Testing fractional doses of COVID-19 vaccines.

Due to the enormous economic, health, and social costs of the COVID-19 pandemic, there are high expected social returns to investing in parallel in multiple approaches to accelerating vaccination. We argue there are high expected social returns to investigating the scope for lowering the dosage of some COVID-19 vaccines. While existing evidence is not dispositive, available clinical data on the immunogenicity of lower doses combined with evidence of a high correlation between neutralizing antibody response and vaccine efficacy suggests that half or even quarter doses of some vaccines could generate high levels of protection, particularly against severe disease and death, while potentially expanding supply by 450 million to 1.55 billion doses per month, based on supply projections for 2021. An epidemiological model suggests that, even if fractional doses are less effective than standard doses, vaccinating more people faster could substantially reduce total infections and deaths. The costs of further testing alternative doses are much lower than the expected public health and economic benefits. However, commercial incentives to generate evidence on fractional dosing are weak, suggesting that testing may not occur without public investment. Governments could support either experimental or observational evaluations of fractional dosing, for either primary or booster shots. Discussions with researchers and government officials in multiple countries where vaccines are scarce suggests strong interest in these approaches.

Chromogenic detection of telomere lengths in situ aids the identification of precancerous lesions in the prostate.

BACKGROUND: Telomeres are terminal chromosomal elements that are essential for the maintenance of genomic integrity. The measurement of telomere content provides useful diagnostic and prognostic information, and fluorescent methods have been developed for this purpose. However, fluorescent-based tissue assays are cumbersome for investigators to undertake, both in research and clinical settings. METHODS: A robust chromogenic in situ hybridization (CISH) approach was developed to visualize and quantify telomere content at single cell resolution in human prostate tissues, both frozen and formalin-fixed, paraffin-embedded (FFPE). RESULTS: This new assay (telomere chromogenic in situ hybridization ["Telo-CISH"]) produces permanently stained slides that are viewable with a standard light microscope, thus avoiding the need for specialized equipment and storage. The assay is compatible with standard immunohistochemistry, thereby allowing simultaneous assessment of histomorphology, identification of specific cell types, and assessment of telomere status. In addition, Telo-CISH eliminates the problem of autofluorescent interference that frequently occurs with fluorescent-based methods. Using this new assay, we demonstrate successful application of Telo-CISH to help identify precancerous lesions in the prostate by the presence of markedly short telomeres specifically in the luminal epithelial cells. CONCLUSIONS: In summary, with fewer restrictions on the types of tissues that can be tested, and increased histologic information provided, the advantages presented by this novel chromogenic assay should extend the applicability of tissue-based telomere length assessment in research and clinical settings.

Use of antimicrobials in pediatric wards of five Brazilian hospitals.

The use of antimicrobials (AMs) in pediatric infections is common practice and use may be inappropriate leading to antimicrobial resistance. Off-label AM use is also common in this group and can result in drug-related problems. There is lack of DUR data in Brazil and in Latin America, specially for AM pediatric use. The aim of this study was to describe the utilization of AMs in hospitalized children in five hospitals in Brazil. We conducted an observational study of the utilization of AMs in pediatric wards in hospitals in the states of Ceará (CE), Sergipe (SE), Rio de Janeiro (RJ), Rio Grande do Sul (RS) and the Federal District (DF). Data derived from patient medical records and prescriptions were collected over a six-month period in each hospital. The number of AMs used by each patient was recorded, and AM use was assessed using Days of therapy (DOT) and Length of therapy (LOT) per 1000 patient days according to different patient characteristics. Off-label (OL) use was described according to age. The study analyzed data from 1020 patients. The sex and age distributions were similar across the five hospitals. However, differences were found for comorbidities, history of ICU admission and length of hospital stay. The most common diseases were respiratory tract infections. There were wide variations in DOT/1000PD (278-517) and LOT/1000PD (265-390). AM utilization was highest in the hospital in SE. The consumption of second-generation penicillins and cephalosporins was high. The prevalence of OL use of AMs was higher for patients in the RJ hospital, in infants, in patients who underwent prolonged hospital stays, and in patients who used multiple AMs. The AM that showed the highest prevalence of OL use was azithromycin, in both oral and parenteral formulations. Overall AM use was high and showed differences in each setting, possibly influenced by local characteristics and by prescribing standards adopted by pediatricians.

