Laboratory Studies Research Articles

Performance of cementitious systems containing calcined clay in a chloride-rich environment: a review by TC-282 CCL

In this review by TC- 282 CCL, a comprehensive examination of various facets of chloride ingress in calcined clay-based concrete in aggressive chloride-rich environments is presented due to its significance in making reinforced concrete structures susceptible to chloride-induced corrosion damages. The review presents a summary of available literature focusing on materials characteristics influencing the chloride resistance of calcined clay-based concrete, such as different clay purity, kaolinite content and other clay minerals, underscoring the significance of pore refinement, pore solution composition, and chloride binding mechanisms. Further, the studies dealing with the performance at the concrete scale, with a particular emphasis on transport properties, curing methods, and mix design, are highlighted. Benchmarking calcined clay mixes with fly ash or slag-based concrete mixes that are widely used in aggressive chloride conditions instead of OPC is recommended. Such comparison could extend the usage of calcined clay as a performance-enhancing mineral admixture in the form of calcined clay or LC2 (limestone-calcined clay). The chloride diffusion coefficient in calcined clay concrete is reported to be significantly lower (about 5–10 times in most literature available so far) compared to OPC, and even lower compared to fly ash and slag-based concrete at early curing ages reported across recent literature made with different types of cements and concrete mixes. Limited studies dealing with reinforcement corrosion point out that calcined clay delays corrosion initiation and reduces corrosion rates despite the reduction in critical chloride threshold. Most of these results on corrosion performance are mainly from laboratory studies and warrant field evaluation in future. Finally, two case studies demonstrating the application of calcined clay-based concrete in real-world marine exposure conditions are discussed to showcase the promising potential of employing low-purity calcined clay-based concrete for reducing carbon footprint and improving durability performance in chloride exposure.

Rethinking hospital postoperative resource use: A national analysis of pediatric appendectomy patients admitted to children’s hospitals

BackgroundThe increased use of remote monitoring and telemedicine support may help alleviate the need for some of the postoperative inpatient hospital care and reduce health care costs, but little is known about current postoperative hospital resource use patterns. We aim to describe hospital resources use patterns in pediatric patients postappendectomy for complicated appendicitis and to evaluate the potential of earlier discharge with remote monitoring. MethodsThis was a retrospective cohort study using the Pediatric Health Information System database for patients who underwent laparoscopic appendectomy for complicated appendicitis between 2016 and 2021. Health care use/costs (antibiotics, intravenous fluids [proxy for diet], analgesics, laboratory studies, and imaging tests) were determined using administrative billing data. Potentially avoidable days were defined as nondischarge days without codes for intravenous opioid pain medication or intravenous fluids. Descriptive statistics and logistic regression were used. ResultsIn total, 24,165 patients were included: 8,300 patients (34.3%) had at least 1 potentially avoidable hospitalization day, totaling 13,970 days or 14.2% of all hospitalization days. Median hospitalization cost was $19,434 [$15,658–$25,157], with accommodation and operating room being the greatest contributors. Public insurance and minority races and ethnicities were associated with greater odds of potentially avoidable days. More than 80% of hospitalized patients had intravenous antibiotics through 10 days postoperatively. More than 20% received opioids daily. ConclusionsMore than one third of the patients who underwent laparoscopic appendectomy for complicated appendicitis could have had at least 1 potentially avoidable hospitalization day. Remote monitoring and telemedicine support should be explored and could help with earlier discharge and lower costs.

PAMAM dendrimers as mediators of dermal and transdermal drug delivery: a review.

Poly(amidoamine) dendrimers have been widely investigated as potential nanomaterials that can enhance the skin permeation of topically applied drugs. This article reviews the studies that have used dendrimers as penetration enhancers and examines the mechanisms by which enhancement is claimed. A wide range of studies have demonstrated that, in certain circumstances and for certain drugs, the incorporation of dendrimers into a topically applied formulation can significantly increase the amount of drug passing into and through the skin. In some cases, dendrimers offered little or no enhancement of skin permeation, suggesting that the drug-dendrimer interaction and the selection of a specific dendrimer were central to ensuring optimal enhancement of skin permeation. Significant interactions between dendrimers and other formulation components were also reported in some cases. Dendrimers offer substantial potential for enhancing drug delivery into and across the skin, putatively by mechanisms that include occlusion and changes to surface tension. However, most of these studies are conducted in vitro and limited progress has been made beyond such laboratory studies, some of which are conducted using membranes of limited relevance to humans, such as rodent skin. Thus, the outcomes and claims of such studies should be treated with caution.

