-
PloS One 2024Meningiomas, the most prevalent primary benign intracranial tumors, often exhibit complicated levels of adhesion to adjacent normal tissues, significantly influencing...
Meningiomas, the most prevalent primary benign intracranial tumors, often exhibit complicated levels of adhesion to adjacent normal tissues, significantly influencing resection and causing postoperative complications. Surgery remains the primary therapeutic approach, and when combined with adjuvant radiotherapy, it effectively controls residual tumors and reduces tumor recurrence when complete removal may cause a neurologic deficit. Previous studies have indicated that slip interface imaging (SII) techniques based on MR elastography (MRE) have promise as a method for sensitively determining the presence of tumor-brain adhesion. In this study, we developed and tested an improved algorithm for assessing tumor-brain adhesion, based on recognition of patterns in MRE-derived normalized octahedral shear strain (NOSS) images. The primary goal was to quantify the tumor interfaces at higher risk for adhesion, offering a precise and objective method to assess meningioma adhesions in 52 meningioma patients. We also investigated the predictive value of MRE-assessed tumor adhesion in meningioma recurrence. Our findings highlight the effectiveness of the improved SII technique in distinguishing the adhesion degrees, particularly complete adhesion. Statistical analysis revealed significant differences in adhesion percentages between complete and partial adherent tumors (p = 0.005), and complete and non-adherent tumors (p<0.001). The improved technique demonstrated superior discriminatory ability in identifying tumor adhesion patterns compared to the previously described algorithm, with an AUC of 0.86 vs. 0.72 for distinguishing complete adhesion from others (p = 0.037), and an AUC of 0.72 vs. 0.67 for non-adherent and others. Aggressive tumors exhibiting atypical features showed significantly higher adhesion percentages in recurrence group compared to non-recurrence group (p = 0.042). This study validates the efficacy of the improved SII technique in quantifying meningioma adhesions and demonstrates its potential to affect clinical decision-making. The reliability of the technique, coupled with potential to help predict meningioma recurrence, particularly in aggressive tumor subsets, highlights its promise in guiding treatment strategies.
Topics: Humans; Meningioma; Elasticity Imaging Techniques; Female; Middle Aged; Male; Meningeal Neoplasms; Aged; Adult; Magnetic Resonance Imaging; Neoplasm Recurrence, Local; Tissue Adhesions; Algorithms
PubMed: 38917107
DOI: 10.1371/journal.pone.0305247 -
MBio Jun 2024causes cryptococcosis, one of the most prevalent fungal diseases, generally characterized by meningitis. There is a limited and not very effective number of drugs...
UNLABELLED
causes cryptococcosis, one of the most prevalent fungal diseases, generally characterized by meningitis. There is a limited and not very effective number of drugs available to combat this disease. In this manuscript, we show the host defense peptide mimetic brilacidin (BRI) as a promising antifungal drug against . BRI can affect the organization of the cell membrane, increasing the fungal cell permeability. We also investigated the effects of BRI against the model system by analyzing libraries of mutants grown in the presence of BRI. In , BRI also affects the cell membrane organization, but in addition the cell wall integrity pathway and calcium metabolism. experiments show BRI significantly reduces survival inside macrophages and partially clears lung infection in an immunocompetent murine model of invasive pulmonary cryptococcosis. We also observed that BRI interacts with caspofungin (CAS) and amphotericin (AmB), potentiating their mechanism of action against . BRI + CAS affects endocytic movement, calcineurin, and mitogen-activated protein kinases. Our results indicate that BRI is a novel antifungal drug against cryptococcosis.
IMPORTANCE
Invasive fungal infections have a high mortality rate causing more deaths annually than tuberculosis or malaria. Cryptococcosis, one of the most prevalent fungal diseases, is generally characterized by meningitis and is mainly caused by two closely related species of basidiomycetous yeasts, and . There are few therapeutic options for treating cryptococcosis, and searching for new antifungal agents against this disease is very important. Here, we present brilacidin (BRI) as a potential antifungal agent against . BRI is a small molecule host defense peptide mimetic that has previously exhibited broad-spectrum immunomodulatory/anti-inflammatory activity against bacteria and viruses. BRI alone was shown to inhibit the growth of , acting as a fungicidal drug, but surprisingly also potentiated the activity of caspofungin (CAS) against this species. We investigated the mechanism of action of BRI and BRI + CAS against . We propose BRI as a new antifungal agent against cryptococcosis.
