Inhibiting Inducible Nitric Oxide Synthase with 1400W Reduces Soman (GD)-Induced Ferroptosis in Long-Term Epilepsy-Associated Neuropathology: Structural and Functional Magnetic Resonance Imaging Correlations with Neurobehavior and Brain Pathology.

Organophosphate (OP) nerve agent (OPNA) intoxication leads to long-term brain dysfunctions. The ineffectiveness of current treatments for OPNA intoxication prompts a quest for the investigation of the mechanism and an alternative effective therapeutic approach. Our previous studies on 1400W, a highly selective inducible nitric oxide synthase (iNOS) inhibitor, showed improvement in epilepsy and seizure-induced brain pathology in rat models of kainate and OP intoxication. In this study, magnetic resonance imaging (MRI) modalities, behavioral outcomes, and biomarkers were comprehensively investigated for brain abnormalities following soman (GD) intoxication in a rat model. T1 and T2 MRI robustly identified pathologic microchanges in brain structures associated with GD toxicity, and 1400W suppressed those aberrant alterations. Moreover, functional network reduction was evident in the cortex, hippocampus, and thalamus after GD exposure, and 1400W rescued the losses except in the thalamus. Behavioral tests showed protection by 1400W against GD-induced memory dysfunction, which also correlated with the extent of brain pathology observed in structural and functional MRIs. GD exposure upregulated iron-laden glial cells and ferritin levels in the brain and serum, 1400W decreased ferritin levels in the epileptic foci in the brain but not in the serum. The levels of brain ferritin also correlated with MRI parameters. Further, 1400W mitigated the overproduction of nitroxidative markers after GD exposure. Overall, this study provides direct evidence for the relationships of structural and functional MRI modalities with behavioral and molecular abnormalities following GD exposure and the neuroprotective effect of an iNOS inhibitor, 1400W. SIGNIFICANT STATEMENT: Our studies demonstrate the MRI microchanges in the brain following GD toxicity, which strongly correlate with neurobehavioral performances and iron homeostasis. The inhibition of iNOS with 1400W mitigates GD-induced cognitive decline, iron dysregulation, and aberrant brain MRI findings.

3-Hydroxy-propanamidines, a New Class of Orally Active Antimalarials Targeting Plasmodium falciparum.

3-Hydroxypropanamidines are a new promising class of highly active antiplasmodial agents. The most active compound 22 exhibited excellent antiplasmodial in vitro activity with nanomolar inhibition of chloroquine-sensitive and multidrug-resistant parasite strains ofPlasmodium falciparum (with IC50 values of 5 and 12 nM against 3D7 and Dd2 strains, respectively) as well as low cytotoxicity in human cells. In addition, 22 showed strong in vivo activity in thePlasmodium berghei mouse model with a cure rate of 66% at 50 mg/kg and a cure rate of 33% at 30 mg/kg in the Peters test after once daily oral administration for 4 consecutive days. A quick onset of action was indicated by the fast drug absorption shown in mice. The new lead compound was also characterized by a high barrier to resistance and inhibited the heme detoxification machinery in P. falciparum.

A small-molecular inhibitor against Proteus mirabilis urease to treat catheter-associated urinary tract infections.

Infection and blockage of indwelling urinary catheters is significant owing to its high incidence rate and severe medical consequences. Bacterial enzymes are employed as targets for small molecular intervention in human bacterial infections. Urease is a metalloenzyme known to play a crucial role in the pathogenesis and virulence of catheter-associated Proteus mirabilis infection. Targeting urease as a therapeutic candidate facilitates the disarming of bacterial virulence without affecting bacterial fitness, thereby limiting the selective pressure placed on the invading population and lowering the rate at which it will acquire resistance. We describe the design, synthesis, and in vitro evaluation of the small molecular enzyme inhibitor 2-mercaptoacetamide (2-MA), which can prevent encrustation and blockage of urinary catheters in a physiologically representative in vitro model of the catheterized urinary tract. 2-MA is a structural analogue of urea, showing promising competitive activity against urease. In silico docking experiments demonstrated 2-MA's competitive inhibition, whilst further quantum level modelling suggests two possible binding mechanisms.