Ongoing outbreak of hepatitis A associated with sexual transmission among men who have sex with men, Portugal, October 2023 to April 2024.

An outbreak of hepatitis A is ongoing in Portugal, with 71 confirmed cases from 7 October 2023 to 24 April 2024. Most cases are male, aged 18-44 years, with many identifying as men who have sex with men (MSM) and reported as suspected sexual transmission. Phylogenetic analysis identified the subgenotype IA, VRD 521-2016 strain, last observed in an MSM-associated multi-country outbreak in 2016 to 2018. We wish to alert colleagues in other countries to investigate potential similar spread.

Quantitative Evaluation of Non-basic Nitrogen-Containing Compounds in Petroleum-Derived Samples by Direct Injection ESI (-) Orbitrap MS.

The quantification of non-basic nitrogen-containing compounds (NCCs) in petroleum-derived samples has become a critical issue due to the undesirable effects of these compounds on the petroleum industry. In addition, there is a lack of analytical methods that allow the direct quantification of NCCs in these matrices. This paper provides strategies for obtaining quantitative information of NCCs in petroleum-derived samples using direct flow injection electrospray ionization (ESI) (-) Orbitrap mass spectrometry without fractionation steps. Benzocarbazole (BC) quantification was performed using the standard addition method. The method was validated, and all analytical parameters demonstrated satisfactory results in the matrix-mix. Paired Student's t-test exhibited the matrix effect (95% confidence level, p < 0.05). Limits of detection ranged from 2.94 to 14.91 µg L-1, and the limits of quantification ranged from 9.81 to 49.69 µg L-1. Intraday and interday accuracy and precision were not above 15%. Quantification of non-basic NCCs was carried out based on two approaches. In approach 1, the non-basic NCCs' total content in petroleum-derived samples was determined by the BC concentration and the total abundance correction. The method presented good performance with the average error of 21, 8.3, and 28% for crude oil, gas oil, and diesel samples, respectively. Approach 2 was based on the multiple linear regression model with regression significant at a 0.05 significance level within average relative errors of 16, 7.8, and 17% for the crude oil, gas oil, and diesel samples, respectively. Then, both approaches successfully predicted the quantification of non-basic NCCs by ESI direct flow injection.

Enlarged fistulotomy of the papilla as access to the biliary tract during ERCP.

BACKGROUND: Demonstration of access to the bile duct through Enlarged Papillary Fistulotomy, a method different from conventional fistulotomy. AIMS: Demonstration of the EFP technique with dissection in layers of the papilla for accessing the common bile duct, its efficiency and safety, rescue of cases of failure in cannulation and cases of access failure by EFP in the first attempt, facilitating cannulation in the second attempt. METHODS: Cross-sectional study, with retrospective data collection from 2233 ERCP exams with 528 EFP procedures, analysis of success and complications. RESULTS: 528 patients underwent EFP on the first attempt, with success in 465 cases (88.06%) and 63 failures (11.94%). Of these failures, 33 patients (52.38%) returned for a second EFP attempt, with success in 30 cases (90.9%) and failure in 3 cases (9.1%). Deep bile duct cannulation was achieved in 93.75% of EFP procedures, and cannulation failure occurred in 33 cases (6.25%). CONCLUSION: EFP showed efficiency in CBD cannulation, did not induce post-ERCP pancreatitis, no cases of perforation or false tract, but resulted in higher rates of minor bleeding, rescued cases of access failure by EFP, facilitated the posterior approach on the second attempt, it is safe, effective, low risk and associated with few comorbidities.

Multiplex immunohistochemical phenotyping of T cells in primary prostate cancer.

