Mental health impact of the Middle East respiratory syndrome,SARS, and COVID-19: A comparative systematic review and meta-analysis

BACKGROUNDOver the last few decades, 3 pathogenic pandemics have impacted the global population; severe acute respiratory syndrome coronavirus (SARS-CoV), Middle East respiratory syndrome coronavirus (MERS-CoV) and SARS-CoV-2. The global disease burden has attributed to millions of deaths and morbidities, with the majority being attributed to SARS-CoV-2. As such, the evaluation of the mental health (MH) impact across healthcare professionals (HCPs), patients and the general public would be an important facet to evaluate to better understand short, medium and long-term exposures. AIMTo identify and report: (1) MH conditions commonly observed across all 3 pandemics; (2) Impact of MH outcomes across HCPs, patients and the general public associated with all 3 pandemics; and (3) The prevalence of the MH impact and clinical epidemiological significance.METHODSA systematic methodology was developed and published on PROSPERO (CRD42021228697). The databases PubMed, EMBASE, ScienceDirect and the Cochrane Central Register of Controlled Trials were used as part of the data extraction process, and publications from January 1, 1990 to August 1, 2021 were searched. MeSH terms and keywords used included Mood disorders, PTSD, Anxiety, Depression, Psychological stress, Psychosis, Bipolar, Mental Health, Unipolar, Self-harm, BAME, Psychiatry disorders and Psychological distress. The terms were expanded with a ‘snowballing’ method. Cox-regression and the Monte-Carlo simulation method was used in addition to I² and Egger’s tests to determine heterogeneity and publication bias. RESULTSIn comparison to MERS and SARS-CoV, it is evident SAR-CoV-2 has an ongoing MH impact, with emphasis on depression, anxiety and post-traumatic stress disorder. CONCLUSIONIt was evident MH studies during MERS and SARS-CoV was limited in comparison to SARS-CoV-2, with much emphasis on reporting symptoms of depression, anxiety, stress and sleep disturbances. The lack of comprehensive studies conducted during previous pandemics have introduced limitations to the “know-how” for clinicians and researchers to better support patients and deliver care with limited healthcare resources.     

Comparative assessment of dentition status among poliomyelitis children in Udaipur,India

To determine and compare the dental caries experience and treatment needs of children with Poliomyelitis at Udaipur, India. Total sample comprised of 344 children with Poliomyelitis (upper limb disability: 33.4%; lower limb disability: 33.7%; both upper and lower limb disability: 32.8%) in the age group of 12–15 years. Clinical examination included recording Dentition Status and Treatment Needs. Chi‐square test, Analysis of variance (ANOVA), multiple logistic and stepwise linear regressions were used for statistical analysis. The mean decayed, missing, filled teeth (DMFT) score (4.47 ± 3.09) was found to be highest among children with Poliomyelitis having both upper and lower limb impairment (p < .05). Stepwise and logistic regression analysis showed that the best predictors for dental caries were disability, socioeconomic status and snacks in between meals. A significant relationship of dental caries with limb involved in impairment draws immediate attention for a planned approach in improving the oral health.     

MicroRNA155 Plays a Critical Role in the Pathogenesis of Cutaneous Leishmania major Infection by Promoting a Th2 Response and Attenuating Dendritic Cell Activity

Interferon (IFN)-γ is indispensable in the resolution of cutaneous leishmaniasis (CL), while the Th2 cytokines IL-4, IL-10, and IL-13 mediate susceptibility. A recent study found that miR155, which promotes CD4⁺ Th1 response and IFN-γ production, is dispensable in the control of Leishmania donovani infection. Here, the role of miR155 in CL caused by L. major was investigated using miR155-deficient (miR155^−/−) mice. Infection was controlled significantly quicker in the miR155^−/− mice than in their wild-type (WT) counterparts, indicating that miR155 contributes to the pathogenesis of CL. Faster resolution of infection in miR155^−/− mice was associated with increased levels of Th1-associated IL-12 and IFN-γ and reduced production of Th2- associated IL-4, IL-10, and IL-13. Concentrations of IFN-γ⁺CD8⁺ T cells and natural killer cells in draining lymph nodes were significantly higher in the L. major−infected miR155^−/− mice than in the infected WT mice, as indicated by flow-cytometry. After in vitro IFN-γ stimulation, nitric oxide and IL-12 production were increased, IL-10 production was decreased, and parasite clearance was enhanced in L. major−infected miR155^−/− DCs compared to those in WT DCs. Furthermore, IFN-γ production from activated miR155^−/− T cells was significantly enhanced in L. major−infected miR155^−/− DCs. Together, these findings demonstrate that miR155 promotes susceptibility to CL caused by L. major by promoting Th2 response and inhibiting DC function.

