Protective effect of ellagic acid on healing alveolar bone after tooth extraction in rat—A histological and immunohistochemical study

Objective

This study has attempted to evaluate the effects of ellagic acid (EA) on alveolar bone healing after tooth extraction in rats.

Design

Twenty-four Sprague Dawley (SD) male rats (200–250 g) were selected and were anaesthetised for the extraction of upper left incisor. Then, the rats were divided into two groups, comprising 12 rats each; the first group has been considered as a control group and was given only normal saline, whereas, the second group (treated group) was intragastrically administrated with EA daily once, for 28 days. Then three rats from each group had been selected on 7th, 14th, 21st, and 28th days to dissect their maxilla tissue either for histological observation and homogenisation purposes. The tissues fixed, decalcified and embedded in paraffin. Serial sections of 5 μm thickness were prepared and stained with haematoxylin and eosin (H&E) for the histological study. Similar sections were taken for immunohistochemical analysis to assess osteocalcin (OSC) and osteopontin (OPN). Furthermore, Malondialdehyde (MDA) and superoxide dismutase (SOD) were measured in homogenated gingival maxilla tissue of rat by commercial kit.

Results

Based on the histological analysis we have identified that, EA treatment has induced earlier trabecular bone deposition in the treated group, resulting in more organised bone matrix on the 14th, 21st, and 28th days after tooth extraction, as against the control group. In comparison to control group, the positive labelling of OSC and OPN of the treated group have been highly expressed in the alveolar socket on 14th, and 21st days, which has indicated a the possibility of formation of new bone trabeculae at the beginning of the mineralisation process, after tooth extraction. In the EA treatment group, lipid per-oxidation (MDA) was significantly decreased (P < 0.05), as opposed to the control group. However, the antioxidant defense enzyme (SOD) was significantly increased in the maxilla tissue treated with EA (P < 0.05), compared to control group, which suggests that, after tooth extraction, EA plays an important role in the protection against the induction of lipid per-oxidation, particularly after 28 days of treatment with EA.

Conclusion

This study has concluded that, EA may accelerated the healing process in teeth socket of rats. Furthermore, the EA treated group showed a stronger positive immunolabelling for OSC and OPN, when compared with the control group.     

Peri-implant bone tissues around retrieved human implants after time periods longer than 5 years: a retrospective histologic and histomorphometric evaluation of 8 cases

Only rarely, it is possible to find in the literature histological reports of human retrieved implants, especially after several years of functional loading. These implants can help us in understanding the reactions of peri-implant bone. The aim of this study was to perform a histologic and histomorphometric analysis of the peri-implant tissues behavior and of the bone–titanium interface in titanium dental implants retrieved from patients after time periods longer than 5 years. The archives of the Implant Retrieval Center of the Dental School of the University of Chieti-Pescara, Italy were searched for human dental implants, retrieved after a loading period of more than 5 years. A total of 8 implants were found: 3 of these had been retrieved after 5 years, 1 after 6 years, one after 10 years, 1 after 14 years, 1 after 18 years, 1 after 22 years. Only the bone to implant contact in the three best threads was evaluated. Compact, mature, lamellar bone, with few and small marrow spaces, was present around the implants. Osteons with Haversian canals were present inside some threads, in close proximity to the interface, at both cortical and trabecular regions. Other osteons had a direction perpendicular to the direction of the long axis of the implants. Numerous reversal lines were present. At higher magnification, no gaps or fibrous, connective tissues were present at the interface. The BIC of the three best threads for all implants varied from 94 to 100 %.In conclusion, within the limitations of the present report histology showed that implants with different surfaces all presented the potential to maintain osseointegration over a long period, with a continuous remodeling at the interface, as indicated by the presence of reversal lines.     

Sports Nutrition and Food Knowledge among Malaysian University Athletes

Sports nutrition and food knowledge can influence athletes’ dietary intake, potentially affecting athletic performance. Limited studies have been conducted to identify sports nutrition and food knowledge among Malaysian university athletes. This study aimed to determine Malaysian university athletes’ knowledge of sports nutrition and food, and their reference sources and preferred sports nutrition education programme. Seventy athletes (52.9% females, mean weight = 61.8 kg; height = 1.66 m) aged 18.5–22.4 years responded to an online survey administered using a Google Form. A score of ≥60% was considered as adequate knowledge. The average overall knowledge score was 58.6%. The highest knowledge score was for sports nutrition, specifically food intake periodicity (84.8%), while the lowest was for general food knowledge on fat (44.6%). An analysis of specific questions revealed a lack of understanding about the recommended daily intake of fruits and vegetables (only 14.3% answered correctly), the roles of vitamins and minerals in energy production (21.4%), and good sources of unsaturated fat (37.2%). The academician was the primary reference source (81%), while magazines were the least referred to sources (36%). The university athletes preferred sports camps (33%) over the other nutrition education programme options. More initiatives are needed to improve Malaysian university athletes’ understanding and knowledge of sports nutrition and general food.     

