Biomedical subjects

P M Jordi

Publications and source records attributed to P M Jordi.

3 recordsLinked to original sources

PubMed1991

Self-planned experimentation (SPEX) practical classes in physiology.

A new form of undergraduate physiology practical experience is described. Students make their acquaintance with the physiological apparatus in the usual manner. At the end of the afternoon each group of four students is allocated an item of equipment with which to perform a true investigative experiment of their own choice, in their own time, the results of which are to be presented 2 weeks later by a randomly chosen member of the group. Students may investigate any question that can be answered using the resources available to them without endangering themselves or their subjects. Marks are awarded for the planning of the experiment (i.e. choice of controls, etc.), the correctness of graphical presentation of the results, the appropriateness of the statistical analysis, and for the discussion. There are no penalties for negative or unexpected results.

Education, Medical, Undergraduate↗

PubMed1990

Effect of negative air ions on morphine-induced changes in the latency of the tail-flick reflex.

Adult male Long-Evans rats were exposed to negatively charged air ions at high concentrations (7 x 10(5)/cm3) for six days. Sham-exposed rats were treated identically except that the source of ions was not activated. At the end of the exposure, the latency of the tail-flick reflex was measured in each rat before and 30 and 60 min after an injection of morphine sulphate. The tail-flick reflex was initiated by thermal stimulation. Two heat settings were employed, the lower considered to impart a submaximal and the higher a maximal thermal stimulus. Three morphine doses were tested: 0.5, 1.0, and 1.5 mg/kg. Statistically significant differences between ion-exposed and sham-exposed rats were observed in tail-flick latencies 30 min after the administration of the two lower doses, but not after the highest dose of morphine sulphate. These differences were found at both intensities of thermal stimulation. Tail-flick latencies measured in each group prior to morphine injection were not affected by negative-ion exposure. The data indicate that exposure of rats to negative air ions tends to inhibit the action of morphine on the latency of the tail-flick reflex at morphine doses below 1.0 mg/kg.

Air Ionization↗

PubMed1986

The effect of exposure to positive space charge on aversive responses to noxious stimuli in rats.

Exposure of rats to positive atmospheric ions for four days or longer results in an increase in aversive response times (tail flick and hot-plate). While these effects are similar to those produced after opiate administration, they could not be inhibited by naloxone treatment. Prompt reversal of the positive ion analgesic effect, however was brought about by treatment with parachlorophenylalanine which lowers brain serotonin levels. The data suggest that the action of positive ions on the pain inhibitory system is dependent upon an intact serotonin pathway and that the effects on this system are mediated via central rather than peripheral neural mechanisms.

Analgesia↗