PubMed: 38916308
DOI: 10.1128/mbio.01031-24 -
BioRxiv : the Preprint Server For... Jun 2024Group B (GBS) asymptomatically colonizes the vagina but can opportunistically ascend to the uterus and be transmitted vertically during pregnancy, resulting in neonatal...
UNLABELLED
Group B (GBS) asymptomatically colonizes the vagina but can opportunistically ascend to the uterus and be transmitted vertically during pregnancy, resulting in neonatal pneumonia, bacteremia and meningitis. GBS is a leading etiologic agent of neonatal infection and understanding the mechanisms by which GBS persists within the polymicrobial female genital mucosa has potential to mitigate subsequent transmission and disease. Type VIIb secretion systems (T7SSb) are encoded by Firmicutes and often mediate interbacterial competition using LXG toxins that contain conserved N-termini important for secretion and variable C-terminal toxin domains that confer diverse biochemical activities. Our recent work characterized a role for the GBS T7SSb in vaginal colonization and ascending infection but the mechanisms by which the T7SSb promotes GBS persistence in this polymicrobial niche remain unknown. Herein, we investigate the GBS T7SS in interbacterial competition and GBS niche establishment in the female genital tract. We demonstrate GBS T7SS-dependent inhibition of mucosal pathobiont both using predator-prey assays and in the murine genital tract and found that a GBS LXG protein encoded within the T7SS locus (herein named group B streptococcal L XG T oxin A ) that contributes to these phenotypes. We identify BltA as a T7SS substrate that is toxic to and upon induction of expression along with associated chaperones. Finally, we show that BltA and its chaperones contribute to GBS vaginal colonization. Altogether, these data reveal a role for a novel T7b-secreted toxin in GBS mucosal persistence and competition.
IMPORTANCE
Competition between neighboring, non-kin bacteria is essential for microbial niche establishment in mucosal environments. Gram-positive bacteria encoding T7SSb have been shown to engage in competition through export of LXG-motif containing toxins, but these have not been characterized in group B (GBS), an opportunistic colonizer of the polymicrobial female genital tract. Here, we show a role for GBS T7SS in competition with mucosal pathobiont , both and . We further find that a GBS LXG protein contributing to this antagonism is exported by the T7SS and is intracellularly toxic to other bacteria; therefore, we have named this protein group B streptococcal L XG T oxin A (BltA). Finally, we show that BltA and its associated chaperones promote persistence within female genital tract tissues These data reveal previously unrecognized mechanisms by which GBS may compete with other mucosal opportunistic pathogens to persist within the female genital tract.
PubMed: 38915665
DOI: 10.1101/2024.06.10.598350 -
BioRxiv : the Preprint Server For... Jun 2024The fungus is an opportunistic pathogen of people that reprograms its translatome to facilitate adaptation and virulence within the host. We studied the role of...
UNLABELLED
The fungus is an opportunistic pathogen of people that reprograms its translatome to facilitate adaptation and virulence within the host. We studied the role of Hog1/p38 in reprogramming translation during thermal stress adaptation, and found that this pathway acts on translation via crosstalk with the Gcn2 pathway, a well-studied regulator of general translation control. Using a combination of molecular assays and phenotypic analysis, we show that increased output from the Gcn2 pathway in a Hog1 deletion mutant is associated with rescue of thermal stress adaptation at both molecular and phenotypic scales. We characterize known outputs of the Hog1 pathway during thermal stress as either Gcn2-dependent or Gcn2-independent, and demonstrate that Hog1 activation regulates the Gcn2 pathway even in the absence of thermal stress. Finally, we implicate this phenomenon in another Hog1-regulated process, morphogenesis, and recapitulate Hog1-Gcn2 crosstalk in the distantly related fungal pathogen, Our results point to an important link between the stress response machinery and translation control, and clarify the etiology of phenotypes associated with Hog1 deletion. More broadly, this study highlights complex interplay between core conserved signal transduction pathways and the utility of molecular assays to better understand how these pathways are connected.
