The relative prevalence of the Omicron variant within SARS-CoV-2 infected cohorts in different countries: A systematic review

The Omicron variant of SARS-CoV-2 was detected in October 2021 and exhibited high transmissibility, immune evasion, and reduced severity when compared to the earlier variants. The lesser vaccine effectiveness against Omicron and its reduced severity created vaccination hesitancy among the public. This review compiled data reporting the relative prevalence of Omicron as compared to the early variants to give an insight into the existing variants, which may shape the decisions regarding the targets of the newly developed vaccines. Complied data revealed more than 90% prevalence within the infected cohorts in some countries. The BA.1 subvariant predominated over the BA.2 during the early stages of the Omicron wave. Moreover, BA.4/BA.5 subvariants were detected in South Africa, USA and Italy between October 2021 and April 2022. It is therefore important to develop vaccines that protect against Omicron as well as the early variants, which are known to cause more severe complications.

Effectiveness of the pre-Omicron COVID-19 vaccines against Omicron in reducing infection, hospitalization, severity, and mortality compared to Delta and other variants: A systematic review

Despite widespread mass rollout programs, the rapid spread of the SARS-CoV-2 Omicron variant called into question the effectiveness of the existing vaccines against infection, hospitalization, severity, and mortality compared to previous variants. This systematic review summarizes and compares the effectiveness of the COVID-19 vaccines, with respect to the above outcomes in adults, children, and adolescents. A comprehensive literature search was undertaken on several databases. Only 51 studies met our inclusion criteria, revealing that the protection from primary vaccination against Omicron infection is inferior to protection against Delta and Alpha infections and wanes faster over time. However, mRNA vaccine boosters were reported to reestablish effectiveness, although to a lower extent against Omicron. Nonetheless, primary vaccination was shown to preserve strong protection against Omicron-associated hospitalization, severity, and death, even months after last dose. However, boosters provide more robust and longer-lasting protection against hospitalizations due to Omicron as compared to only primary series.

Role of previous infection with SARS-CoV-2 in protecting against omicron reinfections and severe complications of COVID-19 compared to pre-omicron variants: a systematic review

BACKGROUND

The SARS-CoV-2 virus elicited a major public concern worldwide since December 2019 due to the high number of infections and deaths caused by COVID-19. The Omicron variant was detected in October 2021 which evolved from the wild-type SARS-CoV-2 and was found to possess many mutations. Omicron exhibited high transmissibility and immune evasion as well as reduced severity when compared to the earlier variants. Although vaccinated individuals were largely protected against infections in previous waves, the high prevalence of both reinfections and breakthrough infections with Omicron was observed. The aim of this review is to understand the effectiveness of previous infection on subsequent reinfection, given its significance in driving public health policy, including vaccination prioritization and lockdown requirements.

METHODS

A comprehensive literature search was conducted using several databases to target studies reporting data related to the effectiveness of the previous infection with SARS-CoV-2 in protecting against the Omicron variant. Screening of the studies, quality assessment and data extraction were conducted by two reviewers for each study.

RESULTS

Only 27 studies met our inclusion criteria. It was observed that previous infection was less effective in preventing reinfections with the Omicron variant compared to the Delta variant irrespective of vaccination status. Furthermore, being fully vaccinated with a booster dose provided additional protection from the Omicron variant. Additionally, most infections caused by Omicron were asymptomatic or mild and rarely resulted in hospitalizations or death in comparison to the Delta wave.

CONCLUSION

A majority of the studies reached a consensus that although previous infection provides some degree of immunity against Omicron reinfection, it is much lower in comparison to Delta. Full vaccination with two doses was more protective against Delta than Omicron. Receiving a booster dose provided additional protection against Omicron. It is therefore clear that neither vaccination nor previous infection alone provide optimal protection; hybrid immunity has shown the best results in terms of protecting against either Omicron or Delta variants. However, additional research is needed to quantify how long immunity from vaccination versus previous infection lasts and whether individuals will benefit from variant-specific vaccinations to enhance protection from infection.

