Ventrolateral Periaqueductal Gray Matter Neurochemical Lesion Facilitates Epileptogenesis and Enhances Pain Sensitivity in Epileptic Rats

The ventrolateral periaqueductal gray matter (vlPAG) plays a critical role in the pathogenesis of migraine and few studies have shown that vlPAG might be involved in the pathophysiology of epilepsy. But its roles in epileptogenesis and comorbid relationship between migraine and epilepsy have never been reported. In this study, the impairments of vlPAG neuronal network during spontaneous recurrent seizure (SRS) development after status epilepticus (SE) were investigated, and the pain sensitivity as well as the SRS investigated after neurochemical lesion to vlPAG to determine the role of vlPAG in epileptogenesis and in migraine comorbidity with epilepsy. Neuronal loss and alterations of excitatory and inhibitory neural transmission within vlPAG accompanied the development of epileptogenesis induced by SE. On the other hand, neurochemical lesion to vlPAG enhanced frequency and duration of spontaneous seizure event and frequency of epileptiform inter-ictal spike discharges in electroencephalography (EEG), but decreased pain threshold in epileptic rats. This indicates an involvement of the pain regulating structure, vlPAG, in the pathogenesis of epilepsy. This may imply that vlPAG network alterations could be a possible underlying mechanism of the interactive comorbid relationship between epilepsy and migraine.

[Effects of β-blockers in patients with septic shock: a meta analysis]

OBJECTIVE

To evaluate the effect of β-blockers in patients with septic shock.

METHODS

PubMed, EMBASE, Cochrane central registration of controlled trials, CNKI and Wanfang Data were searched to identify relevant studies from inception to October 2015.Statistical analysis was performed using STATA 12.0.The random effects model was used due to wide clinical variability across the trials.

RESULTS

After application of the inclusion criteria, 7 trials with 392 patients were included, involving 3 randomized controlled trials (RCT) and 4 quasi-experiments.The results of the meta-analysis for the quasi-experiments showed that compared with baseline, heart rates (standardized mean difference (SMD)=-2.51, 95%CI: -4.32--0.70, P=0.007) and lactate levels (SMD=-0.34, 95%CI: -0.67--0.02, P=0.039) significantly decreased, while no significant differences were seen for mean arterial pressure (SMD=0.01, 95%CI: -0.42-0.44, P=0.969), cardiac index (SMD=-0.35, 95%CI: -1.15-0.44, P=0.385) or norepinephrine requirements (SMD=-0.06, 95%CI: -0.38-0.27, P=0.726) after 24-hour therapy. Among randomized controlled trials, β-blockers, compared with standard care, was associated with reductions in heart rates (P<0.001) , 28-day mortality (RR=0.60, 95%CI: 0.48-0.75, P<0.001) and troponin I levels (P<0.001). While no differences were found between the two groups in other hemodynamic and cardiac function variables, such as mean arterial pressure, cardiac index or stroke volume index (P>0.05).

CONCLUSIONS

The currently available evidence indicates that the use of β-blockers is associated with a significant decrease in heart rate, troponin I levels and 28-day mortality in patients with septic shock, while mean arterial pressure, cardiac index and stroke volume index might remain unchanged.Large scale, muti-center RCTs need to be carried out to confirm the effects of β-blockers in patients with septic shock.

[Influence of 6,7-dimethoxycoumarin on toxicity and pharmacodynamics of cyclophosphamide]

When 40 mg/kg of 6,7-dimethoxycoumarin (DMOC) was given (ip) 15 min before sc cyclophosphamide (Cy), the LD50/7 d of Cy would be raised from 166 +/- 9 (100-245) to 294 +/- 4 (250-346) mg/kg (dose reduction factor 1.78) in Wistar rat. The 7 d survival rate of mice intoxicated by Cy was raised to 26.7%. To give 100 mg/(kg.d) of DMOC for 5 or 24 days, it prevented the chronic toxicity of Cy prolonged the life-span, elevated the 30 d survival rate of rats intoxicated by Cy to 45.3 and 42.5%, respectively. DMOC increased the WBC, weight of thymus and body of rats and mice intoxicated by Cy; raised colony-forming unit and reduced high plasma corticosterone of mice intoxicated by Cy. It also increased the RNA and DNA of bone marrow, liver and spleen. DMOC in combination with Cy did not reduce the antitumor effect of Cy.