Screening in mice of some medicinal plants used for analgesic purposes in the state of São Paulo.

Twelve medicinal plants used popularly for their reputed analgesic properties were tested in mice by the writhing and tail-flick methods. All extractions were made using 50% aqueous ethanol at low temperatures. The oral dose administered was always 1 g solids/kg. While several extracts showed a positive effect in one of the tests, significant effects in both tests were produced by Serjania communis only. Morphine and acetylsalicylic acid were used as reference drugs.

Differential sensitivity of antinociceptive tests to opioid agonists and partial agonists.

1. The antinociceptive activity of a range of opioid agonists and agonist-antagonist analgesics was determined in mice by use of the 55 degrees C hot plate and abdominal constriction assays. 2. Opioid agonists were approximately 10 times more effective in the abdominal constriction assay. 3. The agonist-antagonists produced analgesia only in the abdominal constriction assay, and antagonized the antinociceptive action of opioid agonists in the 55 degrees C hot plate test. 4. These differences were shown to be attributable to the different levels of stimulus employed in the two tests. 5. By comparing the antagonist potencies of the agonist-antagonists in the 55 degrees C hot plate test with their antinociceptive ED50 values in the abdominal constriction assay, an index of intrinsic activity was calculated.

The effect of carbon dioxide inhalation on phase characteristics of breathing movements in healthy newborn infants.

Chest wall distortion (inward motion of the rib cage on inspiration) has been found recently to reduce the tidal volume during active sleep in the neonatal period. To determine some of the factors that relate to the chest wall distortion and the decreased tidal volume seen in active sleep, a quantification of the phase differences between the movements of the chest wall and those of the abdominal wall, and of the relation of their phase differences to tidal volume was performed on data obtained before and during carbon dioxide stimulation in 15 newborn infants sleeping in the prone position. In quiet sleep, the breathing movements were congruent and regular, and the tidal volume and the mean inspiratory flow increased during carbon dioxide stimulation. In active sleep during exposure to carbon dioxide, the chest wall distortion decreased, the breathing movements were incongruent and the degree of the chest wall distortion was negatively correlated with the tidal volume, while the tidal volume and the mean inspiratory flow was increased. Chest wall distortion did not appear in quiet sleep and was decreased in active sleep in spite of increased ventilation during CO2 stimulation. This study favours the idea that chest wall distortion is caused by a well regulated change in neuromuscular activity and not by the strength of diaphragmatic movements overcoming the mechanical stability of the rib cage.

Use of dose-response data to compare the skin sensitizing abilities of dicyclohexylmethane-4,4'-diisocyanate and picryl chloride in two animal species.

Groups of English smooth-haired guinea pigs and BALB/cBy mice were exposed to dicyclohexylmethane-4,4'-diisocyanate (HMDI) and picryl chloride (PiCl) by topical exposure. Guinea pigs were challenged 7 days later by patch testing and responses graded at 24 hr. Application of high doses of each chemical resulted in extensive erythema and a large proportion of animals became sensitized. Lower doses produced less sensitivity. In mice, sensitivity was assessed by extent of ear swelling upon challenge 5 days following the sensitization exposure. In mice, as well as in guinea pigs, a dose-response relationship was apparent between the sensitizing dose and both severity of response and number of animals responding. For mice, comparison of the dose of chemical required to sensitize 50% of the animals (SD50) yielded 0.40 mg/kg for PiCl and approximately 0.20 mg/kg for HMDI. Use of the SD50 should provide a method for assessing the ability of various chemicals to cause contact sensitivity.

Ceruletide acts in the abdomen, not in the brain, to produce satiety.