Severity of the Omicron SARS-CoV-2 variant compared with the previous lineages: A systematic review

The Omicron variant was first detected in October 2021, which evolved from the original SARS-CoV-2 strain and was found to possess many mutations. Immune evasion was one of the notable consequences of these mutations. Despite Omicron exhibiting increased transmissibility, the rates of hospitalizations and deaths among patients infected with this variant were substantially lower when compared to other strains. However, concluding that the Omicron variant is less severe than other variants of SARS-CoV-2 requires consideration of multiple factors, including the vaccination status of infected patients as well as any previous infections with other variants. This review compiled data about any reported indicators of severity in Omicron-infected patients, including studies comparing Omicron with other variants while adjusting for confounders. A comprehensive search was conducted using different databases to target any studies about Omicron. In total, 62 studies met our inclusion criteria and were included in this study. Many studies reported a significantly reduced risk of hospitalization, ICU admission, need for oxygenation/ventilation, and death in Omicron-infected patients compared to patients infected with other variants, such as Delta. Some studies, however, reported comparable severity in Omicron infected patients as to other variants emphasizing a substantial risk for severe illness. Furthermore, the COVID-19 vaccines were less effective against Omicron relative to previous lineages, except after receiving the booster dose. One study recommended vaccination during pregnancy, which may help prevent future cases of severe SARS-CoV-2 pneumonia in neonates and young infants due to the transfer of humoral response from the mother.

The efficacy and effectiveness of the COVID-19 vaccines in reducing infection, severity, hospitalization, and mortality: a systematic review

With the relatively rapid development of the COVID-19 pandemic, vaccine development has become crucial for limiting disease transmission. The accelerated growth in the approved COVID-19 vaccines has sparked concerns about their efficacies which have been assessed by many studies. This systematic review compares the efficacy and effectiveness of seven COVID-19 vaccines. A comprehensive systematic literature search was performed using several databases to identify studies reporting the effectiveness or the efficacy of the vaccines. Only 42 studies met our inclusion criteria, which revealed that the COVID-19 vaccines have successfully reduced the rates of infections, severity, hospitalization, and mortality among the different populations. The full-dose regimen of the Pfizer/BioNTech vaccine is the most effective against infections with the B.1.1.7 and B.1.351 variants. Despite of the high effectiveness of some of the COVID-19 vaccines, more efforts are required to test their effectiveness against the other newly emerging variants.

Neurological Immune-Related Adverse Events After COVID-19 Vaccination: A Systematic Review

Objective

The goal of this study is to compile published data reporting neurological immune-related adverse events following COVID-19 vaccination, not including those relating to hematologic abnormalities such as thrombosis or hemorrhage.

Background

COVID-19 vaccination has been repeatedly shown to reduce the incidence and severity of COVID-19 infection. The expedited timeline of these vaccines has given rise to many discussions pertaining to their safety. Many neurological and non-neurological adverse events have been linked to COVID-19 vaccination including acute MI, anaphylaxis, appendicitis, Bell's palsy, deep vein thrombosis, disseminated intravascular coagulation, encephalomyelitis, transverse myelitis, and many others.

Design/Methods

The following databases were searched in April 2021 using different keywords: PubMed, Medline, Embase, Scopus, Web of Science, Science, Direct, MedRxiv, andLens.org. Studies were included if they reported any adverse immune-related neurological events secondary to COVID-19 vaccination. Studies were excluded if they were not in English, included self-reported events only, or did not report primary data. Screening and extraction were conducted by 2 different reviewers using Covidence.

Results

The search strategy yielded 18 studies which reported a total of 61 patients who had received a COVID-19 vaccination and experienced = 1 neurological adverse events. Most reported adverse events were facial nerve palsy (52.5%), reactivation of herpes zoster (11.5%), Guillian-Barré syndrome (6.6%), demyelinating disease (6.6%), and neuropathy (11.5%). Other reported adverse effects were delirium, periauricular vesicular rash, bilateral sensorineural hearing loss, visual disturbance, gait disturbance, serotonin syndrome, and vestibular ataxia (16.4%).

Conclusions

The symptoms were time-limited and self-resolving in nature. In addition, the incidence of the reported events following COVID-19 vaccination compared to the general population is similar. Hence, there is little to no evidence suggesting a causal relationship between COVID-19 vaccination and neurological adverse events.

