Bilateral Inferior Rectus Schwannoma and Strabismus: A Case Report.

Schwannomas, also known as neurilemomas, are peripheral nerve sheath neoplasms. They can be sporadic or associated with genetic syndromes including neurofibromatosis type 2 (NF2). Schwannomas may lead to symptoms by exerting pressure on nearby structures, such as nerve and muscle fibers. In this study, we present the case of a 22-year-old female with a history of NF2 who, upon examination, presented with a visibly enlarged salmon-colored mass involving the left inferior rectus that she had since the age of 12 years. Ocular examinations revealed a small left hypertropia and exotropia in all gazes. Magnetic resonance imaging confirmed bilateral involvement of the inferior rectus muscles. She had a partial excisional biopsy of the mass involving the left inferior rectus muscle that confirmed the presence of schwannoma. This case highlights the importance of comprehensive evaluation of sensory and motor functions as well as considering orbital schwannomas in cases of strabismus, especially within the context of neurofibromatosis.

Pimavanserin reverses multiple measures of anxiety in a rodent model of post-traumatic stress disorder.

Pimavanserin is a highly selective 5-HT2A inverse agonist in current medical use. Prior studies suggest that 5-HT2A serotonin receptors may play a role in anxiety and emotional memory. Therefore, pimavanserin was tested in a rat model of PTSD to determine whether it might ameliorate PTSD-like symptoms. The lifetime prevalence of PTSD is estimated to be 125% higher in women than men. Consequently, in an effort to create a robust model of PTSD that was more representative of human PTSD prevalence, 20-week old female rats of the emotionally hyperreactive Lewis strain were used for these studies. The rats were single-housed and exposed twice to restraint stress coupled with predator odor or to a sham-stressed condition. Twenty days after the second stress or sham-stress exposure, rats were injected with saline alone or with 0.3 or 1.0 mg/kg pimavanserin, doses that were confirmed to substantially block 5-HT2A receptor activity in this study without causing any non-specific behavioral or adverse effects. One hour later, rats were tested for anxiety through acoustic startle response, the elevated plus-maze and three parameters of open field behavior. Five days later, blood was sampled for plasma corticosterone. The stressed/saline-injected rats had higher anxiety scores and corticosterone levels than sham-stressed/saline-injected rats. Pimavanserin significantly and generally dose-dependently reversed these persistent stress effects, but had no significant effect on the behavioral measures in normal, non-stressed rats. These results, consistent with a role for the 5-HT2A receptor, suggest that pimavanserin might have potential to reduce some consequences of traumatic stress.

Safety and microbiological activity of phage therapy in persons with cystic fibrosis colonized with Pseudomonas aeruginosa: study protocol for a phase 1b/2, multicenter, randomized, double-blind, placebo-controlled trial.

BACKGROUND: Bacteriophages (phages) are a promising anti-infective option for human disease. Major gaps remain in understanding their potential utility. METHODS: This is a randomized, placebo-controlled, double-blind study of a single dose of intravenous phage in approximately 72 clinically stable adult cystic fibrosis volunteers recruited from up to 20 US sites with Pseudomonas aeruginosa airway colonization. The single dose of phage consists of a mixture of four anti-pseudomonal phages. Six sentinel participants will be sequentially enrolled with dose escalation of the phage mixture by one log10 beginning with 4 × 107 plaque-forming units in an unblinded stage 1. If no serious adverse events related to the study product are identified, the trial will proceed to a double-blinded stage 2. In stage 2a, 32 participants will be randomly assigned to one of three phage dosages or placebo in a 1:1:1:1 allocation. An interim analysis will be performed to determine the phage dosage with the most favorable safety and microbiological activity profile to inform phage dosing in stage 2b. During stage 2b, up to 32 additional volunteers will be randomized 1:1 to the phage or placebo arm. Primary outcomes include (1) the number of grade 2 or higher treatment-emergent adverse events, (2) change in log10 P. aeruginosa total colony counts in sputum, and (3) the probability of a randomly selected subject having a more favorable outcome ranking if assigned to receive phage therapy versus placebo. Exploratory outcomes include (1) sputum and serum phage pharmacokinetics, (2) the impact of phage on lung function, (3) the proportion of P. aeruginosa isolates susceptible to the phage mixture before and after study product administration, and (4) changes in quality of life. DISCUSSION: This trial will investigate the activity of phages in reducing P. aeruginosa colony counts and provide insights into the safety profile of phage therapy. TRIAL REGISTRATION: ClinicalTrials.gov NCT05453578. Registered on 12 July 2022.