Pediatric hypophosphatasia: avoid diagnosis missteps!

Hypophosphatasia (HPP) is the dento-osseous disorder caused by deactivating mutation(s) of ALPL, the gene that encodes the "tissue-nonspecific" isoenzyme of alkaline phosphatase (TNSALP). In HPP, 3 natural substrates of cell-surface TNSALP accumulate extracellularly; phosphoethanolamine (PEA), inorganic pyrophosphate (PPi), and pyridoxal 5'-phosphate (PLP). Hypophosphatasemia together with elevated plasma levels of PEA, PPi, and PLP comprise its biochemical signature. PPi can inhibit mineralization and in extracellular excess can impair bone and tooth hardening and perhaps explain weak muscle. Autosomal dominant or autosomal recessive inheritance from among more than 400 mutations of ALPL largely accounts for HPP's broad-ranging severity, greatest among all skeletal diseases. Pediatric HPP spans life-threatening perinatal and infantile forms, childhood forms, and odonto-HPP selectively featuring premature loss of deciduous teeth. ALPL gene testing and TNSALP supplementation therapy have bolstered familiarity with HPP, but there are new considerations for diagnosis. Herein, diagnosis of a boy's mild childhood HPP was delayed by missteps involving his medical and dental history, physical examination, radiographic findings, and clinical laboratory studies. We review how pediatric HPP is now identified. Prompt diagnosis while appreciating the broad-ranging severity of HPP underlies the safe and effective management of this inborn-error-of-metabolism.

Clinical characteristics and prognostic factor in juvenile dermatomyositis: data of the Spanish registry

BackgroundJuvenile Dermatomyositis (JDM) is the most common chronic idiopathic inflammatory myopathy in children. The diagnosis is clinical. Baseline laboratory and complementary studies trace the phenotype of these patients. The objective of this study was to describe epidemiological, clinical and laboratory characteristics at diagnosis of JDM patients included in the Spanish JDM registry, as well as to identify prognostic factors on these patients.MethodsWe retrospectively reviewed clinical features, laboratory tests, and complementary studies at diagnosis of JDM patients included on the Spanish JDM registry. These data were analyzed to assess whether there was a relationship with the development of complications and time to disease inactivity.ResultsOne hundred and sixteen patients from 17 Spanish paediatric rheumatology centres were included, 76 girls (65%). Median age at diagnosis was 7.3 years (Interquartile range (IQR) 4.5–10.2). All patients had pathognomonic skin lesions at the beginning of the disease. Muscle weakness was present in 86.2%. Median Childhood Muscle Assessment Scale was 34 (IQR 22–47). Twelve patients (34%) had dysphagia and 3,5% dysphonia. Anti-p155 was the most frequently detected myositis specific antibody, followed by anti-MDA5. Twenty-nine patients developed calcinosis and 4 presented with macrophage activation syndrome. 70% reached inactivity in a median time of 8.9 months (IQR 4.5–34.8). 41% relapsed after a median time of 14.4 months (IQR 8.6–22.8) of inactivity. Shorter time to treatment was associated with better prognosis (Hazard ratio (HR) = 0.95 per month of evolution, p = 0.02). Heliotrope rash at diagnosis correlates with higher risk of development complications.ConclusionsWe describe heliotrope rash as a risk factor for developing complications in our cohort of JDM patients, an easy-to-evaluate clinical sign that could help us to identify the group of patients we should monitor closely for this complication.