PAD4 selective inhibitor TDFA protects lipopolysaccharide-induced acute lung injury by modulating nuclear p65 localization in epithelial cells.

Protein arginine deiminase 4 (PAD4) serves a critical role in differentiation, development and apoptosis through gene regulation and has emerged as a potential therapeutic target for the treatment of various diseases. However, the roles of PAD4 in lipopolysaccharide (LPS)-induced acute lung injury (ALI) remain largely unknown. To investigate the roles of PAD4 during LPS-induced ALI, the present study detected the trend of PAD4 expression in the lung tissues of ALI mice. Subsequently, the efficiency of TDFA on PAD4 and citrullinated H3 histone were detected. And then, histology, the wet/dry weight ratio, survival rate, activated cells infiltration, oxidative stress levels, tight junction proteins and proinflammatory cytokine expression were detected. In addition, the level of transepithelial electrical resistance (TEER) was assessed. Finally, the level of nuclear P65, total phosphorylated P65 and P65 were measured in vivo and in vitro. The results showed that PAD4 expression was upregulated in the lung tissues of LPS-induced ALI. TDFA efficiently decreased the severity of the lung edema, attenuated the severity of pulmonary injury and improved the survival rate following lethal LPS administration. Besides, TDFA reduced activated cells infiltration and suppressed inflammation related parameters, including proinflammatory cytokines production (TNF-α, IL-6 and IL-1ß) and oxidative stress (MDA, GSH and SOD). Furthermore, TDFA reversed the TEER downregulation tendency and tight junction proteins (ZO-1, Occludin, Claudin-4) levels that represent the integrity of alveolar epithelium. Eventually, TDFA exerts its protective roles through modulating nuclear localization of transcription factor NF-κB P65 in epithelial cells. Taken together, these results indicate that PAD4 inhibition may serve as a promising therapeutic approach for LPS-induced ALI.

The transversus abdominis plane block reduces the cumulative need of analgesic medication following inguinal hernia repair in TAPP technique: a retrospective single center analysis among 838 patients.

PURPOSE: Laparoscopic inguinal hernia repair (IHR) may lead to early postoperative pain. Therefore, opioid and non-opioid analgesic agents are often administered in the post-anesthesia care unit (PACU). To reduce the postoperative cumulative need of analgesic medication, as well as to accelerate the physical recovery time, the transversus abdominis plane (TAP) block has recently been studied. The TAP block is a regional anesthesia technique. Even though there is evidence about the efficacy of the block used in procedure such as an open inguinal hernia repair, the evidence regarding its use for the TAPP (transabdominal preperitoneal) technique remains low. We aim to provide more sufficient evidence regarding this topic. METHODS: A monocentric retrospective observational study investigating the effect of the TAP block prior to primary IHR in TAPP technique was conducted. The data of 838 patients who were operated on using this technique from June 2007 to February 2019 were observed. 72 patients were excluded because of insufficient information regarding their analgesic medication protocol. The patients' data were taken from their files. RESULTS: The patients in the TAP block group (n = 364) did not differ statistically significantly compared to the control group (n = 402) in terms of gender, BMI and age. Individuals of the TAP block group experienced less postoperative pain in the PACU (p < 0.001) and received less analgesic medication (morphine, oxycodone, piritramide, acetaminophen; p < 0.001). CONCLUSION: We assume that the TAP block is a sufficient approach to reduce postoperative pain and analgesic medication administration for IHR in TAPP technique.

The Novel Arylamidine T-2307 Demonstrates In Vitro and In Vivo Activity against Candida auris.

The in vitro and in vivo activity of the arylamidine T-2307 against Candida auris was evaluated. T-2307 demonstrated in vitro activity (MIC ranges ≤ 0.008 to 0.015 µg/ml at 50% inhibition; 0.125 to >4 µg/ml at 100% inhibition). Treatment with T-2307 (3 mg/kg subcutaneous [SC] once daily) also significantly improved survival (70% at 21 days postinfection) and reduced kidney fungal burden (5.06 log10 CFU/g) compared to control (0% survival and 7.09 log10 CFU/g) (P < 0.01).

The Orai Ca2+ channel inhibitor CM4620 targets both parenchymal and immune cells to reduce inflammation in experimental acute pancreatitis.