Ceruletide (caerulein), a decapeptide extracted from the skin of the frog, Hyla caerulea, is very similar in structure to the C-terminal octapeptide of cholecystokinin (CCK-8). Although ceruletide and CCK-8 act through similar or identical receptors to produce the same visceral effects, previous studies in the rat suggested that peripherally administered ceruletide acted directly on the ventromedial hypothalamic (VMH) area to decrease food intake, but peripherally administered CCK-8 acted at a vagally innervated abdominal site to decrease food intake. Since it is unprecedented for these two peptides to produce the same effect by acting at different sites, we investigated the site of action of ceruletide's satiety effect in the rat and compared it to the site of action of CCK-8. The major results were: (1) intraperitoneal administration of ceruletide and CCK-8 inhibited food intake, but intraventricular administration did not; (2) the satiety effect of ceruletide and CCK-8 was not changed by bilateral lesions of the VMH; and (3) the satiety effect of ceruletide and CCK-8 was abolished or markedly reduced by bilateral abdominal vagotomy. We conclude that ceruletide acts at the same vagally innervated abdominal site to produce satiety as CCK-8 does and that neither peptide acts directly on the VMH area.

Analysis of biometrical characters of two mallophagan species treated with a phosphoorganic insecticide.

On the basis of biometrical analysis of various parts of the body in M. gallinae and E. stramineus treated with insecticide (Polwet 5) it was found that only the sizes of abdomen were differently changed in both species. The differentiation of these changes depends on the Polwet 5 concentration used and on the specific morphological features of both species.

[Effect of kallikrein and its inhibitor on absorption from the abdominal cavity in peritonitis]. / Vliianie kallikreina i ego ingibitora na vsasyvanie iz briushnoi polosti pri peritonite.

Experiments were carried out in 195 albino rats. It was established that in acute peritonitis the rate of absorption of the colloid dye (tryptan blue) was sharply decreased. Kallikrein somewhat increased the absorption rate, especially at early terms while the inhibitor (kontrikal) was shown to substantially decrease it. The mode of injection (intravenous or intraperitoneal) failed to influence manifestations of the biological effect of the drug. The data obtained show that a disturbed absorption from the abdominal cavity may be corrected in acute peritonitis by injections of kallikrein.

Leukotrienes C4, D4 and E4: effects on human and guinea-pig cardiac preparations in vitro.

The effects of leukotrienes C4, D4 and E4 (LT C4, D4 and E4) were studied in isolated preparations of guinea-pig and human myocardium in order to assess their contribution to cardiac dysfunction associated with systemic anaphylaxis. LT C4, D4 and E4 all caused long-lasting and dose-related decreases in the contractile force and coronary flow rate of the isolated guinea-pig heart. The rank order of potency was LT D4 greater than C4 greater than E4. The effects of LT C4 and D4 were antagonized by the anti-slow-reacting-substance compound FPL 55712. The negative inotropic effect of LT is unlikely to be secondary to the concomitant reduction in coronary flow because: 1) the same reduction in coronary flow by angiotensin II resulted in a negligible decrease in contractility and 2) the negative inotropic effect of LT also occurred in the electrically paced, noncoronary perfused left atrium and right ventricular papillary muscle of the guinea pig and in pectinate muscles obtained from surgical specimens of human right atrial appendage. LT D4 potentiated the positive chronotropic effect of histamine, supporting the concept that functional interactions occur between the various mediators of immediate hypersensitivity. The cardiac effects of pure synthetic LT are similar to those previously obtained with crude slow-reacting substance of anaphylaxis indicating that the prolonged contractile failure associated with systemic anaphylaxis largely could be due to the negative inotropic effect of LT. Because LT are released in a variety of immunological and inflammatory reactions, their potent myocardial depressant effects may play a role in cardiac dysfunction associated with these reactions.

Study of the comparative effectiveness of Dulcolax, Laxadine, Dorbanex, Normacen and Senokot laxatives in the bowel preparation of patients for radiological examinations.