BACKGROUND: Most prostate cancers are "immune cold" and poorly responsive to immune checkpoint inhibitors. However, the mechanisms responsible for the lack of a robust antitumor adaptive immune response in the prostate are poorly understood, which hinders the development of novel immunotherapeutic approaches. AIMS: Most inflammatory infiltrates in the prostate are centered around benign glands and stroma, which can confound the molecular characterization of the antitumor immune response. We sought to analytically validate a chromogenic-based multiplex immunohistochemistry (IHC) approach applicable to whole slide digital image analysis to quantify T cell subsets from the tumor microenvironment of primary prostatic adenocarcinomas. As an initial application, we tested the hypothesis that PTEN loss leads to an altered antitumor immune response by comparing matched regions of tumors within the same individual with and without PTEN loss. MATERIALS & METHODS: Using the HALO Image Analysis Platform (Indica Labs), we trained a classifier to quantify the densities of eight T cell phenotypes separately in the tumor epithelial and stromal subcompartments. RESULTS: The iterative chromogenic approach using 7 different antibodies on the same slide provides highly similar findings to results using individually stained slides with single antibodies. Our main findings in carcinomas (benign removed) include the following: i) CD4+ T cells are present at higher density than CD8+ T cells; ii) all T cell subsets are present at higher densities in the stromal compartment compared to the epithelial tumor compartment; iii) most CD4+ and CD8+ T cells are PD1+; iv) cancer foci with PTEN loss harbored increased numbers of T cells compared to regions without PTEN loss, in both stromal and epithelial compartments; and v) the increases in T cells in PTEN loss regions were associated with ERG gene fusion status. DISCUSSION: This modular approach can apply to any IHC-validated antibody combination and sets the groundwork for more detailed spatial analyses. CONCLUSION: Iterative chromogenic IHC can be used for whole slide analysis of prostate tissue samples and can complement transcriptomic results including those using single cell and spatial genomic approaches.

An ab initio investigation of the adsorption properties of water on binary AlSi clusters.

The potential of doped aluminium clusters as catalysts for the water splitting reaction has attracted considerable scientific effort, however, the water-cluster interactions, which are a key step in the overall mechanism, are not fully understood. Here, we report an ab initio investigation of water adsorption on AlSi clusters at the MP2 level to elucidate the bonding and structural properties employing unary and binary 8- and 13-atom clusters, namely, Si8, Al2Si6, Al4Si4, Al8, Si13, Al2Si11, Al12Si, and Al13, which were selected by their relevance and energetic stability. We found that H2O binds via the O atom near to the on-top sites of the Si or Al atoms; in particular, there is a strong preference for the Al sites on the binary AlSi clusters, which is supported by the strong adsorption energy. Furthermore, we found a large enhancement of the adsorption energy on the Al2Si6 and Al2Si11 clusters, which can be explained by the cationic character of the Al site, which increases the Coulomb contribution to the Al+-O- interaction.

Structural and homotop optimization of neutral Al-Si nanoclusters.

The geometry and stability of aluminum-silicon alloys up to 13 atoms are investigated using electronic structure methods. The results agree well with available experimental data, while also predicting new potential candidates for detection. The exploration of the potential energy hypersurface of such particles is performed using both a thorough assessment of permutational isomers from selected structures and also using an unbiased genetic algorithm. It is shown that both approaches attain similar results for the specific cases analysed here. Several structures with non-magic number of electrons are shown to be very stable, such as Al4Si4, Al2Si6, Al2Si8, Al8Si4 and Al2Si11. A molecular orbitals analysis based in the spherical jellium model and deviations from it is performed for a better understanding of the properties of selected clusters.

Conformational dynamics of α-synuclein: insights from mass spectrometry.

The aggregation and deposition of α-synuclein in Lewy bodies is associated with the progression of Parkinson's disease. Here, Mass Spectrometry (MS) is used in combination with Ion Mobility (IM), chemical crosslinking and Electron Capture Dissociation (ECD) to probe transient structural elements of α-synuclein and its oligomers. Each of these reveals different aspects of the conformational heterogeneity of this 14 kDa protein. IM-MS analysis indicates that this protein is highly disordered, presenting in positive ionisation mode with a charge state range of 5 ≤z≤ 21 for the monomer, along with a collision cross section range of ∼1600 Å(2). Chemical crosslinking applied in conjunction with IM-MS captures solution phase conformational families enabling comparison with those exhibited in the gas phase. Crosslinking IM-MS identifies 3 distinct conformational families, Compact (∼1200 Å(2)), Extended (∼1500 Å(2)) and Unfolded (∼2350 Å(2)) which correlate with those observed in solution. ECD-Fourier Transform-Ion Cyclotron Resonance Mass Spectrometry (ECD-FT-ICR MS) highlights the effect of pH on α-synuclein structure, identifying the conformational flexibility of the N and C termini as well as providing evidence for structure in the core and at times the C terminus. A hypothesis is proposed for the variability displayed in the structural rearrangement of α-synuclein following changes in solution pH. Following a 120 h aggregation time course, we observe an increase in the ratio of dimer to monomer, but no gross conformational changes in either, beyond the significant variations that are observed day-to-day from this conformationally dynamic protein.