Leishmania are obligate intracellular protozoans that infect phagocytes and cause a spectrum of clinical diseases such as cutaneous leishmaniasis (CL) and visceral leishmaniasis. Common in the tropical and subtropical regions, leishmaniasis affects over 1 billion people worldwide, with an incidence of up to 1 million cases per year.¹ CL is the most common type of Leishmania infection, manifesting as localized skin lesions that can become chronic, leading to significant tissue destruction and disfigurement.^2,3 It is well documented that the induction of a Th1 response and interferon (IFN)-γ are indispensable in the resolution of CL caused by Leishmania major,⁴ whereas disease progression is associated with the induction of a Th2 response and the production of cytokines such as IL-4 and IL-10.⁵ Establishing a disease-resolving response in the host is largely dependent on the ability to mount an appropriate Th1 immune response.⁴ Crucial in this response is the stimulation and activation of DCs that direct T-cell proliferation and differentiation toward IFN-γ–producing Th1 cells.^6,7 In addition to activating of phagocytic cells, IFN-γ induces the production of reactive nitrogen species, specifically nitric oxide (NO), leading to enhanced parasite clearance.⁴miR155 is a recognized regulator of immune cell function and immune response. miR155 enhances macrophage and DC activation and induces inflammatory response,^8,9 and up-regulation of miR155 in CD4⁺ T cells promotes preferential Th1 differentiation and IFN-γ production¹⁰ by suppressing the expression of suppressor of cytokine signaling (SOCS)-1.11, 12, 13, 14 Conversely, miR155 gene–deficient mice exhibit diminished levels of Th1/Th17 cells, macrophages, and DCs.¹⁵ miR155 has also been shown to play a role in regulating effector Th2 response.16, 17, 18 Collectively, these findings suggest that miR155 regulates both Th1 and Th2 responses, which control the outcome of CL caused by L. major. Therefore, the role of miR155 in immunity to L. major using miR155^−/− mice was investigated in the present study. The findings show that miR155 is not required for the induction of a Th1 response and IFN-γ in L. major infection. Rather, miR155 plays a disease-exacerbating role in CL by attenuating DC function and Th1 response and promoting Th2 response.     

Origin of eukaryotic introns: a hypothesis, based on codon distribution statistics in genes, and its implications.

A hypothesis for the origin of introns in eukaryotic genes is developed. By computer simulation it was found that the reading-frame lengths in a random nucleotide sequence are distributed in a negative exponential manner and that there exists an upper limit of about 200 codons in the length of the reading frames (RFs). These characteristics suggest that, if primordial DNA contained a random nucleotide sequence, the most primitive cells would have been under selective pressure to eliminate interfering stop codons in order to increase the length of RFs. Further, they indicate that the only possible way that a coding sequence that is considerably longer than 600 nucleotides could be derived from the short coding sequences occurring in a random sequence would be to splice the short coding sequences and to eliminate the stretches of sequences containing clusters of inframe stop codons. Thus, introns are suggested to be those stretches of sequences containing interfering stop codons that were originally earmarked in the first primitive cells to be eliminated in order to enable the coding for long polypeptides. Because the statistical characteristics of codon distributions in today's eukaryotic DNA sequences resemble closely those of a random sequence and because the upper limit in the length of RFs (200 codons) in a random sequence corresponds precisely to the observed maximum length of exons in today's eukaryotic genes (600 nucleotides), it is suggested that introns originated in the most primitive unicellular eukaryotes when they evolved from primordial sequences. The data from the prokaryotic gene sequences indicate that prokaryotic genes may have been derived originally from primitive unicellular eukaryotic genes by losing introns from them.     

Possible evolution of splice-junction signals in eukaryotic genes from stop codons.

Splice-junction sequence signals are strongly conserved structural components of eukaryotic genes. These sequences border exon/intron junctions and aid in the process of removing introns by the RNA splicing machinery. Although substantial research has been undertaken to understand the mechanism of splicing, little is known about the origin and evolution of these splice signal sequences. Based on the previously published theory that the primitive genes evolved in pieces from primordial genetic sequences to avoid the interfering stop codons, a "stop-codon walk" mechanism is proposed in this paper to have assisted in the evolution of coding genes. This mechanism predicts the presence of stop codons in splice-junction signals inside the introns. Evidence of the consistent presence of stop codons in the splice-junction signals, in a position where they are expected, is shown by the analysis of codon statistics in these signal sequences in the GenBank databank. The results suggest that the splice-junction signals may have evolved from stop codons as a consequence of a selective pressure to avoid stop codons during the original evolution of coding genes. They also suggest that other splice signals within the introns, such as the branch-point sequence, may have evolved from stop codons for similar reasons.     

Emblica officinalis exerts wound healing action through up-regulation of collagen and extracellular signal-regulated kinases (ERK1/2)

During wound healing, the wound site is rich in oxidants, such as hydrogen peroxide, mostly contributed by neutrophils and macrophages. Ascorbic acid and tannins of low molecular weight, namely emblicanin A (2,3-di- O -galloyl-4,6-( S )-hexahydroxydiphenoyl-2-keto-glucono-δ-lactone) and emblicanin B (2,3,4,6-bis-( S )-hexahydroxydiphenoyl-2-keto-glucono-δ-lactone) present in Emblica officinalis (emblica), have been shown to exhibit a very strong antioxidant action. We proposed that addition of these antioxidants to the wound microenvironment would support the repair process. The present investigation was undertaken to determine the efficacy of emblica on dermal wound healing in vivo. Full-thickness excision wounds were made on the back of the rat and topical application of emblica accelerated wound contraction and closure. Emblica increased cellular proliferation and cross-linking of collagen at the wound site, as evidenced by an increase in the activity of extracellular signal-regulated kinase 1/2, along with an increase in DNA, type III collagen, acid-soluble collagen, aldehyde content, shrinkage temperature and tensile strength. Higher levels of tissue ascorbic acid, α-tocopherol, reduced glutathione, superoxide dismutase, catalase, and glutathione peroxidase support the fact that emblica application promotes antioxidant activity at the wound site. In summary, this study provides firm evidence to support that topical application of emblica represents a feasible and productive approach to support dermal wound healing.