A European-Japanese study on peach allergy: IgE to Pru p 7 associates with severity

BACKGROUND

Pru p 3 and Pru p 7 have been implicated as risk factors for severe peach allergy. This study aimed to establish sensitization patterns to five peach components across Europe and in Japan, to explore their relation to pollen and foods and to predict symptom severity.

METHODS

In twelve European (EuroPrevall project) and one Japanese outpatient clinic, a standardized clinical evaluation was conducted in 1231 patients who reported symptoms to peach and/or were sensitized to peach. Specific IgE against Pru p 1, 2, 3, 4 and 7 and against Cup s 7 was measured in 474 of them. Univariable and multivariable Lasso regression was applied to identify combinations of parameters predicting severity.

RESULTS

Sensitization to Pru p 3 dominated in Southern Europe but was also quite common in Northern and Central Europe. Sensitization to Pru p 7 was low and variable in the European centers but very dominant in Japan. Severity could be predicted by a model combining age of onset of peach allergy, probable mugwort, Parietaria pollen and latex allergy, and sensitization to Japanese cedar pollen, Pru p 4 and Pru p 7 which resulted in an AUC of 0.73 (95% CI 0.73-0.74). Pru p 3 tended to be a risk factor in South Europe only.

CONCLUSIONS

Pru p 7 was confirmed as a significant risk factor for severe peach allergy in Europe and Japan. Combining outcomes from clinical and demographic background with serology resulted in a model that could better predict severity than CRD alone.

Gastric functional monitoring by gastric electrical impedance tomography (gEIT) suit with dual-step fuzzy clustering

Gastric Function has been successfully estimated by gastric electrical impedance tomography (gEIT) Suit with dual-step fuzzy clustering. The gEIT Suit which are made of elastic cloth with dual-planar electrodes and compact data acquisition (DAQ) system measures gastric impedance Z to visualize the gastric conductivity distribution σ. The dual-step fuzzy clustering extracts the clustered gastric conductivity distribution ^kσ, which accurately estimates the gastric function. The gEIT Suit with dual-step fuzzy clustering are applied to eight healthy persons during liquid meal consumption to estimate the gastric function under gastric accommodation phase of 200, 400 and 600 mL based on the gastric emptying phase. As the results, the gEIT Suit successfully estimate the gastric function. By the measured impedance Z, the subjects have a mean temporal impedance [Formula: see text]= - 9.27 [Ohm] and p-value of that [Formula: see text] p(Z) = 0.0013[-]as the t-test result. In the case of gastric conductivity distribution σ, the subjects have a value of spatial mean conductivity distribution ⟨σ⟩ = 0.23[-] and p-value of that ⟨σ⟩ p(σ) = 0.0140[-]. Lastly, in the case gastric volume V, subjects have a gastric volume V = 12.44 [%] and p-value p(V) = 0.0664[-].

Structure activity relationship of N-1 substituted 1,5-naphthyrid-2-one analogs of oxabicyclooctane-linked novel bacterial topoisomerase inhibitors as broad-spectrum antibacterial agents (Part-9)

Novel bacterial topoisomerase inhibitors (NBTIs) are the newest members of gyrase inhibitor broad-spectrum antibacterial agents, represented by the most advanced member, gepotidacin, a 4-amino-piperidine linked NBTI, which is undergoing phase III clinical trials for treatment of urinary tract infections (UTI). We have extensively reported studies on oxabicyclooctane linked NBTIs, including AM-8722. The present study summarizes structure activity relationship (SAR) of AM-8722 leading to identification of 7-fluoro-1-cyanomethyl-1,5-naphthyridin-2-one based NBTI (16, AM-8888) with improved potency and spectrum (MIC values of 0.016-4 μg/mL), with Pseudomonas aeruginosa being the least sensitive strain (MIC 4 μg/mL).

“Target Heart Rate” calculated aiming at zero overlap of mitral E and A waves is useful for prediction of long-term outcome for patients with heart failure and reduced ejection fraction

Background

Lower heart rate (HR) is associated with more favourable long-term outcome in patients with heart failure with reduced ejection fraction (HFrEF). However, an optimal threshold of HR remains unclear. Targeted HR (THR), defined by echocardiographic deceleration time (DCT) to eliminated overlap of E and A waves, may aid in risk stratification of HFrEF patients.

Purpose

In this study, we aimed to clarify the impact of on long-term clinical outcome in patients with HFrEF.

Methods

In the multicenter WET-HF registry, 4000 consecutive patients hospitalized for acute decompensated HF (ADHF) were registered between 2006 and 2017. Among them, the patients with EF ≥40% or a history of atrial fibrillation were excluded. THR was calculated based on their DCT value measured in compensated HF phase during the index admission. The following formula was applied; THR (bpm)=93 - 0.13 × deceleration time (DCT, msec). A total of 876 patients with HFrEF were included in the present analysis (age: 72 [60–81], male: 69%) and the patients were divided into the 2 groups of HR at discharge ≤ THR (L group) and > THR (H group). The primary endpoint (PE) was defined as the composite of all-cause death and ADHF re-admission.

