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Topic Review
Biography
Peer Reviewed Entry
Video Entry
Topic Review
Helicobacter Pylori Survival Tactics
Helicobacter pylori is well established as a causative agent for gastritis, peptic ulcer, and gastric cancer. Armed with various inimitable virulence factors, this Gram-negative bacterium is one of few microorganisms that is capable of circumventing the harsh environment of the stomach. The unique spiral structure, flagella, and outer membrane proteins accelerate H. pylori movement within the viscous gastric mucosal layers while facilitating its attachment to the epithelial cells. Furthermore, secretion of urease from H. pylori eases the acidic pH within the stomach, thus creating a niche for bacteria survival and replication. Upon gaining a foothold in the gastric epithelial lining, bacterial protein CagA is injected into host cells through a type IV secretion system (T4SS), which together with VacA, damage the gastric epithelial cells.
701
29 Mar 2022
Topic Review
Beneficial Effects of Thymoquinone against COVID-19
In order to overcome the serious complications associated with COVID-19 and to prevent SARS-CoV-2 entry into the host cell, it is necessary to repurpose drugs with a broad medicinal application as soon as they become available. It is in this pattern that Nigella sativa seeds manifest their extensive therapeutic effects, which have been reported to be particularly effective in the treatment of skin diseases, jaundice, and gastrointestinal problems. One important component of these seeds is thymoquinone (TQ), which has a wide range of beneficial properties, including antioxidant and anti-inflammatory properties, as well as antibacterial and parasitic properties, in addition to anticarcinogenic, antiallergic, and antiviral properties.
700
17 Jan 2023
Topic Review
COVID-19 and Hypothalamic–Pituitary Diseases
Long COVID-19, also known as post-acute sequelae of SARS-CoV-2 infection, is a condition where individuals who have recovered from the acute phase of COVID-19 continue to experience a range of symptoms for weeks or even months afterward. While it was initially thought to primarily affect the respiratory system, it has become clear that Long COVID-19 can involve various organs and systems, including the endocrine system, which includes the pituitary gland. In the context of Long COVID-19, there is a growing understanding of the potential implications for the pituitary gland. The virus can directly affect the pituitary gland, leading to abnormalities in hormone production and regulation.
699
27 Feb 2024
Topic Review
Monoclonal Antibodies in COVID-19
Monoclonal antibodies (MAbs) are one of the emerging therapeutic agents efficacious for treating infectious diseases such as COVID-19. They are one of the fastest-growing pharmaceuticals and are considered to be highly specific in their action. MAbs are lab-grown antibodies that specifically target the pathogen, causing its destruction immediately.
698
19 Nov 2021
Topic Review
Heme Oxygenase 1 for Inflammatory Disease
Heme oxygenase 1 (HO-1), the rate-limiting enzyme in heme degradation, is involved in the maintenance of cellular homeostasis, exerting a cytoprotective role by its antioxidative and anti-inflammatory functions. HO-1 and its end products, biliverdin (BV), carbon monoxide (CO) and free iron (Fe2+), confer cytoprotection against inflammatory and oxidative injury. Additionally, HO-1 exerts antiviral properties against a diverse range of viral infections by interfering with replication or activating the interferon (IFN) pathway. Severe cases of coronavirus disease 2019 (COVID-19), an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), are characterized by systemic hyperinflammation, which, in some cases, leads to severe or fatal symptoms as a consequence of respiratory failure, lung and heart damage, kidney failure, and nervous system complications. Here we summarize the current research on the protective role of HO-1 in inflammatory diseases and against a wide range of viral infections, positioning HO-1 as an attractive target to ameliorate clinical manifestations during COVID-19.