KEY POINTS: This work confirms previous reports that CM4620, a small molecule inhibitor of Ca2+ entry via store operated Ca2+ entry (SOCE) channels formed by stromal interaction molecule 1 (STIM1)/Orai complexes, attenuates acinar cell pathology and acute pancreatitis in mouse experimental models. Here we report that intravenous administration of CM4620 reduces the severity of acute pancreatitis in the rat, a hitherto untested species. Using CM4620, we probe further the mechanisms whereby SOCE via STIM1/Orai complexes contributes to the disease in pancreatic acinar cells, supporting a role for endoplasmic reticulum stress/cell death pathways in these cells. Using CM4620, we show that SOCE via STIM1/Orai complexes promotes neutrophil oxidative burst and inflammatory gene expression during acute pancreatitis, including in immune cells which may be either circulating or invading the pancreas. Using CM4620, we show that SOCE via STIM1/Orai complexes promotes activation and fibroinflammatory gene expression within pancreatic stellate cells. ABSTRACT: Key features of acute pancreatitis include excess cellular Ca2+ entry driven by Ca2+ depletion from the endoplasmic reticulum (ER) and subsequent activation of store-operated Ca2+ entry (SOCE) channels in the plasma membrane. In several cell types, including pancreatic acinar, stellate cells (PaSCs) and immune cells, SOCE is mediated via channels composed primarily of Orai1 and stromal interaction molecule 1 (STIM1). CM4620, a selective Orai1 inhibitor, prevents Ca2+ entry in acinar cells. This study investigates the effects of CM4620 in preventing or reducing acute pancreatitis features and severity. We tested the effects of CM4620 on SOCE, trypsinogen activation, acinar cell death, activation of NFAT and NF-κB, and inflammatory responses in ex vivo and in vivo rodent models of acute pancreatitis and human pancreatic acini. We also examined whether CM4620 inhibited cytokine release in immune cells, fibro-inflammatory responses in PaSCs, and oxidative burst in neutrophils, all cell types participating in pancreatitis. CM4620 administration to rats by i.v. infusion starting 30 min after induction of pancreatitis significantly diminished pancreatitis features including pancreatic oedema, acinar cell vacuolization, intrapancreatic trypsin activity, cell death signalling and acinar cell death. CM4620 also decreased myeloperoxidase activity and inflammatory cytokine expression in pancreas and lung tissues, fMLF peptide-induced oxidative burst in human neutrophils, and cytokine production in human peripheral blood mononuclear cells (PBMCs) and rodent PaSCs, indicating that Orai1/STIM1 channels participate in the inflammatory responses of these cell types during acute pancreatitis. These findings support pathological Ca2+ entry-mediated cell death and proinflammatory signalling as central mechanisms in acute pancreatitis pathobiology.

Efficacy of T-2307, a novel arylamidine, against ocular complications of disseminated candidiasis in mice.

OBJECTIVES: T-2307, a novel arylamidine, shows broad-spectrum activity against pathogenic fungi, including Candida albicans. Ocular candidiasis is one of the serious complications associated with Candida bloodstream infection and is known to be refractory to conventional antifungal agents. The aim of the present study was to clarify the effectiveness of T-2307 against ocular candidiasis using a mouse model. METHODS: We evaluated ocular fungal burden in mice infected with C. albicans that received treatment with antifungal agents [T-2307, liposomal amphotericin B (LAMB) or fluconazole] for 3 consecutive days. We also assessed survival rates of mice after C. albicans infection followed by treatment for 7 consecutive days. In addition, ocular T-2307 concentrations and in vitro effectiveness against C. albicans biofilm formation were evaluated. RESULTS: The ocular fungal burdens were significantly reduced after T-2307 treatment compared with the control group (no treatment received) and were comparable with those observed following treatment with LAMB or fluconazole in both early- and late-phase treatment experiments. In addition, all of the mice treated with antifungal agents survived for 3 weeks after infection, whereas mice in the control group died within 3 days. The ocular T-2307 trough concentration was maintained above the MIC in the infected mice. An in vitro biofilm inhibition experiment showed that T-2307 suppressed C. albicans biofilm formation at the sub-MIC level, which was comparable with amphotericin B. CONCLUSIONS: Given these results in experimental disseminated candidiasis, T-2307 may be an effective treatment against the complication of ocular candidiasis.