Results

Compared to the H group, the L group showed higher prevalence of males (74% vs. 66%, P=0.025) with higher body mass index (BMI, 23.2 vs. 22.2, P=0.016), hemoglobin (Hb, 12.9 vs. 12.4, P=0.031), albumin (Alb, 3.7 vs. 3.6, P=0.039) and larger left atrial diameter (LAD, 44 mm vs. 41 mm, P=0.002) and tricuspid regurgitation pressure gradient (TRPG, 29 mmHg vs. 27 mmHg, P=0.012). Age, estimated glomerular filtration rate (eGFR), LVEF (29% vs. 30%, P=NS) and E/e' (17.7 vs. 16.8, P=NS) were similar for both groups. At discharge, HR was lower in L group (66 [60–71] bpm vs. 80 [74–86] bpm, P<0.001), albeit there were no significant differences in b-blocker prescription (90% vs. 85%, P=0.069) or its dose (3.75 [1.25–7.25] mg vs. 2.5 [1.25–5] mg, P=0.11).

In the survival analysis, the L group showed a significantly lower rate of PE (P=0.03), whereas there was no significant difference in the incidence of PE between the patients with HR at discharge ≥70 bpm and <70 bpm (P=NS).

Multivariate Cox hazard analysis showed that HR at discharge ≤ THR was an independent predictor of PE (hazard ratio 0.67 [0.46–0.97], P=0.037), even after adjusting for confounding factors including age, sex, BMI, Hb, Alb, and b-blocker prescription, whereas HR at discharge <70 bpm was not (hazard ratio 0.94 [0.65–1.33], P=0.71).

Conclusion

THR was associated with long-term outcomes in patients with HFrEF after acute decompensation, suggesting that it may aid in tailored treatment for HR reduction in these patients.

Funding Acknowledgement

Type of funding sources: None. Figure 1Figure 2

Correlation between alterations in blood flow of malignant lymphomas after induction chemotherapies and clinical outcomes: a pilot study utilising contrast-enhanced ultrasonography for early interim evaluation of lymphoma treatment

AIM

To clarify the utility of contrast-enhanced ultrasonography (CEUS) for interim evaluation of response to chemotherapy in lymphoma treatment.

MATERIALS AND METHODS

CEUS was performed both before (day 0) and after the treatment (7 and/or 14 days), and a time-intensity curve was obtained. The patients were divided into two groups (complete remission [CR] group and non-CR group) according to the results of conventional response evaluation, and peak enhancement (PE), time to peak enhancement, perfusion index (PI), the total area under the curve during wash-in (AUC-in), and the total AUC were compared between the groups.

RESULTS

Among 27 patients with various types of lymphoma, the median change ratio of PE and PI at day 7 evaluation were significantly different between the CR group and the non-CR group (0.81 versus 1.39, p=0.017 for PE and 0.92 versus 2.09, p=0.010 for PI). The change ratio of PE < 1.09 (specificity: 86%; sensitivity, 88%) and PI < 1.65 (specificity: 86%; sensitivity: 94%) distinguished CR from non-CR. Patients who achieved a PE change ratio <1.09 or a PI change ratio <1.65 had significantly better estimated progression-free survival (p<0.001).

CONCLUSION

The present study demonstrated that changes in tumour perfusion parameters evaluated with CEUS at 1 week after the treatment initiation were significantly different between lymphoma patients in CR group and non-CR group. Alterations in perfusion parameters evaluated via CEUS could impact the prognosis of lymphoma patients.

Effect of air pollution on acute heart failure hospitalization differ across specific heart failure populations

Introduction

Several report showed the association between ambient air pollution including particular matter under 2.5um (PM2.5) and increasing rate of hospitalization for heart failure. However, these report analyzed mainly cross-sectional, epidemiological data, thus the reports regarding association between vulnerability to PM2.5 and specific populations in acute heart failure (AHF) were scarce.

Purpose

1. To analyze the association between air pollution and rate of hospitalization for AHF

2. To analyze whether the vulnerability to air pollution differ between specific populations in AHF. Methods

A case-cross over analysis was conducted to 4980 consecutive patients registered for multicenter acute heart failure registry in 2017 in our city Japan. This registry enrolled patients transferred to cardiovascular care unit (80 institutions) via emergency medical services across our city area. Logistic regression analysis were conducted to estimate percentage changes in the rate of acute heart failure hospitalization associated with per 1μg/m3 PM2.5 concentration increase. We also conducted subgroup analysis for patients stratified by age, gender, comorbidities, left ventricular ejection fraction, and clinical scenario.

Results

An increase in 1 μg/m3 PM2.5 concentration corresponded to 2.9% (95% CI 1.2–4.6%) increase in AHF hospitalization. Patients with age younger than 75, without prior heart failure hospitalization, without history of hypertension, without anemia, and with reduced ejection fraction were more susceptible to increase in PM2.5 concentration (Figure).

Conclusions

Increase in PM2.5 concentration was associated with increased rate of AHF hospitalization. Effect of PM2.5 may differ across specific AHF subpopulations.

