complex than that of sucrose. The complex behavioral adjustment to the reduced incentive support with quinine probably rendered the behavior vulnerable to interference by DA blocking and effort requirement.

Animals↗
PubMed1988

Preference differences for sucrose solutions in young and aged squirrel monkeys.

Licking patterns and molarity preferences, elicited by two sets of sucrose solutions (0.0 to 1.75 M and 1.0 to 3.0 M), were measured in six young and six aged squirrel monkeys. Sucrose preference thresholds were determined for each age group using sucrose concentrations from 0.025 to 0.1 M. Age was unrelated to sucrose preference thresholds. Consummatory activity of all monkeys increased monotonically as sucrose concentrations increased from 0.0 to 1.0 M. Aged, but not young, monkeys continued to increase consumption until sucrose concentrations exceeded 1.5 M. All monkeys increased consumption by increasing number of licks, number of licking bursts and total time spent licking. Unlike young monkeys, aged monkeys displayed high within animal variability of tongue contact times, exponentially decreasing rates of licking at high molarities, constant consumption efficiency decrements, and consistent negative correlations between tongue contact and following tongue off times.

Aging↗
PubMed1988

Cholecystokinin octapeptide increases passive avoidance latencies in rats.

Intraperitoneal injections of either 0.9% NaCl or cholecystokinin octapeptide (CCK-8) were paired with electrical footshock using a standard passive avoidance conditioning procedure for rats. Passive avoidance behavior was measured either 24 or 48 hr following the conditioning. No CCK-8 effect upon passive avoidance behavior was observed at the 24 hr test, but CCK-8 (100 micrograms/kg and 200 micrograms/kg) produced longer passive avoidance latencies at the 48 hr test. Control rats showed a decrease in passive avoidance latencies from 24 hr to 48 hr, while the CCK-8 rats did not show such a trend.

Animals↗
PubMed1987

Cholecystokinin octapeptide, proglumide, and conditioned taste avoidance in rats.

Past research has shown that large (pharmacological) doses of cholecystokinin octapeptide (CCK-8) can influence conditioned behavior in rats. In the present study rats were allowed to locate and drink from a drinking tube that contained a sucrose solution. Following 30 sec exposure to the sucrose, intraperitoneal injections of NaCl or CCK-8 were given, with several variables measured 24 hr later. CCK-8 (100 micrograms/kg) was found to increase the latency to begin drinking the sucrose. It was also found that CCK-8 (10 micrograms/kg and 100 micrograms/kg) reduced the amount of sucrose consumption following the pairing of sucrose exposure and CCK-8. In addition, CCK-8 (100 micrograms/kg) reduced the amount of time rats spent in the area of the conditioning apparatus where the sucrose was located. These results are consistent with past research which found that CCK-8 can produce conditioned taste avoidance in rats. These results suggest that pharmacological doses of CCK-8 can act as an aversive stimulus during conditioning. Proglumide was found to block all of the effects produced by CCK-8 while producing little effect by itself.

Animals↗
PubMed1986

Licking patterns for sucrose solutions by young and aged squirrel monkeys.

The licking elicited by 0.1, 0.3, and 1.0 M sucrose solutions was measured in six young and six aged squirrel monkeys. All tongue-on and tongue-off times were recorded in addition to conventional measures of lick rate and consumption. Consummatory activity by both groups increased monotonically with sucrose concentration. Aged monkeys displayed greater within animal variability of tongue-on times than did young monkeys. Distributions of pause lengths between licking bursts contained two components, one varying inversely with sucrose concentration, the other varying inversely with age. Distributions of licks per burst contained a component that increased with sucrose concentration but none varying with age. Results indicated that licking deteriorated little with age and that consumption is controlled mainly by length and spacing of bursts, not by individual lick parameters.

Aging↗
PubMed1986

Hedonic reactivity to sucrose in rats: modification by pimozide.

Reward summation functions (RSFs) are an important way to dissociate and quantify hedonic and motor effects of neuroleptics. Previously used only with brain stimulation reinforcement, we demonstrate they will also work using sucrose solution reinforcement. Eighteen male rats were trained to lever press on a CRF schedule for 0.01 ml sucrose solution reinforcers of varying concentration (0.025, 0.05, 0.1, 0.3, 0.5, 0.7, 0.9, 1.1, 1.7, 2.3 M). Making the lever harder to press caused an increase in the asymptote of the function, demonstrating a motor effect. Quinine added to the solutions (0.05%) caused the function to shift right, demonstrating an hedonic effect. Rats injected with 0.2 mg/kg pimozide, a dopamine antagonist, then tested four hours later, showed a right shift in the function with no change in asymptote. Thus, at this dose pimozide affects hedonic and not motor substrates of the CNS. These data demonstrate the generalizability of the RSF method to reinforcers other than brain self-stimulation.