New evolutions in the BACE1 inhibitor field from 2014 to 2018.

ß-Site amyloid precursor protein cleaving enzyme 1 (BACE1) inhibitors offer the potential of disease-modifying treatment for Alzheimer's disease (AD). Since 2014, major breakthroughs have appeared in the field of BACE1 inhibitors. This review provides an overview of amidine-based BACE1 inhibitors between 2014 and 2018. Herein are summarized i) the structure-activity relationship, ii) the physiological results and iii) the potential risks from a lack of selectivity. This review also summarizes clinical scope, results and outlook of the compounds that have been or are currently under development in clinical trials.

Antifungal susceptibility trend and analysis of resistance mechanism for Candida species isolated from bloodstream at a Japanese university hospital.

We compared the susceptibility of six commercially available antifungal agents (fluconazole, itraconazole, voriconazole, caspofungin, micafungin, and amphotericin B) against 133 Candida bloodstream isolates between 2008 and 2013 at Aichi Medical University Hospital. C. albicans was the most common isolate, followed by C. parapsilosis, C. glabrata, and C. tropicalis. MIC90s of voriconazole against C. albicans, C. parapsilosis, and C. tropicalis were the lowest and that of micafungin against C. glabrata was the lowest among the agents tested. Of the 133 isolates, two strains were identified as drug-resistant. One was a fluconazole-resistant C. glabrata strain, in which the ATP-binding cassette (ABC) transporter gene expression was upregulated. The other was a micafungin-resistant C. glabrata strain, that had 13 amino acid substitutions in FKS1 and FKS2, including a novel substitution V1342I in FKS1 hotspot 2. We also evaluated the susceptibility of T-2307, a novel class of antifungal agents used in clinical trials, against the fluconazole- and micafungin-resistant C. glabrata strain; the MICs of T-2307 were 0.0039 and 0.0078 µg/mL, respectively. In conclusion, the incidence of bloodstream infection caused by drug-resistant Candida spp. was rare from 2008 to 2013 at our hospital. Of 133 isolates, only two strains of C. glabrata were resistant to azoles or echinocandins, that upregulated the ABC transporter genes or had novel FKS mutations, respectively.

Inhibition of Inducible Nitric Oxide Synthase Attenuates Deficits in Synaptic Plasticity and Brain Functions Following Traumatic Brain Injury.

Traumatic brain injury (TBI), resulting from external force on the head, usually leads to long-term deficits in motor and cognitive functions. Inducible nitric oxide synthase (iNOS)-mediated excessive inflammation could exacerbate brain damage after TBI. The present study therefore investigated the potential neuroprotective effects of iNOS inhibition after TBI. Male C57BL/6J mice were subjected to controlled cortical impact injury and then treated with high selective iNOS inhibitor 1400W. Expression of iNOS mRNA was determined by quantitative RT-PCR. Western blotting was carried out to determine iNOS protein levels. Motor and cognitive functions, and long-term potentiation (LTP) in the medial prefrontal cortex (mPFC) and hippocampus were examined. Expression of iNOS was induced after TBI in a temporal manner. Treatment with 1400W after TBI improved motor and cognitive functions. TBI mice showed deficits in LTP in both the mPFC and hippocampus, and treatment with 1400W could rescue this impairment. Inhibition of iNOS attenuated deficits in synaptic plasticity and brain functions after TBI. The neuroprotective effect of iNOS inhibition on cognitive function might be via rescuing the TBI-induced LTP impairment.

In vitro and in vivo antifungal activities of T-2307, a novel arylamidine, against Cryptococcus gattii: an emerging fungal pathogen.