Current intensity‐ and polarity‐specific online and aftereffects of transcranial direct current stimulation: An fMRI study

Transcranial direct current stimulation (tDCS) induces polarity‐ and dose‐dependent neuroplastic aftereffects on cortical excitability and cortical activity, as demonstrated by transcranial magnetic stimulation (TMS) and functional imaging (fMRI) studies. However, lacking systematic comparative studies between stimulation‐induced changes in cortical excitability obtained from TMS, and cortical neurovascular activity obtained from fMRI, prevent the extrapolation of respective physiological and mechanistic bases. We investigated polarity‐ and intensity‐dependent effects of tDCS on cerebral blood flow (CBF) using resting‐state arterial spin labeling (ASL‐MRI), and compared the respective changes to TMS‐induced cortical excitability (amplitudes of motor evoked potentials, MEP) in separate sessions within the same subjects (n = 29). Fifteen minutes of sham, 0.5, 1.0, 1.5, and 2.0‐mA anodal or cathodal tDCS was applied over the left primary motor cortex (M1) in a randomized repeated‐measure design. Time‐course changes were measured before, during and intermittently up to 120‐min after stimulation. ROI analyses indicated linear intensity‐ and polarity‐dependent tDCS after‐effects: all anodal‐M1 intensities increased CBF under the M1 electrode, with 2.0‐mA increasing CBF the greatest (15.3%) compared to sham, while all cathodal‐M1 intensities decreased left M1 CBF from baseline, with 2.0‐mA decreasing the greatest (?9.3%) from sham after 120‐min. The spatial distribution of perfusion changes correlated with the predicted electric field, as simulated with finite element modeling. Moreover, tDCS‐induced excitability changes correlated more strongly with perfusion changes in the left sensorimotor region compared to the targeted hand‐knob region. Our findings reveal lasting tDCS‐induced alterations in cerebral perfusion, which are dose‐dependent with tDCS parameters, but only partially account for excitability changes.     

Empathic accuracy and cognition in schizotypal personality disorder

Interpersonal dysfunction contributes to significant disability in the schizophrenia spectrum. Schizotypal Personality Disorder (SPD) is a schizophrenia-related personality demonstrating social cognitive impairment in the absence of frank psychosis. Past research indicates that cognitive dysfunction or schizotypy may account for social cognitive dysfunction in this population. We tested SPD subjects and healthy controls on the Empathic Accuracy (EA) paradigm and the Reading of the Mind in the Eyes Test (RMET), assessing the impact of EA on social support. We also explored whether EA differences could be explained by intelligence, working memory, trait empathy, or attachment avoidance. SPD subjects did not differ from controls in RMET, but demonstrated lower EA during negative valence videos, associated with lower social support. Dynamic, multimodal EA paradigms may be more effective at capturing interpersonal dysfunction than static image tasks such as RMET. Schizotypal severity, trait empathy, and cognitive dysfunction did not account for empathic dysfunction in SPD, although attachment avoidance is related to empathic differences. Empathic dysfunction for negative affect contributes to decreased social support in the schizophrenia spectrum. Future research may shed further light on potential links between attachment avoidance, empathic dysfunction, and social support.     

Investigation on structure,thermodynamic and multifunctional properties of Ni–Zn–Co ferrite for Gd3+ substitution

This study presents a modification of structure-dependent elastic, thermodynamic, magnetic, transport and magneto-dielectric properties of a Ni–Zn–Co ferrite tailored by Gd³⁺ substitution at the B-site replacing Fe³⁺ ions. The synthesized composition of Ni_0.7Zn_0.2Co_0.1Fe_2−xGd_xO₄ (0 ≤ x ≤ 0.12) crystallized with a single-phase cubic spinel structure that belongs to the Fd$\bar{3}$m space group. The average particle size decreases due to Gd³⁺ substitution at Fe³⁺. Raman and IR spectroscopy studies illustrate phase purity, lattice dynamics with cation disorders and thermodynamic conditions inside the studied samples at room temperature (RT = 300 K). Ferromagnetic to paramagnetic phase transition was observed in all samples where Curie temperature (T_C) decreases from 731 to 711 K for Gd³⁺ substitution in Ni–Zn–Co ferrite. In addition, Gd³⁺ substitution reinforces to decrease the A-B exchange interaction. Temperature-dependent DC electrical resistivity (ρ_DC) and temperature coefficient of resistance (TCR) have been surveyed with the variation of the grain size. The frequency-dependent dielectric properties and electric modulus at RT for all samples were observed from 20 Hz to 100 MHz and the conduction relaxation processes were found to spread over an extensive range of frequencies with the increase in the amount of Gd³⁺ in the Ni–Zn–Co ferrite. The RLC behavior separates the zone of frequencies ranging from resistive to capacitive regions in all the studied samples. Finally, the matching impedance (Z/η₀) for all samples was evaluated over an extensive range of frequencies for the possible miniaturizing application.

This study presents a modification of structure-dependent elastic, thermodynamic, magnetic, transport and magneto-dielectric properties of a Ni–Zn–Co ferrite tailored by Gd³⁺ substitution at the B-site replacing Fe³⁺ ions.