Genetic polymorphisms in the region of the trimeric serine hydrolase high-temperature requirement 1 (HTRA1) are associated with increased risk of age-related macular degeneration (AMD) and disease progression, but the precise biological function of HtrA1 in the eye and its contribution to disease etiologies remain undefined. In this study, we have...

Background

Nephropathic cystinosis, a hereditary lysosomal storage disorder caused by dysfunction of the lysosomal cotransporter cystinosin, leads to cystine accumulation and cellular damage in various organs, particularly in the kidney. Close therapeutic monitoring of cysteamine, the only available disease-modifying treatment, is recommended. White blood cell cystine concentration is the current gold standard for therapeutic monitoring, but the assay is technically demanding and is available only on a limited basis. Because macrophage-mediated inflammation plays an important role in the pathogenesis of cystinosis, biomarkers of macrophage activation could have potential for the therapeutic monitoring of cystinosis.

Dependence of drug metabolism on dosing time has long been recognized. However, only recently are the underlying mechanisms for circadian drug metabolism being clarified. Diurnal rhythmicity in expression of drug-metabolizing enzymes is believed to be a key factor determining circadian metabolism. Supporting the notion that biological rhythms are generated and maintained by the circadian clock, a number of diurnal enzymes are under the control of the circadian clock. In general, circadian clock genes generate and regulate diurnal rhythmicity in drug-metabolizing enzymes via transcriptional actions on one or two of three cis-elements (i.e., E-box, D-box, and Rev-erb response element or RAR-related orphan receptor response element). Additionally, cycling or clock-controlled nuclear receptors such as hepatocyte nuclear factor 4α and peroxisome proliferator–activated receptor are contributors to diurnal enzyme expression. These newly discovered mechanisms for each of the rhythmic enzymes are reviewed in this article. We also discuss how the rhythms of enzymes are translated to circadian pharmacokinetics and drug chronotoxicity, which has direct implications for chronotherapeutics. Our discussion is also extended to two diurnal transporters (P-glycoprotein and multidrug resistance-associated protein 2) that have an important role in drug absorption. Although the experimental evidence is lacking in metabolism-based chronoefficacy, circadian genes (e.g., Rev-erbα) as drug targets are shown to account for diurnal variability in drug efficacy.

As yet, very few vaccine candidates with activity in animals against Mycobacterium tuberculosis infection have been tested as therapeutic postexposure vaccines. We recently described two pools of mycobacterial proteins with this activity, and here we describe further studies in which four of these proteins (Rv1738, Rv2032, Rv3130, and Rv3841) were generated as a fusion polypeptide and then delivered in a novel yeast-based platform (Tarmogen) which itself has immunostimulatory properties, including activation of Toll-like receptors. This platform can deliver antigens into both the class I and class II antigen presentation pathways and stimulate strong Th1 and Th17 responses. In mice this fusion vaccine, designated GI-19007, was immunogenic and elicited strong gamma interferon (IFN-) and interleukin-17 (IL-17) responses; despite this, they displayed minimal prophylactic activity in mice that were subsequently infected with a virulent clinical strain. In contrast, in a therapeutic model in the guinea pig, GI-19007 significantly reduced the lung bacterial load and reduced lung pathology, particularly in terms of secondary lesion development, while significantly improving survival in one-third of these animals. In further studies in which guinea pigs were vaccinated with BCG before challenge, therapeutic vaccination with GI-19007 initially improved survival versus that of animals given BCG alone, although this protective effect was gradually lost at around 400 days after challenge. Given its apparent ability to substantially limit bacterial dissemination within and from the lungs, GI-19007 potentially can be used to limit lung damage as well as facilitating chemotherapeutic regimens in infected individuals.

The new decade of the 21^st century (2020) started with the emergence of a novel coronavirus known as SARS-CoV-2 that caused an epidemic of coronavirus disease (COVID-19) in Wuhan, China. It is the third highly pathogenic and transmissible coronavirus after severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV) emerged in humans. The source of origin, transmission to humans, and mechanisms associated with the pathogenicity of SARS-CoV-2 are not yet clear, however, its resemblance to SARS-CoV and several other bat coronaviruses was recently confirmed through genome sequencing-related studies. The development of therapeutic strategies is necessary in order to prevent further epidemics and cure infections. In this review, we summarize current information about the emergence, origin, diversity, and epidemiology of three pathogenic coronaviruses with a specific focus on the current outbreak in Wuhan, China. Furthermore, we discuss the clinical features and potential therapeutic options that may be effective against SARS-CoV-2.

In the context of type 2 diabetes, the definition of therapeutic inertia should include the failure not only to intensify therapy, but also to deintensify treatment when appropriate and should be distinguished from appropriate inaction in cases justified by particular circumstances. Therapy should be intensified when glycemic control deteriorates to prevent long periods of hyperglycemia, which increase the risk of complications. Strategic plans to overcome therapeutic inertia must include actions focused on patients, prescribers, health systems, and payers. Therapeutic inertia affects the management of glycemia, hypertension, and lipid disorders, all of which increase the risk for cardiovascular diseases. Thus, multifactorial interventions that act on additional therapeutic goals beyond glycemia are needed.