697
11 Feb 2022
Topic Review
Vaccinology in the COVID-19 Pandemic Era
Different approaches have been used in parallel to make COVID-19 vaccines, including the use of nucleic acid-based vectors, whole virus (live-attenuated and inactivated), viral vectors (replicating and nonreplicating), adjuvant recombinant protein nanoparticles, and virus-like particles (VLPs). Among the protective antigens of SARS-CoV-2, the attention has mainly focused on the native S protein, which is able to induce potent neutralizing antibodies, even if its presentation to the immune system differs substantially between the different categories of vaccines. However, new evidence is being raised about potential roles for other, more conserved non-spike viral antigens, such as nucleocapsid (N) proteins, which might represent an innovation in the fight against emerging SARS-CoV-2 variants and a source for universal vaccines providing long-lasting immunity.
696
29 Apr 2022
Topic Review
Stem Cell Homing
Stem cells are essential to the regenerative processes with a primary function to replace damaged cells in the body. Their ability to differentiate into functional cells is an outcome of their response to micro-environmental changes, i.e., stem cells’ interaction with signals released by the affected tissue. Cell homing is a stem cell’s ability to find a point of destination, be it a tissue in distress or a niche. Cell homing is a diverse term. Many cell types, including stem cells, progenitors, and mature, specialized T cells, are homing to their respective niches—environments that promote their self-renewable state.
694
27 Apr 2022
Topic Review
Pneumococcal Vaccination during COVID-19
The emergence of new viral infections has increased over the decades. The novel virus is one such pathogen liable for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, popularly known as coronavirus disease 2019 (COVID-19). Most fatalities during the past century’s influenza pandemics have cooperated with bacterial co/secondary infections. Unfortunately, many reports have claimed that bacterial co-infection is also predominant in COVID-19 patients (COVID-19 associated co/secondary infection prevalence is up to 45.0%). In the COVID-19 pandemic, Streptococcus pneumoniae is the most common coinfecting pathogen. Half of the COVID-19 mortality cases showed co-infection, and pneumonia-related COVID-19 mortality in patients >65 years was 23%. The weakening of immune function caused by COVID-19 remains a high-risk factor for pneumococcal disease. Pneumococcal disease and COVID-19 also have similar risk factors. For example, underlying medical conditions on COVID-19 and pneumococcal diseases increase the risk for severe illness at any age; COVID-19 is now considered a primary risk factor for pneumococcal pneumonia and invasive pneumococcal disease. Thus, pneumococcal vaccination during the COVID-19 pandemic has become more critical than ever.
692
06 Jan 2022
Topic Review
Peer Reviewed
Kidney Issues Associated with COVID-19 Disease
Infection with SARS-CoV-2 and the resulting COVID-19 can cause both lung and kidney damage. SARS-CoV-2 can directly infect renal cells expressing ACE2 receptors, resulting in kidney damage, and acute kidney injury (AKI) has been reported in COVID-19 hospitalized patients. The pathophysiology of COVID-19-associated AKI is multifactorial. Local and systemic inflammation, immune system dysregulation, blood coagulation disorders, and activation of the renin-angiotensin-aldosterone system (RAAS) are factors that contribute to the development of AKI in COVID 19 disease. COVID-19 patients with kidney involvement have a poor prognosis, and patients with chronic kidney disease (CKD) infected with SARS-CoV-2 have an increased mortality risk. CKD patients with COVID-19 may develop end-stage renal disease (ESRD) requiring dialysis. In particular, patients infected with SARS-CoV-2 and requiring dialysis, as well as patients who have undergone kidney transplantation, have an increased risk of mortality and require special consideration. Nephrologists and infectious disease specialists face several clinical dilemmas in the prophylaxis and treatment of CKD patients with COVID-19. This entry presents recent data showing the effects of COVID-19 on the kidneys and CKD patients and the challenges in the management of CKD patients with COVID-19, and discusses treatment strategies for these patients.