Legionella colonization and 3D spatial location within a Pseudomonas biofilm

Biofilms are known to be critical for Legionella settlement in engineered water systems and are often associated with Legionnaire’s Disease events. One of the key features of biofilms is their heterogeneous three-dimensional structure which supports the establishment of microbial interactions and confers protection to microorganisms. This work addresses the impact of Legionella pneumophila colonization of a Pseudomonas fluorescens biofilm, as information about the interactions between Legionella and biofilm structures is scarce. It combines a set of meso- and microscale biofilm analyses (Optical Coherence Tomography, Episcopic Differential Interference Contrast coupled with Epifluorescence Microscopy and Confocal Laser Scanning Microscopy) with PNA-FISH labelled L. pneumophila to tackle the following questions: (a) does the biofilm structure change upon L. pneumophila biofilm colonization?; (b) what happens to L. pneumophila within the biofilm over time and (c) where is L. pneumophila preferentially located within the biofilm? Results showed that P. fluorescens structure did not significantly change upon L. pneumophila colonization, indicating the competitive advantage of the first colonizer. Imaging of PNA-labelled L. pneumophila showed that compared to standard culture recovery it colonized to a greater extent the 3-day-old P. fluorescens biofilms, presumably entering in VBNC state by the end of the experiment. L. pneumophila was mostly located in the bottom regions of the biofilm, which is consistent with the physiological requirements of both bacteria and confers enhanced Legionella protection against external aggressions. The present study provides an expedited methodological approach to address specific systematic laboratory studies concerning the interactions between L. pneumophila and biofilm structure that can provide, in the future, insights for public health Legionella management of water systems.

Analysis of load distribution on the plate and lateral hinge of a valgus opening high tibial osteotomy during weight-bearing: a finite element analysis

IntroductionValgus high tibial osteotomy (HTO) is indicated for managing isolated medial knee osteoarthritis in a young patient with a metaphyseal deformity of the proximal tibia. In a medial opening HTO, maintaining the integrity of the lateral hinge is crucial for ensuring proper healing and correction retention. Using a locked plate to stabilize an HTO is common practice, allowing for earlier weight-bearing. The objective of this study was therefore to measure and track the mechanical load distribution on a locked fixation plate and the lateral hinge of an HTO using a finite element (FE) model simulating single-leg stance loading. HypothesisThe working hypothesis was that during weight-bearing, the plate and the lateral hinge absorb stress asymmetrically, predominantly on the plate. Material and methodsA numerical model of an HTO stabilized with a locked plate was developed based on the actual geometry of a healthy proximal tibia (using Autodesk Fusion 360 and Altair HyperWorks software). In this finite element simulation of loading, a mesh convergence study was conducted to optimize the accuracy of the numerical model results. The primary outcome measure was the maximum stress value in the affected areas (Von Mises stress, in MPa) of the plate and the lateral hinge. ResultsThe maximum stress intensity in the plate was approximately 20.29 MPa. The maximum stress intensity in the bony hinge was about 5.6 MPa. The results of the mesh convergence study for the hinge and the plate enabled defining the most suitable model for future FE studies: a 4 mm mesh for all model elements except for the high-stress area in the plate and the hinge, which were meshed with a 0.7 mm element size. This adaptation provided greater precision in the study. DiscussionThere is a distribution and allocation of stress both on the plate and the hinge, underlining the significance of the plate and the absolute necessity of preserving the hinge. Predictably, the plate absorbs the majority of the load, more than three times that of the hinge. ConclusionThe hypothesis is confirmed; however, additional studies would be necessary to validate these numerical results: an experimental component on instrumented cadaveric bones, as well as comparative studies of different fixation plates. Level of EvidenceV, expert opinion; controlled laboratory study.

Crown-of-thorns starfish complete their larval phase eating only nitrogen-fixing Trichodesmium cyanobacteria.

Cyanobacteria of the genus Trichodesmium form extensive blooms that supply new N to nutrient-poor marine ecosystems. Yet little is known about what eats Trichodesmium. In this laboratory study, we show that one of the greatest threats to coral reefs, predatory crown-of-thorns starfish (CoTS), Acanthaster sp., completes their larval phase feeding solely on Trichodesmium. We observed Trichodesmium erythraeum CMP1985 in the stomachs of larvae using florescence microscopy and traced the assimilation of nitrogen from labeled trichomes into larval tissues using stable isotopes. Some larvae fed T. erythraeum were morphologically ready to become benthic juveniles after 19 days. Given that Trichodesmium can be food for CoTS, reported increases in Trichodesmium could be a driving factor in the heightened frequency of CoTS population irruptions that have devastated coral reefs in past decades. Future studies could test this through investigating the diets of wild larvae and incorporating Trichodesmium abundance into models of CoTS population dynamics.