The Prevalence, Magnitude, and Reversibility of Elevated Liver Enzyme Activities in Hyperthyroid Cats Presenting for Iodine-131 Treatment.

OBJECTIVES: The primary objective of this study was to report the prevalence and magnitude of elevated liver enzyme activity in feline hyperthyroidism using a large cohort of cats presenting for iodine-131 treatment. The secondary objective was to determine if elevated liver enzyme activity was a reversible process following successful iodine-131 treatment. METHODS: Cases that presented for a single iodine-131 treatment were retrospectively reviewed. Short-term and long-term follow-up clinicopathologic data was then reviewed for the secondary objective. RESULTS: Two hundred seventeen hyperthyroid cats met the inclusion criteria for the primary objective. In total, 123/217 (56.7%) of the cats had at least one liver enzyme elevation on their chemistry panel, with alanine transaminase activity being the most common. All cats who were successfully treated with iodine-131 had liver enzyme activity within the reference range at short-term follow-up and long-term follow-up points. CONCLUSION AND RELEVANCE: Our study demonstrates that elevated liver values are common in cats presenting for iodine-131 treatment. Additionally, our study demonstrates that even when liver values are markedly elevated prior to treatment, the liver enzyme activity will return to normal after successful resolution of hyperthyroidism using iodine-131 treatment. Investigation into hepatobiliary disease and liver function tests for cats with a diagnosis of hyperthyroidism may be unnecessary as the liver values will likely return to normal with successful iodine-131 treatment.

Considerations for the Use of Phage Therapy in Clinical Practice.

Increasing antimicrobial resistance and medical device-related infections have led to a renewed interest in phage therapy as an alternative or adjunct to conventional antimicrobials. Expanded access and compassionate use cases have risen exponentially but have varied widely in approach, methodology, and clinical situations in which phage therapy might be considered. Large gaps in knowledge contribute to heterogeneity in approach and lack of consensus in many important clinical areas. The Antibacterial Resistance Leadership Group (ARLG) has convened a panel of experts in phage therapy, clinical microbiology, infectious diseases, and pharmacology, who worked with regulatory experts and a funding agency to identify questions based on a clinical framework and divided them into three themes: potential clinical situations in which phage therapy might be considered, laboratory testing, and pharmacokinetic considerations. Suggestions are provided as answers to a series of questions intended to inform clinicians considering experimental phage therapy for patients in their clinical practices.

Outcomes of Combined Transcatheter Aortic Valve Replacement and Peripheral Vascular Intervention in the United States.

OBJECTIVES: The aim of this study was to compare the prevalence and real-world outcomes of patients who require peripheral vascular intervention during the same hospitalization as transcatheter aortic valve replacement (TAVR) compared with TAVR alone. BACKGROUND: There are limited data on the prevalence and outcomes of combined TAVR and percutaneous peripheral vascular intervention. METHODS: All patients who underwent TAVR in 2016 and 2017 were identified using the Nationwide Readmissions Database. Outcomes of patients undergoing TAVR alone were compared with those of patients undergoing combined TAVR and peripheral intervention, TAVR and peripheral intervention with and without a history of peripheral artery disease, and alternative-access TAVR with transfemoral TAVR in individuals undergoing peripheral intervention. The primary outcome was in-hospital mortality. RESULTS: A total of 99,654 hospitalizations were identified, among which 4,397 patients (4.42%) underwent peripheral intervention during the same admission as TAVR. Patients who required peripheral intervention had increased mortality (4.2% vs 1.5%; P < 0.001), stroke (3.5% vs 1.8%; P < 0.001), acute kidney injury (17.6% vs 10.8%; P < 0.001), blood transfusion (16.0% vs 11.3%; P < 0.001), 30-day readmission (16.3% vs 12.1%; P < 0.001), median length of stay (4 days [IQR: 2-8 days] vs 3 days [IQR: 2-5 days]; P < 0.001), and hospitalization charges. Compared with patients undergoing peripheral intervention to facilitate transfemoral TAVR, alternative-access TAVR was associated with increased mortality (4.6% vs 3.0%; P = 0.036), acute kidney injury (22.7% vs 14.3%; P < 0.001), median length of stay (5 days [IQR: 3-10 days] vs 4 days [IQR: 2-7 days]; P < 0.001), and 30-day readmission (18.1% vs 15.5%; P = 0.012). CONCLUSIONS: Peripheral vascular intervention may be used to facilitate transfemoral access or as a bailout for vascular complications during TAVR. Combined TAVR and peripheral intervention is associated with an increased risk for adverse events, though outcomes are better compared with alternative-access TAVR using a nonfemoral approach.