Anaphylaxis and Related Events Post-COVID-19 Vaccination: A Systematic Review

The Coronavirus Disease 2019 (COVID-19), induced by the SARS CoV-2 virus, is responsible for a global pandemic following widespread transmission and death. Several vaccines have been developed to counter this public health crisis using both novel and conventional methods. Following approval based on promising efficacy and safety data, the AstraZeneca, Janssen, Moderna, Pfizer/BioNTech, and SinoVac vaccines have been administered globally among different populations with various reported side effects. Reports of life-threatening anaphylaxis following administration were of particular concern for both healthcare providers and the public. A systematic literature search using PubMed, Embase, Scopus, Web of Science, Science Direct, MedRxiv, and Lens.org databases identified relevant studies reporting anaphylaxis following vaccine administration. This systematic review includes 41 studies reporting anaphylaxis out of 19908 studies that were retrieved for screening. A total of 7942 cases, including 43 deaths, were reported across 14 countries. Most cases occurred following the administration of the first dose. Importantly, the benefits of vaccination far outweigh the risks of anaphylaxis. Subsequently, as populations continue to get vaccinated, it is important for healthcare providers to be able to recognize individuals at risk of developing anaphylaxis. Furthermore, they must be familiar with both the clinical hallmarks and treatment of anaphylactic reactions to minimize long term sequalae and prevent death in vaccinated individuals. This article is protected by copyright. All rights reserved.

Systemic Inflammation May Induce Cardiac Injury in COVID-19 Patients Including Children and Adolescents Without Underlying Cardiovascular Diseases: A Systematic Review

Coronavirus disease 2019(COVID-19) is an ongoing global pandemic with a daily increasing number of affected individuals and a relatively high mortality rate. COVID-19 patients that develop cardiac injury are at increased risk of a worse clinical course with higher rates of mortality. Increasing amounts of evidence suggest that a system-wide inflammatory response and a cytokine storm mediated type syndrome plays a crucial role in disease progression. This systematic review investigates the possible role of hyperinflammation in inducing cardiac injury as one of the severe complications of COVID-19. A systematic literature search was performed using PubMed, Embase and Scopus databases to identify relevant clinical studies that investigated cardiovascular injury manifestations and reported inflammatory and cardiac biomarkers in COVID-19 patients. Only 29 studies met our inclusion criteria and the majority of these studies demonstrated significantly elevated inflammatory and cardiac blood markers. It was evident that underlying cardiovascular diseases may increase the risk of developing cardiac injury. However, many COVID-19 patients included in this review, developed different types of cardiac injury without having any underlying cardiovascular diseases. Furthermore, many of these patients were either children or adolescents. Therefore, age and comorbidities may not always be the two main risk factors that dictate the severity and outcome of COVID-19. Further investigations are required to understand the underlying mechanisms of pathogenicity as an urgent requirement to develop the appropriate treatment and prevention strategies. These strategies may specifically target hyperinflammation as a suspected driving factor for some of the severe complications of COVID-19.

Lymphadenopathy Post‐COVID‐19 Vaccination with Increased FDG Uptake May Be Falsely Attributed to Oncological Disorders: A Systematic Review

Coronavirus disease 2019 (COVID‐19) has caused a global pandemic that continues to cause numerous deaths to date. Four vaccines have been approved by the Food and Drug Administration as of July 2021 to prevent the transmission of COVID‐19: Pfizer, Moderna, AstraZeneca, and Janssen. These vaccines have shown great efficacy and safety profile. One side effect that has been widely reported is post‐COVID‐19 vaccination lymphadenopathy. Due to the mimicry of the lymphadenopathy for metastases in some oncologic patients, there have been reports of patients who underwent biopsies that showed pathologic confirmation of benign reactive lymphadenopathy secondary to the COVID‐19 vaccine. Therefore, understanding the incidence of lymphadenopathy post‐COVID‐19 vaccinations will help guide radiologists and oncologists in their management of patients, both present oncologic patients, and patients with concerns over their newly presenting lymphadenopathy. A systematic literature search was performed using several databases to identify relevant studies that reported lymphadenopathy post‐COVID‐19 vaccination. Our results revealed that several cases have been detected in patients undergoing follow‐up fluorodeoxyglucose (FDG)‐positron emission tomography‐computerized tomography scans where lymph nodes ipsilateral to the vaccine injection site show increased uptake of FDG. Thus, knowledge of the incidence of lymphadenopathy may help avoid unnecessary biopsies, interventions, and changes in management for patients, especially oncologic patients who are at risk for malignancies.