Therapeutic inertia is a prevalent problem in people with type 2 diabetes in primary care and affects clinical outcomes. It arises from a complex interplay of patient-, clinician-, and health system–related factors. Ultimately, clinical practice guidelines have not made an impact on improving glycemic targets over the past decade. A more proactive approach, including focusing on optimal combination agents for early glycemic durability, may reduce therapeutic inertia and improve clinical outcomes.

From a behavioral perspective, therapeutic inertia can happen when obstacles to changing a diabetes treatment plan outweigh perceived benefits. There is a complex interaction of important treatment-related obstacles for people with diabetes (PWD), their treating health care professional (HCP), and the clinical setting in which they interact. Tipping the scales toward more effective action involve strategies that increase perceptions of the benefits of treatment intensification while addressing important obstacles so that treatment changes are seen by both PWD and HCPs as worthwhile and achievable.

Factors contributing to therapeutic inertia related to patients’ medication experiences include concerns about side effects and out-of-pocket costs, stigmatization for having diabetes, confusion about frequent changes in evidence-based guidelines, low health literacy, and social determinants of health. A variety of solutions to this multifactorial problem may be necessary, including integrating pharmacists into interprofessional care teams, using medication refill synchronization programs, maximizing time with patients to discuss fears and concerns, being cognizant of language used to discuss diabetes-related topics, and avoiding stigmatizing patients. Managing diabetes successfully is a team effort, and the full commitment of all team members (including patients) is required to achieve desired outcomes through an individualized approach.

Despite significant advances in therapies for pediatric type 1 diabetes, achievement of glycemic targets remains elusive, and management remains burdensome for patients and their families. This article identifies common challenges in diabetes management at the patient-provider and health care system levels and proposes practical approaches to overcoming therapeutic inertia to enhance health outcomes for youth with type 1 diabetes.

Diabetes educators can be challenged by therapeutic inertia, as has been documented with other health care providers. There are many contributing factors related to the educators themselves, their patients, and the health care system in which they operate. To address this potentially significant barrier to quality patient care, diabetes educators can adopt numerous strategies to maximize their impact and address the factors contributing to therapeutic inertia in their practices.

Many people with diabetes do not achieve individualized treatment targets. Therapeutic inertia, the underuse of effective therapies in preventing serious clinical end points, is a frequent, important contributor to this failure. Clinicians, patients, health systems, payors, and producers of medications, devices, and other products for those with diabetes all play a role in the development of therapeutic inertia and can all help to reduce it.

Immunotherapeutic strategies targeting the rare leukemic stem cell compartment might provide salvage to the high relapse rates currently observed in acute myeloid leukemia (AML). We applied gene expression profiling for comparison of leukemic blasts and leukemic stem cells with their normal counterparts. Here, we show that the T-cell receptor chain alternate reading frame protein (TARP) is over-expressed in de novo pediatric (n=13) and adult (n=17) AML sorted leukemic stem cells and blasts compared to hematopoietic stem cells and normal myeloblasts (15 healthy controls). Moreover, TARP expression was significantly associated with a fms-like tyrosine kinase receptor-3 internal tandem duplication in pediatric AML. TARP overexpression was confirmed in AML cell lines (n=9), and was found to be absent in B-cell acute lymphocytic leukemia (n=5) and chronic myeloid leukemia (n=1). Sequencing revealed that both a classical TARP transcript, as described in breast and prostate adenocarcinoma, and an AML-specific alternative TARP transcript, were present. Protein expression levels mostly matched transcript levels. TARP was shown to reside in the cytoplasmic compartment and showed sporadic endoplasmic reticulum co-localization. TARP-T-cell receptor engineered cytotoxic T-cells in vitro killed AML cell lines and patient leukemic cells co-expressing TARP and HLA-A*0201. In conclusion, TARP qualifies as a relevant target for immunotherapeutic T-cell therapy in AML.

Inadequate insulin secretion in response to glucose is an important factor for β-cell failure in type 2 diabetes (T2D). Although HMG-CoA reductase degradation 1 (HRD1), a subunit of the endoplasmic reticulum–associated degradation complex, plays a pivotal role in β-cell function, HRD1 elevation in a diabetic setting contributes to β-cell dysfunction. We report in this study the excessive HRD1 expression in islets from humans with T2D and T2D mice. Functional studies reveal that β-cell–specific HRD1 overexpression triggers impaired insulin secretion that will ultimately lead to severe hyperglycemia; by contrast, HRD1 knockdown improves glucose control and response in diabetic models. Proteomic analysis results reveal a large HRD1 interactome, which includes v-maf musculoaponeurotic fibrosarcoma oncogene homolog A (MafA), a master regulator of genes implicated in the maintenance of β-cell function. Furthermore, mechanistic assay results indicate that HRD1 is a novel E3 ubiquitin ligase that targets MafA for ubiquitination and degradation in diabetic β-cells, resulting in cytoplasmic accumulation of MafA and in the reduction of its biological function in the nucleus. Our results not only reveal the pathological importance of excessive HRD1 in β-cell dysfunction but also establish the therapeutic importance of targeting HRD1 in order to prevent MafA loss and suppress the development of T2D.