Figure 1

Funding Acknowledgement

Type of funding source: Other. Main funding source(s): Tokyo Metropolitan Government

Investigation of Physiological Swelling on Conductivity Distribution in Lower Leg Subcutaneous Tissue by Electrical Impedance Tomography

There is a strong need for a non-invasive measurement technique that is capable of accurately identifying the physiological condition change or heterogeneity of subcutaneous adipose tissue (SAT) by localizing the abnormalities within the compartment. This paper aims to investigate the feasibility of Electrical Impedance Tomography (EIT) to assess the interstitial fluid in subcutaneous adipose tissue as an enhancement method of bioelectrical impedance spectroscopy (BIS). Here, we demonstrate the preliminary result of EIT with a wearable 16 electrodes sensor. The image-based reference EIT with fat weighted threshold method is proposed. In order to evaluate the performance of our novel method, a physiological swelling experiment is conducted, and Multi-Frequency Bioelectrical Impedance Analysis (MFBIA) is also applied as a comparison with EIT results. The experimental results showed that the proposed method was able to distinguish the physiological swelling condition and effectively to remove the unexpected background noise. Furthermore, the conductivity variation in the subcutaneous layer had a good correlation with extracellular water volume change from MFBIA data; the correlation coefficient R² = 0.927. It is concluded that the proposed method provides a significant prospect for SAT assessment.

2206Prevalence and determinants of complicated grief in bereaved caregivers of patients admitted for cardiovascular diseases

Introduction

Few studies have examined complicated grief in bereaved caregivers of patients with cardiovascular diseases (CVD), in contrast with studies in caregivers of patients with cancers. We examined the prevalence and determinants of complicated grief among bereaved caregivers of patients with CVD.

Methods

We conducted a cross-sectional survey using a self-administered questionnaire for bereaved family members of CVD patients who had died in the cardiology departments of 9 tertiary care centers in Japan. We assessed bereaved caregiver grief status using the Brief Grief Questionnaire (BGQ), and its association with their depression (Patient Health Questionnaire-9 [PHQ-9]). Questionnaire also covered following associated factors: bereaved family member and patient characteristics, end-of-life care (Care Evaluation Scale [CES], a scale for assessment of the structure and process of care); and the quality of the deceased patients' death (Good Death Inventory [GDI]).

Results

A total of 269 bereaved caregivers (mean age, 64±12 years; 35% male) of patients with CVD (heart failure n=155 myocardial infarction n=32, cardiopulmonary arrest n=15, arrhythmia n=8, and others n=59) were enrolled in the study. Overall, 14.1% of the bereaved caregivers had complicated grief (BGQ≥8), 32.3% had subthreshold complicated grief (BGQ=5–7), and 13.3% had depression (PHQ-9≥10). Bereaved caregivers with complicated grief frequently developed depression (58% vs. 6%, p<0.001). Among the bereaved caregivers with complicated grief, the assessment of end-of-life care was worse (CES score: 28 [21–40] vs. 23 [19–39], p=0.04), and the assessment of the deceased patients' quality of death tended to be worse (GDI score: 4.0 [3.0–4.8] vs. 4.3 [3.7–4.9], p=0.05). The cause of admission as well as preferences of the patient and family (e.g., treatment [focusing on extending life vs. relieving discomfort], desire for information, place of end-of-life) were not associated with the prevalence of complicated grief. The prevalence of complicated grief was associated with loss of a spouse, poor psychological health during the deceased patients' admission, and poor preparation for the patient's imminent death (all p<0.05). Bereaved caregivers with complicated grief had experienced more decisional burdens regarding the deceased patients' treatment (55% vs. 25%, p=0.001). Notably, 64% of bereaved caregivers with complicated grief were not treated (i.e., neither routine follow-up by psychiatrists/psychotherapist nor prescription for anti-depressants/tranquilizers).

Conclusions

The prevalence of complicated grief of bereavement was 14.0%. When subthreshold complicated grief was included, the prevalence of complicated grief increased to include half of the caregivers; therefore, routine screening of the bereaved could be recommended. Clinicians should pay particular attention to bereaved families with high risk factors to identify those at risk for future development of complicated grief.

P684Long-term outcomes in patients with cancer undergoing percutaneous coronary intervention: analysis from a Japan multicenter registry

Background

Cancer and cardiovascular disease (CVD) is the most common cause of death in developed countries, and substantial overlap exist in their medical care. However, the detailed and updated information on outcome of cancer patients with cardiovascular disease (CVD), particularly in clinically significant coronary artery disease (CAD) remain unknown.

Purpose

We sought to describe the prevalence and long-term outcomes of cancer patients undergoing percutaneous coronary intervention (PCI), which has become a coronerstone in the management of CVD.

Methods

Patient data extracted from a regional prospectiveprocedure-based multicenter registry for PCI was analyzed. A total of 4,455 patients who underwent PCI at 15 hospitals within metropolitan Tokyo from September 2008 to 2012 were followed for 2 years. “Active” cancer patient was defined as having a history of cancer not cured or in remission. We analyzed in acute and stable presentation.The occurrence of clinical outcomes was assessed via Kaplan-Meier survival curve, and Cox-regression hazard model to adjust for known clinical predictors.

