Trimethylation of histone H3 on lysine 27 (H3K27me3) is a repressive posttranslational modification mediated by the histone methyltransferase EZH2. EZH2 is a component of the polycomb repressive ...complex 2 and is overexpressed in many cancers. In B-cell lymphomas, its substrate preference is frequently altered through somatic mutation of the EZH2 Y641 residue. Herein, we identify mutation of EZH2 A677 to a glycine (A677G) among lymphoma cell lines and primary tumor specimens. Similar to Y641 mutant cell lines, an A677G mutant cell line revealed aberrantly elevated H3K27me3 and decreased monomethylated H3K27 (H3K27me1) and dimethylated H3K27 (H3K27me2). A677G EZH2 possessed catalytic activity with a substrate specificity that was distinct from those of both WT EZH2 and Y641 mutants. Whereas WT EZH2 displayed a preference for substrates with less methylation unmethylated H3K27 (H3K27me0):me1:me2 kcat/Km ratio = 9:6:1 and Y641 mutants preferred substrates with greater methylation (H3K27me0:me1:me2 kcat/Km ratio = 1:2:13), the A677G EZH2 demonstrated nearly equal efficiency for all three substrates (H3K27me0:me1:me2 kcat/Km ratio = 1.1:0.6:1). When transiently expressed in cells, A677G EZH2, but not WT EZH2, increased global H3K27me3 and decreased H3K27me2. Structural modeling of WT and mutant EZH2 suggested that the A677G mutation acquires the ability to methylate H3K27me2 through enlargement of the lysine tunnel while preserving activity with H3K27me0/me1 substrates through retention of the Y641 residue that is crucial for orientation of these smaller substrates. This mutation highlights the interplay between Y641 and A677 residues in the substrate specificity of EZH2 and identifies another lymphoma patient population that harbors an activating mutation of EZH2.
More than 70% of new HIV infections in Asia occurred in eight countries in 2020: Cambodia, China, India, Indonesia, Myanmar, Nepal, Thailand, and Vietnam-with a rising incidence among men who have ...sex with men (MSM). The World Health Organization (WHO) recommends pre-exposure prophylaxis (PrEP) for those at risk of acquiring HIV, yet wide-scale implementation of PrEP, on a daily or event-driven basis, has been limited in Asia.
The Optima HIV model was applied to examine the impact of scaling-up PrEP over five-years to cover an additional 15% of MSM compared with baseline coverage, a target deemed feasible by regional experts. Based on behavioral survey data, we assume that covering 15% of higher-risk MSM will cover 30% of all sexual acts in this group. Scenarios to compare the impact of generic-brand daily dosing of PrEP with generic event-driven dosing (15 days a month) were modelled from the start of 2022 to the end of 2026. Cost-effectiveness of generic versus branded PrEP was also assessed for China, the only country with an active patent for branded, higher cost PrEP. The impact on new HIV infections among the entire population and cost per HIV-related disability-adjusted life year (DALY) averted were estimated from the beginning of 2022 to the end of 2031 and from 2022 to 2051.
If PrEP were scaled-up to cover an additional 15% of MSM engaging in higher-risk behavior from the beginning of 2022 to the end of 2026 in the eight Asian countries considered, an additional 100,000 (66,000-130,000) HIV infections (17%) and 300,000 (198,000-390,000) HIV-related DALYs (3%) could be averted over the 2022 to 2031 period. The estimated cost per HIV-related DALY averted from 2022 to 2031 ranged from US$600 for event-driven generic PrEP in Indonesia to US$34,400 for daily branded PrEP in Thailand. Over a longer timeframe from 2022 to 2051, the cost per HIV-related DALY averted could be reduced to US$100-US$12,700.
PrEP is a critical tool to further reduce HIV incidence in highly concentrated epidemics. Implementing PrEP in Asia may be cost-effective in settings with increasing HIV prevalence among MSM and if PrEP drug costs can be reduced, PrEP could be more cost-effective over longer timeframes.
Platelet rich plasma or PRP is a supraphysiologic concentrate of platelets derived by centrifugation and separation of whole blood components. Along with platelets and plasma, PRP contains various ...cell types including white blood cells (WBC)/leukocytes, both granulocytes (neutrophils, basophils, eosinophils) and agranulocytes (monocytes, lymphocytes). Researchers and clinicians have explored the application of PRP in wound healing and prevention of surgical wound infections, such as deep sternal wounds. We conducted this systematic literature review to evaluate the preclinical and clinical evidence for the antibacterial effect of PRP and its potential mechanism of action. 526 records were identified for screening. 34 unique articles were identified to be included in this literature review for data summary. Overall, the quality of the clinical trials in this review is low, and collectively qualify as Oxford level C. Based on the available clinical data, there is a clear trend towards safety of autologous PRP and potential efficacy in deep sternal wound management. The preclinical and bench data is very compelling. The application of PRP in treatment of wounds or prevention of infection with PRP is promising but there is a need for foundational bench and preclinical animal research to optimize PRP as an antibacterial agent, and to provide data to aid in the design and conduct of well-designed RCTs with adequate power to confirm antimicrobial efficacy of PRP in specific disease states and wound types.