T-cell receptor (TCR)–based therapeutic cells and agents have emerged as a new class of effective cancer therapies. These therapies work on cells that express intracellular cancer-associated proteins by targeting peptides displayed on MHC receptors. However, cross-reactivities of these agents to off-target cells and tissues have resulted in serious, sometimes fatal, adverse events. We have developed a high-throughput genetic platform (termed "PresentER") that encodes MHC-I peptide minigenes for functional immunologic assays and determines the reactivities of TCR-like therapeutic agents against large libraries of MHC-I ligands. In this article, we demonstrated that PresentER could be used to identify the on-and-off targets of T cells and TCR-mimic (TCRm) antibodies using in vitro coculture assays or binding assays. We found dozens of MHC-I ligands that were cross-reactive with two TCRm antibodies and two native TCRs and that were not easily predictable by other methods.

This study showed that treatment with a therapeutic monoclonal immunoglobulin-G1 antibody against phosphorylcholine on oxidized phospholipids preserves coronary flow reserve and attenuates atherosclerotic inflammation as determined by the uptake of ¹⁸F-fluorodeoxyglucose in atherosclerotic mice. The noninvasive imaging techniques represent translational tools to assess the efficacy of phosphorylcholine-targeted therapy on coronary artery function and atherosclerosis in clinical studies.

Purpose:

There are several agents in early clinical trials targeting components of the adenosine pathway including A2AR and CD73. The identification of cancers with a significant adenosine drive is critical to understand the potential for these molecules. However, it is challenging to measure tumor adenosine levels at scale, thus novel, clinically tractable biomarkers are needed.

Purpose:

The development of leptomeningeal melanoma metastases (LMM) is a rare and devastating complication of the late-stage disease, for which no effective treatments exist. Here, we performed a multi-omics analysis of the cerebrospinal fluid (CSF) from patients with LMM to determine how the leptomeningeal microenvironment shapes the biology and therapeutic responses of melanoma cells.

Treating malaria in HIV-coinfected individuals should consider potential drug-drug interactions. Artemether-lumefantrine is the most widely recommended treatment for uncomplicated malaria globally. Lumefantrine is metabolized by CYP3A4, an enzyme that commonly used antiretrovirals often induce or inhibit. A population pharmacokinetic meta-analysis was conducted using individual participant data from 10 studies with 6,100 lumefantrine concentrations from 793 nonpregnant adult participants (41% HIV-malaria-coinfected, 36% malaria-infected, 20% HIV-infected, and 3% healthy volunteers). Lumefantrine exposure increased 3.4-fold with coadministration of lopinavir-ritonavir-based antiretroviral therapy (ART), while it decreased by 47% with efavirenz-based ART and by 59% in the patients with rifampin-based antituberculosis treatment. Nevirapine- or dolutegravir-based ART and malaria or HIV infection were not associated with significant effects. Monte Carlo simulations showed that those on concomitant efavirenz or rifampin have 49% and 80% probability of day 7 concentrations <200 ng/ml, respectively, a threshold associated with an increased risk of treatment failure. The risk of achieving subtherapeutic concentrations increases with larger body weight. An extended 5-day and 6-day artemether-lumefantrine regimen is predicted to overcome these drug-drug interactions with efavirenz and rifampin, respectively.

Infections with nontuberculous mycobacteria (NTM) have a poor prognosis in patients with underlying respiratory diseases. Clofazimine (CFZ) showed both experimental and clinical promising results against clinically relevant NTM. However, there are no data on CFZ in combination with the current recommended treatment; therefore, we aimed to study its in vivo activity in an aerosol mouse model of Mycobacterium avium. In an aerosol infection BALB/c mouse model using M. avium strain Chester, we treated 58 mice with four combinations of rifampin (RIF) at 10 mg/kg, CFZ at 25 mg/kg, and clarithromycin (CLR) and ethambutol (EMB) at 100 mg/kg. Treatment efficacy was assessed on the basis of lung CFU counts after 2 (M2) and 4 (M4) months of treatment. At M2, CLR-RIF-EMB was slightly but significantly more efficient than CFZ-RIF-EMB (3.02 ± 0.12 versus 3.55 ± 0.28, respectively, P < 0.01), whereas CLR-CFZ-EMB and CLR-CFZ-RIF-EMB dramatically decreased lung CFU counts by 4.32 and 4.47 log₁₀, respectively, compared to untreated group. At M4, CLR-RIF-EMB was significantly more efficient than CFZ-RIF-EMB (2 ± 0.53 versus 2.66 ± 0.22, respectively, P = 0.01). The addition of CLZ to CLR dramatically decreased the lung CFU count, with CFU counts 5.41 and 5.79 log₁₀ lower in the CLR-CFZ-EMB and CLR-CFZ-RIF-EMB groups, respectively, than in the untreated group. The addition of CFZ to CLR seems to improve the efficacy of CLR as early as M2 and was confirmed at M4. CFZ, in addition to RIF and EMB, on the other hand, is less effective than CLR-RIF-EMB. These results need to be confirmed by similar studies along with CFZ potential for shortening treatment.