Results

Within the studied patients, 173 (3.9%) had a concomitant “active” cancer at the time of intervention. There was a significant difference between the patients with and without active cancer in each situation. In stable presentation, cancer group were older, lower BMI, frequently had silent ischemia, COPD and cerebrovascular/peripheral disease, and less often had dyslipidemia compared with non-cancer group. In acute presentation, cancer group were older, frequently had COPD, CKD, peripheral disease and history of HF compared with non-cancer group. The prescription rate of RAAS inhibitor was lower in the cancer group than in the non-cancer group in acute presentation. Notably, in both acute and stable presentation, these patients had significantly higher risk of all-cause mortality (HR 8.01: 95%, p<0.001 and HR5.53: 95%, p<0.001, respectively), and they were also at higher risk of major cardo- and cerebrovascular events (MACCE; HR2.38, p<0.001, HR2.33, p=0.001), when referenced to non-cancer patients after 2 year of follow-up.

Conclusion

Cancer patient was present in 3.9% of all PCI patients and was strongly associated with both non-cardiac and cardiac adverse events.

P2622Use of intravenous vasodilators in patients hospitalized with acute heart failure: insights from Tokyo cardiovascular care unit network database

Background

Despite recommendations from clinical practice guidelines, there is scant evidence confirming the effects of vasodilators on clinical outcomes in patients with acute heart failure (AHF).

Purpose

We sought to investigate the effects of intravenous vasodilators on clinical outcomes and to identify the potential patient populations that would benefit from its use.

Methods

Data of 26 212 consecutive patients urgently hospitalized for AHF between 2009 and 2015 were extracted from a multicenter data registration system (Tokyo Cardiovascular Care Unit Network Database, including 72 institutions within the Tokyo metropolitan area in Japan). Patients who did not present with typical AHF episodes, including those without pulmonary congestion on physical and/or chest X-ray and serum B-type natriuretic peptide level <500 pg/ml, as well as those who had hypotension and/or hypoperfusion (systolic blood pressure [SBP] <100 mmHg) as dominant presentation, were excluded. Propensity scores were calculated with multiple imputation and 1:1 matching performed between patients with and without vasodilators. The primary endpoint was in-hospital mortality and the secondary endpoints were length of intensive/cardiovascular care unit (ICU/CCU) stay and hospital stay.

Results

Overall, 8 863 patients were included in the present analysis; they were predominantly male (57%) with a median age of 79 (interquartile range: 70–86) years. Compared with the group without vasodilator use, the vasodilator group had higher SBPs and heart rates and higher frequency of assisted ventilation use, but lower frequency of intravenous diuretics use. After propensity score matching, there were no significant differences in in-hospital mortality rates (7.8% vs. 8.9% in patients without vasodilators, p=0.16) or in length of ICU/CCU stay (5.8 days vs. 5.4 days, p=0.44) and hospital stay (22.7 days vs. 23.8 days, p=0.22) between the groups. However, in subgroup analyses, favorable impacts of vasodilator use on in-hospital mortality were observed among patients who had higher SBPs and among those who had no atrial fibrillation upon admission (Figure). In addition, vasodilators were likely to be more effective in AHF patients with SBP increasing; while levels below 140 mmHg of SBP appeared to be associated with an increased risk for mortality among patients treated with vasodilators compared with those without vasodilators.

Figure 1

Conclusions

In patients with AHF, vasodilator use was not universally associated with improved in-hospital outcomes; however, its effect was dependent of individual clinical presentation. Detailed phenotyping might aid tailoring of treatment strategies for patients with AHF.

Acknowledgement/Funding

the Tokyo Metropolitan Government

Development of three-dimensional integrated microchannel-electrode system to understand the particles' movement with electrokinetics

An optical transparent 3-D Integrated Microchannel-Electrode System (3-DIMES) has been developed to understand the particles' movement with electrokinetics in the microchannel. In this system, 40 multilayered electrodes are embedded at the 2 opposite sides along the 5 square cross-sections of the microchannel by using Micro Electro-Mechanical Systems technology in order to achieve the optical transparency at the other 2 opposite sides. The concept of the 3-DIMES is that the particles are driven by electrokinetic forces which are dielectrophoretic force, thermal buoyancy, electrothermal force, and electroosmotic force in a three-dimensional scope by selecting the excitation multilayered electrodes. As a first step to understand the particles' movement driven by electrokinetic forces in high conductive fluid (phosphate buffer saline (PBS)) with the 3-DIMES, the velocities of particles' movement with one pair of the electrodes are measured three dimensionally by Particle Image Velocimetry technique in PBS; meanwhile, low conductive fluid (deionized water) is used as a reference. Then, the particles' movement driven by the electrokinetic forces is discussed theoretically to estimate dominant forces exerting on the particles. Finally, from the theoretical estimation, the particles' movement mainly results from the dominant forces which are thermal buoyancy and electrothermal force, while the velocity vortex formed at the 2 edges of the electrodes is because of the electroosmotic force. The conclusions suggest that the 3-DIMES with PBS as high conductive fluid helps to understand the three-dimensional advantageous flow structures for cell manipulation in biomedical applications.

