Protective Effects of Cannabidiol Against Hippocampal Cell Death and Cognitive Impairment Induced by Bilateral Common Carotid Artery Occlusion in Mice

The present study investigated whether cannabidiol (CBD), a major non-psychoactive constituent of marijuana, protects against hippocampal neurodegeneration and cognitive deficits induced by brain ischemia in adult mice. Male Swiss mice were subjected to a 17 min of bilateral common carotid artery occlusion (BCCAO) and tested in the Morris water maze 7 days later. CBD (3, 10, and 30 mg/kg) was administered 30 min before and 3, 24, and 48 h after BCCAO. After behavioral testing, the brains were removed and processed to evaluate hippocampal cell survival and degeneration using Nissl staining and FluoroJade C histochemistry, respectively. Astroglial response was examined using immunohistochemistry for glial fibrillary acidic protein (GFAP). CBD (3–30 mg/kg) improved spatial learning performance in BCCAO mice. The Nissl and FJC staining results showed a decrease in hippocampal neurodegeneration after CBD (10 and 30 mg/kg) treatment. GFAP immunoreactivity was also decreased in ischemic mice treated with CBD (30 mg/kg). These findings suggest a protective effect of CBD on neuronal death induced by ischemia and indicate that CBD might exert beneficial therapeutic effects in brain ischemia. The mechanisms that underlie the neuroprotective effects of CBD in BCCAO mice might involve the inhibition of reactive astrogliosis.     

Nd:YAG laser influence on tensile bond strength of self-etching adhesive systems

OBJECTIVE: We evaluated the tensile bond strength of composite resin on enamel and dentine, treated with Nd:YAG laser before and after bonding procedures. BACKGROUND DATA: The use of laser radiation in dentistry is being developed day by day. One of the possible applications of dental lasers includes increasing the quality of self-etching bonding systems. METHODS: Forty-eight human teeth were used and separated into six groups: Group 1 (enamel control), Clearfil Liner Bond 2V (CLB 2V); group 2 (enamel), Nd:YAG + CLB 2V; group 3 (enamel), CLB 2V + Nd:YAG; group 4 (dentine control), CLB 2V; group 5 (dentine), Nd:YAG + CLB 2V; group 6 (dentine), CLB 2V + Nd:YAG. Tensile bond strength was performed. RESULTS: Enamel means (15,54) were lower than dentine means (20,38). Bond strength of laser before (15,73) was lower than laser after (20,65). Interaction results G1 x G3; G2 x G3; G4 x G1; G2 x G5 were statistically significant. Conclusions: Tensile bond strength of composites reached with self-etching adhesive systems were greater in dentine than in enamel. The best moment for application of Nd:YAG laser is after the use of adhesive system. Self-etching adhesive systems tested in this study can be used together with Nd:YAG laser without compromising to adhesion to dentine.     

Long-term decrease in Na,K-ATPase activity after pilocarpine-induced status epilepticus is associated with nitration of its alpha subunit

Temporal lobe epilepsy (TLE) is the most common type of epilepsy with about one third of TLE patients being refractory to antiepileptic drugs. Knowledge about the mechanisms underlying seizure activity is fundamental to the discovery of new drug targets. Brain Na⁺,K⁺-ATPase activity contributes to the maintenance of the electrochemical gradients underlying neuronal resting and action potentials as well as the uptake and release of neurotransmitters. In the present study we tested the hypothesis that decreased Na⁺,K⁺-ATPase activity is associated with changes in the alpha subunit phosphorylation and/or redox state. Activity of Na⁺,K⁺-ATPase decreased in the hippocampus of C57BL/6 mice 60 days after pilocarpine-induced status epilepticus (SE). In addition, the Michaelis–Menten constant for ATP of α2/3 isoforms increased at the same time point. Nitration of the α subunit may underlie decreased Na⁺,K⁺-ATPase activity, however no changes in expression or phosphorylation state at Ser⁹⁴³ were found. Further studies are necessary define the potential of nitrated Na⁺,K⁺-ATPase as a new therapeutic target for seizure disorders.     

