Copper Complexes with N,N,N-Tridentate Quinolinyl Anilido-Imine Ligands: Synthesis and Their Catalytic Application in Chan-Lam Reactions

The treatment of 2-(ArNC(H))C6H4-HNC9H6N with n-BuLi and the subsequent addition of CuCl2 afforded the anilido-aldimine Cu(II) complexes 1-5 Cu[{2-[ArN=C(H)]C6H4}N(8-C9H6N)]Cl (Ar = 2,6-iPr2C6H3 (1), 2,4,6-(CH3)3C6H2 (2), 4-OCH3C6H4 (3), 4-BrC6H4 (4), 4-ClC6H4 (5)), respectively. All the copper complexes were fully characterized by IR, EPR and HR-MS spectra. The X-ray diffraction analysis reveals that 2 and 4 are mononuclear complexes, and the Cu atom is sitting in a slightly square-planar geometry. These Cu(II) complexes have exhibited excellent catalytic activity in the Chan-Lam coupling reactions of benzimidazole derivatives with arylboronic acids, achieving the highest yields of up to 96%.

Nitric Oxide-Loaded Bioinspired Lipoprotein Normalizes Tumor Vessels To Improve Intratumor Delivery and Chemotherapy of Albumin-Bound Paclitaxel Nanoparticles

The disorganized vasculatures in tumors represent a substantial challenge of intratumor nanomedicine delivery to exert the anticancer effects. Herein, we rationally designed a glutathione (GSH)-activated nitric oxide (NO) donor loaded bioinspired lipoprotein system (NO-BLP) to normalize tumor vessels and then promote the delivery efficiency of sequential albumin-bound paclitaxel nanoparticles (PAN) in tumors. NO-BLP exhibited higher tumor accumulation and deeper penetration versus the counterpart liposomal formulation (NO-Lipo) in 4T1 breast cancer tumors, thus producing notable vascular normalization efficacy and causing a 2.33-fold increase of PAN accumulation. The sequential strategy of NO-BLP plus PAN resulted in an 81.03% inhibition of tumor growth in 4T1 tumors, which was better than the NO-BLP monotherapy, PAN monotherapy, and the counterpart NO-Lipo plus PAN treatment. Therefore, the bioinspired lipoprotein of NO-BLP provides an encouraging platform to normalize tumor vessels and promote intratumor delivery of nanomedicines for effective cancer treatment.

Full factorial design, physicochemical characterization, ex vivo investigation, and biological assessment of glutathione-loaded solid lipid nanoparticles for topical application

l-Glutathione (GSH) has exceptional antioxidant activities against UVA irradiation-induced oxidative stress and is used widely for combatting skin ageing. However, topical administration of GSH is challenging due to its inability to penetrate the stratum corneum (SC). This study aims to evaluate the solid lipid nanoparticles (SLNs) carrier system for improving the skin penetration and stability of GSH. The GSH-loaded SLNs (GSH-SLNs) were prepared by the double emulsion technique and were optimized by a full factorial design. The optimized GSH-SLNs formulation had a mean particle size of 305 ± 0.6 nm and a zeta potential of + 20.1 ± 9.5 mV, suitable for topical delivery. The ex-vivo penetration study using human skin demonstrated a 3.7-fold improvement of GSH penetration across SC with GSH-SLNs when compared with aqueous GSH. GSH-SLNs prolonged antioxidant activity on UVA irradiated fibroblast cells when compared to GSH solution, preventing UVA-induced cell death and promoting cell growth for times over 48 h. This research has illustrated that as a carrier system, SLNs were able to enhance the physicochemical stability, skin penetration, and drug deposition in the viable epidermis and dermis layers of the skin for GSH, while also maintaining the ability to protect human skin fibroblast cells against oxidative stress caused by UVA irradiation. This delivery system shows future promise as a topical delivery platform for the topical delivery of GSH and other chemically similar bioactive compounds for improving skin health.