Molecular dynamics-guided optimization of BGM0504 enhances dual-target agonism for combating diabetes and obesity

The dual activation of glucagon-like peptide-1 receptor (GLP-1R) and glucose-dependent insulinotropic polypeptide receptor (GIPR) has emerged as a promising therapeutic strategy for managing type 2 diabetes and obesity. Tirzepatide, a dual agonist peptide, has exhibited superior clinical efficacy in glycemic and weight control compared to selective GLP-1R agonists. Nevertheless, the structural basis of Tirzepatide's extended half-life, attributed to an acylation side chain on the parent peptide, raises questions regarding its partial agonistic activity. Employing molecular dynamics simulations, we explored the dynamic processes of peptide-receptor interactions. We uncovered a crucial salt bridge between parent peptide and GLP-1R/GIPR at K20, a feature not discernible in cryo-electron microscopy structures. Building upon these insights, we developed an optimization strategy based on the parent peptide which involved repositioning the acylation side chain. The results of both in vitro and in vivo experiments demonstrated that the optimized peptide has twofold to threefold increase in agonistic activity compared to Tirzepatide while maintaining its extended half-life in plasma. This led to the design of BGM0504, which proved to be more effective than its predecessor, Tirzepatide, in both laboratory and animal studies.

Assessing lethal and sublethal effects of pesticides on honey bees in a multifactorial context

The registration of novel pesticides that are subsequently banned because of their unexpected negative effects on non-target species can have a huge environmental impact. Therefore, the pre-emptive evaluation of the potential effects of new compounds is essential. To this aim both lethal and sublethal effects should be assessed in a realistic scenario including the other stressors that can interact with pesticides. However, laboratory studies addressing such interactive effects are rare, while standardized laboratory-based protocols focus on lethal effects and not on sub-lethal effects.We propose to assess both lethal and sublethal effects in a multifactorial context including the other stressors affecting the non-target species. We tested this approach by studying the impact on honey bees of the insecticide sulfoxaflor in combination with a common parasite, a sub-optimal temperature and food deprivation. We studied the survival and the transcriptome of honey bees, to assess both the lethal and the potential sublethal effects of the insecticide, respectively. With this method we show that a field realistic concentration of sulfoxaflor in food does not affect the survival of honey bees; however, the significant impact on some key genes indicates that sublethal effects are possible in a realistically complex scenario.Moreover, our results demonstrate the feasibility and reliability of a novel approach to hazard assessment considering the interactive effects of pesticides. We anticipate our approach to be a starting point for a paradigm shift in toxicology: from an unifactorial, mortality-centered assessment to a multifactorial, comprehensive approach. This is something of the utmost importance to preserve pollination, thus contributing to the sustainability of our food production system.

Assessment of the accuracy and reliability of clinical thermometers for body temperature measurements at the hospital: A laboratory study

Assessment of the accuracy and reliability of clinical thermometers for body temperature measurements at the hospital: A laboratory study

Laboratory Study on Wave Attenuation by Elastic Mangrove Model with Canopy

This study evaluates the effectiveness of artificial Kandelia obovata forests in wave attenuation through physical model experiments conducted in a wave flume. The experiments meticulously replicated real-world hydrodynamic conditions and mangrove movement responses using the principles of gravitational and motion similarity, with a scaled 1:10 model of Kandelia obovata. Our approach included comparative experiments against a 1:100 gradient concrete slope to isolate the effects of seabed friction and flume wall reflections. The wave height was measured using strategically placed wave gauges. The findings indicated that the artificial Kandelia obovata forests significantly attenuated waves, with a decrease in the total attenuation capacity as the water depth increased from 2.75 m to 3.28 m under both regular and irregular waves. The elastic mangrove model with a canopy effect led to a 15% increase in wave attenuation over cylindrical models. Predictive models using multivariate nonlinear regression and back propagation neural networks showed that the latter provided a superior accuracy in estimating wave transmission coefficients