Objectives: T-2307, a novel arylamidine, exhibits potent broad-spectrum activities against the majority of fungal pathogens. In this study, the antifungal activity of T-2307 against Cryptococcus gattii was evaluated in comparison with those of amphotericin B, fluconazole and voriconazole in vitro and in vivo . Methods: The MICs for 15 clinical isolates were determined according to CLSI guidelines and time-kill studies were performed using C. gattii YF2784. In a murine model for intranasal pulmonary infection caused by C. gattii YF2784, the test compounds were administered once daily for 7 days from 2 h or 14 days post-infection. The viable counts in the lungs and brain were determined at 21 days post-infection. Results: The MIC range, MIC 50 , MIC 90 and geometric mean MIC of T-2307 were 0.0078-0.0625, 0.0313, 0.0625 and 0.0394 mg/L, respectively. The MIC of T-2307 was significantly lower than those of fluconazole, voriconazole and amphotericin B. T-2307 showed concentration-dependent fungicidal activity at 4 times the MIC or higher. Administration of T-2307 at 2 mg/kg/day, amphotericin B at 1 mg/kg/day and fluconazole at 160 mg/kg/day from 2 h post-infection significantly reduced viable counts in the lungs and brain. However, when the administration was started 14 days post-infection, only T-2307 significantly reduced the viable counts in both the lungs and the brain at 1 mg/kg/day. Conclusions: T-2307 shows excellent in vitro and in vivo antifungal activities against C. gattii and would be a promising new candidate for the treatment of cryptococcosis.

TOWARDS A TREATMENT FOR DIABETIC RETINOPATHY: Intravitreal Toxicity and Preclinical Safety Evaluation of Inducible Nitric Oxide Synthase Inhibitors.

BACKGROUND: The purpose of this study is to determine the maximum tolerated dose of a single intravitreal injection of aminoguanidine and 1400W, 2 inhibitors of inducible nitric oxide synthase, in rabbit eyes. Inhibition of inducible nitric oxide synthase has already been shown to be beneficial in various animal models of diabetic eye disease. METHODS: Groups of 4 New Zealand white rabbits were injected with balanced salt solution in the right eye and a single dose of either aminoguanidine (5, 1, 0.25 mg) or 1400W (2 mg and 0.4 mg) in the left eye. Toxicity was assessed by slit-lamp and fundus examination, intraocular pressure and pachymetric measurements, and electrophysiologic and histologic analysis. RESULTS: Eyes injected with high doses of aminoguanidine (5 mg) or 1400W (2 mg) demonstrated severe retinal vascular attenuation and infarction. Lower doses of intravitreal aminoguanidine (1 mg) and 1400W (0.4 mg) caused no significant toxic ocular effects in rabbit eyes. CONCLUSION: If the difference in vitreal volume between rabbit eyes and human eyes is taken into account, aminoguanidine (2.7 mg) and 1400W (1 mg) would be reasonable intravitreal doses to test for safety and efficacy in early clinical trials.

Vascular mimicry in glioblastoma following anti-angiogenic and anti-20-HETE therapies.

Glioblastoma (GBM) is one hypervascular and hypoxic tumor known among solid tumors. Antiangiogenic therapeutics (AATs) have been tested as an adjuvant to normalize blood vessels and control abnormal vasculature. Evidence of relapse exemplified in the progressive tumor growth following AAT reflects development of resistance to AATs. Here, we identified that GBM following AAT (Vatalanib) acquired an alternate mechanism to support tumor growth, called vascular mimicry (VM). We observed that Vatalanib induced VM vessels are positive for periodic acid-Schiff (PAS) matrix but devoid of any endothelium on the inner side and lined by tumor cells on the outer-side. The PAS+ matrix is positive for basal laminae (laminin) indicating vascular structures. Vatalanib treated GBM displayed various stages of VM such as initiation (mosaic), sustenance, and full-blown VM. Mature VM structures contain red blood cells (RBC) and bear semblance to the functional blood vessel-like structures, which provide all growth factors to favor tumor growth. Vatalanib treatment significantly increased VM especially in the core of the tumor, where HIF-1α was highly expressed in tumor cells. VM vessels correlate with hypoxia and are characterized by co-localized MHC-1+ tumor and HIF-1α expression. Interestingly, 20-HETE synthesis inhibitor HET0016 significantly decreased GBM tumors through decreasing VM structures both at the core and at periphery of the tumors. In summary, AAT induced resistance characterized by VM is an alternative mechanism adopted by tumors to make functional vessels by transdifferentiation of tumor cells into endothelial-like cells to supply nutrients in the event of hypoxia. AAT induced VM is a potential therapeutic target of the novel formulation of HET0016. Our present study suggests that HET0016 has a potential to target therapeutic resistance and can be combined with other antitumor agents in preclinical and clinical trials.

