Prevention of HIV transmission in the workplace: category II (emergency service) workers.
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Biomedical subjects
Publications and source records attributed to K Mueller.
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Enkephalin (ENK) and/or cholecystokinin octapeptide (CCK-8) were infused into nucleus accumbens of rats prior to injection with saline or 1.0 mg/kg amphetamine. Behavior was observed in an open-field paradigm which allowed assessment of locomotor stereotypy (repetitive routes or patterns of locomotion) as well as assessment of lines crossed and rears. Neither CCK nor ENK nor the combination of the two affected the behavior of saline-injected rats in the open field. CCK enhanced the locomotor stereotypy produced by amphetamine without affecting any of the other behaviors recorded. ENK had no effect on the behavior of amphetamine-treated rats when given alone, but ENK prevented the effect of CCK. Thus, enkephalin and CCK interact to modulate amphetamine-induced locomotor stereotypy.
The ability of haloperidol (0.1 mg/kg) to reduce the amphetamine-induced (2 and 5 mg/kg) increase in ascorbic and uric acid in anterior caudate and in nucleus accumbens was tested using voltammetry in vivo. In both areas, haloperidol reduced the amphetamine-induced increase in uric acid. In both areas, haloperidol only marginally affected the amphetamine-induced increase in ascorbic acid. Amphetamine-induced increases in uric acid were more nearly dose-related than changes in ascorbic acid. Of the two compounds, uric acid seems more likely to be associated with dopamine.
Both dopaminergic and nondopaminergic drugs produce hyperlocomotion in rats. Dopaminergic drugs also produce focused stereotypy (absence of locomotion and intense sniffing or licking/biting of a restricted area of the environment). Some drugs produce repetitive routes of locomotion; this phenomenon might represent a combination of hyperlocomotion and stereotypy. Scopolamine (an acetylcholine antagonist) and apomorphine (a dopamine agonist) both produce hyperlocomotion in rats; apomorphine also produces focused stereotypy but scopolamine does not. This research determines whether these drugs also produce locomotor stereotypy as measured by gamma. Scopolamine (0.5 and 2.0 mg/kg) produced locomotor stereotypy at both doses. Apomorphine (1.0, 2.0, and 3.0 mg/kg) failed to reliably produce locomotor stereotypy. Thus, there is not necessarily a relationship between the ability of a drug to produce focused stereotypy and the ability of the drug to produce locomotor stereotypy.
Linear sweep voltammetry was used to investigate the effects of amphetamine (which enhances the release of dopamine) and/or pilocarpine (a cholinergic agonist) on the release of ascorbic acid and uric acid in brain areas differing in dopamine and acetylcholine concentrations. In caudate, nucleus accumbens, and hippocampus, the magnitude of the amphetamine-induced increase in ascorbic acid was roughly correlated with dopamine content of the brain area tested. Cingulate cortex was a notable exception; the increase in ascorbic acid was greater than that in nucleus accumbens. Pilocarpine produced the greatest increase in ascorbic acid in cingulate cortex, even though cingulate cortex has the lowest acetylcholine concentration of the brain areas tested. Except for cingulate cortex, the ascorbic acid data were consistent with the hypothesis that amphetamine and pilocarpine release different pools of ascorbic acid. The uric acid data were consistent with the hypothesis that amphetamine and pilocarpine release the same pool of uric acid. The unexpected findings in cingulate cortex may point to an important role of ascorbic acid in this brain area.
Series of 3-piperidinyl- and 3-piperazinylrifamycins and to a certain extent 3-hydrazonorifamycins all bearing lipophilic side chains were found to exert potent hypolipidemic activity in lowering both serum cholesterol and LDL-cholesterol in rats. Starting from 3-[N'-(2,4,6-trimethylbenzyl)-N-piperazinyl]rifamycin SV (compound 25), a series of derivatives were synthesized with the aim of dissociating the hypolipidemic from the antibacterial activity, leading to the 8-O,N-dipivaloyl derivative of 25 (compound 48), which is devoid of any antibacterial activity but shows about 50-60% reduction of LDL-cholesterol and 20-30% reduction of serum cholesterol at a dose of 10 mg/kg. Compound 48 was selected for further pharmacological evaluation.
Linear sweep voltammetry with carbon paste electrodes was used to monitor extracellular ascorbic acid (AA) in the caudate nucleus and nucleus accumbens of behaving rats. Amphetamine (2 or 5 mg/kg) was administered 4, 6 and 8 days after surgery. In general the amphetamine-induced increase in AA was greater in the caudate than in the nucleus accumbens. Furthermore, in the nucleus accumbens the amphetamine-induced increase in AA was very similar on all test days, but in the caudate the increase in AA produced by 5 mg/kg amphetamine was progressively larger on each test day. Thus AA seems to be regulated differently in the caudate and nucleus accumbens.