Characteristics and Outcomes of Patients With Acute Coronary Syndrome Who Received Percutaneous Coronary Intervention During Snowy Days.

BACKGROUND: Acute coronary syndrome (ACS) is affected by several weather conditions. Studies from different geographical locations have yielded mixed results regarding the outcomes of patients presenting with ACS during snowy days, and we aim to report the Cleveland Clinic experience. METHODS: Patients who presented with an ACS and underwent percutaneous coronary intervention (PCI) from July 1, 2009 to September 30, 2017 were divided into ST-segment elevation myocardial infarction (STEMI), and non-ST segment elevation ACS (NSTE-ACS). According to snowy day arrival, we compared in-hospital mortality, culprit lesion anatomy, and door-to-balloon (DTB) time (in STEMI patients). Findings were confirmed in propensity-score matched cohorts. RESULTS: A total of 6878 patients were included: 1608 patients with STEMI (139 snowy-day vs 1469 non-snowy day PCIs) and 5270 NSTE-ACS (419 snowy-day vs 4851 non-snowy day PCIs). Right coronary artery territories accounted for most of the stented culprit lesions in all STEMI and NSTE-ACS snowy-day PCIs. While left anterior descending artery lesions were predominant in NSTE-ACS non-snowy day PCIs. There was no difference in in-hospital mortality between the snowy-day vs non-snowy day groups (4.3% vs 4.5% in the STEMI group [P=.92] and 1.2% vs 1.7% in the NSTE-ACS group [P=41]). In STEMI patients, mean DTB times were similar (43 ± 55.1 minutes vs 46.7 ± 59.6 minutes; P=.61), which remained true after hours, during weekends and holidays. Outcomes were similar in propensity-score matched cohorts. CONCLUSION: At our institution, snowy days do not seem to affect in-patient mortality. In STEMI patients, DTB times were similar in those who underwent PCI regardless of the snowfall.

Simultaneous Pulmonary Artery Pressure and Left Ventricle Stroke Volume Assessment Predicts Adverse Events in Patients With Pulmonary Embolism.

Background Certain echocardiographic parameters may serve as early predictors of adverse events in patients with hemodynamically compromising pulmonary embolism (PE). Methods and Results An observational analysis was conducted for patients with acute pulmonary embolism evaluated by a Pulmonary Embolism Response Team (PERT) between 2014 and 2020. The performance of clinical prediction algorithms including the Pulmonary Embolism Severity Index and Carl Bova score were compared using a ratio of right ventricle and left ventricle hemodynamics by dividing the pulmonary artery systolic pressure by the left ventricle stroke volume. The primary outcome of in-hospital mortality, cardiac arrest, and the need for advanced therapies was evaluated by univariate and multivariable analyses. Of the 343 patients meeting the inclusion criteria, 215 had complete data. Pulmonary artery systolic pressure/left ventricle stroke volume was a clear predictor of the primary end point (odds ratio [OR], 2.31; P=0.005), performing as well or better than the Pulmonary Embolism Severity Index (OR, 1.43; P=0.06) or the Bova score (OR, 1.28; P=0.01). Conclusions This study is the first study to demonstrate the utility of early pulmonary artery systolic pressure/left ventricle stroke volume in predicting adverse clinical events in patients with acute pulmonary embolism. Pulmonary artery systolic pressure/left ventricle stroke volume may be a surrogate marker of ventricular asynchrony in high-risk pulmonary embolism and should be prognostically evaluated.

A Pragmatic Approach to Weaning Temporary Mechanical Circulatory Support: A State-of-the-Art Review.