Acotiamide Hydrochloride, a Therapeutic Agent for Functional Dyspepsia, Enhances Acetylcholine-induced Contraction via Inhibition of Acetylcholinesterase Activity in Circular Muscle Strips of Guinea Pig Stomach

Acotiamide is a first-in-class prokinetic drug approved in Japan for the treatment of functional dyspepsia. Given that acotiamide enhances gastric motility in conscious dogs and rats, we assessed the in vitro effects of this drug on the contraction of guinea pig stomach strips and on acetylcholinesterase (AChE) activity in stomach homogenate following fundus removal. We also investigated the serotonin 5-HT4 receptor agonist mosapride, dopamine D2 receptor and AChE inhibitor itopride, and representative AChE inhibitor neostigmine. Acotiamide (0.3 and 1 μM) and itopride (1 and 3 μM) significantly enhanced the contraction of gastric body strips induced by electrical field stimulation (EFS), but mosapride (1 and 10 μM) did not. Acotiamide and itopride significantly enhanced the contraction of gastric body and antrum strips induced by acetylcholine (ACh), but not that induced by carbachol (CCh). Neostigmine also significantly enhanced the contraction of gastric body strips induced by ACh, but not that by CCh. In contrast, mosapride failed to enhance contractions induced by either ACh or CCh in gastric antrum strips. Acotiamide exerted mixed inhibition of AChE, and the percentage inhibition of acotiamide (100 μM) against AChE activity was markedly reduced after the reaction mixture was dialyzed. In contrast, itopride exerted noncompetitive inhibition on AChE activity. These results indicate that acotiamide enhances ACh-dependent contraction in gastric strips of guinea pigs via the inhibition of AChE activity, and that it exerts mixed and reversible inhibition of AChE derived from guinea pig stomach.

Structure activity relationship of C-2 ether substituted 1,5-naphthyridine analogs of oxabicyclooctane-linked novel bacterial topoisomerase inhibitors as broad-spectrum antibacterial agents (Part-5)

Oxabicyclooctane linked novel bacterial topoisomerase inhibitors (NBTIs) are new class of recently reported broad-spectrum antibacterial agents. They target bacterial DNA gyrase and topoisomerase IV and bind to a site different than quinolones. They show no cross-resistance to known antibiotics and provide opportunity to combat drug-resistant bacteria. A structure activity relationship of the C-2 substituted ether analogs of 1,5-naphthyridine oxabicyclooctane-linked NBTIs are described. Synthesis and antibacterial activities of a total of 63 analogs have been summarized representing alkyl, cyclo alkyl, fluoro alkyl, hydroxy alkyl, amino alkyl, and carboxyl alkyl ethers. All compounds were tested against three key strains each of Gram-positive and Gram-negative bacteria as well as for hERG binding activities. Many key compounds were also tested for the functional hERG activity. Six compounds were evaluated for efficacy in a murine bacteremia model of Staphylococcus aureus infection. Significant tolerance for the ether substitution (including polar groups such as amino and carboxyl) at C-2 was observed for S. aureus activity however the same was not true for Enterococcus faecium and Gram-negative strains. Reduced clogD generally showed reduced hERG activity and improved in vivo efficacy but was generally associated with decreased overall potency. One of the best compounds was hydroxy propyl ether (16), which mainly retained the potency, spectrum and in vivo efficacy of AM8085 associated with the decreased hERG activity and improved physical property.

Structure activity relationship of pyridoxazinone substituted RHS analogs of oxabicyclooctane-linked 1,5-naphthyridinyl novel bacterial topoisomerase inhibitors as broad-spectrum antibacterial agents (Part-6)

Oxabicyclooctane linked 1,5-naphthyridinyl-pyridoxazinones are novel broad-spectrum bacterial topoisomerase inhibitors (NBTIs) targeting bacterial DNA gyrase and topoisomerase IV at a site different than quinolones. Due to lack of cross-resistance to known antibiotics they present excellent opportunity to combat drug-resistant bacteria. A structure activity relationship of the pyridoxazinone moiety is described in this Letter. Chemical synthesis and activities of NBTIs with substitutions at C-3, C-4 and C-7 of the pyridoxazinone moiety with halogens, alkyl groups and methoxy group has been described. In addition, substitutions of the linker NH proton and its transformation into amide analogs of AM-8085 and AM-8191 have been reported. Fluoro, chloro, and methyl groups at C-3 of the pyridoxazinone moiety retained the potency and spectrum. In addition, a C-3 fluoro analog showed 4-fold better oral efficacy (ED50 3.9 mg/kg) as compared to the parent AM-8085 in a murine bacteremia model of infection of Staphylococcus aureus. Even modest polarity (e.g., methoxy) is not tolerated at C-3 of the pyridoxazinone unit. The basicity and NH group of the linker is important for the activity when CH2 is at the linker position-8. However, amides (with linker position-8 ketone) with a position-7 NH or N-methyl group retained potency and spectrum suggesting that neither basicity nor hydrogen-donor properties of the linker amide NH is essential for the activity. This would suggest likely an altered binding mode of the linker position-7,8 amide containing compounds. The amides showed highly improved hERG (functional IC50 >30 μM) profile.