In a series of four experiments the benzodiazepine triazolam was tested for reinforcing effects and for effects on reinforcement induced by amphetamine and morphine. Reinforcement was assessed in a conditioned place preference paradigm. Triazolam did not produce reinforcing or aversive effects when administered in doses ranging from 0.0625 to 0.5 mg/kg. Triazolam did attenuate reinforcing effects produced by 0.75 and 1.25 mg/kg amphetamine. No effect of triazolam was observed on morphine-induced reinforcement. These results indicate that the administration of triazolam can affect the brain mechanisms that mediate the reinforcing effects of amphetamine but not morphine.
Rat open field behavior is often used as a tool to study the behavioral effects of drugs. In this report, drug-induced patterns of locomotion in an open field were studied with the aid of a simple new statistic. Briefly, the animal's path through the open field is converted into a series of trips. Gamma (gamma) estimates the probability that the animal will repeat the trip that it has just exhibited; thus gamma quantifies "locomotor stereotypy". Trip lengths can also be compared across drug groups. Thus caffeine has no effect on gamma even though it produces a dose-related increase in locomotions. Caffeine does not produce amphetamine-like stereotypy. On the other hand, amphetamine produces a dose-related increase in gamma. Although gamma was designed to detect any pattern of locomotor behavior, rats treated with high doses of amphetamine almost always exhibited the same pattern of locomotor behavior - repetitive trips around the perimeter of the open field. Although further characterization of the statistic is necessary, these findings suggest that gamma has potential for quantifying "locomotor stereotypy" and for providing a more subtle description of locomotor behavior in general.
Cholecystokinin (CCK) and dopamine (DA) coexist in both cell body and terminal areas of a mesolimbic pathway that projects from the ventral tegmental area (VTA) to the nucleus accumbens (N ACC). Autoradiography reveals extensive CCK binding sites in the N ACC, but not in the VTA. However, iontophoresis of CCK into the VTA results in activation or deactivation of DA neuronal firing rates, and bursting activity (depending on the dose of CCK administered). CCK could have neuromodulatory effects on mesolimbic DA neurons. In two studies, behavioral effects of infusions of CCK into the VTA were examined in the conditioned place preference (CPP) paradigm. The CPP paradigm is a behavioral test used to assess reinforcement induced by drug administration. Drugs with reinforcing properties can condition preferences for novel environments. CCK infusions into VTA (0.0, 0.04, 0.4, and 4.0 ng/cannula) potentiated amphetamine CPPs in a dose-dependent linear manner. CCK infusions by themselves did not have significant effects in the CPP paradigm. Results indicate a neuromodulatory role for CCK on the neuronal mechanisms that mediate the reinforcing effects of amphetamine. Results also implicate sites of action for CCK in the VTA.
Gamma (gamma) is a recently proposed statistic that quantifies and describes the repetitive patterns of locomotion (locomotor stereotypy) exhibited by amphetamine-treated rats in an open field. The time-course of locomotor stereotypy after 1, 2, 3, and 4 mg/kg amphetamine was investigated in this research. Locomotor stereotypy was often evident during the first observation period after amphetamine. Lower doses of amphetamine produced qualitatively different locomotor stereotypy than higher doses. Rats given higher doses of amphetamine exhibited locomotor stereotypy during the "hyperactivity" phase of the three-phase response produced by higher doses of amphetamine (hyperactivity; absence of locomotions, increased sniffing, biting etc.; hyperactivity). Contrary to expectations, rats injected with 2 mg/kg amphetamine exhibited the highest and most sustained increase in gamma. We conclude that locomotor stereotypy is an important component of the behavioral effects of amphetamine in rats. Whether locomotor stereotypy and focused stereotypy are similar phenomena is still unclear.
The combination of haloperidol + caerulein has been reported to produce a long-lasting reduction of amphetamine-induced hyperlocomotions in rats. This study was designed to replicate those findings and to determine whether haloperidol + caerulein produce any unique effect on amphetamine-induced locomotor stereotypy. In two experiments, haloperidol + caerulein failed to produce a long-lasting reduction in amphetamine-induced hyperlocomotions. Although haloperidol reduced the locomotor stereotypy produced by higher doses of amphetamine, caerulein had no effect, either alone or combined with haloperidol.