Impact of mobile and stationary phases on siRNA duplex stability in liquid chromatography.

Nucleic acid duplexes are typically analyzed in non-denaturing conditions. Melting temperature (Tm) is the property used to measure duplex stability; however, it is not known how the chromatographic conditions and mobile phase composition affect the duplex stability. We employed differential scanning calorimetry (DSC) method to measure the melting temperature of chemically modified silencing RNA duplex (21 base pairs, 0.15 mM duplex concentration) in mobile phases commonly used in reversed-phase, ion-pair reversed-phase, size exclusion and hydrophilic interaction chromatography. We investigated mobile phases consisting of ammonium acetate, alkylammonium ion-pairing reagents, alkali-ion chlorides, magnesium chloride, and additives including methanol, ethanol, acetonitrile and hexafluoroisopropanol. Increasing buffer concentration enhanced the duplex stability (Tm was 67.1 - 78.2 °C for 10-100 mM [Na+] concentration). The melting temperature decreases with the increase in cation size (70.2 °C in 10 mM [Li+], 68.1 °C in 10 mM [NH4+], 65.6 °C in 10 mM [Cs+], and 56.6 °C in 10 mM [triethylammonium+] solutions). Inclusion of 20 % of organic solvent in buffer reduced the melting temperature by 1-3 °C, and denaturation power increases in the order MeOH

Incidental finding of intramural splenic heterotopy in the colon mimicking subepithelial neoplasm: a case report.

AIM: The aim of this case report is describe an unprecedented case with histological and immunohistochemical diagnosis of splenic heterotopy in the colon using material obtained by endoscopic ultrasound-guided biopsy. BACKGROUND: Splenic heterotopia is a benign condition characterized by the implantation of splenic tissue in areas distant from its usual anatomical site, such as the peritoneum, omentum, mesentery, liver, pancreas, and subcutaneous tissue and, more rarely, in locations such as the colon and brain. It is generally associated with a history of splenic trauma or splenectomy and typically does not cause specific symptoms. CASE PRESENTATION: A 35-year-old white male patient who was healthy, with no history of trauma or splenectomy, but had a family history of colorectal neoplasia underwent colonoscopy for screening. The examination revealed a large bulge in the proximal descending colon, covered by normal-appearing mucosa. Endoscopic ultrasound-guided puncture was performed with a 22 gauge fine needle biopsy, and the histopathological and immunohistochemical analysis results were consistent with a heterotopic spleen. CONCLUSIONS: This is the first report of a primary intramural colic splenosis case with histological and immunohistochemical diagnosis of splenic heterotopia in the colon, using material obtained by endoscopic ultrasound and ultrasound-guided biopsy.

Bipolar androgen therapy plus nivolumab for patients with metastatic castration-resistant prostate cancer: the COMBAT phase II trial.

Cyclic high-dose testosterone administration, known as bipolar androgen therapy (BAT), is a treatment strategy for patients with metastatic castration-resistant prostate cancer (mCRPC). Here, we report the results of a multicenter, single arm Phase 2 study (NCT03554317) enrolling 45 patients with heavily pretreated mCRPC who received BAT (testosterone cypionate, 400 mg intramuscularly every 28 days) with the addition of nivolumab (480 mg intravenously every 28 days) following three cycles of BAT monotherapy. The primary endpoint of a confirmed PSA50 response rate was met and estimated at 40% (N = 18/45, 95% CI: 25.7-55.7%, P = 0.02 one-sided against the 25% null hypothesis). Sixteen of the PSA50 responses were achieved before the addition of nivolumab. Secondary endpoints included objective response rate (ORR), median PSA progression-free survival, radiographic progression-free survival (rPFS), overall survival (OS), and safety/tolerability. The ORR was 24% (N = 10/42). Three of the objective responses occurred following the addition of nivolumab. After a median follow-up of 17.9 months, the median rPFS was 5.6 (95% CI: 5.4-6.8) months, and median OS was 24.4 (95% CI: 17.6-31.1) months. BAT/nivolumab was well tolerated, resulting in only five (11%) drug related, grade-3 adverse events. In a predefined exploratory analysis, clinical response rates correlated with increased baseline levels of intratumoral PD-1 + T cells. In paired metastatic tumor biopsies, BAT induced pro-inflammatory gene expression changes that were restricted to patients achieving a clinical response. These data suggest that BAT may augment antitumor immune responses that are further potentiated by immune checkpoint blockade.

