A systematic review and meta-analysis of the epidemiological characteristics of COVID-19 in children.

BACKGROUND: Several individual studies from specific countries have reported rising numbers of pediatric COVID-19 cases with inconsistent reports on the clinical symptoms including respiratory and gastrointestinal symptoms as well as diverse reports on the mean age and household exposure in children. The epidemiological characteristics of COVID-19 in children are not fully understood, hence, comprehensive meta-analyses are needed to provide a better understanding of these characteristics. METHODS: This review was conducted in Medline, Scopus, Cochrane library, Embase, Web of Science, and published reports on COVID-19 in children. Data were extracted by two independent researchers and a third researcher resolved disputes. STATA software and the random-effect model were used in the synthesis of our data. For each model, the heterogeneity between studies was estimated using the Q Cochrane test. Heterogeneity and publication bias were calculated using the I2 statistic and Egger's/Begg's tests. RESULTS: The qualitative systematic review was performed on 32 articles. Furthermore, the meta-analysis estimated an overall rate of involvement at 12% (95% CI: 9-15%) among children, with an I2 of 98.36%. The proportion of household exposure was calculated to be 50.99% (95% CI: 20.80%-80.80%) and the proportion of admitted cases was calculated to be 45% (95% CI: 24%-67%). Additionally, the prevalence of cough, fatigue, fever and dyspnea was calculated to be 25% (95% CI: 0.16-0.36), 9% (95% CI: 0.03-0.18), 33% (95% CI: 0.21-0.47) and 9% (95% CI: 0.04-0.15), respectively. It is estimated that 4% (95% CI: 1-8%) of cases required intensive care unit admission. CONCLUSIONS: The pediatric clinical picture of COVID-19 is not simply a classic respiratory infection, but unusual presentations have been reported. Given the high incidence of household transmission and atypical clinical presentation in children, we strongly recommend their inclusion in research and population-based preventive measures like vaccination as well as clinical trials to ensure efficacy, safety, and tolerability in this age group.

Prevalence of Septated First Dorsal Compartment Among Iranian Patients with De Quervain Tenosynovitis.

Background: A septum in the first extensor compartment and variation of abductor pollicis longus (APL) and extensor pollicis brevis (EPB) tendons affect the development and treatment of the de Quervain disease. This study aimed to determine the prevalence of septum and the number of APL and EPB tendons in Iranian surgical de Quervain patients. Methods: In this case series, we evaluated 37 consecutive wrists from September 2019 to April 2020 that were evaluated and surgically explored by the same senior surgeon; and the number of tendons and the existence of septum were recorded. Results: Patients were mainly women (24 [67.6%]), and the mean age was 50.43 ± 16.42 years. Seven (18.9%) patients had one, 23 (62.2%) had two, and 7 (18.9%) patients had three APL tendons. All patients had EPB tendons, 34 (91.9%) had 1 EPB tendon, and 3 (8.1%) had 2 EPB tendons. A septum was observed in 23 (62.2%) patients. Conclusion: The most functional variation in Iranian patients consists of 2 APL tendons and 1 EPB tendon. Also, most affected wrists had a septum in the first extensor compartment.

Comparison between the effects of quercetin on seizure threshold in acute and chronic seizure models.

Flavonoids are important constituents of food and beverages, and several studies have shown that they have neuroactive properties. Many of these compounds are ligands for γ-aminobutyric acid type A receptors in the central nervous system. This study aimed to investigate the anticonvulsant effects of quercetin (3,3',4',5,7-pentahydroxyflavone), which is a flavonoid found in plants, in rats treated with pentylenetetrazole in acute and chronic seizure models. Single intraperitoneal administration of quercetin did not show anticonvulsive effects against acute seizure. Similarly, multiple oral pretreatment with quercetin did not have protective effects against acute seizure. However, multiple intraperitoneal administration of quercetin (25 and 50 mg/kg) significantly increased time to death compared with the control (p < 0.001). However, quercetin pretreatment had no significant effects on the pattern of convulsion development during all periods of kindling. But on the test day, quercetin (100 mg/kg) could significantly increase generalized tonic-clonic seizure onset (GTCS) and decrease GTCS duration compared with the control (p < 0.01, p < 0.05). We conclude that quercetin has a narrow therapeutic dose range for anticonvulsant activities in vivo, and it has different effects on the seizure threshold. The different effects of quercetin on seizure threshold may occur through several mechanisms.