Collateral flow and pulsatility during large vessel occlusions: insights from a quantitative in vitro study

Acute ischemic stroke caused by large vessel occlusions is being increasingly treated with neurovascular interventions. The hemodynamics within the collateral system of the circle of Willis (CoW) hemodynamics play a fundamental role in therapy success. However, transient in vivo data on pathological collateral flow during large vessel occlusions are not available. Moreover, there are no flow models that accurately simulate the hemodynamic conditions in the CoW during large vessel occlusions. We used a circulatory loop to generate highly reproducible cerebrovascular-like flows and pressures and used non-invasive flow visualization and high-resolution flow and pressure measurements to acquire detailed, time-dependent hemodynamics inside an anatomical phantom of the CoW. After calibrating a physiological reference case, we induced occlusions in the 1. middle cerebral artery, 2. terminal carotid artery, and 3. basilar artery; and measured the left posterior communicating artery flow. Mean arterial pressure and pulse pressure remained unchanged in the different occlusion cases compared to the physiological reference case, while total cerebral flow decreased by up to 19%. In all three occlusion cases, reversed flow was found in the left posterior communicating artery compared to the reference case with different flow magnitudes and pulsatility index values. The experimental results were compared with clinical findings, demonstrating the capability of this realistic cerebrovascular flow setup. This novel cerebrovascular flow setup opens the possibility for investigating different topics of neurovascular interventions under various clinical conditions in controlled preclinical laboratory studies.

Perspective on Theoretical and Experimental Advances in Atmospheric Photochemistry.

Research that explores the chemistry of Earth's atmosphere is central to the current understanding of global challenges such as climate change, stratospheric ozone depletion, and poor air quality in urban areas. This research is a synergistic combination of three established domains: earth observation, for example, using satellites, and in situ field measurements; computer modeling of the atmosphere and its chemistry; and laboratory measurements of the properties and reactivity of gas-phase molecules and aerosol particles. The complexity of the interconnected chemical and photochemical reactions which determine the composition of the atmosphere challenges the capacity of laboratory studies to provide the spectroscopic, photochemical, and kinetic data required for computer models. Here, we consider whether predictions from computational chemistry using modern electronic structure theory and nonadiabatic dynamics simulations are becoming sufficiently accurate to supplement quantitative laboratory data for wavelength-dependent absorption cross-sections, photochemical quantum yields, and reaction rate coefficients. Drawing on presentations and discussions from the CECAM workshop on Theoretical and Experimental Advances in Atmospheric Photochemistry held in March 2024, we describe key concepts in the theory of photochemistry, survey the state-of-the-art in computational photochemistry methods, and compare their capabilities with modern experimental laboratory techniques. From such considerations, we offer a perspective on the scope of computational (photo)chemistry methods based on rigorous electronic structure theory to become a fourth core domain of research in atmospheric chemistry.

The Role of Gut Microbiota in the Neuroprotective Effects of Selenium in Alzheimer's Disease.

The objective of the present review was to provide a timely update on the molecular mechanisms underlying the beneficial role of Se in Alzheimer's disease pathogenesis, and discuss the potential role of gut microbiota modulation in this neuroprotective effect. The existing data demonstrate that selenoproteins P, M, S, R, as well as glutathione peroxidases and thioredoxin reductases are involved in regulation of Aβ formation and aggregation, tau phosphorylation and neurofibrillary tangles formation, as well as mitigate the neurotoxic effects of Aβ and phospho-tau. Correspondingly, supplementation with various forms of Se in cellular and animal models of AD was shown to reduce Aβ formation, tau phosphorylation, reverse the decline in brain antioxidant levels, inhibit neuronal oxidative stress and proinflammatory cytokine production, improve synaptic plasticity and neurogenesis, altogether resulting in improved cognitive functions. In addition, most recent findings demonstrate that these neuroprotective effects are associated with Se-induced modulation of gut microbiota. In animal models of AD, Se supplementation was shown to improve gut microbiota biodiversity with a trend to increased relative abundance of Lactobacillus, Bifidobacterium, and Desulfivibrio, while reducing that of Lachnospiracea_NK4A136, Rikenella, and Helicobacter. Moreover, the relative abundance of Se-affected taxa was significantly associated with Aβ accumulation, tau phosphorylation, neuronal oxidative stress, and neuroinflammation, indicative of the potential role of gut microbiota to mediate the neuroprotective effects of Se in AD. Hypothetically, modulation of gut microbiota along with Se supplementation may improve the efficiency of the latter in AD, although further detailed laboratory and clinical studies are required.