A Potent Inhibitor of Protein Sequestration by Expanded Triplet (CUG) Repeats that Shows Phenotypic Improvements in a Drosophila Model of Myotonic Dystrophy.

Myotonic dystrophy is the most common form of adult-onset muscular dystrophy, originating in a CTG repeat expansion in the DMPK gene. The expanded CUG transcript sequesters MBNL1, a key regulator of alternative splicing, leading to the misregulation of numerous pre-mRNAs. We report an RNA-targeted agent as a possible lead compound for the treatment of myotonic dystrophy type 1 (DM1) that reveals both the promise and challenges for this type of small-molecule approach. The agent is a potent inhibitor of the MBNL1-rCUG complex with an inhibition constant (Ki ) of 25±8 nm, and is also relatively nontoxic to HeLa cells, able to dissolve nuclear foci, and correct the insulin receptor splicing defect in DM1 model cells. Moreover, treatment with this compound improves two separate disease phenotypes in a Drosophila model of DM1: adult external eye degeneration and larval crawling defect. However, the compound has a relatively low maximum tolerated dose in mice, and its cell uptake may be limited, providing insight into directions for future development.

Biological Efficacy and Toxicity of Diamidines in Myotonic Dystrophy Type 1 Models.

Myotonic dystrophy type 1 (DM1) is a disease characterized by errors in alternative splicing, or "mis-splicing". The causative agent of mis-splicing in DM1 is an inherited CTG repeat expansion located in the 3' untranslated region of the DM protein kinase gene. When transcribed, CUG repeat expansion RNA sequesters muscleblind-like (MBNL) proteins, which constitute an important family of alternative splicing regulators. Sequestration of MBNL proteins results in the mis-splicing of its regulated transcripts. Previous work has demonstrated that pentamidine, a diamidine which is currently FDA-approved as an antiparasitic agent, was able to partially reverse mis-splicing in multiple DM1 models, albeit at toxic concentrations. In this study, we characterized a series of pentamidine analogues to determine their ability to reverse mis-splicing and their toxicity in vivo. Experiments in cell and mouse models demonstrated that compound 13, also known as furamidine, effectively reversed mis-splicing with equal efficacy and reduced toxicity compared to pentamidine.

The leukotriene B4 receptor (BLT) antagonist BIIL284 decreases atherosclerosis in ApoE-/- mice.

Leukotriene B4 (LTB4) induces proinflammatory signaling through BLT receptors expressed in atherosclerotic lesions. Either genetic or pharmacological targeting of the high affinity LTB4 receptor, BLT1, reduces atherosclerosis in different mouse models. The low affinity BLT2 receptor for LTB4 may transduce additional pro-atherogenic signaling, but combined BLT1 and BLT2 receptor antagonism has not previously been explored in atherosclerosis. The aim of the present study was to unravel the effects of the BLT receptor antagonist BIIL284 in apolipoprotein E deficient mice in terms of atherosclerotic lesion size and composition, as well as on arterial matrixmetalloproteinase (MMP) activity and plasma cytokines. Oral administration of BIIL284 (0.3-3mg/kg) dose-dependently decreased atherosclerotic lesion size after 12 weeks. In addition, significantly smaller aortic lesions were observed in mice treated with BIIL284 (3mg/kg) for 24 weeks. The reduced atherosclerosis was associated with less lesion smooth muscle cells, less arterial MMP activities and lower plasma levels of TNF-α and IL-6. Taken together, these results suggest a therapeutic value of BLT receptor antagonism in atherosclerosis.

20-Hydroxyeicosatetraenoic Acid Inhibition by HET0016 Offers Neuroprotection, Decreases Edema, and Increases Cortical Cerebral Blood Flow in a Pediatric Asphyxial Cardiac Arrest Model in Rats.