Levosimendan exerts anticonvulsant properties against PTZ-induced seizures in mice through activation of nNOS/NO pathway: Role for KATP channel.

AIMS: Although approving new anticonvulsants was a major breakthrough in the field of epilepsy control, so far we have met limited success in almost one third of patients suffering from epilepsy and a definite and reliable method is yet to be found. Levosimendan demonstrated neuroprotective effects and reduced mortality in conditions in which seizure can be an etiology of death; however, the underlying neuroprotective mechanisms of levosimendan still eludes us. In the light of evidence suggesting levosimendan can be a KATP channel opener and nitrergic pathway activator, levosimendan may exert antiseizure effects through KATP channels and nitrergic pathway. MAIN METHODS: In this study, the effects of levosimendan on seizure susceptibility was studied by PTZ-induced seizures model in mice. KEY FINDINGS: Administration of a single effective dose of levosimendan significantly increased seizures threshold and the nitrite level in the hippocampus and temporal cortex. Pretreatment with noneffective doses of glibenclamide (a KATP channel blocker) and L-NAME (a non-selective NOS inhibitor) neutralize the anticonvulsant and nitrite elevating effects of levosimendan. While 7-NI (a neural NOS inhibitor) blocked the anticonvulsant effect of levosimendan, Aminoguanidine (an inducible NOS inhibitor) failed to affect the anticonvulsant effects of levosimendan. Cromakalim (a KATP channel opener) or l-arginine (an NO precursor) augmented the anticonvulsant effects of a subeffective dose of levosimendan. Moreover, co-administration of noneffective doses of Glibenclamide and L-NAME demonstrated a synergistic effect in blocking the anticonvulsant effects of levosimendan. SIGNIFICANCE: Levosimendan has anticonvulsant effects possibly via KATP/nNOS/NO pathway activation in the hippocampus and temporal cortex.

The role of NMDA receptor and nitric oxide/cyclic guanosine monophosphate pathway in the antidepressant-like effect of dextromethorphan in mice forced swimming test and tail suspension test.

Depression is a devastating disorder which has a high impact on the wellbeing of overall society. As such, need for innovative therapeutic agents are always there. Most of the researchers focused on N-methyl-d-aspartate receptor to explore the antidepressant like activity of new therapeutic agents. Dextromethorphan is a cough suppressant agent with potential antidepressant activity reported in mouse force swimming test. Considering N-methyl-d-aspartate as a forefront in exploring antidepressant agents, here we focused to unpin the antidepressant mechanism of dextromethorphan targeting N-methyl-d-aspartate receptor induced nitric oxide-cyclic guanosine monophosphate signaling. Dextromethorphan administered at a dose of 10 and 30mg/kg i.p significantly reduced the immobility time. Interestingly, this effect of drug (30mg/kg) was inhibited when the animals were pretreated either with N-methyl-d-aspartate (75mg/kg), or l-arginine (750mg/kg) as a nitric oxide precursor and/or sildenafil (5mg/kg) as a phosphodiesterase 5 inhibitor. However, the antidepressant effect of Dextromethorphan subeffective dose (3mg/kg) was augmented when the animals were administered with either L-NG-Nitroarginine methyl ester (10mg/kg) non-specific nitric oxide synthase inhibitor, 7-Nitroindazole (30mg/kg) specific neural nitric oxide synthase inhibitor, MK-801 (0.05mg/kg) an N-methyl-d-aspartate receptor antagonist but not aminoguanidine (50mg/kg) which is specific inducible nitric oxide synthase inhibitor as compared to the drugs when administered alone. No remarkable effect on locomotor activity was observed during open field test when the drugs were administered at the above mentioned doses. Therefore, it is evident that the antidepressant like effect of Dextromethorphan is owed due to its inhibitory effect on N-methyl-d-aspartate receptor and NO- Cyclic guanosine monophosphate pathway.