Temporary mechanical circulatory support (TMCS) provides short-term support to patients with or at risk of refractory cardiogenic shock. Although indications, contraindications, and complications of TMCS may guide device selection, optimal strategies for device weaning and explant remain poorly defined. Under the revised adult heart allocation policy implemented by the United Nations for Organ Sharing in October 2018, rejustification of heart transplant listing status includes demonstrating TMCS dependency with attempted device wean trials. However, standardized device-specific weaning and explant protocols have not been proposed or evaluated. This review highlights when to use percutaneous TMCS in cardiogenic shock, with a focus on weaning and explant considerations. Terminology for important concepts that guide device escalation, de-escalation, and explantation have been defined. Clinical, hemodynamic, metabolic, and imaging features have been defined, which can guide a tailored approach to TMCS weaning and explant based on the approach used at the Cleveland Clinic. A narrative review of published studies that have reported TMCS weaning protocols and survey results of member centers from CS-MCS working group centers is also provided. Future research is needed to better understand optimal timing and implementation of standardized protocols to achieve successful TMCS weaning and explant.

Iterative Exponential Growth of Oxygen-Linked Aromatic Polymers Driven by Nucleophilic Aromatic Substitution Reactions.

This work presents the first transition metal-free synthesis of oxygen-linked aromatic polymers by integrating iterative exponential polymer growth (IEG) with nucleophilic aromatic substitution (SNAr) reactions. Our approach applies methyl sulfones as the leaving groups, which eliminate the need for a transition metal catalyst, while also providing flexibility in functionality and configuration of the building blocks used. As indicated by 1) 1H-1H NOESY NMR spectroscopy, 2) single-crystal X-ray crystallography, and 3) density functional theory (DFT) calculations, the unimolecular polymers obtained are folded by nonclassical hydrogen bonds formed between the oxygens of the electron-rich aromatic rings and the positively polarized C-H bonds of the electron-poor pyrimidine functions. Our results not only introduce a transition metal-free synthetic methodology to access precision polymers but also demonstrate how interactions between relatively small, neutral aromatic units in the polymers can be utilized as new supramolecular interaction pairs to control the folding of precision macromolecules.

Fc-Optimized Anti-CCR8 Antibody Depletes Regulatory T Cells in Human Tumor Models.

FOXP3+ regulatory T cells (Treg) play a critical role in mediating tolerance to self-antigens and can repress antitumor immunity through multiple mechanisms. Therefore, targeted depletion of tumor-resident Tregs is warranted to promote effective antitumor immunity while preserving peripheral homeostasis. Here, we propose the chemokine receptor CCR8 as one such optimal tumor Treg target. CCR8 was expressed by Tregs in both murine and human tumors, and unlike CCR4, a Treg depletion target in the clinic, CCR8 was selectively expressed on suppressive tumor Tregs and minimally expressed on proinflammatory effector T cells (Teff). Preclinical mouse tumor modeling showed that depletion of CCR8+ Tregs through an FcyR-engaging anti-CCR8 antibody, but not blockade, enabled dose-dependent, effective, and long-lasting antitumor immunity that synergized with PD-1 blockade. This depletion was tumor Treg-restricted, sparing CCR8+ T cells in the spleen, thymus, and skin of mice. Importantly, Fc-optimized, nonfucosylated (nf) anti-human CCR8 antibodies specifically depleted Tregs and not Teffs in ex vivo tumor cultures from primary human specimens. These findings suggest that anti-CCR8-nf antibodies may deliver optimal tumor-targeted Treg depletion in the clinic, providing long-term antitumor memory responses while limiting peripheral toxicities. SIGNIFICANCE: These findings show that selective depletion of regulatory T cells with an anti-CCR8 antibody can improve antitumor immune responses as a monotherapy or in combination with other immunotherapies. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/81/11/2983/F1.large.jpg.

Clinical Impact of Contralateral Carotid Occlusion in Patients Undergoing Carotid Artery Revascularization.