The effectiveness of five laxatives - Dulcolax, Normacen, Laxadine, Dorbanex and Senokot in the bowel preparation of adult patients for radiological examinations has been compared. The value of using suppositories in addition to the tablets in those preparations that have tablet and suppository forms has also been assessed. The use of Dulcolax tablets plus suppository was most effective. Dulcolax, especially its suppository, was however very expensive and more frequently attended by side effects when compared with the other preparations. Normacen tablet was the second most effective and it is cheap and quite free of side effects. It is therefore given the position of first choice. Laxadine tablet plus its suppository was third best. It is cheap and free of side effects. Dorbanex was fourth best but it is rather expensive. Senokot tablet was the least effective but it is cheap and relatively free from side effects. In those laxatives with tablet and suppository forms, the use of both tablet and suppository is much more effective than the use of the tablet form alone.

The local antinociceptive and topical anti-inflammatory effects of propyl gallate in rodents.

1 In common with several anti-inflammatory, analgesic, local anaesthetic and antioxidant drugs, propyl gallate in vitro inhibited the biosynthesis of prostaglandin E2 and F2alpha from arachidonic acid by a prostaglandin synthetase from bull seminal vesicles. 2 In common with analgesic drugs, propyl gallate reduced the ability of arachidonic acid, acetylcholine or acetic acid to cause abdominal constriction in mice. 3 Using a new method for evaluating anti-inflammatory activity, we demonstrated the effectiveness of aspirin or indomethacin given subcuteneously before u.v. irradiation of guinea-pig ears, the prophylactic action of topically applied sunscreen agents and the therapeutic value of bufexamac and propyl gallate applied after irradiation.

Effect of cannabinoids on the abdominal constriction response in mice: within cannabinoid interactions.

After oral administration to mice, delta9-tetrahydrocannabinol (THC) and cannabinol (CBN) caused a dose-dependent suppression of the abdominal constriction response to formic acid. Cannabinol was 50 times less active than THC and cannabidiol (CBD) was without effect. The effects of THC and CBN were additive. CBD antagonised the antinociceptive effects of both THC and CBN in a dose-dependent manner.

[Biological action of cement dust in intraperitoneal and intratracheal tests]. / Vurkhu biologichnoto vuzdeistvie na tsimentoviia prakh pri intraperitonealniia i intratrakhealniia test.

The morphological changes occuring upon intraperitoneal and intratracheal application of cement with free silica content amounting to 1.30% are described. Initially, the changes in the peritoneal cavity are mainly necrotic and exudative, while after subsiding, the granulomas formed around the uneliminated dust particles predominate without exhibiting fibrotic phenomena. Upon intratracheal application, lesions typical of cement occur, coined by the authors with the term "experimental cement pneumopathy". It is a matter of changes presenting as "pseudopolyp" formations around the small bronchi and bronchioli, slipping into their lumen and thus causing its obturation. In the final stages of the experiment, a definitive peribronchial fibrosis with perifocal and subpleural emphysema is developed around the involved bronchi.

Effect ofO-(beta-hydroxyethyl)rutoside on intestinal tract cells following partial body irradiation. / Der Einfluss von O-(beta-Hydroxyäthyl)-rutosid auf Zellen des Darmtraktes nach Teilkörperbestrahlung

In the present study the influence of O-(beta-hydroxyethyl)-rutoside (HR) on the intestinal cells of irradiated mice was investigated. The mitotic activity in the duodenum after irradiation of the abdomen with 800 and 1200 R was shown to be significantly increased during the recovery phase after application of HR. The number of irradiation induced stem cell pycnoses was markedly reduced by HR in the case of both radiation doses. The initially decreased incorporation rate of H3-thymidine was found to increase more rapidly during the first few hours after irradiation in animals pretreated with HR than in those untreated. Cytogenesis of goblet cells, in the duodenum proved to be favourably influenced by HR. During the recovery phase the values were found to be above those observed in the control group and in the untreated animals. The mitosis free interval in the rectal cells immediately after irradiation proved to be shortened in the pretreated animals and the re-increase of the mitotic activity was found to be accelerated. The number of cell pycnoses was also markedly reduced after application of HR, while the incorporation rate of H3-thymidine was accelerated. The radiosensitivity of the goblet cells was not influenced by HR. Disorders in differentiation of the muciferous cells were observed in both test groups.