Antibiotics revolutionized the treatment of infectious diseases; however, it is now clear that broad-spectrum antibiotics alter the composition and function of the host’s microbiome. The microbiome plays a key role in human health, and its perturbation is increasingly recognized as contributing to many human diseases. Widespread broad-spectrum antibiotic use has also resulted in the emergence of multidrug-resistant pathogens, spurring the development of pathogen-specific strategies such as monoclonal antibodies (MAbs) to combat bacterial infection. Not only are pathogen-specific approaches not expected to induce resistance in nontargeted bacteria, but they are hypothesized to have minimal impact on the gut microbiome. Here, we compare the effects of antibiotics, pathogen-specific MAbs, and their controls (saline or control IgG [c-IgG]) on the gut microbiome of 7-week-old, female, C57BL/6 mice. The magnitude of change in taxonomic abundance, bacterial diversity, and bacterial metabolites, including short-chain fatty acids (SCFA) and bile acids in the fecal pellets from mice treated with pathogen-specific MAbs, was no different from that with animals treated with saline or an IgG control. Conversely, dramatic changes were observed in the relative abundance, as well as alpha and beta diversity, of the fecal microbiome and bacterial metabolites in the feces of all antibiotic-treated mice. Taken together, these results indicate that pathogen-specific MAbs do not alter the fecal microbiome like broad-spectrum antibiotics and may represent a safer, more-targeted approach to antibacterial therapy.

The comparative efficacy of ceftazidime-avibactam and meropenem-vaborbactam for treatment of carbapenem-resistant Enterobacteriaceae (CRE) infections remains unknown. This was a multicenter, retrospective cohort study of adults with CRE infections who received ceftazidime-avibactam or meropenem-vaborbactam for ≥72 hours from February 2015 to October 2018. Patients with a localized urinary tract infection and repeat study drug exposures after the first episode were excluded. The primary endpoint was clinical success compared between treatment groups. Secondary endpoints included 30- and 90-day mortality, adverse events (AE), 90-day CRE infection recurrence, and development of resistance in patients with recurrent infection. A post hoc subgroup analysis was completed comparing patients who received ceftazidime-avibactam monotherapy, ceftazidime-avibactam combination therapy, and meropenem-vaborbactam monotherapy. A total of 131 patients were included (ceftazidime-avibactam, n = 105; meropenem-vaborbactam, n = 26), 40% of whom had bacteremia. No significant difference in clinical success was observed between groups (62% versus 69%; P = 0.49). Patients in the ceftazidime-avibactam arm received combination therapy more often than patients in the meropenem-vaborbactam arm (61% versus 15%; P < 0.01). No difference in 30- and 90-day mortality resulted, and rates of AE were similar between groups. In patients with recurrent infection, development of resistance occurred in three patients that received ceftazidime-avibactam monotherapy and in no patients in the meropenem-vaborbactam arm. Clinical success was similar between patients receiving ceftazidime-avibactam and meropenem-vaborbactam for treatment of CRE infections, despite ceftazidime-avibactam being used more often as a combination therapy. Development of resistance was more common with ceftazidime-avibactam monotherapy.

Tedizolid (TZD) and daptomycin (DAP) were assessed in a rat endocarditis model against Enterococcus faecalis, Enterococcus faecium (resistant to vancomycin and ampicillin), and Staphylococcus aureus. As a monotherapy, TZD for 5 days was not effective in a comparison with no-treatment controls, while DAP for 5 days was significantly effective against these bacteria. Step-down therapy (DAP for 3 days followed by TZD for 2 days) was as effective as DAP for 5 days and was comparable to 3 days of DAP plus ceftriaxone against all bacteria and to 3 days of DAP plus gentamicin against E. faecalis OG1RF.

Animal models of bacterial infection have been widely used to explore the in vivo activity of antibacterial drugs. These data are often submitted to the U.S. Food and Drug Administration to support human use in an investigational new drug application (IND). To better understand the range and scientific use of animal models in regulatory submissions, a database was created surveying recent pneumonia models submitted as part of IND application packages. The IND studies were compared to animal models of bacterial pneumonia published in the scientific literature over the same period of time. In this review, we analyze the key experimental design elements, such as animal species, immune status, pathogens selected, and route of administration, and study endpoints.

Nacubactam is a novel β-lactamase inhibitor with dual mechanisms of action as an inhibitor of serine β-lactamases (classes A and C and some class D) and an inhibitor of penicillin binding protein 2 in Enterobacteriaceae. The safety, tolerability, and pharmacokinetics of intravenous nacubactam were evaluated in single- and multiple-ascending-dose, placebo-controlled studies. Healthy participants received single ascending doses of nacubactam of 50 to 8,000 mg, multiple ascending doses of nacubactam of 1,000 to 4,000 mg every 8 h (q8h) for up to 7 days, or nacubactam of 2,000 mg plus meropenem of 2,000 mg q8h for 6 days after a 3-day lead-in period. Nacubactam was generally well tolerated, with the most frequently reported adverse events (AEs) being mild to moderate complications associated with intravenous access and headache. There was no apparent relationship between drug dose and the pattern, incidence, or severity of AEs. No clinically relevant dose-related trends were observed in laboratory safety test results. No serious AEs, dose-limiting AEs, or deaths were reported. After single or multiple doses, nacubactam pharmacokinetics appeared linear, and exposure increased in an approximately dose-proportional manner across the dose range investigated. Nacubactam was excreted largely unchanged into urine. Coadministration of nacubactam with meropenem did not significantly alter the pharmacokinetics of either drug. These findings support the continued clinical development of nacubactam and demonstrate the suitability of meropenem as a potential β-lactam partner for nacubactam. (The studies described in this paper have been registered at ClinicalTrials.gov under NCT02134834 [single ascending dose study] and NCT02972255 [multiple ascending dose study].)