Lenrispodun is a potent and highly selective inhibitor of phosphodiesterase (PDE) type 1, which is thought to prolong intracellular second messenger signaling within cortical and subcortical ...dopaminergic brain regions. This is the first study of a PDE1 inhibitor in healthy volunteers using behavioral and neuroimaging approaches to examine its effects on neural targets and to provide a safety and tolerability assessment. The primary objectives were to determine whether lenrispodun induces changes in BOLD fMRI signals in the inferior frontal gyrus (IFG) during the stop signal task, and the dorsal anterior insula (dAI) during the extinction phase of a fear conditioning/extinction task. Using a double-blind, placebo-controlled, within-subjects design, 26 healthy individuals (22 completed all fMRI sessions) received in random order a single oral dose of placebo, lenrispodun 1.0 milligram (mg) or lenrispodun 10.0 mg and completed several tasks in the scanner including the stop signal (n = 24) and fear conditioning/extinction tasks (n = 22). Prespecified region-of-interest analyses for the IFG and dAI were computed using linear mixed models. Lenrispodun induced increases in IFG activity during the stop signal task at 1.0 mg (Cohen's d = 0.63) but not 10.0 mg (Cohen's d = 0.07) vs. placebo. Lenrispodun did not induce changes in dAI activity during fear extinction at either dose. Exploratory outcomes revealed changes in cardiac interoception. Lenrispodun administration was well-tolerated. These results provide evidence that 1.0 mg lenrispodun selectively improved neural inhibitory control without altering fear extinction processing. Future investigations should determine whether lenrispodun improves inhibitory control in target populations such as individuals with attention deficit hyperactivity disorder. Trial registration: ClinicalTrials.gov identifier: NCT03489772.
Fungal infections are a rising threat to our immunocompromised patient population, as well as other nonimmunocompromised patients with various medical conditions. However, little progress has been ...made in the past decade to improve fungal diagnostics. To jointly address this diagnostic challenge, the Fungal Diagnostics Laboratory Consortium (FDLC) was recently created. The FDLC consists of 26 laboratories from the United States and Canada that routinely provide fungal diagnostic services for patient care. A survey of fungal diagnostic capacity among the 26 members of the FDLC was recently completed, identifying the following diagnostic gaps: lack of molecular detection of mucormycosis; lack of an optimal diagnostic algorithm incorporating fungal biomarkers and molecular tools for early and accurate diagnosis of
pneumonia, aspergillosis, candidemia, and endemic mycoses; lack of a standardized molecular approach to identify fungal pathogens directly in formalin-fixed paraffin-embedded tissues; lack of robust databases to enhance mold identification with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry; suboptimal diagnostic approaches for mold blood cultures, tissue culture processing for Mucorales, and fungal respiratory cultures for cystic fibrosis patients; inadequate capacity for fungal point-of-care testing to detect and identify new, emerging or underrecognized, rare, or uncommon fungal pathogens; and performance of antifungal susceptibility testing. In this commentary, the FDLC delineates the most pressing unmet diagnostic needs and provides expert opinion on how to fulfill them. Most importantly, the FDLC provides a robust laboratory network to tackle these diagnostic gaps and ultimately to improve and enhance the clinical laboratory's capability to rapidly and accurately diagnose fungal infections.
Children with inflammatory bowel disease (IBD) undergo imaging using ionizing radiation and may be exposed to high cumulative radiation. We hypothesized that children with IBD have high exposure to ...radiation from medical imaging.
An Institutional Review Board (IRB)-approved retrospective chart review from 2002-2008 was performed on all patients with IBD. Radiographic studies performed were recorded and exposure for each study was estimated.
A total of 117 children with IBD (86 Crohn's disease CD, 31 ulcerative colitis UC) were evaluated. The median current exposure was 15.1 mSv in CD and 7.2 mSv in UC (P = 0.005). Computed tomography (CT) scan and small bowel follow-through (SBFT) were responsible for 43% and 36% of all radiation exposures, respectively. The rate of radiation was higher in CD compared to UC (4.3 versus 2.2 mSv/yr). In CD, the rate of exposure was highest in the first 3 years of diagnosis (8.2 mSv/yr), and no different between the 3-5 year follow-up and 5+ year follow-up groups (3.8 versus 4.3 mSv/yr). Using the annual dose rate in those followed for more than 3 years, an estimated 47 out of 78 (60%) children (40 CD, 7 UC) would exceed 50 mSv by 35 years of age.