Structure activity relationship of substituted 1,5-naphthyridine analogs of oxabicyclooctane-linked novel bacterial topoisomerase inhibitors as broad-spectrum antibacterial agents (Part-4)

Bacterial resistance is rapidly growing, necessitating the need to discover new agents. Novel bacterial topoisomerase inhibitors (NBTIs) are new class of broad-spectrum antibacterial agents targeting bacterial DNA gyrase and topoisomerase IV. This class of inhibitors binds to an alternative binding site relative to fluoroquinolones and shows no cross-resistance to quinolones. NBTIs consist of three structural motifs. A structure activity relationship of the left hand motif 1,5-naphthyridine of oxabicyclooctane-linked NBTIs is described. Fifty five compounds were evaluated against a panel of key Gram-positive and Gram-negative strains of bacteria, as well as for hERG activity and five compounds were tested for in vivo efficacy in murine model of Staphylococcus aureus infection. These studies suggest that only a narrow range (activating and deactivating) of substitutions at C-2 and C-7 are tolerated for optimal antibacterial activity and spectrum. An alkoxy (methoxy) and CN at C-2, and a halogen and hydroxyl at C-7, appeared to be preferred in this series. Substitutions on the other three carbons generally have detrimental effect on the activity. No clear hERG activity SAR emerged from these substitutions.

Tricyclic 1,5-naphthyridinone oxabicyclooctane-linked novel bacterial topoisomerase inhibitors as broad-spectrum antibacterial agents-SAR of left-hand-side moiety (Part-2)

Novel bacterial topoisomerase inhibitors (NBTIs) represent a new class of broad-spectrum antibacterial agents targeting bacterial Gyrase A and ParC and have potential utility in combating antibiotic resistance. A series of novel oxabicyclooctane-linked NBTIs with new tricyclic-1,5-naphthyridinone left hand side moieties have been described. Compounds with a (R)-hydroxy-1,5-naphthyridinone moiety (7) showed potent antibacterial activity (e.g., Staphylococcus aureus MIC 0.25 μg/mL), acceptable Gram-positive and Gram-negative spectrum with rapidly bactericidal activity. The compound 7 showed intravenous and oral efficacy (ED50) at 3.2 and 27 mg/kg doses, respectively, in a murine model of bacteremia. Most importantly they showed significant attenuation of functional hERG activity (IC50 >170 μM). In general, lower logD attenuated hERG activity but also reduced Gram-negative activity. The co-crystal structure of a hydroxy-tricyclic NBTI bound to a DNA-gyrase complex exhibited a binding mode that show enantiomeric preference for R isomer and explains the activity and SAR. The discovery, synthesis, SAR and X-ray crystal structure of the left-hand-side tricyclic 1,5-naphthyridinone based oxabicyclooctane linked NBTIs are described.

C1–C2-linker substituted 1,5-naphthyridine analogues of oxabicyclooctane-linked NBTIs as broad-spectrum antibacterial agents (part 7)

Substitutions around linker positions C-1 and C-2 suggest that the C-2α hydroxy group is the best for activity.

Dietary Yeasts Reduce Inflammation in Central Nerve System via Microflora

Objectives

The intestinal microflora affects the pathogenesis of several autoimmune diseases by influencing immune system function. Some bacteria, such as lactic acid bacteria, have been reported to have beneficial effects on immune function. However, little is known about the effects of yeasts. Here, we aimed to investigate the effects of various dietary yeasts contained in fermented foods on experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS), and to elucidate the mechanisms underlying these effects.

Methods

The effects of eight yeasts selected from 18 types of yeasts contained in fermented foods were examined using an EAE model. Of these, Candida kefyr was investigated by analyzing the intestinal microflora and its effects on intestinal and systemic immune states.

Results

Administration of C. kefyr ameliorated the severity of EAE. Reduced numbers of Th17 cells, suppressed interleukin (IL)-6 production by intestinal explants, and increased Tregs and CD103-positive regulatory dendritic cells in mesenteric lymph nodes (MLNs) were observed. Analysis of 16s-rDNA from feces of C. kefyr-treated mice demonstrated increased Lactobacillales and decreased Bacteroides compared to control flora. Transfer of intestinal microbiota also resulted in decreased Bacteroides and ameliorated symptoms of EAE. Thus, oral administration of C. kefyr ameliorated EAE by altering the microflora, accompanied by increased Tregs and CD103-positive regulatory dendritic cells in MLNs and decreased Th17 cells in the intestinal lamina propria.

Interpretation

Oral ingestion of C. kefyr may have beneficial effects on MS by modifying microflora. In addition, our findings also suggested the potential health benefits of dietary yeasts.

