Complex Regional Pain Syndrome Type I: Evidence for the CB1 and CB2 Receptors Immunocontent and Beneficial Effect of Local Administration of Cannabidiol in Mice

Introduction: Complex regional pain syndrome type I (CRPS-I) is a debilitating neuropathic painful condition associated with allodynia, hyperalgesia, sudomotor and/or vasomotor dysfunctions, turning investigation of its pathophysiology and new therapeutic strategies into an essential topic. We aim to investigate the impact of ischemia/reperfusion injury on the immunocontent of CB1 and CB2 cannabinoid receptor isoforms in the paws of mice submitted to a chronic postischemia pain (CPIP) model and the effects of local administration of cannabidiol (CBD) on mechanical hyperalgesia. Methods: Female Swiss mice, 30-35 g, were submitted to the CPIP model on the right hind paw. Skin and muscle samples were removed at different periods for western blot analysis. Results: No changes in the immunocontent of CB1 and CB2 receptors in paw muscle tissues after ischemia-reperfusion were observed. CBD promoted an antihyperalgesic effect in both phases. AM281 reversed the effect of CBD, whereas ruthenium red abolished the late phase. Conclusion: Our results point to the possible beneficial effects of local administration of CBD in modulating CRPS-I in humans. As possible targets for CBD antihyperalgesia in this model, the contribution of cannabinoid receptor CB1, in addition to TRPM8 is suggested.

Rapid maxillary expansion: Do banded teeth develop more external root resorption than non-banded anchorage teeth?

OBJECTIVE

To compare external root resorption (ERR) when bands and wires are used as orthodontic anchorage during rapid maxillary expansion (RME).

MATERIALS AND METHODS

Histologic analysis was performed on 108 sites from 18 maxillary first premolars and on 36 sites from six mandibular first premolars in nine subjects (mean age = 15.2 ± 1.4 years) 3 months after RME. Maxillary teeth were pooled into two groups (n = 54 each) according to the type of orthodontic anchorage (band group [BG] vs wire group [WG]). Anchorage type was randomly chosen in a split-mouth design. Mandibular first premolars, which were not subjected to orthodontic forces, were used as the control group (CG).

RESULTS

All premolars in the BG and WG showed ERR at the level of the cementum and dentin. Repair with cementum cells was observed in all resorption areas, but complete repair was rarely found. No statistically significant difference was found between the BG and WG with regard to the ERR. No association was found between the root height position (middle or cervical third) and the incidence of ERR. Buccal root surfaces showed a higher amount of ERR compared with the palatal and interproximal surfaces. ERR was not found in any teeth in the CG.

CONCLUSION

All maxillary first premolars subjected to RME showed ERR and partial cementum repair. Banded teeth did not develop more ERR than nonbanded anchorage teeth.

Expression of genes associated with the biosynthetic pathways of abscisic acid, gibberellin, and ethylene during the germination of lettuce seeds

Seed germination and dormancy are complex phenomena that are controlled by many genes and environmental factors. Such genes are indicated by phytohormones that interact with each other, and may cause dormancy or promote seed germination. The objective of this study was to investigate gene expression associated with the biosynthetic pathways of abscisic acid (ABA), gibberellic acid (GA), and ethylene (ET) in dormant and germinated lettuce seeds. The expressions of LsNCED, LsGA3ox1, and ACO-B were evaluated in germinating and dormant seeds from the cultivars Everglades, Babá de Verão, Verônica, Salinas, Colorado, and Regina 71. The expressions of LsNCED, LsGA3ox1, and ACO-B were related to the biosynthesis of ABA, GA, and ET, respectively; therefore, the presence of these substances depends on genotype. LsNCED expression only occurred in dormant seeds, and was connected to dormancy. LsGA3ox1expression only occurred in germinated seeds, and was connected to germination. The ACO-B gene was involved in ET biosynthesis, and was expressed differently in germinated and dormant seeds, depending on the genotype, indicating different functions for different characteristics. Furthermore, sensitivity to phytohormones appeared to be more important than the expression levels of LsNCED, LsGA3ox1, or ACO-B.

The effect of the surface functionalization and the electrolyte concentration on the electrical conductance of silica nanochannels

It is known that the conductance of nanochannels as a function of electrolyte concentration deviates from a linearly proportional relationship and approaches a value independent of the concentration as the electrolyte concentration is lowered. Most of the proposed models account for this behavior by considering a constant surface charge density and an ideal electrolyte solution. However, at low electrolyte concentrations, the ideal electrolyte approximation is no longer valid because the ions that result from the atmospheric carbon dioxide dissolution in water dominate the ionic concentration. In this paper, arrays of silica nanochannels were electrically characterized via conductance measurements. The conductance at low salt concentrations is modeled by a variable surface charge model that accounts for all ionic species in solution. This model was used to determine the variable surface charge of the bare silica nanochannels as well as of chemically modified nanochannels. The model correctly predicted the variation of the nanochannel conductance observed after silane (aminopropyldimethylethoxysilane) functionalization and single-strand DNA immobilization. Finally, pH modification of bulk KCl solutions was employed as an alternative method of changing the surface charge of silica nanochannels. Surface charge calculated from conductance measurements performed at different bulk pH values confirmed that the surface charge of the silica nanochannel walls is sensitive to the H(+) concentration.

