Point-of-care diagnosis of COVID-19 disease based on antigen tests

AIMS

This review is focused on the laboratory diagnoses of the coronavirus disease 2019 (COVID-19) by recognizing the antigen of the causative agent SARS-CoV-2 virus. Various antigen tests are available in this moment and these tests are being further developed in order to reach a better diagnostic value. The issue is reviewed in a complex view.

METHODS

In this work, a complex survey of the current literature was made. The relevant and recent papers related to antigen tests of COVID-19 are discussed and cited. Basic specifications of the antigen tests and competitive methods were also scrutinized in the current literature.

RESULTS

The survey of the current literature (years 2019 ‒ 2021) was made and diagnostic methods like lateral flow tests (lateral flow immunochromatographic assay) and various types of biosensors were specified as tools for COVID-19 diagnosis and their application to be used as a point-of-care test is considered.

CONCLUSIONS

Small hand-held assays applicable in the point-of-care conditions for diagnosis of COVID-19 by analysis of SARS-CoV-2 antigen are the means of a growing interest and these means undergo a significant development leading to the improvements of their specifications and applicability to the current praxis. Merit of the assays is discussed in this paper (Tab. 3, Fig. 2, Ref. 109).

COVID-19 molecular level laboratory diagnoses

AbstractAIMS: Aims: The Coronavirus Disease 2019 (COVID-19) caused not only global pandemic, but it also pointed at unprepared health care systems and countermeasures were introduced under the pressure of urgent circumstances. This review is focused on discussion and critical evaluation of instrumental tools for COVID-19 diagnosis that were developed in the last months.

METHODS

Survey of actual literature and scientific reports was made. The most substantial analytical and diagnostical methods were identified and described. Principles and limitations of the methods are described, and actual papers are cited in this review.

RESULTS

Analytical and diagnostical methods like Polymerase Chain Reaction (PCR), Loop-mediated isothermal Amplification (LAMP), Lateral Flow Immunochromatography Assay (LFIA), Enzyme-Linked Immunosorbent Assay (ELISA), biosensors and ChemiLuminescence ImmunoAssay (CLIA) are discussed for assay of viral particles, antigens and specific host antibodies in blood, serum, plasma, nasopharyngeal swab and other samples in order to diagnose COVID-19.

CONCLUSIONS

The Coronavirus Disease 2019 (COVID-19) is an emerging disease that has spread over the world since the end of year 2019. The global epidemic pointed at the necessity to introduce sensitive methods for instrumental diagnosis of COVID-19 and distinguishing it from the other viral diseases. (Tab. 2, Ref. 96).

Bacillus anthracis as a biological warfare agent: infection, diagnosis and countermeasures

AIM

Bacillus anthracis is a causative agent of zoonotic anthrax disease. In the last years, significant progress in therapy and diagnosis of anthrax was made. Concurrently, knowledge about anthrax progression, molecular pathology and release of anthrax toxin during the disease has improved. This review covers the recent progress in this field.

METHODS

In this review, specifications of B. anthracis, anthrax disease, medical and biomedical countermeasures and diagnostic tools were surveyed. The actual literature was summarized and relevance of the microorganism as a biological warfare agent and the ways how to reduce its impact including therapeutic protocols were written and discussed.

RESULTS

Currently, the microorganism is considered one of the top biological warfare agents due to lethality, long term stability of spores, easy dissemination and production. The recent research is focused on countermeasures suitable for reduction of consequences by a misuse of the microorganism in form of biological weapon (Tab. 3, Fig. 1, Ref. 101). Text in PDF www.elis.sk.

Copper and copper nanoparticles toxicity and their impact on basic functions in the body

Copper is a biogenic metal having multiple functions in basic processes in organisms and it is common in all kingdoms of life. Limited intake of copper is a problem; however, doses of copper exceeding the recommended alimentary source are problematic as well and toxicity is soon manifested. Impact of copper nanoparticles on human health is another serious issue taken into consideration in this review. Regarding to copper toxicity, neurodegenerative disorders including Alzheimer and Parkinson diseases are suspected to be linked to copper toxicity or copper can contribute to their progression. Wilson and Menke diseases are also described as examples of copper intolerance. This paper is focused on the description, literature survey and discussion of the current knowledge about copper and copper nanoparticles toxicity and their involvement in various pathological processes (Tab. 6, Fig. 2, Ref. 171). Keywords: reactive oxygen species; Alzheimer disease; acetylcholinesterase; copper; Fenton reaction; disorder; heavy metal; pollution; nanoparticle.