Vasoconstrictive and vasodilatory eicosanoids generated after cardiac arrest (CA) may contribute to cerebral vasomotor disturbances and neurodegeneration. We evaluated the balance of vasodilator/vasoconstrictor eicosanoids produced by cytochrome P450 (CYP) metabolism, and determined their role on cortical perfusion, functional outcome, and neurodegeneration after pediatric asphyxial CA. Cardiac arrest of 9 and 12 minutes was induced in 16- to 18-day-old rats. At 5 and 120 minutes after CA, we quantified the concentration of CYP eicosanoids in the cortex and subcortical areas. In separate rats, we inhibited 20-hydroxyeicosatetraenoic acid (20-HETE) synthesis after CA and assessed cortical cerebral blood flow (CBF), neurologic deficit score, neurodegeneration, and edema. After 9 minutes of CA, vasodilator eicosanoids markedly increased versus sham. Conversely, after 12 minutes of CA, vasoconstrictor eicosanoid 20-HETE increased versus sham, without compensatory increases in vasodilator eicosanoids. Inhibition of 20-HETE synthesis after 12 minutes of CA decreased cortical 20-HETE levels, increased CBF, reduced neurologic deficits at 3 hours, and reduced neurodegeneration and edema at 48 hours versus vehicle-treated rats. In conclusion, cerebral vasoconstrictor eicosanoids increased after a pediatric CA of 12 minutes. Inhibition of 20-HETE synthesis improved cortical perfusion and short-term neurologic outcome. These results suggest that alterations in CYP eicosanoids have a role in cerebral hypoperfusion and neurodegeneration after CA and may represent important therapeutic targets.

Chemotherapy of second stage human African trypanosomiasis: comparison between the parenteral diamidine DB829 and its oral prodrug DB868 in vervet monkeys.

Human African trypanosomiasis (HAT, sleeping sickness) ranks among the most neglected tropical diseases based on limited availability of drugs that are safe and efficacious, particularly against the second stage (central nervous system [CNS]) of infection. In response to this largely unmet need for new treatments, the Consortium for Parasitic Drug Development developed novel parenteral diamidines and corresponding oral prodrugs that have shown cure of a murine model of second stage HAT. As a rationale for selection of one of these compounds for further development, the pharmacokinetics and efficacy of intramuscular (IM) active diamidine 2,5-bis(5-amidino-2-pyridyl)furan (DB829; CPD-0802) and oral prodrug2,5-bis[5-(N-methoxyamidino)-2-pyridyl]furan (DB868) were compared in the vervet monkey model of second stage HAT. Treatment was initiated 28 days post-infection of monkeys with T. b. rhodesiense KETRI 2537. Results showed that IM DB829 at 5 mg/kg/day for 5 consecutive days, 5 mg/kg/day every other day for 5 doses, or 2.5 mg/kg/day for 5 consecutive days cured all monkeys (5/5). Oral DB868 was less successful, with no cures (0/2) at 3 mg/kg/day for 10 days and cure rates of 1/4 at 10 mg/kg/day for 10 days and 20 mg/kg/day for 10 days; in total, only 2/10 monkeys were cured with DB868 dose regimens. The geometric mean plasma Cmax of IM DB829 at 5 mg/kg following the last of 5 doses was 25-fold greater than that after 10 daily oral doses of DB868 at 20 mg/kg. These data suggest that the active diamidine DB829, administered IM, should be considered for further development as a potential new treatment for second stage HAT.

Discovery of a series of efficient, centrally efficacious BACE1 inhibitors through structure-based drug design.

The identification of centrally efficacious ß-secretase (BACE1) inhibitors for the treatment of Alzheimer's disease (AD) has historically been thwarted by an inability to maintain alignment of potency, brain availability, and desired absorption, distribution, metabolism, and excretion (ADME) properties. In this paper, we describe a series of truncated, fused thioamidines that are efficiently selective in garnering BACE1 activity without simultaneously inhibiting the closely related cathepsin D or negatively impacting brain penetration and ADME alignment, as exemplified by 36. Upon oral administration, these inhibitors exhibit robust brain availability and are efficacious in lowering central Amyloid ß (Aß) levels in mouse and dog. In addition, chronic treatment in aged PS1/APP mice effects a decrease in the number and size of Aß-derived plaques. Most importantly, evaluation of 36 in a 2-week exploratory toxicology study revealed no accumulation of autofluorescent material in retinal pigment epithelium or histology findings in the eye, issues observed with earlier BACE1 inhibitors.