Factors Associated with the Development of Chronic Pain after Surgery for Breast Cancer: A Prospective Cohort from a Tertiary Center in the United States

Chronic pain has been shown to affect up to 60% of patients undergoing surgery for breast cancer. Besides younger age, other risk factors for the development of chronic pain have not been consistent in previous studies. The objective of the current investigation was to detect the prevalence and risk factors for the development of chronic pain after breast cancer surgery by examining a patient population from a tertiary cancer center in the United States. The study was a prospective observational cohort study. Subjects were evaluated at least 6 months after the surgical procedure. Subjects responded to the modified short form Brief pain inventory and the short form McGill pain questionnaire to identify and characterize pain. Demographic, surgery, cancer treatment, and perioperative characteristics were recorded. Propensity matching regression analysis were used to examine risk factors associated with the development of chronic pain. 300 patients were included in the study. 110 reported the presence of chronic pain. Subjects with chronic pain reported median (interquartile range [IQR]) rating of worst pain in the last 24 hours of 4 (2–5) and a median (IQR) rating on average pain in the last 24 hours of 3 (1–4) on a 0–10 numeric rating scale. Independent risk factors associated with the development of chronic pain were age, OR (95% CI) of 0.95 (0.93–0.98) and axillary lymph node dissection, 7.7 (4.3–13.9) but not radiation therapy, 1.05(0.56–1.95). After propensity matching for confounding covariates, radiation was still not associated with the development of chronic pain. Chronic pain after mastectomy continues to have a high prevalence in breast cancer patients. Younger age and axillary lymph node dissection but not radiation therapy are risk factors for the development of chronic pain. Preventive strategies to minimize the development of chronic pain are highly desirable.     

Physical exercise is associated with better fat mass distribution and lower insulin resistance in spinal cord injured individuals

Objectives

The aim of the study was to compare total and regional body composition and their relationship with glucose homeostasis in physically active and non-active individuals with cervical spinal cord injury (c-SCI).

Methods

Individuals with lesion level between C5–C7 were divided into two groups: physically active (PA; n = 14; who practiced physical exercise for at least 3 months, three times per week or more, minimum of 150 minutes/week): and non-physically active (N-PA n = 8). Total fat mass (t-FM) and regional fat mass (r-FM) were assessed by dual energy X-ray absorptiometry. Fasting plasma insulin (FPI) was determined by enzyme-linked immunosorbent assay.

Results

PA group present lower (P < 0.01) total fat mass (t-FM), % and kg, regional fat mass (r-FM), % and kg, FPI levels and HOMA index, while they had higher (P < 0.001) total free fat mass (t-FFM), %, and regional free fat mass (r-FFM), %, compared to the N-PA group. In the N-PA group, FPI and HOMA index were negatively (P < 0.05) correlated with FFM% (r = −0.71, −0.69, respectively) and positively correlated to trunk-FM (r = 0.71, 0.69, respectively) and trunk-FM:t-FM (kg) ratio (r = 0.83, 0.79, respectively).

Conclusion

Physical exercise is associated with lower t-FM, r-FM, and insulin resistance, which could contribute to the decrease of the risk of cardiovascular and metabolic conditions in individuals with c-SCI.     

Co-Infected HIV/Hepatitis Patients Compared With Chronic Liver Patients and Healthy Individuals: Respiratory Assessment Through Surface Electromyography and Spirometry

IntroductionCo-infected HIV and hepatitis subjects are candidates for a liver transplantation because of progressive liver disease. Chronic liver disease, co-infected or not, requires assessment of respiratory function before liver transplantation. The respiratory evaluation of these 2 groups compared with healthy individuals can define deficits, and this can impair a full recovery after transplant surgery.ObjectiveThis study sought to compare the respiratory profile in co-infected patients with chronic liver disease who are candidates for liver transplantation with that of healthy subjects.MethodsThrough respiratory evaluation of flows and lung volumes (spirometry), muscle activity (surface electromyography), and maximum pressure (manovacuometer), 250 people were distributed into 3 groups: 14 patients with HIV and liver disease, 65 healthy subjects, and 171 patients with chronic liver disease. The mean age (years) was respectively 47.5 ± 6.2, 48.3 ± 14.1, and 52.9 ± 8.5. The average body mass index (kg/m²) of the groups was 24.6 ± 4.5, 26.0 ± 3.2, and 28.5 ± 5.3, respectively.ResultsThere was a statistical difference among the groups in the root means square (RMS) rectus abdominis (μV) (P = .0016), RMS diaphragm (μV) (P = .0001), maximal inspiratory pressure (cmH₂O) (P = .001), forced exhaled volume at the end of first second (%) (P = .002), and maximal mid expiratory flow 25% to 75% (%) (P = .0001) for the Kruskal-Wallis test. The multivariate analysis among the groups showed that the RMS diaphragm had a tendency to discriminate the co-infected subjects.ConclusionsThe co-infected HIV group showed a muscle deficit of diaphragm and rectus abdominis activity, and the liver disease group showed lower indexes in volumes and respiratory flows.