BACKGROUND: The presence of a contralateral carotid occlusion (CCO) is an established high-risk feature for patients undergoing carotid endarterectomy (CEA) and is traditionally an indication for carotid artery stenting (CAS). Recent observational data have called into question whether CCO remains a high-risk feature for CEA. OBJECTIVES: The purpose of this study was to determine the clinical impact of CCO among patients undergoing CEA and CAS in a contemporary nationwide registry. METHODS: All patients undergoing CEA or CAS from 2007 to 2019 in the NCDR CARE (National Cardiovascular Data Registry Carotid Artery Revascularization and Endarterectomy) and PVI (Peripheral Vascular Intervention) registries were included. The primary exposure was the presence of CCO. The outcome was a composite of in-hospital death, stroke, and myocardial infarction. Multivariable logistic regression and inverse-probability of treatment weighting were used to compare outcomes. RESULTS: Among 58,423 patients who underwent carotid revascularization, 4,624 (7.9%) had a CCO. Of those, 68.9% (n = 3,185) underwent CAS and 31.1% (n = 1,439) underwent CEA. The average age of patients with CCO was 69.5 ± 9.7 years, 32.6% were women, 92.8% were Caucasian, 51.7% had a prior transient ischemic attack or stroke, and 45.4% presented with symptomatic disease. Over the study period, there was a 41.7% decrease in the prevalence of CCO among patients who underwent carotid revascularization (p < 0.001), but CAS remained the primary revascularization strategy. Unadjusted composite outcome rates were lower in patients with CCO after CAS (2.1%) than CEA (3.6%). Following adjustment, CCO was associated with a 71% increase in the odds of an adverse outcome after CEA (95% confidence interval: 1.27 to 2.30; p < 0.001) compared with no increase after CAS (adjusted odds ratio: 0.94; 95% confidence interval: 0.72 to 1.22; p = 0.64). CONCLUSIONS: CCO remains an important predictor of increased risk among patients undergoing CEA, but not CAS.

Phosphorylation of the Retinal Ribbon Synapse Specific t-SNARE Protein Syntaxin3B Is Regulated by Light via a Ca2 +-Dependent Pathway.

Neurotransmitter release at retinal ribbon-style synapses utilizes a specialized t-SNARE protein called syntaxin3B (STX3B). In contrast to other syntaxins, STX3 proteins can be phosphorylated in vitro at T14 by Ca2+/calmodulin-dependent protein kinase II (CaMKII). This modification has the potential to modulate SNARE complex formation required for neurotransmitter release in an activity-dependent manner. To determine the extent to which T14 phosphorylation occurs in vivo in the mammalian retina and characterize the pathway responsible for the in vivo phosphorylation of T14, we utilized quantitative immunofluorescence to measure the levels of STX3 and STX3 phosphorylated at T14 (pSTX3) in the synaptic terminals of mouse retinal photoreceptors and rod bipolar cells (RBCs). Results demonstrate that STX3B phosphorylation at T14 is light-regulated and dependent upon the elevation of intraterminal Ca2+. In rod photoreceptor terminals, the ratio of pSTX3 to STX3 was significantly higher in dark-adapted mice, when rods are active, than in light-exposed mice. By contrast, in RBC terminals, the ratio of pSTX3 to STX3 was higher in light-exposed mice, when these terminals are active, than in dark-adapted mice. These results were recapitulated in the isolated eyecup preparation, but only when Ca2+ was included in the external medium. In the absence of external Ca2+, pSTX3 levels remained low regardless of light/dark exposure. Using the isolated RBC preparation, we next showed that elevation of intraterminal Ca2+ alone was sufficient to increase STX3 phosphorylation at T14. Furthermore, both the non-specific kinase inhibitor staurosporine and the selective CaMKII inhibitor AIP inhibited the Ca2+-dependent increase in the pSTX3/STX3 ratio in isolated RBC terminals, while in parallel experiments, AIP suppressed RBC depolarization-evoked exocytosis, measured using membrane capacitance measurements. Our data support a novel, illumination-regulated modulation of retinal ribbon-style synapse function in which activity-dependent Ca2+ entry drives the phosphorylation of STX3B at T14 by CaMKII, which in turn, modulates the ability to form SNARE complexes required for exocytosis.

Size-selective Catalytic Polymer Acylation with a Molecular Tetrahedron.