Oxidative stress in Alzheimer disease as a target for therapy

In the recent time, neurodegenerative disorders like Alzheimer disease were recognized for their significant role in the current healthcare because of their growing incidence and costs for health insurance systems. Effective therapy is missing and even etiology of the diseases like Alzheimer disease is not deeply known. In the case of Alzheimer disease, it is probable that oxidative stress is at least a factor involved in the disease. Nevertheless, the current literature is controversial and ambiguous in this matter. This review is focused on mapping the role of oxidative stress as well as on a consideration that oxidative stress represents the pathway at which a therapeutic strategy can be aimed. This paper provides a survey of contemporary literature on oxidative stress in Alzheimer disease and discusses the opportunities for establishing a therapy based on interfering the stress (Fig. 5, Ref. 117).

Galantamine has impact on immunity in mice exposed to keyhole limpet hemocyanin

OBJECTIVES

In this work, we hypothesized whether galantamine could interact with the cholinergic anti-inflammatory pathway and modulate immunity this way.

BACKGROUND

Galantamine is a drug used for the therapy of Alzheimer disease. The drug inhibits enzyme acetylcholinesterase in the central nervous system, which causes better availability of neurotransmitter acetylcholine.

METHODS

In the experiment, we immunized BALB/c laboratory mice by keyhole limpet hemocyanin (KLH) in combination with galantamine in a dose 0.02-0.5 mg/kg. The animals were sacrificed from 1 to 7 days after the substances applications and plasma was collected in order to examine immunochemical markers by enzyme-linked immunosorbent assay.

RESULTS

We found significant drop in production of immunoglobulins and interleukin (IL) 4 level while IL2, IL4 and tumour necrosis factor α remained unaltered for the whole experiment. We infer that galantamine causes better availability of acetylcholine also in blood system, where the neurotransmitter interacts with nicotinic acetylcholine receptors on macrophages and initiates cholinergic anti-inflammatory pathway.

CONCLUSIONS

In a conclusion, galantamine can cause lower efficacy of vaccination or immunity response to an infectious disease and the phenomenon should be taken into consideration in the current therapy (Tab. 1, Fig. 2, Ref. 24).

Freund´s complete adjuvant effect on BALB/c mice: an insight into inflammation and oxidative stress after immunity challenge

Freund´s complete adjuvant (FCA) is a mean used for improving immunization efficacy in experiments and veterinary medicine. Despite high efficacy, it is not used in human vaccination due to number of adverse effects. Arthritis can be an example of a typical adverse consequence. In this work, we decided to investigate the link between oxidative stress and inflammation in animals exposed to FCA. BALB/c mice received either saline or FCA in doses 10-50 µl and were euthanized from one to three days after infection. Interleukins (IL) IL-2, IL-4 and tumor necrosis factor α (TNF-α) were determined in plasma. Ferric reducing antioxidant power (FRAP), malondialdehyde by thiobarbituric acid reactive substances assay (TBARS), reduced glutathione (GSH) and caspase-3 were measured in livers, muscles and other organs. We determined significant effect of FCA on TBARS and GSH in the livers. Beside this, TBARS were altered in muscles as well. Inflammation was confirmed by increased level of TNF-α. Taking the results into account, we infer that the harmful effect of FCA is mediated not only by inflammation but also by oxidative. This should be considered when pathological consequences of FCA are scored.