Dehydrogenative Synthesis of Quinolines and Quinazolines via Ligand-Free Cobalt-Catalyzed Cyclization of 2-Aminoaryl Alcohols with Ketones or Nitriles

We present a convenient and efficient protocol to synthesize quinolines and quinazolines in one pot under mild conditions. A variety of substituted quinolines were synthesized in good to excellent yields (up to 97% yield) from the dehydrogenative cyclizations of 2-aminoaryl alcohols and ketones catalyzed by readily available Co(OAc)₂·4H₂O. This cobalt catalytic system also showed high activity in the reactions of 2-aminobenzyl alcohols with nitriles, affording various quinazoline derivatives (up to 95% yield). The present protocol offers an environmentally benign approach for the synthesis of N-heterocycles by employing an earth-abundant cobalt salt under ligand-free conditions.

Biomechanical study of extramedullary and intramedullary fixation in the treatment of unstable intertrochanteric reversed-tilt fractures of the femur

Background

To investigate the efficacy of the 135° hip screw, 95° intramedullary hip screw (IMHS) and 95° hip screw in the treatment of intertrochanteric reverse dip fracture of the femur.

Methods

We retrospectively analyzed 125 matched pairs of human femurs (median age 64 years) which were osteotomized at a 33° angle in the left femur and extended downward from the minor trochanter to simulate a reverse oblique intertrochanteric fracture. The right femur served as a control. The left femur (n=4) was implanted with a 135° hip screw, 95° hip screw, or IMHS. A strain detector was placed distal to the fracture site to monitor fragment strain. The lateral displacement of the proximal femur was measured by a linear variable differential transformer. An Instron tester measured stiffness, strain, and lateral displacement at 25° adduction, and 90° adduction with vertical loads on the femoral head. A 2 cm gap was then formed at the fracture site to simulate comminution and the mechanical test was repeated.

Results

Before the formation of the gap, there was no significant difference in stiffness among different bone structures (P>0.05), but after the formation of the gap, the stiffness of all the adduction structures decreased (P=0.03), and the difference in adduction was statistically significant (135° hip screw: 46.6%±3%; 95° hip screw: 22.9%±2%; IMHS: 53.7%±7.8%; P<0.05). Similar results were found for the abduction and buckling positions. There was no significant difference in the lateral displacement of the gap before (P=0.92) and after (P=0.26), but a significant difference in the failure load was found (135° hip screw: 1,222±560 N; 95° hip screw: 2,566±283 N; IMHS: 4,644±518 N; P=0.02).

Conclusions

There was no statistically significant difference in stiffness among different structures (P>0.05). However, in the presence of gaps, IMHS bone implant structures are much stiffer than 135° and 95° structures and have a greater destructive load.

An experimental model of the epithelial to mesenchymal transition and pro-fibrogenesis in urothelial cells related to bladder pain syndrome/interstitial cystitis

Background

Suitable in vitro models are needed to investigate urothelial epithelial to mesenchymal transition (EMT) and pro-fibrogenesis phenotype in bladder pain syndrome/interstitial cystitis (BPS/IC). This study is to establish a novel experimental BPS/IC cell model and explore how different concentrations of tumor necrosis factor (TNF)-α influence the EMT and pro-fibrogenesis phenotype of urothelial cells.

Methods

SV-HUC-1 urothelial cells were cultured with 2, 10, or 50 ng/mL TNF-α to mimic chronic inflammatory stimulation. The EMT and pro-fibrogenesis phenotype, including production of collagen I and pro-fibrosis cytokines, were estimated after 72 h of culture.

Results

The bladder urothelial cells of BPS/IC exhibited upregulated vimentin, TNF-α and TNF receptor, downregulated E-cadherin, and increased collagen I. Higher concentrations of TNF-α (10 and 50 ng/mL) produced an obvious mesenchymal morphology, enhanced invasion and migratory capacity, increased expression of vimentin, and decreased expression of E-cadherin. Collagen I was increased in cells treated with 2 and 10 ng/mL TNF-α after 72 h. Secretion of interleukin (IL)-6 and IL-8 was promoted with 10 and 50 ng/mL TNF-α, while that of IL-1β or transforming growth factor-β was unaffected. Slug and Smad2 were upregulated by TNF-α after 72 h. The Smad pathway was activated most strongly with 10 ng/mL TNF-α and Slug pathway activation was positively correlated with the concentration of TNF-α.

Conclusions

Sustained 10 ng/mL TNF-α stimulation induced the EMT and pro-fibrogenesis phenotype resembling BPS/IC in SV-HUC-1 cells. Minor inflammatory stimulation induced the pro-fibrogenesis phenotype while severe inflammatory stimulation was more likely to produce significant EMT changes. Different degrees of activation of the Slug and Smad pathways may underlie this phenomenon.

