Pyridostigmine bromide alters locomotion and thigmotaxis of rats: gender effects.

Male rats and female rats in the proestrous and metestrous stages of estrus were tested to determine the effects of pyridostigmine bromide on locomotion rate and thigmotactic response using doses of 3.0, 10.0, and 30.0 mg/kg. Thirty minutes after administration of the pyridostigmine bromide the rats were videorecorded for 2 h in a 1 m2 open-field arena. The rats' activities were analyzed for the drug's effect on speed throughout the 2 h and during six 20-min segments. Also, the times that the rats were observed moving through the central 50% of the arena were determined. Locomotion rates decreased significantly, and thigmotaxses increased significantly in all groups of rats as a dose response to pyridostigmine bromide. Habituation occurred over 2 h for both responses, primarily during the first 40 min. Female rats were more affected than males, but metestrous and proestrous females did not differ significantly in their responses. At the 30 mg/kg the effect was persistent throughout the test period. Proestrous females dosed at 30 mg/kg had much higher pyridostigmine bromide serum levels than metestrous females and males.     

Conservering van cosmetica en contactlensvloeistoffen

Conclusie De verscheidenheid aan conserveermiddelen die in cosmetica worden toegepast, is zeer groot. Het is wenselijk het gebruik van deze verbindingen zo beperkt mogelijk te houden in verband met ongewenste bijwerkingen voor de gebruikers. Een effectieve conservering van produkten, waarin micro-organismen goed kunnen groeien, is echter noodzakelijk. Deskundige microbiologische begeleiding bij de ontwikkeling en fabricage van cosmetische produkten is dan ook essentieel.

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Voordracht gehouden tijdens het symposium Conserveermiddelen op 13 november 1980 te Rotterdam.

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Dit artikel wordt gelijktijdig geplaatst in De Waren Chemicus.     

Inhibition of heparanase-mediated degradation of extracellular matrix heparan sulfate by non-anticoagulant heparin species

Incubation of human platelets, human neutrophils, or highly metastatic mouse lymphoma cells with sulfate-labeled extracellular matrix (ECM) results in heparanase-mediated release of labeled heparan sulfate cleavage fragments (0.5 less than Kav less than 0.85 on Sepharose 6B). This degradation was inhibited by native heparin both when brought about by intact cells or their released heparanase activity. Degradation of heparan sulfate in ECM may facilitate invasion of normal and malignant cells through basement membranes. The present study tested the heparanase inhibitory effect of nonanticoagulant species of heparin that might be of potential use in preventing heparanase mediated extravasation of bloodborne cells. For this purpose, we prepared various species of low-sulfated or low-mol-wt heparins, all of which exhibited less than 7% of the anticoagulant activity of native heparin. N-sulfate groups of heparin are necessary for its heparanase inhibitory activity but can be substituted by an acetyl group provided that the O-sulfate groups are retained. O-sulfate groups could be removed provided that the N positions were resulfated. Total desulfation of heparin abolished its heparanase inhibitory activity. Heparan sulfate was a 25-fold less potent heparanase inhibitor than native heparin. Efficiency of low-mol-wt heparins to inhibit degradation of heparan sulfate in ECM decreased with their main molecular size, and a synthetic pentasaccharide, representing the binding site to antithrombin III, was devoid of inhibitory activity. Similar results were obtained with heparanase activities released from platelets, neutrophils, and lymphoma cells. We propose that heparanase inhibiting nonanticoagulant heparins may interfere with dissemination of bloodborne tumor cells and development of experimental autoimmune diseases.     

Repeated coadministrations of pyridostigmine bromide, DEET, and permethrin alter locomotor behavior of rats

Interactions of pyridostigmine bromide (PB), permethrin (PERM), and the insect repellent DEET (DEET) have been suggested as possible causes of Gulf War Syndrome (GWS) in humans. Open field locomotor studies have long been used in behavioral toxicology. Using male and female Sprague-Dawley rats, video-computer analyses, and the isobolographic method we have determined the effects on locomotor speed and thigmotaxis following repeated administration of single-, double-, or triple-drug or vehicle controls in an open field. The effects were measured 24 hours after 7 daily drug administrations. Single-drug administrations caused no significant effects. Double-drug administrations resulted in significant effects in the following cases: males given PB + DEET had a significantly slower locomotion rate; males given DEET + PERM had a significantly faster locomotion rate; females given PB + DEET had a significantly slower locomotion rate; and females given PB + PERM spent significantly more time in the center zone (less thigmotaxis). Triple-drug administration caused no significant effect. These results in comparison with behavioral studies in chickens and insects show certain similarities. The implications of the lasting effects on animal models are relevant to GWS in humans.     

Conflicting priorities: evaluation of an intervention to improve nurse-parent relationships on a Tanzanian paediatric ward

Background  

Patient, or parent/guardian, satisfaction with health care provision is important to health outcomes. Poor relationships with health workers, particularly with nursing staff, have been reported to reduce satisfaction with care in Africa. Participatory research approaches such as the Health Workers for Change initiative have been successful in improving provider-client relationships in various developing country settings, but have not yet been reported in the complex environment of hospital wards. We evaluated the HWC approach for improving the relationship between nurses and parents on a paediatric ward in a busy regional hospital in Tanzania.     

Biological evaluation of intervertebral disc cells in different formulations of gellan gum‐based hydrogels

Gellan gum (GG)‐based hydrogels are advantageous in tissue engineering not only due to their ability to retain large quantities of water and provide a similar environment to that of natural extracellular matrix (ECM), but also because they can gelify in situ in seconds. Their mechanical properties can be fine‐tuned to mimic natural tissues such as the nucleus pulposus (NP). This study produced different formulations of GG hydrogels by mixing varying amounts of methacrylated (GG‐MA) and high‐acyl gellan gums (HA‐GG) for applications as acellular and cellular NP substitutes. The hydrogels were physicochemically characterized by dynamic mechanical analysis. Degradation and swelling abilities were assessed by soaking in a phosphate buffered saline solution for up to 170 h. Results showed that as HA‐GG content increased, the modulus of the hydrogels decreased. Moreover, increases in HA‐GG content induced greater weight loss in the GG‐MA/HA‐GG formulation compared to GG‐MA hydrogel. Potential cytotoxicity of the hydrogel was assessed by culturing rabbit NP cells up to 7 days. An MTS assay was performed by seeding rabbit NP cells onto the surface of 3D hydrogel disc formulations. Viability of rabbit NP cells encapsulated within the different hydrogel formulations was also evaluated by Calcein‐AM and ATP assays. Results showed that tunable GG‐MA/HA‐GG hydrogels were non‐cytotoxic and supported viability of rabbit NP cells. Copyright © 2012 John Wiley & Sons, Ltd.