The perspective of caffeine and caffeine derived compounds in therapy

Caffeine (1,3,7-trimethylxanthine) is a plant secondary metabolite with a significant impact on multiple processes and regulatory pathways in the body. Though major part of the population meets caffeine via coffee, tea or chocolate, it has also an important role in pharmacology and it is used as a supplementary substance in medicaments. Currently, the ability of caffeine to ameliorate some neurodegenerative disorders is proved in some studies. This review describes basic data about caffeine including toxicity, pharmacokinetics, biological mechanism of the action, and metabolism. Beside this, promising applications of caffeine, new medicaments and derivatives are discussed. Relevant papers and inventions are depicted in the manuscript. Caffeine is a pharmacologically promising substance that deserves big consideration in the current research and development. The compound has several reasons to be an object of scientific interest and to be used for pharmacology purposes. Despite an extensive research for a long time, no significantly negative effects on human health were proved hence caffeine can be considered as a completely safe compound. The recent data about amelioration of neurodegenerative and other disorders are promising and deserving more work on the issue. ARTICLE HIGHLIGHTS: Caffeine is a purine alkaloid from plants and it has a broad use in current pharmacology. Caffeine is a competitive antagonist of neurotransmitter adenosine on adenosine receptors. The substance is added as a supplementary to drugs and food.Besides interfering on adenosine receptors, caffeine interacts with acetylcholinesterase, monoamine oxidase, phosphodiesterase, ryanodine receptors and others.Current research is devoted to the role of caffeine in neurodegenerative diseases and immunity alteration. New chemical compounds based on caffeine moiety are prepared (Tab. 4, Fig. 6, Ref. 149).

Ascorbic acid: an old player with a broad impact on body physiology including oxidative stress suppression and immunomodulation: a review

Ascorbic acid is a low molecular weight antioxidant well known as anti-scorbut acting vitamin C in humans, primates and guinea pigs. This review summarizes basic data about ascorbic acid in its physiological action point of view. It is divided into biochemistry of ascorbic acid synthesis, mechanism of antioxidant action and participation in anabolism, pharmacokinetics and excretion, exogenous ascorbic acid immunomodulatory effect and participation in infectious diseases, impact on irradiation and intoxication pathogenesis, and supplementary demands. The primary intention was to consider ascorbic acid not only as an antioxidant but also as a chemical compound affecting multiple pathways with a potential beneficial impact in many diseases and processes in human body.

[New methods increasing assisted reproduction results]

OBJECTIVE

The brief review of historical development and application of the assisted reproduction methods at our centre and the recent methods increasing the assisted reproduction results. The new mentioned methods are sperm selection before the intracytoplazmatic sperm injection (PICSI = preselected sperm intracytoplasmic injection) and continuous embryo development monitoring.

DESIGN

Review article.

Macrophage-assisted inflammation and pharmacological regulation of the cholinergic anti-inflammatory pathway

Macrophages play an important role in the immune system. They also participate in multiple processes including angiogenesis and triggering of inflammation. The present study summarizes pieces of knowledge on the importance of macrophages in disease, especially the inflammation. Special attention is paid to the cholinergic anti-inflammatory pathway (CAP) associated with the nicotinic acetylcholine receptor (nAChR) and the parasympathetic nervous system. The current pharmacological effectiveness in suppressing the inflammation in general and the septic shock in particular, is limited. CAP was discovered recently and it seems to be a suitable target for the development of new drugs. Moreover, available drugs binding to either nAChR or acetylcholinesterase (AChE) are candidates for either an inhibition or enhancement of CAP. Though the current scientific databases do not include all necessary data on the association of CAP with body functions and the research is quite intensive, the objective of the present review is to introduce the current trends and to critically evaluate CAP and macrophage-associated pathways.

Biochemical insight into soman intoxication and treatment with atropine, HI-6, trimedoxime, and K203 in a rat model

OBJECTIVE

The present experiment is based on biochemical assessment of nerve agent soman intoxication and atropine, respectively atropine and HI-6, trimedoxime or K203 treatment in rats.

BACKGROUND

Nerve agents are toxic substances irreversibly inhibiting enzyme acetylcholinesterase (AChE). Treatment is typically based on application of atropine and oxime reactivator. Atropine is able to protect overstimulation of muscarinic acetylcholine receptors. Application of oxime reactivator enable return of AChE activity and full suppression of intoxication.

METHODS

In a total, fifteen biochemical markers were assayed in plasma or blood of intoxicated animals. 42 rats were divided into 7 groups each 6 individuals. The first group was exposed to atropine; the second group was exposed to one LD50 of soman and atropine. The groups 3-5 were exposed in a same way as the second group and were treated with oxime reactivators: HI-6 (group 3), trimedoxime (4) and K203 (5). The sixth group was control treated with saline solution only. The last (seventh) group was intoxicated with soman only.

RESULTS

The most striking shifts were found for blood acetylcholinesterase and plasma creatinine, glucose, inorganic phosphate as well as uric acid. Lactate dehydrogenase and aspartate aminotransferase assays were useless due to soman interference.