The Biginelli reaction with an imidazolium-tagged recyclable iron catalyst: kinetics, mechanism, and antitumoral activity.

The present work describes the synthesis, characterization, and application of a new ion-tagged iron catalyst. The catalyst was employed in the Biginelli reaction with impressive performance. High yields have been achieved when the reaction was carried out in imidazolium-based ionic liquids (BMI⋅PF6, BMI⋅NTf2, and BMI⋅BF4), thus showing that the ionic-liquid effects play a role in the reaction. Moreover, the ion-tagged catalyst could be recovered and reused up to eight times without any noticeable loss in activity. Mechanistic studies performed by using high-resolution electrospray-ionization quadrupole-time-of-flight mass (HR-EI-QTOF) spectrometry and kinetic experiments indicate only one reaction pathway and rule out the other two possibilities under the development conditions. The theoretical calculations are in accordance with the proposed mechanism of action of the iron catalyst. Finally, the 37 dihydropyrimidinone derivatives, products of the Biginelli reaction, had their cytotoxicity evaluated in assays against MCF-7 cancer cell linages with encouraging results of some derivatives, which were virtually non-toxic against healthy cell linages (fibroblasts).

Probing deep into the interaction of a fluorescent chalcone derivative and bovine serum albumin (BSA): an experimental and computational study.

In the present manuscript, a novel fluorescent chalcone derivative is synthesized and its photophysical properties are fully characterized. The designed fluorophore is applied as a probe to study protein-dye interactions with bovine serum albumin. Circular dichroism gave interesting results on the thermodynamics of the interaction. NMR spectroscopy, especially relaxation measurements, revealed the atoms in the chalcone derivative that interacts with the protein upon binding. Molecular docking calculations indicate that the most favourable binding sites are near the two tryptophan residues. Furthermore, ab initio and DFT calculations offer insights into the reactivity and physicochemical properties of this novel fluorophore.

Proteomic analysis of Cryptostegia grandiflora latex, purification, characterization, and biological activity of two osmotin isoforms.

Although latex fluids are found in >20,000 plant species, the biochemical composition and biological function of their proteins are still poorly explored. Thus, this work aimed to conduct a proteomic analysis of Cryptostegia grandiflora latex (CgLP) for subsequent purification and characterization of an antifungal protein. After 2D-SDS-PAGE and mass spectrometry, 27 proteins were identified in CgLP, including a polygalacturonase inhibitor, cysteine peptidases, pathogenesis-related proteins (PR-4), and osmotins. Then, two osmotin isoforms (CgOsm) were purified, and a unique N-terminal sequence was determined (1ATFDIRSNCPYTVWAAAVPGGGRRLDRGQTWTINVAPGTA40). The PCR products revealed a cDNA sequence of 609 nucleotides for CgOsm, which encoded a polypeptide with 203 amino acid residues. The structure of CgOsm has features of typical osmotin or thaumatin-like proteins (TLPs), such as 16 conserved Cys residues, REDDD and FF motifs, an acidic cleft, and three main domains. Atomic force microscopy (AFM) and bioinformatics suggested that CgOsm is associated with three chain units. This result was interesting since the literature describes osmotins and TLPs as monomers. AFM also showed that Fusarium falciforme spores treated with CgOsm were drastically damaged. Therefore, it is speculated that CgOsm forms pores in the membrane of these cells, causing the leakage of cytoplasmic content.

Chromogenic detection of telomere lengths in situ aids the identification of precancerous lesions in the prostate.