Selective catalysis at the molecular level represents a cornerstone of chemical synthesis. However, it still remains an open question how to elevate tunable catalysis to larger length scales to functionalize whole polymer chains in a selective manner. We now report a hydrazone-linked tetrahedron with wide openings, which acts as a catalyst to size-selectively functionalize polydisperse polymer mixtures. Our experimental and computational evidence supports a dual role of the hydrazone-linked tetrahedron. To accelerate functionalization of the polymer substrates, the tetrahedron (i) unfolds the polymer substrates and/or breaks the polymer aggregates as well as (ii) enables target sites (amino groups) on the polymers to coordinate with catalytic units (triglyme) attached to the tetrahedron. With the tetrahedron as the catalyst, we find that the reactivity of the shorter polymers increases selectively. Our findings enable the possibility to engineer hydrolytically stable molecular polyhedra as organocatalysts for size-selective polymer modification.

Selective Monofunctionalization Enabled by Reaction-History-Dependent Communication in Catalytic Rotaxanes.

Selective monofunctionalization of substrates with distant, yet equally reactive functional groups is difficult to achieve, as it requires the second functional group to selectively modulate its reactivity once the first functional group has reacted. We now show that mechanically interlocked catalytic rings can effectively regulate the reactivity of stoppering groups in rotaxanes over a distance of about 2 nm. Our mechanism of communication is enabled by a unique interlocked design, which effectively removes the catalytic rings from the substrates by fast dethreading as soon as the first reaction has taken place. Our method not only led to a rare example of selective monofunctionalization, but also to a "molecular if function". Overall, the study presents a way to get distant functional groups to communicate with each other in a reaction-history-dependent manner by creating linkers that can ultimately perform logical operations at the molecular level.

Impella RP as a bridge to cardiac transplant for refractory late right ventricular failure in setting of left ventricular assist device.

Right ventricular (RV) failure remains a major complication after surgical implantation of a left ventricular assist device (LVAD). While the use of a percutaneous RV assist device has been described as a short-term bridge to recovery in end-stage heart failure patients with early post-operative RV failure after index LVAD implant, management of refractory late RV failure remains challenging in these patients. We report the first successful case of extended Impella RP use as a safe and effective bridge to orthotopic heart transplant in an LVAD patient with refractory, haemodynamically significant late RV failure. The Impella RP provided support for 37 days. Haemodynamically intolerant arrhythmia precluded use of inotropic support. No adverse complications related to percutaneous Impella RP support were seen. We also review potential considerations for mechanical circulatory support strategies in this setting: central RV assist device cannulation requires sternotomy incision that can impact subsequent cardiac surgeries, while percutaneous Protek Duo insertion requires adequate vessel size and patency. With an LVAD in situ, veno-arterial extracorporeal membrane oxygenation was not considered for isolated RV support in this case. The patient is currently over 6 months post-orthotopic heart transplant.

The African Green Monkey Model of Pneumonic Plague and US Food and Drug Administration Approval of Antimicrobials Under the Animal Rule.

BACKGROUND: Additional treatment options for pneumonic plague, the most severe form of infection by Yersinia pestis, are needed, as past US Food and Drug Administration (FDA) approvals were not based on clinical trials that meet today's standards, and multiple drugs are sought to counter resistance or use in special populations. Due to the sporadic nature of outbreaks and the low number of pneumonic cases of disease, we sought FDA approval of antimicrobials for treatment under the Animal Efficacy Rule, where efficacy can be demonstrated in 1 or more well-characterized animal models that sufficiently represent human disease. METHODS: A model was developed in African green monkeys (AGMs) after challenge with a lethal dose of Y. pestis delivered as an aerosol, in 4 independent studies in 3 laboratories. The primary data points were bacteremia (daily), body temperature and heart rate (continuously monitored by telemetry), and survival. In antimicrobial efficacy studies, human-equivalent doses of gentamicin, ciprofloxacin, levofloxacin, and doxycycline were administered upon fever onset for 10 days. RESULTS: Disease in AGMs was similar to case reports of human disease. Fever was determined to be a reliable sign of disease and selected as a treatment trigger. Gentamicin was 60%-80% effective depending on the dose given to animals. Ciprofloxacin and levofloxacin were found to be >90% efficacious. These data were submitted to FDA and plague indications were approved. Doxycycline was less effective. CONCLUSIONS: The AGM model of pneumonic plague is reproducible, well-characterized, and mimics human disease. It has been used to support plague indications for fluoroquinolones and to test the efficacy of additional antimicrobials.

Effect of Delaying Treatment on Efficacy of Ciprofloxacin and Levofloxacin in the African Green Monkey Model of Pneumonic Plague.

