Childhood asthma outcomes during the COVID-19 pandemic: Findings from the PeARL multi-national cohort

Background

The interplay between COVID‐19 pandemic and asthma in children is still unclear. We evaluated the impact of COVID‐19 pandemic on childhood asthma outcomes.

Methods

The PeARL multinational cohort included 1,054 children with asthma and 505 non‐asthmatic children aged between 4 and 18 years from 25 pediatric departments, from 15 countries globally. We compared the frequency of acute respiratory and febrile presentations during the first wave of the COVID‐19 pandemic between groups and with data available from the previous year. In children with asthma, we also compared current and historical disease control.

Results

During the pandemic, children with asthma experienced fewer upper respiratory tract infections, episodes of pyrexia, emergency visits, hospital admissions, asthma attacks, and hospitalizations due to asthma, in comparison with the preceding year. Sixty‐six percent of asthmatic children had improved asthma control while in 33% the improvement exceeded the minimal clinically important difference. Pre‐bronchodilatation FEV₁ and peak expiratory flow rate were improved during the pandemic. When compared to non‐asthmatic controls, children with asthma were not at increased risk of LRTIs, episodes of pyrexia, emergency visits, or hospitalizations during the pandemic. However, an increased risk of URTIs emerged.

Conclusion

Childhood asthma outcomes, including control, were improved during the first wave of the COVID‐19 pandemic, probably because of reduced exposure to asthma triggers and increased treatment adherence. The decreased frequency of acute episodes does not support the notion that childhood asthma may be a risk factor for COVID‐19. Furthermore, the potential for improving childhood asthma outcomes through environmental control becomes apparent.

Huperzia saururus, activity on synaptic transmission in the hippocampus

Huperzia saururus (Lam.) Trevis. (Lycopodiaceae) known as cola de quirquincho is used in folk medicine to improve memory. The cholinergic neurons of the basal forebrain, including those in the medial septum, and in the vertical limbs of the diagonal band of Broca and the nucleus basalis of Meynert, provide a major source of cholinergic enervation of the cortex and hippocampus. These neurons have also been shown to play an important role in learning and memory processes. Thus, the effects of this traditional Argentinean species were studied in relation to its activity on synaptic transmission in the hippocampus. The alkaloid extract obtained first by decoction of the aerial parts and by subsequent alkaline extraction, was purified by using a Sephadex LH 20 packed column. Electrophysiological experiments were developed with the purified extract (E(2)) on rat hippocampus slices, thus eliciting long-term potentiation (LTP). Results show a marked increase in the hippocampal synaptic plasticity. The threshold value for generation of LTP was 22 +/- 1.01 Hz on average for E(2), while for controls it was 86 +/- 0.92 Hz. All of these factors could explain the use of Huperzia saururus as a memory improver as is reported in the ethnomedicine.

Hippocampus and locus coeruleus activity on rats chronically treated with diazepam

The neural mechanisms underlying benzodiazepine (BZD) dependence remain equivocal. The present studies tested the hypothesis that similar neural circuitry might be involved in the effects of chronic 7-chloro-1-methyl-5-phenyl-3H-1,4-benzodiazepine-2(1H)-one, diazepam (DZ, Roche), administration and withdrawal. The results of our study showed an increased hippocampal synaptic plasticity in slices from rats chronically treated with DZ (5 mg/kg/18 days), assessed as a decrease of the threshold in the stimulation rate for long-term potentiation (LTP) elicitation. Rats with the same schedule of DZ administration but without signs of withdrawal behaved similarly to vehicle-treated ones (VEH), in the threshold to induce LTP. Furthermore, the activity of locus coeruleus (LC) norepinephrine (NE) neurons in rats tested 24 h after the last DZ injection showed a significant increase. On the other hand, rats that after chronic DZ administration did not develop signs of withdrawal and exhibited a similar pattern of discharge on LC-NE nucleus compared with their controls. We conclude that chronic DZ administration enhances both hippocampal synaptic plasticity and activity of LC-NE neurons. This neural system could be the biological substrate underlying the behavioral alterations accompanying chronic DZ administration and withdrawal.