Current treatments for Acanthamoeba keratitis rely on a combination of chlorhexidine gluconate, propamidine isethionate, and polyhexamethylene biguanide. These disinfectants are nonspecific and inherently toxic, which limits their effectiveness. Furthermore, in 10% of cases, recurrent infection ensues due to the difficulty in killing both trophozoites and double-walled cysts. Therefore, development of efficient, safe, and target-specific drugs which are capable of preventing recurrent Acanthamoeba infection is a critical unmet need for averting blindness. Since both trophozoites and cysts contain specific sets of membrane sterols, we hypothesized that antifungal drugs targeting sterol 14-demethylase (CYP51), known as conazoles, would have deleterious effects on A. castellanii trophozoites and cysts. To test this hypothesis, we first performed a systematic screen of the FDA-approved conazoles against A. castellanii trophozoites using a bioluminescence-based viability assay adapted and optimized for Acanthamoeba. The most potent drugs were then evaluated against cysts. Isavuconazole and posaconazole demonstrated low nanomolar potency against trophozoites of three clinical strains of A. castellanii. Furthermore, isavuconazole killed trophozoites within 24 h and suppressed excystment of preformed Acanthamoeba cysts into trophozoites. The rapid action of isavuconazole was also evident from the morphological changes at nanomolar drug concentrations causing rounding of trophozoites within 24 h of exposure. Given that isavuconazole has an excellent safety profile, is well tolerated in humans, and blocks A. castellanii excystation, this opens an opportunity for the cost-effective repurposing of isavuconazole for the treatment of primary and recurring Acanthamoeba keratitis.

The RESTORE-IMI 1 phase 3 trial demonstrated the efficacy and safety of imipenem-cilastatin (IMI) combined with relebactam (REL) for treating imipenem-nonsusceptible infections. The objective of this analysis was to compare the outcomes among patients meeting eligibility requirements based on central laboratory susceptibility versus local laboratory susceptibility. Patients with serious infections caused by imipenem-nonsusceptible, colistin-susceptible, and imipenem-REL-susceptible pathogens were randomized 2:1 to IMI-REL plus placebo or colistin plus IMI for 5 to 21 days. The primary endpoint was a favorable overall response. Key endpoints included the clinical response and all-cause mortality. We compared outcomes between the primary microbiological modified intent-to-treat (mMITT) population, where eligibility was based on central laboratory susceptibility testing, and the supplemental mMITT (SmMITT) population, where eligibility was based on local, site-level testing. The SmMITT (n = 41) and MITT (n = 31) populations had similar baseline characteristics, including sex, age, illness severity, and renal function. In both analysis populations, favorable overall response rates in the IMI-REL treatment group were >70%. Favorable clinical response rates at day 28 were 71.4% for IMI-REL and 40.0% for colistin plus IMI in the mMITT population, whereas they were 75.0% for IMI-REL and 53.8% for colistin plus IMI in the SmMITT population. Day 28 all-cause mortality rates were 9.5% for IMI-REL and 30.0% for colistin plus IMI in the mMITT population, whereas they were 10.7% for IMI-REL and 23.1% for colistin plus IMI in the SmMITT population. The outcomes in the SmMITT population were generally consistent with those in the mMITT population, suggesting that outcomes may be applicable to the real-world use of IMI-REL for treating infections caused by imipenem-nonsusceptible Gram-negative pathogens. (This study has been registered at ClinicalTrials.gov under identifier NCT02452047.)

Helicobacter pylori is an important risk factor for gastric ulcers. However, antibacterial therapies increase the resistance rate and decrease the eradication rate of H. pylori. Inspired by the microaerophilic characteristics of H. pylori, we aimed at effectively establishing an oxygen-enriched environment to eradicate and prevent the recurrence of H. pylori. The effect and the mechanism of an oxygen-enriched environment in eradicating H. pylori and preventing the recurrence were explored in vitro and in vivo. During oral administration and after drug withdrawal, H. pylori counts were evaluated by Giemsa staining in animal cohorts. An oxygen-enriched environment in which H. pylori could not survive was successfully established by adding hydrogen peroxide into several solutions and rabbit gastric juice. Hydrogen peroxide effectively killed H. pylori in Columbia blood agar and special peptone broth. Minimum inhibition concentrations and minimum bactericidal concentrations of hydrogen peroxide were both relatively stable after promotion of resistance for 30 generations, indicating that hydrogen peroxide did not easily promote resistance in H. pylori. In models of Mongolian gerbils and Kunming mice, hydrogen peroxide has been shown to significantly eradicate and effectively prevent the recurrence of H. pylori without toxicity and damage to the gastric mucosa. The mechanism of hydrogen peroxide causing H. pylori death was related to the disruption of bacterial cell membranes. The oxygen-enriched environment achieved by hydrogen peroxide eradicates and prevents the recurrence of H. pylori by damaging bacterial cell membranes. Hydrogen peroxide thus provides an attractive candidate for anti-H. pylori treatment.