Lymphadenopathy has been widely reported post‐COVID‐19 vaccination including patients undergoing follow‐up FDG‐PET‐CT scans which showed increased FDG uptake

Care must be taken before suspecting lymph node metastasis or deciding for lymphadenectomy following COVID‐19 vaccination

Cardiovascular and haematological events post COVID-19 vaccination: A systematic review

Since COVID‐19 took a strong hold around the globe causing considerable morbidity and mortality, a lot of effort was dedicated to manufacturing effective vaccines against SARS‐CoV‐2. Many questions have since been raised surrounding the safety of the vaccines, and a lot of media attention to certain side effects. This caused a state of vaccine hesitancy that may prove problematic in the global effort to control the virus. This review was undertaken with the aim of putting together all the reported cardiovascular and haematological events post COVID‐19 vaccination in published literature and to suggest possible mechanisms to explain these rare phenomena.

Neurological Immune Related Adverse Events Post-COVID-19 Vaccination: A Systematic Review

The COVID-19 pandemic has affected millions of individuals worldwide. The global scientific effort to design an effective vaccine against this virus has led to the development of several vaccine candidates. The expedited roll-out of these vaccines has created some public distrust regarding the safety of these new vaccines. This review compiles clinical data from reports of diagnosed immune-related neurological events that have occurred post-COVID-19 vaccine administration with the exception of those secondary to hematological abnormalities. A systematic literature search was performed, using several databases, to identify reports of post-vaccination adverse neurological events. The search resulted in 18 studies that met our criteria. These studies included 78 patients who had received COVID-19 vaccines and experienced at least one neurological adverse effect. The most common neurological event was Facial nerve palsy (62.3% of all events). Other less frequently reported events included the reactivation of herpes zoster, Guillain-Barre Syndrome, other demyelinating diseases, and neuropathy. The underlying mechanism was hypothesized to be related to vaccine-induced type 1 interferon production leading to decreased tolerance of the myelin sheath antigens. Other hypotheses include vaccine-induced transient lymphopenia and immune dysregulation. Most of the reported events were time-limited and resolved spontaneously. Given the rarity of reported neurological events compared to the total number of vaccines administered, and the similarity in the incidence of events between COVID-19 vaccines and other more common vaccines, there is little evidence to support a causal relationship between COVID-19 vaccines and adverse neurological events. This article is protected by copyright. All rights reserved.

Systemic inflammation in COVID‐19 patients may induce various types of venous and arterial thrombosis: A systematic review

COVID‐19 is a global pandemic with a daily increasing number of affected individuals. Thrombosis is a severe complication of COVID‐19 that leads to a worse clinical course with higher rates of mortality. Multiple lines of evidence suggest that hyperinflammation plays a crucial role in disease progression. This review compiles clinical data of COVID‐19 patients who developed thrombotic complications to investigate the possible role of hyperinflammation in inducing hypercoagulation. A systematic literature search was performed using PubMed, Embase, Medline and Scopus to identify relevant clinical studies that investigated thrombotic manifestations and reported inflammatory and coagulation biomarkers in COVID‐19 patients. Only 54 studies met our inclusion criteria, the majority of which demonstrated significantly elevated inflammatory markers. In the cohort studies with control, D‐dimer was significantly higher in COVID‐19 patients with thrombosis as compared to the control. Pulmonary embolism, deep vein thrombosis and strokes were frequently reported which could be attributed to the hyperinflammatory response associated with COVID‐19 and/or to the direct viral activation of platelets and endothelial cells, two mechanisms that are discussed in this review. It is recommended that all admitted COVID‐19 patients should be assessed for hypercoagulation. Furthermore, several studies have suggested that anticoagulation may be beneficial, especially in hospitalized non‐ICU patients. Although vaccines against SARS‐CoV‐2 have been approved and distributed in several countries, research should continue in the field of prevention and treatment of COVID‐19 and its severe complications including thrombosis due to the emergence of new variants against which the efficacy of the vaccines is not yet clear.