Telomeres are terminal chromosomal elements that are essential for the maintenance of genomic integrity. The measurement of telomere content provides useful diagnostic and prognostic information, and fluorescent methods have been developed for this purpose. However, fluorescent-based tissue assays are cumbersome for investigators to undertake, both in research and clinical settings. Here, a robust chromogenic in situ hybridization (CISH) approach was developed to visualize and quantify telomere content at single cell resolution in human prostate tissues, both frozen and formalin-fixed, paraffin-embedded (FFPE). This new assay ("Telo-CISH") produces permanently stained slides that are viewable with a standard light microscope, thus avoiding the need for specialized equipment and storage. The assay is compatible with standard immunohistochemistry, thereby allowing simultaneous assessment of histomorphology, identification of specific cell types, and assessment of telomere status. In addition, Telo-CISH eliminates the problem of autofluorescent interference that frequently occurs with fluorescent-based methods. Using this new assay, we demonstrate successful application of Telo-CISH to help identify precancerous lesions in the prostate by the presence of markedly short telomeres specifically in the luminal epithelial cells. In summary, with fewer restrictions on the types of tissues that can be tested, and increased histologic information provided, the advantages presented by this novel chromogenic assay should extend the applicability of tissue-based telomere length assessment in research and clinical settings.

Adverse Drug Reactions to Anti-infectives in Hospitalized Children: A Multicenter Study in Brazil.

INTRODUCTION: Adverse drug reactions (ADRs) to anti-infectives affect especially hospitalized children and contribute to increased morbidity, mortality, length of stay, and costs in healthcare systems. OBJECTIVE: To assess ADRs associated with anti-infective use in Brazilian hospitalized children. METHODS: A prospective cohort study was conducted in 5 public hospitals over 6 months. Children aged 0-11 years and 11 months who were hospitalized for more than 48 h and prescribed anti-infectives for over 24 h were included. RESULTS: A total of 1020 patients met the inclusion criteria. Of these, 152 patients experienced 183 suspected ADRs. Most reactions were related to the gastrointestinal system (65.6%), followed by skin reactions (18.6%). Most reactions were classified as probable causality (58.5%), moderate severity (61.1%), and unavoidable (56.2%). Our findings showed that ADRs were associated with increased length of stay (P < .001), increased length of therapy (P < .015), increased days of therapy (P = .038), and increased number of anti-infectives prescribed per patient (P < .001). CONCLUSION: Almost 15% of hospitalized children exposed to anti-infectives presented suspected ADRs. Their occurrence was classified as probable, of moderate severity, and unavoidable. ADRs were significantly influenced by the length of hospital stay and the number of anti-infectives prescribed per patient.

Mechanistic studies on Lewis acid catalyzed Biginelli reactions in ionic liquids: evidence for the reactive intermediates and the role of the reagents.

This paper describes the use of common Lewis acids supported in imidazolium-based ionic liquids as the catalysts to promote the Biginelli reaction. The ionic liquid effect and the reaction mechanism are discussed on the basis of nuclear magnetic resonance (NMR), electrospray ionization mass spectrometry (ESI-MS), and theoretical calculations. Indeed, the results showed that the ionic medium plays a fundamental role in the synthesis of biologically active dihydropyrimidinones due to the stabilization of the charged intermediates proposed in the mechanism. When conducted in an ionic liquid as solvent, the reaction mechanism is more complex than in other Lewis acid catalyzed Biginelli reactions.

Corrole isomers: intrinsic gas-phase shapes via traveling wave ion mobility mass spectrometry and dissociation chemistries via tandem mass spectrometry.

Corrole and four of its isomers with subtle structural changes promoted by exchange of nitrogen and carbon atoms in the corrole ring have been studied by traveling wave ion mobility mass spectrometry and collision induced dissociation experiments. Significant differences in shapes and charge distributions for their protonated molecules were found to lead to contrasting gas phase mobilities, most particularly for corrorin, the most "confused" isomer. Accordingly, corrorin was predicted by B3LYP/6-31g(d,p) and collisional cross section calculations to display the most compact tri-dimensional structure, whereas NCC4 and corrole were found to be the most planar isomers. Better resolution between the corrole isomers was achieved using the more polarizable and massive CO(2) as the drift gas. Sequential losses of HF molecules were found to dominate the dissociation chemistry of the protonated molecules of these corrole isomers, but their unique structures caused contrasting labilities towards CID, whereas NCC4 showed a peculiar and structurally diagnostic loss of NH(3), allowing its prompt differentiation from the other isomers.