[Fraction of gemistocytic astrocytes and immunoexpression of p53 protein in astrocytomas grade II and III (WHO)]

Twenty-two patients with astrocytomas, grade II or III WHO, were studied from 1990 to 1998. In all cases, histopathology showed that the astrocytomas had a gemistocytic component. The aims of this study were to establish the fraction of gemistocytic astrocytes, to investigate p53 protein immunoexpression and to evaluate correlations between these two parameters with the tumour outcome. Tumor cells were quantified at high-power magnification (x400). At least 1000 neoplastic cells (small neoplastic astrocytes plus gemistocytes) were counted in each specimen. The percentage of gemistocytes was defined as the gemistocytic index. Nuclear expression of p53 protein was evaluated in neoplastic astrocytes and gemistocytes. Both the frequency (7/22) as well the p53 immunoexpression indices in gemistocytes, regardless of the grade of the astrocytomas, were inferior from those reported in the literature. No correlation was found between the gemistocytic indices and the p53 immunoexpression.

Ca(2+)/nicotinamide adenine dinucleotide phosphate-dependent H(2)O(2) generation is inhibited by iodide in human thyroids

A calcium and NAD(P)H-dependent H(2)O(2)-generating activity has been studied in paranodular thyroid tissues from four patients with cold thyroid nodules and from nine diffuse toxic goiters. H(2)O(2) generation was detected both in the particulate (P 3,000 g) and in the microsomal (P 100,000 g) fractions of paranodular tissue surrounding cold thyroid nodules (PN), with the same biochemical properties described for NADPH oxidase found in porcine and human thyroids. In PN tissues, the particulate NADPH oxidase activity (224 +/- 38 nmol H(2)O(2) x h(-1) x mg(-1) protein) was similar to that described for the porcine thyroid enzyme. However, no NADPH oxidase activity was detectable in the particulate fractions from eight diffuse toxic goiter patients treated with iodine before surgery; all but one also received propylthiouracil or methimazole in the preoperative period. Thyroid cytochrome c reductase (diffuse toxic goiters = 438 +/- 104 nmol NADP(+) x h(-1) x mg(-1) protein; PN = 78 +/- 10 nmol NADP(+) x h(-1) x mg(-1) protein) and thyroperoxidase (diffuse toxic goiters = 621 +/- 179 U x g(-1) protein; PN = 232 +/- 121 U x g(-1) protein) activities were unaffected by iodide. Thus, the human NADPH oxidase seems to be inhibited by iodinated compounds in vivo and probably is an enzyme involved in the Wolff-Chaikoff effect. Our findings reinforce the hypothesis that thyroid NADPH oxidase is responsible for the production of H(2)O(2) necessary for thyroid hormone biosynthesis.

Dilated cardiomyopathy in two transgenic mouse lines expressing activated G protein alpha(q): lack of correlation between phospholipase C activation and the phenotype

We previously described a transgenic mouse line (alpha(q)*52) in which cardiac-specific expression of activated G alpha(q)protein (HA alpha(q)*) leads to activation of phospholipase C beta (PLC beta), the immediate downstream target of HA alpha(q)*, with subsequent development of cardiac hypertrophy and dilation. We now describe a second, independent line in the same genetic background (alpha(q)*44h) with lower expression of HA alpha(q)* protein that ultimately results in the same phenotype: dilated cardiomyopathy (DCM) with severely impaired left ventricular systolic function (assessed by M-mode and 2D echocardiography), but with a much delayed disease onset. We asked if PLC activation correlates with the development of the phenotype. At 12-14 months, 65% of alpha(q)*44h mice still had normal cardiac function and ventricular weight/body weight ratios (VW/BW). However, their basal PLC activity, which began to increase in ventricles at 6 months, was threefold higher than in wild-type by 12 months. This increase was even more pronounced than in 2.5-month-old alpha(q)*52 mice, in which a twofold increase was accompanied by a 25% increase in VW/BW. Furthermore, at 12-14 months the increase in PLC activity in alpha(q)*44h mice with and without DCM was comparable. Thus, the delayed time course in alpha(q)*44h mice unmasked a lack of correlation between PLC activation and development of DCM in response to HA alpha(q)* expression, suggesting a role for additional pathways and/or mechanisms. It also revealed a differential temporal regulation of protein kinase C isoform expression. The markedly different ages of disease onset in these two mouse lines provide a model for studying both genetic modifying factors and potential environmental influences in DCM.