Structures of kibdelomycin bound to Staphylococcus aureus GyrB and ParE showed a novel U-shaped binding mode

Bacterial resistance to antibiotics continues to pose serious challenges as the discovery rate for new antibiotics fades. Kibdelomycin is one of the rare, novel, natural product antibiotics discovered recently that inhibits the bacterial DNA synthesis enzymes gyrase and topoisomerase IV. It is a broad-spectrum, Gram-positive antibiotic without cross-resistance to known gyrase inhibitors, including clinically effective quinolones. To understand its mechanism of action, binding mode, and lack of cross-resistance, we have co-crystallized kibdelomycin and novobiocin with the N-terminal domains of Staphylococcus aureus gyrase B (24 kDa) and topo IV (ParE, 24 and 43 kDa). Kibdelomycin shows a unique "dual-arm", U-shaped binding mode in both crystal structures. The pyrrolamide moiety in the lower part of kibdelomycin penetrates deeply into the ATP-binding site pocket, whereas the isopropyl-tetramic acid and sugar moiety of the upper part thoroughly engage in polar interactions with a surface patch of the protein. The isoproramic acid (1,3-dioxopyrrolidine) and a tetrahydropyran acetate group (Sugar A) make polar contact with a surface area consisting of helix α4 and the flexible loop connecting helices α3 and α4. The two arms are connected together by a rigid decalin linker that makes van del Waals contacts with the protein backbone. This "dual-arm", U-shaped, multicontact binding mode of kibdelomycin is unique and distinctively different from binding modes of other known gyrase inhibitors (e.g., coumarins and quinolones), which explains its lack of cross-resistance and low frequency of resistance. The crystal structures reported in this paper should enable design and discovery of analogues with better properties and antibacterial spectrum.

Oxabicyclooctane-linked novel bacterial topoisomerase inhibitors as broad spectrum antibacterial agents

Bacterial resistance is eroding the clinical utility of existing antibiotics necessitating the discovery of new agents. Bacterial type II topoisomerase is a clinically validated, highly effective, and proven drug target. This target is amenable to inhibition by diverse classes of inhibitors with alternative and distinct binding sites to quinolone antibiotics, thus enabling the development of agents that lack cross-resistance to quinolones. Described here are novel bacterial topoisomerase inhibitors (NBTIs), which are a new class of gyrase and topo IV inhibitors and consist of three distinct structural moieties. The substitution of the linker moiety led to discovery of potent broad-spectrum NBTIs with reduced off-target activity (hERG IC50 > 18 μM) and improved physical properties. AM8191 is bactericidal and selectively inhibits DNA synthesis and Staphylococcus aureus gyrase (IC50 = 1.02 μM) and topo IV (IC50 = 10.4 μM). AM8191 showed parenteral and oral efficacy (ED50) at less than 2.5 mg/kg doses in a S. aureus murine infection model. A cocrystal structure of AM8191 bound to S. aureus DNA-gyrase showed binding interactions similar to that reported for GSK299423, displaying a key contact of Asp83 with the basic amine at position-7 of the linker.

Treatment of a Gilbert's Syndrome Patient with Irinotecan, Leucovorin and 5-Fluorouracil

The patient was an elderly male who had radical surgery for sigmoid cancer in 2001. Owing to metastasis of his cancer to the left supraclavicular lymph nodes in 2002, the patient was admitted to our hospital for systemic chemotherapy. We started treatment with irinotecan, leucovorin, 5-fluorouracil (IFL). After administering 100 mg/m2 of irinotecan, 250 mg/m2 leucovorin and 600 mg/m2 5-fluorouracil to the patient on day 1, grade 3 leukopenia developed rapidly and grade 4 thrombocytopenia was observed on day 5. We excluded irinotecan from the medication and continued the administration of 5-fluorouracil and leucovorin, but his tumors had not been reduced sufficiently. Based on some examination results, we assumed that the patient had Gilbert's syndrome and that the severe side effects that occurred were due to prolongation of SN38 metabolism. We again administered irinotecan but at reduced dose (25 mg/m2). Four courses of this modified IFL were administered safely and the response was favorable.

Acotiamide, a new orally active acetylcholinesterase inhibitor, stimulates gastrointestinal motor activity in conscious dogs

BACKGROUND Acotiamide hydrochloride (acotiamide), a novel selective acetylcholinesterase (AChE) inhibitor, has proven significantly effective in treating functional dyspepsia (FD) in clinical trials, particularly in alleviating meal-related symptoms. In the present study, we examined the gastrointestinal prokinetic effects of acotiamide administered orally or intraduodenally in conscious dogs and investigated in vivo and ex vivo anti-AChE activity of acotiamide to clarify its mechanism of prokinetic action.

METHODS

Gastrointestinal motility was measured in conscious dogs with chronically implanted force transducers.

KEY RESULTS

Oral administration of acotiamide stimulated postprandial gastroduodenal and colonic motor activities. Measurement of gastrointestinal motility showed that acotiamide, like itopride and mosapride, enhanced gastric antral motility. Further, acotiamide markedly improved clonidine (an α(2) -adrenoceptor agonist)-induced hypomotility in a dog model of gastric motor dysfunction. The postprandial gastric antral motility enhanced by acotiamide was completely abolished on treatment with the muscarinic receptor antagonist atropine. Results of an in vivo experiment on anti-AChE activity showed clearly increased acetylcholine-induced gastric motility on intraduodenal administration of acotiamide, just as observed with the AChE inhibitor neostigmine. Further, in ex vivo experiment, intraduodenal administration of acotiamide significantly inhibited AChE activity in canine gastric antrum.