The Interplay Between the Immune System, the Renin-Angiotensin-Aldosterone System (RAAS), and RAAS Inhibitors May Modulate the Outcome of COVID-19: A Systematic Review

Since the discovery of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), numerous research has been undertaken to delineate the various effects of the virus which manifests in many ways all over the body. The association between the SARS-CoV-2 invasion mechanism and the renin-angiotensin-aldosterone system (RAAS) receptors, created many debates about the possible consequences of using RAAS-modulating drugs including angiotensin-converting enzyme inhibitors (ACEi) and angiotensin II receptor blockers (ARBs) during the pandemic. Many clinical studies were conducted to assess the outcomes of coronavirus disease 2019 (COVID-19) in patients who use ACEi/ARBs following the arguments claiming to discontinue these drugs as a precautionary measure. Although several studies mainly analyzed the outcomes of the disease, this review aimed to compare specific blood markers in both groups of COVID-19 patients to gain better insight into the interaction of ACEi/ARBs with different body functions during the infection. Several databases were searched using a combination of keywords followed by screening and data extraction. Only 28 studies met our inclusion criteria, the majority of which showed no significant difference between the inflammation markers of COVID-19 patients who used or did not use ACEi/ARBs. Interestingly, 6 studies reported lower inflammatory markers in COVID-19 patients who used ACEi/ARBs, and 6 studies reported better outcomes among the same group. We therefore concluded that the use of ACEi/ARBs may not lead to worse prognosis of COVID-19 and may even play a protective role against the hyperinflammatory response associated with COVID-19.

A Comparative Pilot Study of Bacterial and Fungal Dysbiosis in Neurodevelopmental Disorders and Gastrointestinal Disorders: Commonalities, Specificities and Correlations with Lifestyle

Gastrointestinal disorders (GIDs) are a common comorbidity in patients with neurodevelopmental disorders (NDDs), while anxiety-like behaviors are common among patients with gastrointestinal diseases. It is still unclear as to which microbes differentiate these two groups. This pilot study aims at proposing an answer by exploring both the bacteriome and the mycobiome in a cohort of 55 volunteers with NDD, GID or controls, while accounting for additional variables that are not commonly included such as probiotic intake and diet. Recruited participants answered a questionnaire and provided a stool sample using the Fisherbrand collection kit. Bacterial and fungal DNA was extracted using the Qiagen Stool minikit. Sequencing (16sRNA and ITS) and phylogenetic analyses were performed using the PE300 Illumina Miseq v3 sequencing. Statistical analysis was performed using the R package. Results showed a significant decrease in bacterial alpha diversity in both NDD and GID, but an increased fungal alpha diversity in NDD. Data pointed at a significant bacterial dysbiosis between the three groups, but the mycobiome dysbiosis is more pronounced in NDD than in GID. Fungi seem to be more affected by probiotics, diet and antibiotic exposure and are proposed to be the main key player in differentiation between NDD and GID dybiosis.

Fecal microbiota transplants: A review of emerging clinical data on applications, efficacy, and risks (2015-2020)

As the importance of the gut microbiota in health and disease is a subject of growing interest, fecal microbiota transplantation (FMT) was suggested as an attractive therapeutic strategy to restore homeostasis of the gut microbiota, thereby treating diseases that were associated with alteration of the gut microbiota. FMT involves the administration of fresh, frozen, or dried fecal microorganisms from the gut of a healthy donor into the intestinal tract of a patient. This rediscovery of the potential benefits of an ancient practice was accompanied by a rapid progression of our understanding of the roles and mechanisms of gut microbes in the pathogenesis of disease. With a growing number of diseases being associated with dysbiosis or the alteration of gut microbiota, FMT was suggested as an attractive therapeutic strategy to "reset the gut" and initiate clinical resolutions or remissions. The number of FMT clinical trials is increasing worldwide, but no trials are registered in the Gulf region; this suggested the need for raising awareness of the latest studies on FMT. This review presented the emergent preclinical and clinical data to give an overview of the potential clinical applications, the benefits, and inconveniences that were worth considering for eventual future testing of fecal transplants in Qatar and the Middle East. This study highlighted the diversity of methods tested and commented on the variables that can affect the assessment of the effectiveness of FMT in specific diseases. The risks associated with FMT and the threat of antimicrobial resistance for this therapeutic approach were reviewed. From gastrointestinal diseases to neurodevelopmental disorders, understanding the roles of the gut microbiota in health and disease should be at the heart of developing novel, standardized, yet personalized, methods for this ancient therapeutic approach.

