Activity Meter Test

Locomotor activity can be quantified in rodents by a variety of means. The method described below uses interruptions of photoelectric beams. The difference between Irwin estimations of drug effects on spontaneous activity and activity meter tests is mainly a question of quantification. Activity meter tests are generally carried out using automated apparatus with a larger number of animals, and are therefore less labor intensive but permit more precise statistical analyses. The quantitative data obtained enable the generation of dose-response curves and more precise estimations of the minimal effective dose (MED) or the dose which increases or decreases locomotion by 50 % (ED50). 

Ten rats are studied per group. The test is performed blind. 

The test substance is usually evaluated at 4 doses, administered p.o. 60 minutes before the test, and compared with a vehicle control group. 

Caffeine (32mg/kg p.o.) and chlorpromazine (16mg/kg p.o.), administered under the same experimental conditions, are used as reference substances. The basic experiment therefore includes 7 groups. 

The data are usually analyzed using Student s t tests. 

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The present Section describes basic protocols satisfying ICH S7A recommendations for core battery CNS studies. Included are protocols for measuring general behavioral signs induced by test substances (Irwin Test), effects on spontaneous locomotion (Activity Meter Test), effects on neuromuscular coordination (Rotarod Test), effects on the convulsive threshold (Electroconvulsive Shock (ECS) Threshold and PTZ Seizure Tests), interaction with hypnotics (Barbital Interaction Test) and effects on the pain threshold (Hot Plate Test). 

Another complication with activity meter tests is the phenomenon of habituation. All animals placed in an unknown environment will tend to explore it more at the beginning of the exposure with a decline in exploration with time. This can be clearly seen in most activity meters despite the apparent simplicity of the test environment. Thus, when locomotion is followed over sequential time slots, an apparent increase or decrease in drag effect over time cannot simply be interpreted as a change in its pharmacological activity. The substance may be interacting with the process of habituation. It is for this reason that activity meters are not the ideal means of measuring the duration of drag action. 

Fig. 1. Activity meter test. Effects of caffeine and chlorpromazine (p.o.) on locomotion in the rat.

Because the activity meter evaluates spontaneous behavior, the behavioral baseline is intrinsically variable and subject to many kinds of influence, including lighting, apparatus cleanliness, ambient temperature, noise level, and even time of day. As a consequence, particular care has to be taken to ensure constant experimental conditions to obtain reproducible results. Furthermore, when comparing different drug treatments, it is important to take advantage of the fact that several animals can be evaluated simultaneously, by distributing the different treatments in a balanced fashion over the test period, and even in the positions within the experimental apparatus or of the observation chambers in the experimental room. 

More important is the time at which a test substance is administered in relation to placing the animal in the activity meter. Because of potential interactions of the test substance with the process of habituation, we think it is important to start testing when the drag effect has had time to reach its maximum, i.e. an appropriate interval after drag administration. If the animal is treated and immediately placed in the activity meter, the kind of drug effect observed may critically depend on the interaction between the onset of drag action and the habituation process. 

Using a nomograph requires only the vessel volume in meters, selecting the dust class. St-1, St-2 or St-3 from Table 7-28. Using Tables 7-29 or 7-30 select the Kst value determined experimentally. The reduced pressure, Pfed. (maximum pressure actually developed during a vented deflagration, termed reduced explosion pressure) must not exceed strength of vessel (see earlier discussion) and the Psut, i.e., the vent device release pressure. Note that the static activation pressure, Pjj, must be determined from experimental tests of the manufacture of relief panels such as rupture disks. 

If the pH level of drilling fluid drops and the hydrogen sulfide test result is negative, there is a good possibility that carbon dioxide will be present. Positive results of microbial activity tests (described later) also indicate the possibility of carbon dioxide presence. Carbon dioxide meters are also available commercially and can be used. 