CONCLUSION

It was demonstrated that treatment was able to protect poisoned animals from metabolic disorder represented by hyperglycemia and nephropathy represented by hyperuricemia and elevated creatinine. Soman exposure and treatment with the oxime reactivators and/or atropine contains quite complex and still not well understood side mechanisms (Tab. 2, Fig. 1, Ref. 25).

Pralidoxime--the gold standard of acetylcholinesterase reactivators--reactivation in vitro efficacy

OBJECTIVE

In this work, we aim to summarize the universality of this compound, its reactivation potential when different cholinesterase inhibitors are used.

BACKGROUND

Pralidoxime is considered as a gold standard of acetylcholinesterase reactivators--antidotes used in case of nerve agent poisonings. It has been commercially available for many years. However, several studies deem this oxime an old-fashion antidote.

METHODS

Pralidoxime was synthesized at our department. The reactivating efficacy was tested on 10% (w/v) rat brain homogenate that had been incubated with appropriate inhibitor for 30 minutes to reach 96% inhibition of AChE. Then, pralidoxime was added for 10 minutes. Measurements were performed at 25 degrees C, pH 8, and 10(-3) and 10(-5) M concentrations of AChE reactivators. The activities of brain AChE were measured by a potentiostatic method.

RESULTS

No sufficient reactivation was achieved at the concentration of 10(-5) M, which is a concentration that can be reached after administration of therapeutic doses. At a higher dose (10(-3) M), pralidoxime reactivated AChE inhibited by paraoxon, chlorpyrifos, Russian VX, VX and sarin.

CONCLUSION

From the obtained results, it is clear that pralidoxime seems to be a poor reactivator of AChE inhibited by organophosphorous AChE inhibitors and thus cannot be labeled as a universal reactivator (Tab. 1, Fig. 3, Ref. 31).

Piezoelectric immunosensor for the direct and rapid detection of Francisella tularensis

A novel immunosensing device based on a piezoelectric sensor for direct detection of the biological warfare agent Francisella tularensis was developed. This sensor includes mouse polyclonal antibody immobilized in a layer of protein A covalently linked to the gold electrode of the sensor. The immunosensor is able to detect F. tularensis with the limit of detection 10(5) CFU/mL with a typical measuring cycle > 5 min. The sensor was successfully evaluated for rapid detection of F. tularensis spikes in drinking water and milk; no deterioration of sensitivity in comparison with buffer solutions was observed. The proposed concept of a rapid measurement of microbial agents seems to be promising for evaluation of samples after short pre-cultivation enrichment.

CIRCADIAN BLOOD PRESSURE VARIABILITY AND EXERCISE THERAPY

The objective of this study was to find if there was a relationship between the time when cardiovascular rehabilitation was running in the patients after myocardial infarction and an average daily value of systolic and diastolic blood pressure at 7-day ambulatory blood pressure monitoring.Systolic and diastolic pressures significantly increased in patients who underwent cardiovascular rehabilitation in the morning from 9.00 a.m. to 10.15 a.m., and significantly decreased in those who did their physical exercise in the afternoon from 1.30 p.m. to 2.45 p.m., compared to their blood pressure values on days without rehabilitation.

ANALYSIS OF BAROREFLEX FUNCTION BY MEANS OF MATHEMATICAL MODEL

Re-evaluation of all functions of baroreflex by means of a simple mathematical model of circulation was the aim of the present study. The following states are modelled: 1. Rest. 2. Immediately after baroreceptor denervation. 3. Several days after denervation. 4. Physical exercise before denervation. 5. Physical exercise several days after denervation. Despite the same cardiac contractility and the same vasodilatation in working muscles as before denervation the cardiac output is by one third lower after baroreceptor denervation. In conclusion, a model simulation revealed the common regulation of blood pressure and blood volume by baroreflex and kidneys as a primary function of baroreflex.