689
05 Sep 2023
Topic Review
Combination Antibody Therapy against Pseudomonas aeruginosa Infections
Despite advances in antimicrobial therapy and even the advent of some effective vaccines, Pseudomonas aeruginosa (P. aeruginosa) remains a significant cause of infectious disease, primarily due to antibiotic resistance. Although P. aeruginosa is commonly treatable with readily available therapeutics, these therapies are not always efficacious, particularly for certain classes of patients (e.g., cystic fibrosis (CF)) and for drug-resistant strains. Combinations of monoclonal antibodies against different targets and epitopes have demonstrated synergistic efficacy with each other as well as in combination with antimicrobial agents typically used to treat these infections. Such a strategy has reduced the ability of infectious agents to develop resistance. This entry highlights potential targets secreted by P. aeruginosa that future polyclonal antibodies may directed against in order to develop more efficacious treatments against these infections.
687
06 Jan 2022
Topic Review
Central Nervous System in Trichinellosis
Trichinellosis is a parasitic disease caused by the consumption of raw meat infected with larvae of nematode in the genus Trichinella.
685
22 Feb 2022
Topic Review
Social Determinants of Health and Microbiome in Children
The evolving field of microbiome research offers an excellent opportunity for biomarker identification, understanding drug metabolization disparities, and improving personalized medicine. However, the complexities of host–microbe ecological interactions hinder clinical transferability. Among other factors, the microbiome is deeply influenced by age and social determinants of health, including environmental factors such as diet and lifestyle conditions. In this entry, the bidirectionality of social and host–microorganism interactions in health will be discussed.
685
20 Dec 2021
Topic Review
Subacute Thyroiditis and the COVID-19
Subacute thyroiditis (SAT), also known as De Quervain or granulomatous thyroiditis, is caused by a viral infection, especially (but not exclusively) of the upper respiratory tract or by post-viral inflammation. Since 2020, the entity has been listed in association with the coronavirus disease 2019 (COVID-19) infection, and since 2021 it has been related to the vaccine against the virus.
684
02 Jun 2022
Topic Review
Vaccines for Bovine Mycoplasmoses
Two of the most important diseases of cattle are caused by mycoplasmas. Mycoplasma bovis is a world-wide bovine pathogen that can cause pneumonia, mastitis and arthritis. Due to its increasing resistance to antimicrobial therapy, vaccination is the principal focus of the control of infection, but effective vaccines are currently lacking. Despite being eradicated from most parts of the world, Mycoplasma mycoides subsp. mycoides, the cause of contagious bovine pleuropneumonia (CBPP), continues to plague sub-Saharan Africa. Numerous new experimental vaccines have been developed over the last 20 years to improve on protection afforded by the T1/44, a live vaccine in continuous use in Africa for over 60 years, but none so far have succeeded; indeed, many have exacerbated the disease.
682
23 Jun 2021
Topic Review
Gut Microbiome and Adjuvant Treatment of COVID-19
High expression of the transmembrane protein angiotensin I converting enzyme 2 (ACE2), more than 100-times higher as in the lung, and transmembrane serine protease 2 (TMPRSS2) in the gastrointestinal tract leads to infection with SARS-CoV-2. According to meta-analysis data, 9.8–20% of COVID-19 patients experience gastrointestinal symptoms, where diarrhoea is the most frequent, and about 50% shed viruses with high titre through their faeces, where a first faecal transmission was reported. Furthermore, gut inflammation, intestinal damage, and weakening of the gut mucosal integrity that leads to increased permeability has been shown in different studies for COVID-19 patients. This can lead to increased inflammation and bacteraemia. Low mucosal integrity combined with low intestinal damage is a good predictor for disease progression and submission to the intensive care unit (ICU). Several pilot studies have shown that the gut microbiome of COVID-19 patients is changed, microbial richness and diversity were lower, and opportunistic pathogens that can cause bacteraemia were enriched compared to a healthy control group. In a large proportion of these patients, dysbiosis was not resolved at discharge from the hospital and one study showed dysbiosis is still present after 3 months post COVID-19. Consequently, there might be a link between dysbiosis of the gut microbiome in COVID-19 patients and chronic COVID-19 syndrome (CCS). Various clinical trials are investigating the benefit of probiotics for acute COVID-19 patients, the majority of which have not reported results yet. However, two clinical trials have shown that a certain combination of probiotics is beneficial and safe for acute COVID-19 patients. Mortality was 11% for the probiotic treatment group, and 22% for the control group. Furthermore, for the probiotic group, symptoms cleared faster, and an 8-fold decreased risk of developing a respiratory failure was calculated. In conclusion, evidence is arising that inflammation, increased permeability, and microbiome dysbiosis in the gut occur in COVID-19 patients and thus provide new targets for adjuvant treatments of acute and chronic COVID-19. More research in this area is needed.