Targeting the gut microbiome: A brief report on the awareness, practice, and readiness to engage in clinical interventions in Qatar

BACKGROUND

There has been a growing global interest in the role of gut microbiota in the pathogenesis of diseases and the potentials of targeting the microbiome in clinical interventions. Very few clinical studies in Qatar focused on gut microbiome. This study aimed to assess the awareness of healthcare professionals, scientists, and the general public on the role of gut microbiota in health and diseases and, more specifically, in disorders of the gut-brain axis such as neurodevelopmental disorders (NDDs) or gastrointestinal (GI) disorders. It also aimed to evaluate the readiness of the population to engage in clinical trials involving dietary interventions or fecal transplants.

METHODS

A total of 156 participants were recruited to answer questionnaires-from healthcare professionals and scientists (HSs; n = 44) and the general public (n = 112). Participants from the general public self-reported their diagnosis of NDDs-autism or attention deficit hyperactivity disorder (n = 36)-or GI diseases or disorders (n = 18) or as having none of them (n = 58). Two questionnaires for HSs and for the general public were distributed, and basic descriptive and statistical analyses were conducted using the Fisher's exact test.

RESULTS

Among the participating HSs, 95% admitted that they had minimum to no knowledge on the role of gut microbes in health and diseases, and only 15.9% felt that their peers were knowledgeable about it. Nevertheless, 97.7% of HSs thought that gut microbiota should be considered when devising treatment plans as 79.1% believed that gut dysbiosis is involved in the pathogenesis of diseases. For the general public, 54% stated that they have read about studies on the potential benefits of microbes in the prevention, treatment, and management of diseases, with a higher proportion of them belonging to the GI group (p = 0.0523). The GI group was also more aware of the existence of the use of fecal transplants for treating their condition (p = 0.01935). Awareness was also reflected in participants' attempts to engage in dietary changes, as 40% tried a dietary intervention, which has noticeably changed their or their child's symptoms. This study reported a highly significant association between being exposed to multiple antibiotic courses before three years of age and being part of the NDD group (p = 0.0003). Public readiness to engage in interventions that target the gut microbiome, such as intensive dietary interventions or even fecal transplants, was perceived by HSs to be lower than what was stated by the public, with 87.96% of public being ready to engage in intensive dietary interventions and 66.98% in fecal transplants.

CONCLUSION

The study revealed that the role of gut microbes in health and diseases, and especially through the gut-brain axis, is still unclear in both the scientific community and general public. While acknowledging the importance of gut microbes, the lack of information regarding the link between lifestyle and gut microbes is considered to hold the public in the precontemplation/contemplation stages of the transtheoretical model of behavioral change. An interdisciplinary approach to new knowledge produced by microbiome studies is needed to run awareness campaigns and continue professional development activities on the benefits of lifestyle-based modulation of gut microbiome, thus engaging the general public in lifestyle changes and facilitating clinical research in human microbiome investigations in Qatar.

Importance of Dietary Changes During the Coronavirus Pandemic: How to Upgrade Your Immune Response

The new coronavirus pandemic continues to spread causing further public health, social, and economic issues. The disparities in the rates of death between countries poses questions about the importance of lifestyle habits and the immune status of populations. An exploration of dietary habits and COVID-19-related death might unravel associations between these two variables. Indeed, while both nutritional excess and deficiency are associated with immunodeficiency, adequate nutrition leading to an optimally functioning immune system may be associated with better outcomes with regards to preventing infection and complications of COVID-19, as well as developing a better immune response to other pathogenic viruses and microorganisms. This article outlines the key functions of the immune system and how macronutrients, micronutrients, and metabolites from the gut microbiome can be essential in the development of an efficient immune system. In addition, the effects of intermittent fasting on the inflammatory state as well as metabolic parameters will be discussed.

The role of gut microbiota in atopic asthma and allergy, implications in the understanding of disease pathogenesis