Pergolide mesylate can improve sexual dysfunction in patients with Parkinson's disease: the results of an open, prospective, 6-month follow-up

One of the most disabling problems in males suffering from advanced Parkinson's disease (PD) is complex sexual dysfunction. The effect of dopamine replacement or dopaminergic stimulation on sexual dysfunction has been recently examined and described in patients treated by L-DOPA or apomorphine. Pergolide mesylate is another dopamine agonist with a known high affinity to hD(2S) subtype and a lower affinity to hD(2L) subtype of D2 dopaminergic receptors. It has been repeatedly shown to be a highly effective treatment of the complicated and advanced stages of PD. The current study has been designed to assess its efficacy in the treatment of sexual dysfunction, which frequently accompanies the complicated stage of PD in males. Fourteen male patients suffering from PD, each of whom had been treated with L-DOPA, and in whom additional treatment with peroral dopaminergic agonist (DA) was needed, were followed for a 6-month period. Pergolide mesylate (Permax) was given to each patient, and titrated to a total daily dose of 3 mg. All of the patients were taking L-DOPA. The assessments performed before the start of pergolide treatment consisted of a neurological examination, including Unified Parkinson's Disease Rating Scale (UPDRS) III and IV subscales scoring, Mini Mental State Examination (MMSE) scoring, the neuropsychological examination including Zung scale scoring to exclude depression, biochemical and haematological examinations including the examination of prolactine serum levels; and a sexological examination during which the patients filled-in the International Index of Erectile Function (IIEF) questionnaire. These examinations were repeated during the control assessments at months 1, 3 and 6. To compare the examination results, anova, Friedmann's anova (non-parametric) and Tukey post hoc tests were used. There were statistically significant differences between the values of UPDRS III motor subscale, UPDRS IV (complications of therapy) subscale and all subscales of IIEF when months 0 and 1 were compared with the results obtained at months 3 and 6. The differences between months 0 and 1 and months 3 and 6 (in these items) were virtually insignificant. In conclusion, pergolide substantially improved sexual function in the younger male patients who were still interested in sexual activities. In such cases, the introduction of pergolide might be a better choice than treatment with sildenafile, which usually meets several contraindications in common PD male population.

[Importance of regular screening for genital chlamydiosis in adolescents]

OBJECTIVE

Determination of prevalence of genital chlamydiosis in similar group of adolescents as in that examined two years ago. Comparison of the results with the previous ones to confirm positive impact of a repeated screening on drop of prevalence of the infection. Another objective is to make the epidemiological data on genital chlamydiosis in the countries of the "Eastern Block" more accurate, and at the same time to assess the most suitable screening method.

DESIGN

Prospective epidemiological study aimed at finding whether the repeated screening examinations of genital chlamydiosis in adolescents will result in decreased incidence of the infection.

SETTING

Veterinary Research Institute, Department of Clinical Microbiology of the Faculty Hospital, Regional Hygienic Station, Department of Gynecology and Obstetrics, Medical Faculty, Masaryk University, Brno.

METHODS

The groups under testing comprised male and female students of two secondary medical schools and one private grammar school older than 18 (n = 232, of which 33 were boys and 199 girls). Direct detection of C. trachomatis was carried out from the urinary sediment of the sample of morning urine using ligase reaction, polymerase chain reaction, ELISA and direct immunofluorescence.

RESULTS

Identical positive result of C. trachomatis detection by four methods was obtained 4 times, i.e. 1.7%. The result of LCR and PCR were positive identically (4 times), ELISA and IF were, besides the above results, positive in other 1 resp. 5 cases.

CONCLUSION

Screening examinations of genital chlamydiosis were performed in adolescents in the town of Brno. Morning samples of urine from 232 students of secondary schools were examined on C. trachomatis using the following methods: LCR, PCR, ELISA, and IF. The LCR and PCR were positive 4 times, ELISA 5 times, IF 9 times. Positive results by LCR and PCR were identical. ELISA and IF were positive in other cases. Noninvasive methods are suitable for screening of latent genital chlamydiosis and for estimation of its prevalence. The authors of the study recommend the ligase chain reaction (LCR) as a most suitable screening method.

[Magnetic resonance in urogynecology]

OBJECTIVE

The aim of the study was to review the use of the MRI in urogynaecology and to describe an original method for the construction of 3D computer models of pelvic floor.

DESIGN

Pilot study.

SETTING

Department of Obstetrics and Gynaecology, Institute of Sexuology, 1st Faculty of Medicine, Charles University, Prague, Department of Radiodiagnostics, Charles University, Hradec Králové.

METHODS

A review of the use of the MRI in urogynaecology was made. A new method was introduced for creation of computer 3D models of female pelvis based on the data obtained by the MRI.

RESULTS

Five complex computer models of the female pelvic organs and pelvic floor were created. Many so far estimated details were visualized.

CONCLUSION

The use of MRI in urogynaecology can bring important data about the functional anatomy of female pelvic floor.