682
23 Nov 2021
Topic Review
Pathogenetic Analogies of Preeclampsia and COVID-19
Preeclampsia is an obstetric pathology that, surprisingly, resembles the pathology of COVID-19. Both diseases are characterized by significant alterations in the renin-angiotensin system (RAS). RAS-mediated mechanisms may explain their primary clinical-pathological features, which are suggestive of an underlying microvascular dysfunction, with induction of vasculopathy, coagulopathy, and inflammation.
681
16 May 2022
Topic Review
Sepsis and HMGB1 Release
Sepsis remains a common cause of death in intensive care units, accounting for approximately 20% of total deaths worldwide. Its pathogenesis is partly attributable to dysregulated inflammatory responses to bacterial endotoxins (such as lipopolysaccharide, LPS), which stimulate innate immune cells to sequentially release early cytokines (such as tumor necrosis factor (TNF) and interferons (IFNs)) and late mediators (such as high-mobility group box 1, HMGB1). Below is a brief summary of the intricate mechanisms underlying the regulation of bacterial endotoxin-induced HMGB1 release.
678
13 Sep 2021
Topic Review
Potential Association of
Cutibacterium acnes
with Sarcoidosis
The immunohistochemical detection of Cutibacterium acnes in sarcoid granulomas suggests its potential role in granuloma formation. C. acnes is the sole microorganism ever isolated from sarcoid lesions. Histopathologic analysis of some sarcoid lymph nodes reveals latent infection and intracellular proliferation of cell-wall-deficient C. acnes followed by insoluble immune-complex formation. Activation of T helper type 1 (Th1) immune responses by C. acnes is generally higher in sarcoidosis patients than in healthy individuals. Pulmonary granulomatosis caused by an experimental adjuvant-induced allergic immune response to C. acnes is preventable by antimicrobials, suggesting that the allergic reaction targets C. acnes commensal in the lungs. C. acnes is the most common bacterium detected intracellularly in human peripheral lungs and mediastinal lymph nodes. In predisposed individuals with hypersensitive Th1 immune responses to C. acnes, granulomas may form to confine the intracellular proliferation of latent C. acnes triggered by certain host-related or drug-induced conditions.
678
31 Jan 2023
Topic Review
Post-COVID Syndrome
Post-COVID syndrome is increasingly recognized as a new clinical entity in the context of SARS-CoV-2 infection.
675
23 Jun 2021
Topic Review
Membrane Efflux Pumps of Pathogenic Vibrio Species
Infectious diseases caused by bacterial species of the Vibrio genus have had considerable significance upon human health for centuries. V. cholerae is the causative microbial agent of cholera, a severe ailment characterized by profuse watery diarrhea, a condition associated with epidemics, and seven great historical pandemics. V. parahaemolyticus causes wound infection and watery diarrhea, while V. vulnificus can cause wound infections and septicemia. Species of the Vibrio genus with resistance to multiple antimicrobials have been a significant health concern for several decades. Mechanisms of antimicrobial resistance machinery in Vibrio spp. include biofilm formation, drug inactivation, target protection, antimicrobial permeability reduction, and active antimicrobial efflux. Integral membrane-bound active antimicrobial efflux pump systems include primary and secondary transporters, members of which belong to closely related protein superfamilies. The RND (resistance-nodulation-division) pumps, the MFS (major facilitator superfamily) transporters, and the ABC superfamily of efflux pumps constitute significant drug transporters for investigation.
672
11 Mar 2022
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