IMPORTANCE
is an opportunistic pathogen of people that causes deadly cryptococcal meningitis, which is is responsible for an estimated 19% of AIDS-related mortality. When left untreated, cryptococcal meningitis is uniformly fatal, and in patients receiving the most effective antifungal regimens, mortality remains high. Thus, there is a critical need to identify additional targets that play a role in adaptation to the human host and virulence. This study explores the role of the stress response kinases Hog1 and Gcn2 in thermoadaptation, which is pre-requisite for virulence. Our results show that compensatory signaling occurs via the Gcn2 pathway when Hog1 is deleted, and that disruption of both pathways increases sensitivity to thermal stress. Importantly, our study highlights the insufficiency of using single gene deletion mutants to study gene function, since many phenotypes associated with Hog1 deletion were driven by Gcn2 signaling in this background, rather than loss of direct Hog1 activity.
PubMed: 38915642
DOI: 10.1101/2024.06.11.598457 -
Scientific Reports Jun 2024Variations in the biomechanical stiffness of brain tumors can not only influence the difficulty of surgical resection but also impact postoperative outcomes. In a...
Variations in the biomechanical stiffness of brain tumors can not only influence the difficulty of surgical resection but also impact postoperative outcomes. In a prospective, single-blinded study, we utilize pre-operative magnetic resonance elastography (MRE) to predict the stiffness of intracranial tumors intraoperatively and assess the impact of increased tumor stiffness on clinical outcomes following microsurgical resection of vestibular schwannomas (VS) and meningiomas. MRE measurements significantly correlated with intraoperative tumor stiffness and baseline hearing status of VS patients. Additionally, MRE stiffness was elevated in patients that underwent sub-total tumor resection compared to gross total resection and those with worse postoperative facial nerve function. Furthermore, we identify tumor microenvironment biomarkers of increased stiffness, including αSMA + myogenic fibroblasts, CD163 + macrophages, and HABP (hyaluronic acid binding protein). In a human VS cell line, a dose-dependent upregulation of HAS1-3, enzymes responsible for hyaluronan synthesis, was observed following stimulation with TNFα, a proinflammatory cytokine present in VS. Taken together, MRE is an accurate, non-invasive predictor of tumor stiffness in VS and meningiomas. VS with increased stiffness portends worse preoperative hearing and poorer postoperative outcomes. Moreover, inflammation-mediated hyaluronan deposition may lead to increased stiffness.
Topics: Humans; Meningioma; Neuroma, Acoustic; Elasticity Imaging Techniques; Female; Male; Middle Aged; Biomarkers, Tumor; Aged; Prospective Studies; Adult; Meningeal Neoplasms; Treatment Outcome; Tumor Microenvironment; Magnetic Resonance Imaging
PubMed: 38914647
DOI: 10.1038/s41598-024-64597-1 -
PloS One 2024Tick-borne encephalitis (TBE) is usually diagnosed based on the presence of TBE virus (TBEV)-specific IgM and IgG antibodies in serum. However, antibodies induced by...
Tick-borne encephalitis (TBE) is usually diagnosed based on the presence of TBE virus (TBEV)-specific IgM and IgG antibodies in serum. However, antibodies induced by vaccination or cross-reactivity to previous flavivirus infections may result in false positive TBEV serology. Detection of TBEV RNA may be an alternative diagnostic approach to detect viral presence and circumvent the diagnostic difficulties present when using serology. Viral RNA in blood is commonly detectable only in the first viremic phase usually lasting up to two weeks, and not in the second neurologic phase, when the patients contact the health care system and undergo diagnostic work-up. TBEV RNA has previously been detected in urine in a few retrospective TBE cases in the neurologic phase, and furthermore RNA of other flaviviruses has been detected in patient saliva. In this study, blood, saliva and urine were collected from 31 hospitalised immunocompetent patients with pleocytosis and symptoms of aseptic meningitis and/or encephalitis, suspected to have TBE. We wanted to pursue if molecular testing of TBEV RNA in these patient materials may be useful in the diagnostics. Eleven of the 31 study patients were diagnosed with TBE based on ELISA detection of TBEV specific IgG and IgM antibodies. None of the study patients had TBEV RNA detectable in any of the collected patient material.