The aim of this work was to evaluate the pharmacokinetics of amikacin in Mexican patients with different renal functions receiving once-daily dosing regimens and the influence of clinical and demographical covariates that may influence the optimization of this antibiotic. A prospective study was performed in a total of 63 patients with at least one determination of amikacin plasma concentration. Population pharmacokinetic (PK) parameters were estimated by nonlinear mixed-effects modeling; validations were performed for dosing recommendation purposes based on PK/pharmacodynamic simulations. The concentration-versus-time data were best described by a one-compartment open model with proportional interindividual variability associated with amikacin clearance (CL) and volume of distribution (V); residual error followed a homoscedastic trend. Creatinine clearance (CL_CR) and ideal body weight (IBW) demonstrated significant influence on amikacin CL and V, respectively. The final model [CL (liters/h) = 7.1 x (CL_CR/130)^0.84 and V (liters) = 20.3 x (IBW/68)^2.9] showed a mean prediction error of 0.11 mg/liter (95% confidence interval, –3.34, 3.55) in the validation performed in a different group of patients with similar characteristics. There is a wide variability in amikacin PK parameters in Mexican patients. This leads to inadequate dosing regimens, especially in patients with augmented renal clearance (CL_CR of >130 ml/min). Optimization based on the final population PK model in Mexican patients may be useful, since reliability and clinical applicability have been demonstrated in this study.

Dalbavancin offers a possible treatment option for infectious peritonitis associated with peritoneal dialysis (PD) due to its coverage of Gram-positive bacteria and pharmacokinetic properties. We aimed to evaluate the clinical pharmacokinetics (PK) and pharmacodynamics of dalbavancin in a prospective, randomized, open-label, crossover PK study of adult patients with end-stage renal disease ESRD who were receiving PD. Sampling occurred prior to a single 30-min infusion of dalbavancin at 1,500 mg and at 1, 2, 3, 4, and 6 h and 7 and 14 days postadministration. Concentration-time data were analyzed via noncompartmental analysis. Pharmacodynamic parameters against common infectious peritonitis-causing pathogens were evaluated. Ten patients were enrolled. Patients were a median of 55 years old and had a median weight of 78.2 kg, 50% were female, and 70% were Caucasian. The terminal plasma half-life of dalbavancin was 181.4 ± 35.5 h. The day 0 to day 14 dalbavancin mean area under the curve (AUC) was 40,573.2 ± 9,800.3 mg·h/liter. The terminal-phase half-life of dalbavancin within the peritoneal fluid was 4.309 x 10⁸ ± 1.140 x 10⁹ h. The day 0 to day 14 dalbavancin mean peritoneal fluid AUC was 2,125.0 ± 1,794.3 mg·h/liter. The target plasma AUC/MIC was attained with the intravenous dose in all 10 patients for all Staphylococcus and Streptococcus species at the recommended MIC breakpoints. The intraperitoneal arm of the study was stopped early, because the first 3 patients experienced moderate to severe pain and bloating within 1 h following the administration of dalbavancin. Dalbavancin at 1,500 mg administered intravenously can be utilized without dose adjustment in peritoneal dialysis patients and will likely achieve the necessary peritoneal fluid concentrations to treat peritonitis caused by typical Gram-positive pathogens.

Plasmodium vivax relapse is one of the major causes of sustained global malaria transmission. Primaquine (PQ) is the only commercial drug available to prevent relapses, and its efficacy is dependent on metabolic activation by cytochrome P450 2D6 (CYP2D6). Impaired CYP2D6 function, caused by allelic polymorphisms, leads to the therapeutic failure of PQ as a radical cure for P. vivax malaria. Here, we hypothesized that the host immune response to malaria parasites modulates susceptibility to P. vivax recurrences in association with CYP2D6 activity. We performed a 10-year retrospective study by genotyping CYP2D6 polymorphisms in 261 malaria-exposed individuals from the Brazilian Amazon. The immune responses against a panel of P. vivax blood-stage antigens were evaluated by serological assays. We confirmed our previous findings, which indicated an association between impaired CYP2D6 activity and a higher risk of multiple episodes of P. vivax recurrence (risk ratio, 1.75; 95% confidence interval [CI], 1.2 to 2.6; P = 0.0035). An important finding was a reduction of 3% in the risk of recurrence (risk ratio, 0.97; 95% CI, 0.96 to 0.98; P < 0.0001) per year of malaria exposure, which was observed for individuals with both reduced and normal CYP2D6 activity. Accordingly, subjects with long-term malaria exposure and persistent antibody responses to various antigens showed fewer episodes of malaria recurrence. Our findings have direct implications for malaria control, since it was shown that nonimmune individuals who do not respond adequately to treatment due to reduced CYP2D6 activity may present a significant challenge for sustainable progress toward P. vivax malaria elimination.