Radiation exposure from medical imaging is high in a subset of children diagnosed with IBD. Estimation of radiation exposure at age 35 suggests a significant portion of children with IBD will have high radiation exposure in their lifetime. Nonionizing imaging such as magnetic resonance imaging (MRI) and ultrasound should be offered to children with IBD as an alternative to current imaging that employs radiation.
Rationale
Medications are urgently needed to treat symptoms of drug withdrawal and mitigate dysphoria and psychiatric comorbidities that drive opioid abuse and relapse. ITI-333 is a novel molecule in ...development for treatment of substance use disorders, psychiatric comorbidities, and pain.
Objective
Characterize the preclinical profile of ITI-333 using pharmacological, behavioral, and physiological assays.
Methods
Cell-based assays were used to measure receptor binding and intrinsic efficacy of ITI-333; animal models were employed to assess effects on opioid reinstatement, precipitated oxycodone withdrawal, and drug abuse liability.
Results
In vitro, ITI-333 is a potent 5-HT
2A
receptor antagonist (K
i
= 8 nM) and a biased, partial agonist at μ-opioid (MOP) receptors (K
i
= 11 nM; lacking β-arrestin agonism) with lesser antagonist activity at adrenergic α
1A
(K
i
= 28 nM) and dopamine D
1
(K
i
= 50 nM) receptors. In vivo, ITI-333 blocks 5-HT
2A
receptor-mediated head twitch and MOP receptor-mediated effects on motor hyperactivity in mice. ITI-333 alone is a naloxone-sensitive analgesic (mice) which suppresses somatic signs of naloxone-precipitated oxycodone withdrawal (mice) and heroin cue-induced reinstatement responding without apparent tolerance or physical dependence after chronic dosing (rats). ITI-333 did not acutely impair gastrointestinal or pulmonary function (rats) and was not intravenously self-administered by heroin-maintained rats or rhesus monkeys.
Conclusions
ITI-333 acts as a potent 5-HT
2A
receptor antagonist, as well a biased MOP receptor partial agonist with low intrinsic efficacy. ITI-333 mitigates opioid withdrawal/reinstatement, supporting its potential utility as a treatment for OUD.
Background
Insulation defects are observed in 3–39 % of laparoscopic instruments. Electrosurgical injuries due to insulation defects or capacitive coupling remain an issue in laparoscopic surgery ...with a prevalence of 0.6–5 per thousand cases. Shielded instruments with active electrode monitoring (AEM) have been postulated to prevent these injuries. The benefit of these instruments has not been quantified. Most bowel injuries are unrecognized intra-operatively. Injury is revealed only after the patient exhibits peritonitis symptoms and surgical intervention to repair the bowel is required. These injuries may result in devastating and costly complications or mortality. The extent of bowel injury possible with commonly used generator settings and associated energy output has never been histologically defined. Our objectives in this experimental study were: quantify and compare the energy released through insulation defects or capacitive coupling with standard unshielded monopolar versus shielded instruments with (AEM), determine energy required to cause a visible burn, and relate the histological burn depth to a given amount of energy.
Methods
Ex vivo porcine jejunum was used for tissue testing. An oscilloscope measured energy output from three common electrosurgical generators at recommended power settings with standard or AEM instruments with insulation defects and in capacitive coupling scenarios. Presence of a visible burn was noted, and depth of tissue damage for a given amount of energy was measured histologically.
Results
All samples that received ≥3.8 J of energy had visible burns. As little as 10 J caused full wall thickness burns. 3.8 J was exceeded at the 30- and 50-W power settings in every experimental scenario using standard monopolar instruments; AEM instruments never approached this much energy.
Conclusions
Serious burn injury results from small amounts of energy leaked from standard instruments. AEM instruments appeared protective and did not leak sufficient energy to cause burn injuries to the bowel.
Abstract Background Bipolar devices are routinely used to seal blood vessels instead of sutures and clips. Recent work examining the impact of vascular proteins on bipolar seal performance found that ...collagen and elastin (CE) content within porcine arteries was a significant predictor of a vessel's burst pressure (VBPr). This study examined seal performance across a range of human blood vessels to investigate whether a similar relationship existed. In addition, we compared VBPr and CE content between porcine and human blood vessels. Our primary hypothesis is that higher collagen-to-elastin ratio will predict higher VBPr in human vasculature. Methods In six cadavers, 185 blood vessels from nine anatomic locations were sealed using a bipolar electrosurgical system. A linear mixed model framework was used to evaluate the impact of vessel diameter and CE content on VBPr. Results The effect of CE ratio on VBPr is modified by vessel size, with CE ratio having larger influence on VBPr in smaller diameter vessels. Seal burst pressure of vessels 2–5 mm in diameter was significantly associated with their CE content. Comparison of average VBPr between species revealed porcine carotid and iliac arteries (440–670 mmHg) to be the best vessel types for predicting the seal strength of most human blood vessels (420–570 mmHg) examined. Conclusions CE content significantly modified the seal strength of small to medium sized blood vessels but had limited impact on vessels >5 mm.
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