Preosteoblast Adhesion and Viability Study of Freeze-Dried Bovine Bone Block Scaffold Coated with Human Umbilical Cord Mesenchymal Stem Cell Secretome.

Combining a three-dimensional scaffold with growth factors before implantation is one method used to increase scaffold bioactivity in bone tissue engineering. The mesenchymal stem cell (MSC)-conditioned medium (CM), called secretome, contains many proteins and growth factors required for tissue repair and growth. This study evaluated the bioactivity of a bovine bone scaffold combined with the secretome of human umbilical cord MSCs (hUC-MSCs) by analyzing MC3T3-E1 cell adhesion and viability on the scaffold. This in vitro laboratory study evaluated the effect of hUC-MSC secretome applied to bovine bone scaffolds processed using various techniques on MC3T3-E1 cell adhesion and viability. The three experimental groups included deproteinized bovine bone mineral-secretome (DBBM-CM), freeze-dried bovine bone-secretome (FDBB-CM), and decellularized FDBB-CM, whereas the control group was treated with DBBM alone. The cell adhesion test was performed using the centrifugation method after 6 and 24 hours, whereas the cell viability test was conducted using the trypan blue exclusion method after 24, 48, and 72 hours. Cell attachment was visualized after 4',6-diamidino-2-phenylindole staining and viewed under inverted fluorescence microscopy. Statistical analyses were performed using one-way analysis of variance, followed by a post hoc test in cases of significant differences. Statistical analyses showed significantly greater adhesion of the preosteoblasts to the FDBB-CM scaffold at 6 hours (p = 0.002). The results of the adhesion test at 24 hours and the viability tests at all observation times showed no significant differences (p > 0.05). This study found that the average MC3T3-E1 cell adhesions and viabilities were highest for the FDBB-CM and DBBM-CM scaffolds. DBBM scaffolds with the secretome had better cell adhesion and viability than those without the secretome. The addition of MSC secretome increased bovine bone scaffold bioactivity especially in DBBM and FDBB scaffolds.

3-D X-ray computed tomography in the analyses of intraocular lenses explanted because of postoperative opacification.

X-ray computed tomography (X-ray CT) describes the acquisition and reconstruction of 2-D X-ray transmission images to create a 3-D representation of the specimen. The aim of this study was to use this technology in the analyses of intraocular lenses (IOLs) explanted because of optical opacification occurring postoperatively. John A. Moran Eye Center, and Utah Nanofab, University of Utah, Salt Lake City, Utah, USA. Laboratory Study. A hydrophilic acrylic and a silicone lens (the later from an eye with asteroid hyalosis) explanted because of postoperative calcification, as well as a polymethylmethacrylate (PMMA) lens explanted because of snowflake degeneration underwent analysis under gross and light microscopy. Then, they were attached to an appropriate support and scanned under a Zeiss Xradia Versa X-ray microscope. After data acquisition, data segmentation was performed with a commercially available program to separate image data into components. Morphology, size/volume, and specific location of calcified deposits on the surface or within the substance of explanted IOLs could be demonstrated by X-ray CT within the entire volume of each lens with high contrast and resolution. The PMMA lens showed multiple spaces/fissures in relation to Nd:YAG pitting of the optic, and what appeared to be sheets of delaminated PMMA material at different levels within the optic substance. The key benefit of X-ray CT is that it can be done without physically sectioning the specimen. This preliminary study demonstrates that this technology can be potentially useful in the imaging and analyses of explanted, opacified lenses.