This study was conducted in treatment-naive adults with drug-susceptible pulmonary tuberculosis in Port-au-Prince, Haiti, to assess the safety, bactericidal activity, and pharmacokinetics of nitazoxanide (NTZ). This was a prospective phase II clinical trial in 30 adults with pulmonary tuberculosis. Twenty participants received 1 g of NTZ orally twice daily for 14 days. A control group of 10 participants received standard therapy over 14 days. The primary outcome was the change in time to culture positivity (TTP) in an automated liquid culture system. The most common adverse events seen in the NTZ group were gastrointestinal complaints and headache. The mean change in TTP in sputum over 14 days in the NTZ group was 3.2 h ± 22.6 h and was not statistically significant (P = 0.56). The mean change in TTP in the standard therapy group was significantly increased, at 134 h ± 45.2 h (P < 0.0001). The mean NTZ MIC for Mycobacterium tuberculosis isolates was 12.3 μg/ml; the mean NTZ maximum concentration (C_max) in plasma was 10.2 μg/ml. Negligible NTZ levels were measured in sputum. At the doses used, NTZ did not show bactericidal activity against M. tuberculosis. Plasma concentrations of NTZ were below the MIC, and its negligible accumulation in pulmonary sites may explain the lack of bactericidal activity. (This study has been registered at ClinicalTrials.gov under identifier NCT02684240.)

We report a systematic, cellular phenotype-based antimalarial screening of the Medicines for Malaria Venture Pathogen Box collection, which facilitated the identification of specific blockers of late-stage intraerythrocytic development of Plasmodium falciparum. First, from standard growth inhibition assays, we identified 173 molecules with antimalarial activity (50% effective concentration [EC₅₀] ≤ 10 μM), which included 62 additional molecules over previously known antimalarial candidates from the Pathogen Box. We identified 90 molecules with EC₅₀ of ≤1 μM, which had significant effect on the ring-trophozoite transition, while 9 molecules inhibited the trophozoite-schizont transition and 21 molecules inhibited the schizont-ring transition (with ≥50% parasites failing to proceed to the next stage) at 1 μM. We therefore rescreened all 173 molecules and validated hits in microscopy to prioritize 12 hits as selective blockers of the schizont-ring transition. Seven of these molecules inhibited the calcium ionophore-induced egress of Toxoplasma gondii, a related apicomplexan parasite, suggesting that the inhibitors may be acting via a conserved mechanism which could be further exploited for target identification studies. We demonstrate that two molecules, MMV020670 and MMV026356, identified as schizont inhibitors in our screens, induce the fragmentation of DNA in merozoites, thereby impairing their ability to egress and invade. Further mechanistic studies would facilitate the therapeutic exploitation of these molecules as broadly active inhibitors targeting late-stage development and egress of apicomplexan parasites relevant to human health.

Currently, the expansion of the novel human respiratory coronavirus (known as SARS-CoV-2 [severe acute respiratory syndrome coronavirus 2], COVID-2019 [coronavirus disease 2019], or 2019-nCoV [2019 novel coronavirus]) has stressed the need for therapeutic alternatives to alleviate and stop this new epidemic. The previous epidemics of infections by high-morbidity human coronaviruses, such as SARS-CoV in 2003 and the Middle East respiratory syndrome coronavirus (MERS-CoV) in 2012, prompted the characterization of compounds that could be potentially active against the currently emerging novel coronavirus, SARS-CoV-2. The most promising compound is remdesivir (GS-5734), a nucleotide analog prodrug currently in clinical trials for treating Ebola virus infections. Remdesivir inhibited the replication of SARS-CoV and MERS-CoV in tissue cultures, and it displayed efficacy in nonhuman animal models. In addition, a combination of the human immunodeficiency virus type 1 (HIV-1) protease inhibitors lopinavir/ritonavir and interferon beta (LPV/RTV–IFN-β) was shown to be effective in patients infected with SARS-CoV. LPV/RTV–IFN-β also improved clinical parameters in marmosets and mice infected with MERS-CoV. Remarkably, the therapeutic efficacy of remdesivir appeared to be superior to that of LPV/RTV–IFN-β against MERS-CoV in a transgenic humanized mouse model. The relatively high mortality rates associated with these three novel human coronavirus infections, SARS-CoV, MERS-CoV, and SARS-CoV-2, have suggested that proinflammatory responses might play a role in the pathogenesis. It remains unknown whether the generated inflammatory state should be targeted. Therapeutics that target the coronavirus alone might not be able to reverse highly pathogenic infections. This minireview aims to provide a summary of therapeutic compounds that have shown potential in fighting SARS-CoV-2 infections.