Asthma is a clinical syndrome characterized by chronic airway inflammation. There is mounting evidence on the role of microbiota in the development of asthma. This review focuses on the role of microbiota in maintaining the integrity of the epithelia and their role in regulating the immune response. The review compiles data from multiple studies on the role of microbiota in the innate immune response and the development and differentiation of CD4⁺ T cells, a major component of the adaptive arm of the immune response. As a result of dysbiosis, invariant natural killer T cells may induce T helper 2 cell differentiation and immunoglobulin E isotype switching through the release of interleukin-4 and interleukin-13. Furthermore, degradation of immunoglobulin A antibodies, increased circulating mast cells and basophils, and inflammation are among other mechanisms by which dysbiosis can induce or exacerbate asthma. After explaining the underlying mechanisms, the review derives conclusions from studies that investigate dysbiosis in infancy and the development of asthma later in life. The review also includes studies that investigate asthmatic mothers and the development of asthma in children and the role of dysbiosis in that regard. Finally, the review explains the statistical relationship between eczema and asthma through multiple studies that investigate the role of dysbiosis in both atopic states. This review provides insight into the role of dysbiosis in asthma, and an understanding that is required to establish clinical trials which aim to modulate the gut microbiota as a means of preventing and treating asthma.

DNA barcoding of fish species reveals low rate of package mislabeling in Qatar

DNA barcoding technique has made it possible to authenticate various species used for food and medicinal purposes. In the identification of seafood species, studies are concentrated in North America, Europe, and Asia. Elsewhere, including countries in the Middle East and North Africa, studies of this sort are scarce. This study focuses on packaged fresh or minimally processed fish fillet available at eight major supermarket chains in Qatar. A cocktail of eight primers attached with M13 tails established for fish species identification was adopted to facilitate PCR and sequencing. Sequences were compared with those available in the Barcode of Life Databases (BOLD Systems) and BLAST in NCBI databases. Among the 62 unique fish packages with resolved sequences, only three are confirmed to be mislabeled, at a rate of about 5%. Two of the substituted species are high value items while the third species was replaced by another, equally low-cost species. The relatively low rate of mislabeling in the samples is perhaps a result of strict local food safety regulations, which may have led to high consistency between the package labels and their contents.

Factors associated with early extubation after superior cavopulmonary connection: analysis from single ventricle reconstruction trial

BACKGROUND

To evaluate the landscape of early extubation, and identify factors associated with early extubation (≤ 24 h) after superior cavopulmonary connection (stage 2 operation) among children with single ventricle anatomy.

METHODS

Patients undergoing stage 2 operation after Norwood operation from the Pediatric Heart Network Single Ventricle Reconstruction (SVR) trial public-use dataset were included. Elastic net regularized logistic regression models were fitted to evaluate the factors associated with early extubation after stage 2 operation.

RESULTS

In total, 390 patients from 15 North American centers qualified for inclusion. Of these, 42 patients (10.8%) were extubated in operating room, 151 patients (38.7%) were extubated outside the operating room within the first 24 h after stage 2 operation, and the remaining 197 patients (50.5%) required mechanical ventilation for > 24 h. In adjusted models, factors associated with early extubation after stage 2 operation were elective timing of stage 2 operation, lower incidence of post-Norwood complications, shorter CPB duration for stage 2 operation, and no cardiac catheterization after Stage 2 operation. We also performed multiple other alternative analyses to identify factors associated with early extubation that demonstrated same associations as the primary model. The mean hospital length of stay after Stage 2 operation was 20% shorter among patients with early extubation.

CONCLUSIONS

Data from this large multicenter study demonstrate that approximately one-half of the patients undergoing operation for superior cavopulmonary connection are extubated within 24 h after heart operation. Furthermore, early extubation is associated with shorter hospital length of stay.

Bacterial diversity in soil enrichment cultures amended with 2 (2-methyl-4-chlorophenoxy) propionic acid (mecoprop)

Summary The tfdA gene encodes for an alpha-ketoglutarate-dependent dioxygenase enzyme which catalyses the first step of the degradation of phenoxyalkanoic acid herbicides such as 2 (2-methyl-4-chlorophenoxy) propionic acid (mecoprop). The bacterial diversity of soil enrichment cultures containing mecoprop was examined by Denaturing Gradient Gel Electrophoresis (DGGE) and clone libraries of both 16S rRNA genes and tfdA genes. The 16S rRNA gene sequences were diverse and clustered with either the Beta- or Gammaproteobacteria. The 16S rRNA gene sequence from a bacterial strain isolated from an enrichment culture, grown on R-mecoprop, which represented a dominant band in the DGGE profiles, had a high 16S rRNA sequence identity (100%) to Burkholderia glathei. This is the first report that B. glathei is implicated in mecoprop degradation. PCR amplification of the tfdA genes detected class III tfdA genes only, and no class I or class II tfdA sequences were detected. To understand the genes involved the degradation of specific mecoprop (R-) and (S-) enantiomers, oligonucleotide probes targeting the tfdA, rdpA, sdpA and cadA genes were hybridized to DNA extracted from enrichment cultures grown on either R-mecoprop or (R/S) racemic mecoprop. Strong hybridization signals were obtained with sdpA and tfdA probes using DNA extracted from cultures grown on racemic mecoprop. A strong hybridization signal was also obtained with the rdpA probe with DNA extracted from the cultures grown on R-mecoprop. This suggests the rdpA gene is involved in R-mecoprop degradation while tfdA, sdpA and cadA genes are involved in the degradation of both R- and S-mecoprop.