Topics: Humans; Encephalitis, Tick-Borne; Encephalitis Viruses, Tick-Borne; Saliva; RNA, Viral; Male; Female; Middle Aged; Adult; Aged; Immunoglobulin M; Immunoglobulin G; Antibodies, Viral; Aged, 80 and over; Immunocompetence; Hospitalization
PubMed: 38913668
DOI: 10.1371/journal.pone.0305603 -
JCI Insight Jun 2024
Topics: Neutrophils; Demyelinating Diseases; Humans; Meninges; Gray Matter; Male; Female; Middle Aged; Adult; Magnetic Resonance Imaging; Aged; Aging; Age Factors
PubMed: 38912582
DOI: 10.1172/jci.insight.183445 -
Journal of the Medical Library... Jan 2024In 1928, Alexander Fleming (1881-1955) identified penicillin, the world's first antibiotic. It was a chance discovery that could have easily been missed had Fleming not...
In 1928, Alexander Fleming (1881-1955) identified penicillin, the world's first antibiotic. It was a chance discovery that could have easily been missed had Fleming not taken a second look at a contaminated Petri dish. The discovery of penicillin marked a profound turning point in history as it was the first time deadly infections such as bacterial pneumonia, sepsis, diphtheria, meningitis, and puerperal fever after childbirth could be cured, and it paved the way for the development of additional antibiotics. The Alexander Fleming Laboratory Museum, one of several London Museums of Health and Medicine, is a reconstruction of Fleming's laboratory in its original location at St. Mary's Hospital. As if stepping back in time, visitors gain a glimpse into the man, his bacteriology work, and the events surrounding this important finding. For those unable to travel to London, this article provides a brief narrative of the fascinating story.
Topics: History, 20th Century; Humans; Penicillins; History, 19th Century; Anti-Bacterial Agents; London
PubMed: 38911526
DOI: 10.5195/jmla.2024.1780 -
Journal of Neuroendovascular Therapy 2024To report the rare case of a patient with a perianeurysmal cyst following stent-assisted coil embolization of an unruptured vertebral artery aneurysm.
OBJECTIVE
To report the rare case of a patient with a perianeurysmal cyst following stent-assisted coil embolization of an unruptured vertebral artery aneurysm.
CASE PRESENTATION
A 63-year-old woman underwent stent-assisted coil embolization for an unruptured vertebral artery aneurysm embedded in the brainstem (pons). Complete occlusion of the aneurysm was successfully achieved. However, subsequent magnetic resonance imaging (MRI) conducted 8 months after the procedure showed perilesional edematous changes surrounding the aneurysm, and at 20 months, cyst formation was observed in the vicinity of the aneurysm. Progressive enlargement of the cyst eventually led to the development of paralysis and dysphagia, necessitating cyst fenestration surgery. Although postoperative reduction in the cyst size was achieved, the patient experienced complications in the form of aspiration pneumonia and bacterial meningitis, which resulted in a life-threatening condition.
CONCLUSION
Aneurysms embedded in the brain parenchyma should be carefully followed up, recognizing the risk of perianeurysmal cyst formation after coil embolization.
PubMed: 38911484
DOI: 10.5797/jnet.cr.2023-0088 -
Open Medicine (Warsaw, Poland) 2024To investigate the clinical efficacy of dexamethasone (Dex) combined with isoniazid in tuberculous meningitis (TBM) and its effect on peripheral blood T cell subsets.
OBJECTIVE
To investigate the clinical efficacy of dexamethasone (Dex) combined with isoniazid in tuberculous meningitis (TBM) and its effect on peripheral blood T cell subsets.
METHODS
A total of 235 patients with TBM were divided into the control group (117 cases) and the observation group (118 cases). Both groups were given conventional treatment, the control group was further given isoniazid, and the observation group was further given Dex combined with isoniazid. The therapeutic effect and improvement of clinical symptoms were evaluated, peripheral blood T lymphocyte subsets and neurological function were observed, and patients' prognosis was evaluated.
RESULTS
The total effective rate of the observation group was higher. The recovery time of cerebrospinal fluid (CSF) pressure, CSF protein content, CSF cell count, and hospital stays in the observation group were shorter. The duration of cervicogenic headache, fever, vomiting, and coma in the observation group was shorter. CD3 and CD4/CD8 proportions in the observation group were higher, and CD8 proportion was lower. The NIHSS score and MRS score of the observation group were lower, as well as the incidence of adverse reactions.
CONCLUSION
Dex combined with isoniazid alleviates clinical symptoms and neurological abnormalities and regulates peripheral blood T cell subsets in TBM.
PubMed: 38911253
DOI: 10.1515/med-2024-0948