The half-life of the 2,3,7,8-tetrachlorodibenzo-p-dioxin in isooctane was estimated to be 40 min for the 0.5 meter exposure and 3 hours for the one meter exposure. The half-life in 1-octanol was essentially the same. The 24-hour photolysis products of the 2,3,7,8-tetrachlorodibenzo-p-dioxin were examined by gas chromatography. The smallest concentration of 2,3,7,8-tetrachlorodibenzo-p-dioxin that could be detected by the instrument was 0.5 ppm. When an injection of the 24-hour photolysis product was made, no tetra was detected. An additional confirmation of the disappearance of the 2,3,7,8-tetrachlorodibenzo-p-dioxin in the 24-hour photolysis products was obtained when thej yiaterial was submitted to the Chemical-Biology Research Laboratory for rabbit testing. No chloracnegenic activity was indicated. ... 

After the activation period, the reactor temperature was decreased to 453 K, synthesis gas (H2 CO = 2 1) was introduced to the reactor, and the pressure was increased to 2.03 MPa (20.7 atm). The reactor temperature was increased to 493 K at a rate of 1 K/min, and the space velocity was maintained at 5 SL/h/gcat. The reaction products were continuously removed from the vapor space of the reactor and passed through two traps, a warm trap maintained at 373 K and a cold trap held at 273 K. The uncondensed vapor stream was reduced to atmospheric pressure through a letdown valve. The gas flow was measured using a wet test meter and analyzed by an online GC. The accumulated reactor liquid products were removed every 24 h by passing through a 2 pm sintered metal filter located below the liquid level in the CSTR. The conversions of CO and H2 were obtained by gas chromatography (GC) analysis (micro-GC equipped with thermal conductivity detectors) of the reactor exit gas mixture. The reaction products were collected in three traps maintained at different temperatures a hot trap (200°C), a warm trap (100°C), and a cold trap (0°C). The products were separated into different fractions (rewax, wax, oil, and aqueous) for quantification. However, the oil and wax fractions were mixed prior to GC analysis. 

Before injection, monitoring probes re placed on the outlet lines close a the exit from the tank being tested. These probes consist of a l-in.-diarr.-tter, thalium-activated sodium-iodide scintillation crystal, a small portable meter, and a recorder. 

The catalytic activity of the silylated and the non-silylated Ti-MCM-41 materials was tested in epoxidation of cyclohexene using tercbutylhydroperoxide (TBHP) as oxidant. In a typical catalytic run 56 mmol of olefin were mixed with 14 mmol of TBHP (olefin/TBHP ratio = 4) at the reaction temperature, 60°C. Under these reactions conditions the water content was 2 wt.%. Then, 30 mg of catalyst (0.5wt% catalyst) were added to the reaction medium. This instant was taken as time zero of reaction, and aliquots of the reaction media were withdrawn at different reaction times and subsequently analyzed by Gas Chromatography using a 5 % phenylsilicone column (HP-5) of 25 meters length. 

Swedish Study. Occupational exposure to 2,U-D and 2,U,5-T was also studied in a forest situation in Sweden (23) The materials used were butoxy ethyl ester formulations of 2,U-D or of a 2 1 2,U-D/2,U,5-T mixture applied as a 2 emulsion in water using tractor drawn equipment. The spray was applied at a rate of 2 to 3 kilograms total active ingredient per hectare (1.8 to 2.7 lb/A) to a distance of about 20 meters from both sides of the tractor. Two areas of about 70 to 80 hectares were sprayed during the test week. The temperature was about 20°C from Monday through Thursday with little wind, and was 10-15°C on Friday with sporadic wind. 

Figure 3 is a schematic diagram of the pilot-test flow control system. The flow in the pilot-test tank was stratified into upper and lower zones created by the five upper injection/extraction wells and the five lower injection/extraction wells. The feed water was dispensed through a flow totalizer into the injection wells via a manifold and a series of ten controllable flow meters. The lower injection wells were fed directly with Beaverton city water. The upper injection wells were fed from three 6800-L tanks. Using three tanks allowed one tank to be actively supplying feed water, one to be full with the appropriate input solution, and one to be... 

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