CONCLUSIONS & INFERENCES

Our findings revealed that acotiamide administered through the alimentary tract exerts gastroprokinetic action via cholinergic pathways by inhibiting AChE activity. These results may also confirm the mechanism of action in clinical efficacy of acotiamide on FD.

Antiproteinuric effect of angiotensin-converting enzyme inhibitors and an angiotensin II receptor blocker in patients with lupus nephritis

Although the effects of angiotensin II receptor blockers (ARBs) on non-diabetic glomerulonephritis have been reported, studies of their effects on collagen-vascular diseases, particularly lupus nephritis, are limited. In this retrospective, observational study, systemic lupus erythematosus (SLE) patients (n = 7) with lupus nephritis and uncontrolled proteinuria were treated with an angiotensin-converting enzyme inhibitor followed by the ARB losartan (25 - 50 mg/day). Urinary protein excretion and renal function were evaluated. After 12 months of losartan, mean urinary protein excretion decreased significantly by 84.8%. Mean systolic and diastolic blood pressures also decreased significantly during the 12 months of losartan treatment, although not in normotensive patients. Complement 4, total complement activity and anti-dsDNA antibody levels, which are indices of SLE activity, and serum creatinine levels, which is an index of renal function, showed no change in response to losartan treatment. A more extensive evaluation of the effects of ARBs in patients with lupus nephritis and poorly controlled proteinuria is required.

Spiking expression of mu-crystallin mRNA during treatment with methimazole in patients with graves' hyperthyroidism

mu-Crystallin is an NADPH-dependent cytosolic T3-binding protein. A knockout study in mice showed that mu-crystallin has a physiological function as a reservoir of T3 in the cytoplasm in vivo. Patients with nonsyndromic deafness were reported to have point mutations in the mu-crystallin gene. The expression of mu-crystallin is regulated by multiple factors. The present study was performed to determine whether thyroid function is related to the expression of mu-crystallin mRNA in peripheral mononuclear cells. We examined 23 normal healthy male and female subjects and 15 patients with Graves' disease. mu-Crystallin protein expression was determined immunohistochemically in peripheral mononuclear cells. The expression of mu-crystallin mRNA was assessed by reverse transcription of total RNA from peripheral mononuclear cells followed by quantitative PCR. mu-Crystallin protein was detected in peripheral mononuclear cells. The mRNA expression was negatively correlated with age in normal female subjects. The values in female subjects were significantly higher than those in males. The values were positively correlated with serum TSH concentration. The values of the thyrotoxic patients with Graves' disease were lower than those in healthy subjects. A transient increase in mu-crystallin expression was observed within 14-42 days after the initial treatment with antithyroid medication. Thyroid hormone inversely relates to the expression of mu-crystallin mRNA in euthyroid mononuclear cells. Abrupt suppression of thyroid function leads to overexpression of mu-crystallin mRNA in thyrotoxic mononuclear cells. Thyroid hormone-regulated mu-crystallin expression may control thyroid hormone action via the intracytoplasmic T (3) capacity.

Efficacy of quinolones against secondary pneumococcal pneumonia after influenza virus infection in mice

We established a mouse model of secondary pneumococcal pneumonia after influenza virus infection and investigated the efficacy of several quinolones against pneumonia in this model. Gatifloxacin exhibited the highest efficacy among the quinolones examined and is probably useful for the treatment of secondary bacterial pneumonia.

Cultivation of Neisseria gonorrhoeae in liquid media and determination of its in vitro susceptibilities to quinolones

The cultivation of Neisseria gonorrhoeae by use of fastidious broth (FB) was evaluated. FB was found to be able to support the growth of all N. gonorrhoeae strains tested in this study without a rapid decrease in the viable count after exponential growth. After 24 h of incubation at 35 degrees C with 5% CO(2), viable counts of all strains reached over 10(8) CFU/ml in FB. Similar growth of the wild-type strain and its target-altered quinolone-resistant derivatives was observed. The susceptibilities of laboratory-adapted strains and clinical isolates to quinolones were tested by the microdilution method using FB. The MICs determined by microdilution were not significantly different from those determined by the agar dilution method recommended by the CLSI (formerly National Committee for Clinical Laboratory Standards). Moreover, the concentration-dependent time-kill of quinolones such as gatifloxacin and ciprofloxacin was observed in FB. At 2 to 4 times the MIC, gatifloxacin and ciprofloxacin were predominantly bactericidal against N. gonorrhoeae WHO A. At the MIC, the activities of both quinolones ranged from bactericidal to bacteriostatic. At 0.25 to 0.5 times the MIC, gonococcal growth was comparable to that of the growth control. These results suggest that the cultivation of N. gonorrhoeae by use of FB may be useful for evaluation of the antibacterial effects of quinolones.