Assessing dehydroepiandrosterone in saliva: a simple radioimmunoassay for use in studies of children, adolescents and adults

While salivary assays for some hormones are widely used, the availability of assays for salivary DHEA is limited. By adapting a commercially available radioimmunoassay serum kit, we developed a reliable, efficient and sensitive measure of DHEA in saliva that does not require separation or extraction. The minimum detection limit was 4.0 pg/ml. Intra-assay coefficients of variation (CV%) were on average 4.05, and inter-assay CVs averaged 9.70. Method accuracy, determined by spike recovery, and linearity, determined by serial dilution, averaged 99.55 and 92.03%. Levels in matched serum and saliva samples showed strong linear relationships for adult males and females. Specific guidelines are developed for sample collection, storage, and preparation procedures. Reference ranges for salivary DHEA levels are provided for 64 children ages 8-11, 96 adolescents ages 12-17 and 48 adults ages 30-45. Salivary DHEA levels are shown to reflect developmental, gender and diurnal differences.

Preferential activation of the vastus medialis oblique, vastus lateralis, and hip adductor muscles during isometric exercises in females

Disagreement exists as to whether the individual components of the quadriceps femoris can be preferentially activated, i.e., that one muscle component is activated to a greater degree of its maximum voluntary contraction ability than the remaining components. Preferential activation of the vastus medialis (VM) might be useful in the treatment of knee patients demonstrating VM atrophy. The purpose of the present investigation was to determine if the vastus medialis oblique (VMO), vastus lateralis (VL), and hip adductor (HA) muscles were preferentially activated in females during the following maximal voluntary isometric exercises: 1) unilateral quadriceps setting (QS) with the ankle positioned in neutral, 2) unilateral quadriceps setting combined with ankle dorsiflexion (QS + D), and 3) maximal bilateral hip adduction. Integrated electromyography (IEMG in mV.sec) was determined for the VMO, VL, and HA muscles of the preferred leg (i.e., that used to kick a ball) of 20 healthy females. Data were normalized using QS exercise as the reference exercise. Nonnormalized IEMG (+/-SD) of the VMO and VL was similar during QS [i.e., VMO = 1050 (+/-802) mV.sec, VL = 1075 (+/-738) mV. sec] and QS + D exercises [i.e., VMO = 1191 (+/-738) mV.sec, VL = 1202 (+/-836) mV.sec], but significantly less than these values during hip adduction exercise [i.e., VMO = 174 (+/-62) mV. sec, VL = 194 (+/-70) mV.sec]. Nonnormalized IEMG of the HA muscles was similar during both QS and QS+D [i.e., 286 (+/-405) mV.sec and 195 (+/-432) mV.sec], but significantly higher than these values during hip adduction exercise [i.e., 413 (+/-235) mV.sec]. Normalized IEMG (+/-SD)(%) demonstrated similar patterns, i.e., the ratios for the VMO and the VL muscles did not differ from one another under either QS + D [i.e., VMO = 121 (+/-60)%, VL = 116 (+/-40)%] or hip adduction conditions [i.e., VMO = 33 (+/-24)%, VL = 36 (+/-25)%]. As a result, the degree of activation of the two muscles was considered the same. These results suggest no preferential activation of the quadriceps femoris component muscles during QS, QS + D, and hip adduction exercises in the nonweight-bearing position. The use of hip adduction to preferentially activate the VMO over the VL compared with QS exercises was not substantiated. A mean increase of 20% in the VMO and VL myoelectric activity during QS (as demonstrated by the normalized IEMG), by the addition of dorsiflexion, may be clinically significant. However, further study is required.