Comparison of neurosensory devices in detecting cutaneous thresholds related to protective sensibility: A cross-sectional study in São Paulo, Brazil

AIMS

To quantify the static and moving cutaneous sensibility threshold of diabetic patients using a neurosensory device for quantitative pressure detection.

METHODS

Three hundred thirty-four (n = 334) patients with type 2 diabetes and no previous history of wounds on the feet were studied using the one- and two-point static (1SP;2 SP) and one- and two-point moving (1MP;2 MP) tests through the pressure-specified sensory device (PSSD) on the cutaneous territory of the dorsal first web, hallux pulp, and medial calcaneal. In addition, patients were evaluated using the Semmes-Weinstein monofilament (SWM) No. 5.07 and tuning fork (128 Hz), which were used as normality parameters to detect the loss of protective sensibility. The same examinations were used to assess the control group (228 nondiabetic).

RESULTS

Altered values were observed for the static and moving tests over the three studied nerve territories. In comparing the sensibility threshold between diabetic patients who were sensitive and nonsensitive to SWM 5.07, we observed that this filament is not the most indicated for identifying the loss of sensibility in these patients. The prevalence of patients at risk varied between 85 and 89%. The biochemical marker associated with these high rates was HbA1c (p = 0.02).

CONCLUSIONS

Numeric quantification of the pressure threshold allowed us to determine the functional deficit of nerve fibers. Our findings suggest that the neurosensory device should be used as an adjuvant tool to evaluate the degree of loss of sensation on the skin.

Radiopacity and Porosity of Bulk-fill and Conventional Composite Posterior Restorations—Digital X-ray Analysis

Objectives:

To compare radiopacity and porosity as expressed by the presence of voids in restorations carried out using bulk-fill and incremental filling techniques to restore large mesio-occlusal-distal (MOD) cavities.

Methods:

Fifty-five molars with MOD preparations were incrementally filled with Filtek Z-350XT (Z350XT) or bulk-fill composite: Filtek Bulk Fill/Z-350XT (FBF/Z350XT), Venus Bulk Fill/Charisma Diamond (VBF/CHA), SDR/Esthet-X HD (SDR/EST-X), Tetric EvoCeram Bulk Fill (TEC). Digital radiographic images (Vistascan scanner) were taken of restored molars and analyzed at the gingival and isthmus floors. Radiodensity measurements were performed using standardized points symmetrically distributed over each region of composite and tooth structure. Three calibrated evaluators visually assessed the presence of voids. Confidence intervals were calculated, and data were analyzed using analysis of variance and χ2 tests.

Results:

TEC and VBF/CHA showed significantly higher radiodensities, while the lowest values were observed for FBF/Z350XT and Z350XT. Radiodensity at the cervical regions tended to be greater than that found at the isthmus floor. The lowest incidence of voids was found for VBF/CHA, whereas the incremental insertion technique resulted in the highest rate of voids.

Conclusion:

Bulk-fill composite resin demonstrated an adequate level of radiodensity and a reduced presence of voids compared with the incremental filling technique.

D-serine prevents cognitive deficits induced by acute stress

Increasing evidence indicates that acute stress disrupts cognitive functions mediated by glutamate-NMDA receptors, although the mechanisms are not fully understood. Here we investigated whether d-serine and glycine, the endogenous co-agonists of the NMDA receptor, are regulated by acute stress. We studied the biochemical and behavioral effects of acute restraint stress in C57BL/6 mice. Acute restraint stress decreased d-serine levels in the prefrontal cortex and glycine levels in the hippocampus. Behaviorally, acute stress impaired memory consolidation in the object recognition task and prepulse inhibition of the startle response. Importantly, d-serine administration (1 g/kg, i.p.) prevented both stress-induced impairments. Taken together, our results show for the first time an interplay between stress and d-serine and warrant further research on the role of d-serine in stress-related disorders.

Triiodothyronine modulates thymocyte migration

Triiodothyronine (T(3)) exerts several effects on thymus physiology. In this sense, T(3) is known to stimulate thymic microenvironmental cells to enhance the production of extracellular matrix (ECM) moieties, which are relevant in thymocyte migration. Here, we further investigated the in vivo influence of T(3) on ECM production, as well as on ECM-related T-cell migration events. For this, BALB/c mice were subjected to two protocols of T(3) treatment: long-term (30 days) i.p. daily T(3) injections or short-term (16 h) after a single T(3) intrathymic injection. These two treatments did promote an enhancement in the expression of fibronectin and laminin, in both cortex and medullary regions of the thymic lobules. As revealed by the long-term treatment, the expression of ECM protein receptors, including VLA-4, VLA-5 and VLA-6, was also increased in thymocyte subsets issued from T(3)-treated mice. We further used thymic nurse cells (TNC) as an in vitro system to study the ECM-related migration of immature thymocytes in the context of thymic epithelial cells. Even a single intrathymic injection of T(3) resulted in an increase in the ex vivo exit of thymocytes from TNC lymphoepithelial complexes. Accordingly, when we evaluated thymocyte migration in transwell chambers pre-coated with ECM proteins, we found an increase in the numbers of migrating cells, when thymocytes were derived from T(3)-treated mice. Overall, our data show that in vivo intrathymic short-term i.p. long-term T(3) treatments are able to modulate thymocyte migration, probably via ECM-mediated interactions.

Thymus involution in alloxan diabetes: analysis of mast cells

We previously reported that alloxan-induced diabetes results in reduction in the number and reactivity of mast cells at different body sites. In this study, the influence of diabetes on thymic mast cells was investigated. Thymuses from diabetic rats showed marked alterations including shrinkage, thymocyte depletion, and increase in the extracellular matrix network, as compared to those profiles seen in normal animals. Nevertheless, we noted that the number and reactivity of mast cells remained unchanged. These findings indicate that although diabetes leads to critical alterations in the thymus, the local mast cell population is refractory to its effect. This suggests that thymic mast cells are under a different regulation as compared to those located in other tissues.