To obtain the optimal dosage regimen in patients receiving extracorporeal membrane oxygenation (ECMO), we developed a population pharmacokinetics model for cefpirome and performed pharmacodynamic analyses. This prospective study included 15 patients treated with cefpirome during ECMO. Blood samples were collected during ECMO (ECMO-ON) and after ECMO (ECMO-OFF) at predose and 0.5 to 1, 2 to 3, 4 to 6, 8 to 10, and 12 h after cefpirome administration. The population pharmacokinetic model was developed using nonlinear mixed effects modeling and stepwise covariate modeling. Monte Carlo simulation was used to assess the probability of target attainment (PTA) and cumulative fraction of response (CFR) according to the MIC distribution. Cefpirome pharmacokinetics were best described by a two-compartment model. Covariate analysis indicated that serum creatinine concentration (SCr) was negatively correlated with clearance, and the presence of ECMO increased clearance and the central volume of distribution. The simulations showed that patients with low SCr during ECMO-ON had lower PTA than patients with high SCr during ECMO-OFF; so, a higher dosage of cefpirome was required. Cefpirome of 2 g every 8 h for intravenous bolus injection or 2 g every 12 h for extended infusion over 4 h was recommended with normal kidney function receiving ECMO. We established a population pharmacokinetic model for cefpirome in patients with ECMO, and appropriate cefpirome dosage regimens were recommended. The impact of ECMO could be due to the change in patient status on consideration of the small population and uncertainty in covariate relationships. Dose optimization of cefpirome may improve treatment success and survival in patients receiving ECMO. (This study has been registered at ClinicalTrials.gov under identifier NCT02581280.)

Ceftobiprole is an advanced-generation broad-spectrum cephalosporin antibiotic with potent and rapid bactericidal activity against Gram-positive pathogens, including methicillin-resistant Staphylococcus aureus, as well as susceptible Gram-negative pathogens, including Pseudomonas sp. pathogens. In the case of Pseudomonas aeruginosa, ceftobiprole acts by inhibiting P. aeruginosa penicillin-binding protein 3 (PBP3). Structural studies were pursued to elucidate the molecular details of this PBP inhibition. The crystal structure of the His-tagged PBP3-ceftobiprole complex revealed a covalent bond between the ligand and the catalytic residue S294. Ceftobiprole binding leads to large active site changes near binding sites for the pyrrolidinone and pyrrolidine rings. The S528 to L536 region adopts a conformation previously not observed in PBP3, including partial unwinding of the α11 helix. These molecular insights can lead to a deeper understanding of β-lactam-PBP interactions that result in major changes in protein structure, as well as suggesting how to fine-tune current inhibitors and to develop novel inhibitors of this PBP.

Of four genotypes of Encephalitozoon cuniculi, E. cuniculi genotype II is considered to represent a parasite that occurs in many host species in a latent asymptomatic form, whereas E. cuniculi genotype III seems to be more aggressive, and infections caused by this strain can lead to the death of even immunocompetent hosts. Although albendazole has been considered suitable for treatment of Encephalitozoon species, its failure in control of E. cuniculi genotype III infection has been reported. This study determined the effect of a 100x recommended daily dose of albendazole on an Encephalitozoon cuniculi genotype III course of infection in immunocompetent and immunodeficient mice and compared the results with those from experiments performed with a lower dose of albendazole and E. cuniculi genotype II. The administration of the regular dose of abendazole during the acute phase of infection reduced the number of affected organs in all strains of mice and absolute counts of spores in screened organs. However, the effect on genotype III was minor. Surprisingly, no substantial effect was recorded after the use of a 100x dose of albendazole, with larger reductions seen only in the number of affected organs and absolute counts of spores in all strains of mice, implying variations in albendazole resistance between these Encephalitozoon cuniculi genotypes. These results imply that differences in the course of infection and the response to treatment depend not only on the immunological status of the host but also on the genotype causing the infection. Understanding how microsporidia survive in hosts despite targeted antimicrosporidial treatment could significantly contribute to research related to human health.

There is an ongoing need for safe and effective anti-bedbug compounds. Here, we tested the toxicity of three antimicrobial agents against bedbugs when administered orally. We reveal that doxycycline has direct insecticidal activity at 250 μg/ml (0.025%) that is particularly strong against immature bedbugs and appears to be independent of antimicrobial activity. Future studies to determine the mechanisms behind this property could be useful for the development of orally active insecticides or anti-bedbug therapeutics.

Carcinoma-associated fibroblasts (CAF) are a potential therapeutic target for both direct and indirect regulation of cancer progression and therapy response. In this issue of Cancer Research, Ford and colleagues investigate the influence of CAF on the immune environment of tumors, specifically focusing on the regulation of CD8+ T cells, required for immune therapy response. Their work suggests a role for stromally expressed NADPH oxidase 4 (NOX4) as a modulator of reactive oxygen species that in turn can reduce the number of CD8+ T cells locally. Inhibition of NOX4 increased CD8+ T cells and restored responsiveness to immune therapy, suggesting an indirect stromally targeted avenue for therapy resensitization.See related article by Ford et al., p. 1846

Bamboo is a renewable material that when microwaved becomes stronger by weight than steel or concrete – which could make it ideal for constructing buildings, cars and planes

A man with a 'devil gremlin' tattoo is being sought by police after a teen was dragged into the bushes and raped in south-east London.

Police are searching for a man they wish to speak to following the attempted rape of a woman in north-east London street.

A woman in her 40s was allegedly gang-raped after police quarantined her in a school overnight in India.

Police are searching for a man in connection with an alleged rape at Embankment in central London.

A huge blaze broke out at a 48-storey skyscraper in the United Arab Emirates city of Sharjah.