Preexposure to drug administration context blocks the development of tolerance to sedative effects of diazepam

The development of tolerance to benzodiazepine (BDZ) and other psychoactive agents such as morphine, alcohol, and barbiturates is thought to be a contingent or learning phenomenon. In a previous report, we demonstrated a positive correlation between the development of tolerance to the sedative effects of diazepam (DZ) and hippocampal synaptic plasticity. The results of the present work show that the development of tolerance to the hypolocomotor action of DZ (5 mg/kg) for 4 days and the associated increase in synaptic plasticity are context specific. Because animal preexposure to the drug administration context blocks both the tolerance sedative effects of DZ and the increased hippocampal synaptic plasticity, observed after 4 days of DZ administration, we propose the increased synaptic plasticity on hippocampal development as one of the biological substrates to the tolerance to DZ. Besides, the continuous administration of DZ did not induce a conditioning opponent response in these animals.

[Effects of fiber administration in the prevention of gallstones in obese patients on a reducing diet. A clinical trial]

Nearly 30% of the obese patients treated with hypoenergetic diets for weight reduction develop gallstone disease (GD). Until the present time, the use of ursodeoxycholic acid (UDA) is the only available therapeutic measure to avoid the development of GD. Dietary fiber induce a bile acid synthesis. A double-blind clinical trial was conducted to compare the effect of rational diet plus UDA vs a rational diet supplemented with Psyllium plantago (Pp) for the prevention of GD in obese subjects undergoing a weight-reduction diet. Patients with a body mass index (BMI = weight in Kg/square height in m) of 30 Kg/m2 or more and with normal gallbladder and biliary tree ultrasound (GBUS) were included. Weight-reduction diets were individually calculated for each patient according to their energy expenditure (EE). Patients were randomly and blindly assigned either to group I (diet + 750 mg UDA + fiber placebo) or group II (diet + 15 g Pp+ UDA placebo). An anthropometric evaluation was performed to each patient before and after the two-month treatment, as well as resting EE by indirect calorimetry, GBUS and endoscopy for the determination of cholesterol crystals in duodenal bile. Weight reduction was similar in both groups (group I = 6 +/- 2 Kg vs group II = 6 +/- 3 Kg). GD development was observed in one patient of group I (5.5%) and two patients of group II (p > 0.05). All patients with GD lost a minimum of 4 Kg during the study period. GD development did not correlate with the presence of crystals in the duodenal bile at the beginning of the study. Our results suggest a beneficial effect of a rational diet with fiber supplementation to prevent GD development in obese patients included in a weight reduction program.

[Utilization of different microbiological markers in the study of Haemophilus influenzae]

The present study includes 178 Haemophilus influenzae strains isolated in different pediatric hospitals from Havana, Cuba, during 1991-1994, associated to divers infections (meningitis, respiratory sepsis, primary bacteremia). A combination of various typing and subtyping methods was used as epidemiological markers: serotyping (slide agglutination with diagnostical serum a-f and latex agglutination), biotyping according to Killian's procedures (by determination of indole production, urease and ornithine decarboxylase activity), subtyping by fermentative profiles according to Roberts' methods (glucose, maltose, xylose and fructose) and outer membrane protein profile subtyping (vesicles extraction by a modified Barenkamp's method, analysis by lineal and gradient SDS-PAGE and assessment according to our own classification system). Serotype b was identified in 89.3%, biotype I was the most frequent (79.1%), other biotypes (II, III, IV and V) were also identified. Fermentative profile D (glucose, maltose, xylose and fructose positive) was the most frequent (52.8%) while profile G (glucose, maltose, xylose positive and fructose negative) represented 20.2%. Other known profiles were present. PA2 (33.7%) was the most frequent OMP subtype. Even though 11 different protein subtypes were found, the 77.5% of the strains were located in only three OMP electrophoretic subtypes (PA2, PC1, LA2).

[Antimicrobial resistance in Haemophilus influenzae in the city of Havana, Cuba]

Fifty five Haemophilus influenzae strains were studied to determine their resistance to different antimicrobial drugs. They were isolated in Habana City, Cuba, during June 1992 to May 1993, from invasive and non invasive infections. An agar dilution method, according to NCCLS guidelines, was employed. We observed that 49%, 47.3% and 27.3% were resistant to ampicillin, tetracycline and chloramphenicol, respectively. beta-lactamase production was demonstrated in 22 strains (40%). There was neither resistance to ceftriaxone, cefotaxime nor rifampicin. 36.4% of the strains were multiresistant, being described 7 different resistance patterns. The rate of resistance to the drugs was substantially higher among serotype b than among non type b strains.