The Role of Ginseng as an Anti-Asthmatic Agent

Objective: Ginseng is one of the most commonly used herbal medicines in Asia owing to its anti-inflammatory, cognitive, and immune effects. Many of these properties can be attributed to the ginsenosides, major pharmacological agents of ginseng. Ginsenosides influence the innate and humoral immune responses, and previous studies have described ginsenosides as potential therapeutic agents for respiratory disorders. Asthma affects over 300 million people worldwide and is underdiagnosed and undertreated, despite the availability of diagnostic tools and therapies. This review summarizes current studies on ginseng as an anti-asthmatic agent in murine models. Methods: PubMed, EMBASE, and Cochrane databases were used to conduct a systematic search of published literature until March 29, 2023. Eight full-text articles that examined the association between ginseng and asthma were reviewed. Results: The findings of this study demonstrate that Korean red ginseng, Korean white ginseng, and ginsenosides exert an anti-asthmatic effect, primarily through reduction in mucus cell hypersecretion, inflammatory cell infiltration, Th2 cytokines, and inhibition of inflammatory NFB and COX2 pathways. Conclusion: We suggest that ginseng has a therapeutic potential for the treatment of asthma. As this analysis utilized murine models, the anti-asthmatic effects of ginseng must be further supported by laboratory studies and clinical trials.

Bibliometric analysis of the top 100 most-cited articles concerning the use of propolis in dentistry

Aim: The objective of this bibliometric analysis was to identify and analyze the key characteristics of the 100 most-cited articles related to the use of propolis in dentistry. Methods: The search was conducted in the Web of Science Core Collection, and two independent reviewers selected the articles, excluding meeting articles. The number of citations for each article was compared across the Scopus and Google Scholar databases. The extracted data included the number and density of citations, year of publication, journal and impact factor, study design and theme, country and continent, institution, keywords, and authors. VOSviewer software was employed to generate collaborative network maps. Spearman correlation and Poisson regression analyses were performed on the data. Results: The number of citations ranged from 26 to 247, with a citation density varying between 1.08 and 20.00. Articles were published between 1991 and 2021, with laboratory studies (70%) and antimicrobial activity (39%) being the most prevalent study design and theme, respectively. The most discussed dental specialty was microbiology (49%). Rosalen PL (27%) emerged as the author with the highest number of articles, and the University of Campinas (Brazil) was the most prolific institution. Poisson regression indicated a declining trend in citations over the years, though literature reviews exhibited higher citation performance. Brazil contributed the highest percentage of articles (41%). Conclusion: In conclusion, the 100 most-cited articles predominantly comprised laboratory studies investigating the antimicrobial activity of propolis, primarily originating from Brazil, with notable emphasis on the University of Campinas.

TABES DORSALIS: IS THE DIAGNOSIS A CHALLENGE NOWADAYS?

Purpose: To present a rare case of neurosyphilis, the tertiary form of syphilitic infection, following adequate but belated treatment and manifesting with a variety of clinical signs and further progression to tabetic neurosyphilis. Known as the "great imitator", neurosyphilis is often misdiagnosed and underestimated. Materials/methods: A 48-year-old male patient was admitted to the Neurology clinic of UMHAT "Dr Georgi Stranski" Pleven, Bulgaria, with progressive neurological deficit including numbness in the lower limbs, imbalance and wide-based gait. The T2W- MRI showed abnormally high longitudinal signals at Th12-L1 level, consistent with transverse myelitis. CSF analysis revealed leucocytic pleocytosis, elevated proteins and normal glucose. The nerve conduction studies confirmed sensory motor polyneuropathy. Results: After treatment with intravenous aqueous crystalline (IV) penicillin, 2 million intravenously every 4 hours for 20 days, the sensory symptoms reduced. The coordination disturbances persisted, but the gate showed moderate improvement. Conclusions: The diagnosis of syphilitic myelitis, known as tabes dorsalis, is always complex, not only because of its rarity but because of its unique clinical presentation with multiple clinical symptoms, mimicking other more common neurological disorders. Though confirmation of the diagnosis needs a lot of laboratory and neuroimaging studies, the option of effective specific treatment is worth all the efforts.