Animals↗
PubMed1986

Centrally-administered opioid selective agonists inhibit drinking in the rat.

The effects of intracerebroventricular injection of mu (morphine), kappa (dynorphin-(1-13), ethylketocyclazocine, and U50,488H), and delta ([D-Pen2, D-Pen5]enkephalin) opioid agonists on water intake of 14 hr water deprived rats was studied. All agonists caused a dose related decrease in time spent drinking, with a rank order potency of dynorphin-(1-13) greater than morphine greater than ethylketocyclazocine greater than [D-Pen2, D-Pen5]enkephalin = U50, 488H. With the exception of morphine, all of the compounds increased the latency to begin drinking, but only at the highest doses tested. The rank order potency for this endpoint was dynorphin-(1-13) = ethylketocyclazocine greater than [D-Pen2, D-Pen5]enkephalin greater than U50, 488H. The potent inhibition of drinking following centrally-given dynorphin-(1-13), at doses that did not affect the latency to begin drinking, supports a role for endogenous dynorphin in the homeostatic control of water balance. This function may not be primarily mediated through activation of a kappa opioid receptor since dynorphin-(1-13) was 80-230 times more potent than the selective kappa agonist, U50,488H or ethylketocyclazocine.

3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cycloh↗
PubMed1985

Dopaminergic behavior in frontal decorticated rats.

Decortication of the frontal neocortex in rats enhanced the increased general activity caused by methamphetamine, 0.15 mg/kg, SC. However, the low, 0.1 mg/kg, SC, and high, 0.5 mg/kg, SC, dose effects of apomorphine were not affected by the decortication. The cataleptic effect of haloperidol, 2 mg/kg, SC, was decreased. The data suggest that the frontal cortex may inhibit dopamine release in mesolimbic and nigrostriatal areas. However, the sensitivity of presynaptic or postsynaptic dopamine receptor systems in the nucleus accumbens area appears to be unaltered by frontal decortication.

Animals↗
PubMed1985

Altered responding to cholecystokinins and dopaminergic agonists following 6-hydroxydopamine treatment in rats.

Production of lesions in the brain dopamine (DA) system by intraventricular injection of 6-hydroxydopamine (6-OHDA) resulted in increased responses to apomorphine (0.5 mg/kg, sc) and reduced responses to methamphetamine (0.15 mg/kg, sc). It also made animals increase responding to cholecystokinin octapeptide (CCK-8; 0.5-2 micrograms, intracerebroventricularly [icv]) and reduce responding to cholecystokinin tetrapeptide (CCK-4; 0.5-2 micrograms, icv). Response changes were quantified by measuring the level of general activity. The result indicates that DA dysfunction can affect not only DA receptor sensitivity but also the sensitivity of the CCK system. The response to CCK-8 was partially blocked by a selective CCK-8 antagonist, proglumide (5 micrograms, icv), a result suggesting the involvement of the CCK-8 receptor system. Thus, manipulation of one neuronal system could induce sensitivity changes in another closely related system.

Animals↗
PubMed1984

Analgesic effects of enkephalin analogs in rats.

The analgesic effects of intracerebroventricular injections of Met-enkephalin and five of its analogs in a dose of 10 micrograms each were quantified with a hot plate test in rats. Two analogs showed analgesic effect. [D-Ala2, Met5]-enkephalin had a weak and short-lasting analgesic effect. [D-Ala2, Met5]-enkephalinamide (DALA) had a striking and long-lasting analgesic effect. However, sulfation of tyrosine residue totally abolished the analgesic action of DALA. The analgesic effect of DALA was not affected by preinjection of its sulfated analog.

Analgesia↗
PubMed1984

Cholecystokinin tetrapeptide, proglumide and open-field behavior in rats.

The effect of cholecystokinin tetrapeptide (CCK-4) was studied in an open field situation. CCK-4 increased locomotion and rearing and the effect was enhanced by proglumide, a selective antagonist of CCK-8. This is in sharp contrast to our earlier findings that CCK-8 decreased the open-field behavior and that proglumide completely blocked the effect. Thus, the effects of CCK-4 and CCK-8 appear to be opposite to each other in that one is excitatory and the other inhibitory to open-field responses.

Animals↗