Illness behavior and personality changes during a 2-year follow-up period were studied in 40 patients with chronic prostatitis. In the first study, the existence of psychic problems among the subjects was high. Sexual problems were striking. During the follow-up period the personality of the patients did not change, but subjective well-being, both psychosocial and somatic, was impaired. Sexual problems and homosexual behavior also increased. In addition, the cooperation of the patients markedly decreased and their illness behavior became problematic. The results indicate a strong need for psychic support of these patients.
CGP 28238 (6-(2,4-difluorophenoxy)-5-methylsulfonylamino-1-indanone ) exhibits very potent anti-inflammatory activity in rat adjuvant arthritis (ED40 = 0.05 mg/kg, p.o.) and pronounced analgesic and antipyretic activity in acute models in mice and rats (ED50 2-5 mg/kg, p.o.), but has clear advantages over reference NSAIDs with respect to gastro-intestinal tolerability. Threshold doses for gastro-intestinal ulcerogenicity in rats after single and repeated (10x) doses were found to be 30 mg/kg, p.o., and prostaglandin (PGE2) production in rat gastric and ileal mucosa was only marginally inhibited (ED50 greater than 30 mg/kg, p.o.). On the other hand, PGE2 production in rat inflammatory exudate and thromboxane synthesis in rat blood were inhibited with ED50 values of less than or equal to 2 mg/kg, p.o. Although CGP28238 does not inhibit cyclooxygenase in bovine seminal vesicle microsomal preparations (IC50 greater than 10(-3) mol/l), potent inhibition of prostaglandin synthesis was shown in various in vitro systems using human and animal cells with IC50 values of less than 10(-6) mol/l. IL-1-stimulated bone resorption and PGE2 production in murine calvarial cultures were inhibited with IC50 values of 3 x 10(-7) and 2 x 10(-8) mol/l, respectively. 5-Lipoxygenase (murine macrophages), phospholipase A2 (human PMN) and phospholipase C (human platelets) were not inhibited. CGP 28238 may represent a novel highly potent anti-inflammatory compound with improved gastro-intestinal safety.
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The present study examined the behavioral effects of continuous subcutaneous infusion of amphetamine (AMPH) to rats. Saline and 3 AMPH doses were infused for 96 hr (0.2 mg/kg/hr, 0.55 mg/kg/hr, 0.9 mg/kg/hr; n = 12). Locomotor behavior, grooming, gnawing and licking, sniffing, and head-bobbing were recorded for each animal for 1 hr in the light cycle and 1 hr in the dark cycle. The low dose AMPH animals exhibited increased locomotor activity. The medium and high dose groups developed similar behavioral patterns consisting of increased grooming and sniffing and changes in circadian rhythms of activity. Although most behaviors exhibited were similar to those discussed in previous literature describing the effects of chronic amphetamine, the pattern of the behaviors was not. Furthermore, continuous administration of AMPH seems to reliably increase the frequency of behaviors which are rarely observed after acute or chronic amphetamine. This finding has important implications since administration of AMPH to rats has been suggested to be an animal model of schizophrenia.
The frequency of clinically significant coronary artery disease (CAD) among stroke patients and the impact of CAD on stroke rehabilitation were studied in 132 patients with first thrombotic or embolic stroke who participated in comprehensive rehabilitation. Sixty-one patients (46%) had a history of CAD, and 16 of the 61 also had congestive heart failure (CAD-CHF). Patients with CAD, and especially those with CAD-CHF, had significantly longer intervals from stroke onset to rehabilitation admission (p less than 0.001), and once in rehabilitation they experienced three times as many cardiac complications (p less than 0.001). While all patient groups improved function during rehabilitation, those with CAD and CAD-CHF improved significantly less than did those without CAD (p less than 0.01). Patients with CAD did least well with rolling, moving in bed, transferring from a wheelchair to bed, and walking. CHF not only adversely influenced overall function and mobility task performance but also affected the potential for achieving functional gains. These data suggest that specific measures of function and rehabilitation are affected by CAD and that the levels of achievement for patients with CAD-CHF are limited.
The cholinergic agonist pilocarpine (2 and 4 mg/kg) produced a dose-related increase in striatal AA levels as measured by linear sweep voltammetry. The cholinergic antagonist scopolamine (0.5 and 0.6 mg/kg) blocked the pilocarpine-induced increase in AA levels, but methscopolamine (which does not cross the blood-brain barrier) reduced the pilocarpine effect only by about 20%. Pilocarpine alone had little effect on UA levels. Scopolamine (0.6 mg/kg) produced a dramatic increase in UA levels that was reduced by pilocarpine. Methscopolamine had little effect (less than 10%) on extracellular UA levels. Thus cholinergic drugs modulate striatal extracellular AA levels by predominantly central rather than peripheral effects.