BACKGROUND: Ciprofloxacin and levofloxacin, 2 fluoroquinolone antimicrobials, are ≥90% effective for the treatment of inhalational plague when administered within 2-6 hours of fever onset in African green monkeys (AGM). Based on data in the AGM model, these antimicrobials were approved under the Food and Drug Administration's Animal Efficacy Rule. However, that data did not address the issue of how long treatment with these antimicrobials would remain effective after fever onset. METHODS: The AGM model of pneumonic plague was used to explore the effect of delaying treatment with ciprofloxacin and levofloxacin on efficacy. In 2 studies, AGMs were challenged with inhaled lethal doses of Yersinia pestis. Treatment with ciprofloxacin and levofloxacin was initiated from 0 to up to 30 hours after fever onset. RESULTS: Challenged animals all developed fever within 78 hours and were treated with ciprofloxacin (n = 27) or levofloxacin (n = 29) at various predetermined time points postfever. When administered 10 hours after fever onset, 10 days of ciprofloxacin and levofloxacin treatment remained very effective (90 or 100%, respectively). The efficacy of both antimicrobials declined as treatment initiation was further delayed. Statistical analyses estimated the treatment delay times at which half of the AGMs were no longer expected to survive as 19.7 hours for ciprofloxacin and 26.5 hours for levofloxacin. CONCLUSIONS: This study demonstrates that there is a narrow window following fever onset during which ciprofloxacin and levofloxacin are fully effective treatment options for pneumonic plague in AGMs. Since the timing of disease is similar in humans and AGMs, these AGM data are reasonably likely to predict response times for treatment in humans.

Inverse agonists of the 5-HT2A receptor reduce nicotine withdrawal signs in rats.

Previous work has shown that chronic nicotine administration causes adaptive changes in 5-HT2A receptor expression. Based on this relationship, it was hypothesized that inactivating 5-HT2A receptors with the inverse agonists pimavanserin and volinanserin (MDL100907), would reduce the symptoms of nicotine withdrawal syndrome. Sprague-Dawley rats were rendered nicotine-dependent by subcutaneous infusion of nicotine bitartrate, 9 mg/kg/day for seven days. The infusions were then terminated, and 22 h later, rats were observed under "blind" conditions for somatically expressed behavioral nicotine withdrawal signs. One hour before observations, the nicotine dependent rats were injected i.p. with saline alone, or either 0.3 or 1.0 mg/kg pimavanserin in saline. Total withdrawal signs were reduced in a dose-dependent manner. A one-way ANOVA (total withdrawal signs as a function of dose) was highly significant, as was the descending linear trend of withdrawal signs as a function of dose. The 1.0 mg/kg dose reduced withdrawal signs nearly to the level exhibited by a comparison group of non-dependent rats injected with saline. A second experiment was conducted in a similar manner, which showed that volinanserin at 1.0 mg/kg but not 0.25 mg/kg also reduced nicotine withdrawal signs to nearly the level of non-dependent rats. In vitro experiments demonstrated that both pimavanserin and volinanserin potently antagonize 5-HT2A receptors, with approximately 25-fold, and 300-fold selectivity over 5-HT2C receptors, respectively. The results suggest that the 5-HT2A receptor contributes to mediating nicotine withdrawal syndrome, and thus represents a potential target for interventions to aid smoking cessation.

Software for designing rigorous and replicable preclinical research: The Experimental Design Accelerator.

In recent years, there have been concerns about research practices in basic and preclinical biomedical research. There have been problems with non-replicable results, and experimental designs lacking internal validity or external or translational validity. The Experimental Design Accelerator (XDA) is Internet-based, interactive software designed to help those trying to design, conduct and document rigorous, replicable and relevant experiments. It leads the investigator step-by-step through a series of decisions that will define the experimental design. It provides background regarding the significance of each decision and the advantages and disadvantages of each possible choice. For example, it leads the researcher to address issues such as choosing a research model, developing testable hypotheses, identifying extraneous variables, dealing with random and systematic error, picking appropriate sample size and picking appropriate statistical analyses. There are also sections to help conduct the experiment consistent with its design and to document the study to facilitate accurate replication. Helpful features include access to an online statistics book and provisions for rapid contact with consulting experts. A number of potential uses for such novel interactive software tools will be discussed.