Synthesis and structure-activity relationships for a new class of tetrahydronaphthalene amide inhibitors of Mycobacterium tuberculosis

Drug resistant tuberculsosis (TB) is global health crisis that demands novel treatment strategies. Bacterial ATP synthase inhibitors such as bedaquiline and next-generation analogues (such as TBAJ-876) have shown promising efficacy in patient populations and preclinical studies, respectively, suggesting that selective targeting of this enzyme presents a validated therapeutic strategy for the treatment of TB. In this work, we report tetrahydronaphthalene amides (THNAs) as a new class of ATP synthase inhibitors that are effective in preventing the growth of Mycobacterium tuberculosis (M.tb) in culture. Design, synthesis and comprehensive structure-activity relationship studies for approximately 80 THNA analogues are described, with a small selection of compounds exhibiting potent (in some cases MIC₉₀ <1 μg/mL) in vitro M.tb growth inhibition taken forward to pharmacokinetic and off-target profiling studies. Ultimately, we show that some of these THNAs possess reduced lipophilic properties, decreased hERG liability, faster mouse/human liver microsomal clearance rates and shorter plasma half-lives compared with bedaquiline, potentially addressing of the main concerns of persistence and phospholipidosis associated with bedaquiline.

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Tetrahydronaphthalene amides are novel inhibitors of M.tb in culture.

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Selective and potent inhibitors of the mycobacterial ATP synthase.

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Improved hERG liability, clearance and half-life compared to bedaquiline.

Multimodal echocardiography in the diagnosis of masses localized to the proximal portions of pulmonary arteries

Proximal pulmonary artery masses are exceedingly rare, and their diagnosis and therapy are important and challenging for clinicians. This study reviews our experience exploring the value of a combination of transthoracic echocardiography and contrast echocardiography for the differential diagnosis of proximal pulmonary artery masses. Between January 2018 and June 2021, 44 patients diagnosed with a mass attached to the major pulmonary artery and straddling the bilateral pulmonary arteries or pulmonary valve on transthoracic echocardiography were referred to this study. Contrast echocardiography was performed in 17 patients. Masses were diagnosed based on their site of attachment, shape, size, mobility, hemodynamic consequences on transthoracic echocardiography, and tissue perfusion on contrast echocardiographic perfusion imaging. Pathological data were collected from medical records and analyzed. The most frequent location of proximal pulmonary artery masses was the major pulmonary artery trunk. Twelve patients underwent complete mass resection, whereas nine patients underwent percutaneous pulmonary artery biopsy puncture and had a pathological diagnosis. Another 24 patients were confirmed with the validation methods. Contrast echocardiography has good sensitivity and specificity for differentiating thrombi from pulmonary artery sarcomas (PAS). The mass types were distributed as follows: thrombi (19, 43%), PAS (15, 34%), metastatic tumors (6, 14%), vegetations (3, 7%), and primary benign lesions (1, 2%). The majority of proximal pulmonary artery masses were thrombi or PAS. A combination of transthoracic echocardiography and contrast echocardiography offers advantages in the early identification of proximal pulmonary masses and provides clinically important information about the characteristics of masses, especially for differentiating thrombi from PAS.

Needle Adjustment Free (NAF) running suture technique (PAN suture) in laparoscopic partial nephrectomy

BACKGROUND

It is proposed a new running suture technique called Needle Adjustment Free (NAF) technique, or PAN suture. The efficiency and the safety were evaluated in laparoscopic partial nephrectomy.

METHODS

This new running suture technique avoids the Needle Adjustment method used in traditional techniques. The new continuous suture technique (11 patients) was compared with the traditional continuous suture method (33 patients) used in both transperitoneal and retroperitoneal laparoscopic partial nephrectomy (LPN) in terms of suture time (ST), warm ischemia time (WIT), blood loss (BL), open conversion rate and post-op discharge time, post-op bleeding, post-op DVT, ΔGFR (affected side, 3 months post-op). Differences were considered significant when P < 0.05.

RESULTS

ST in the PAN suture group was 30.37 ± 16.39 min, which was significant shorter (P = 0.0011) than in the traditional technique group which was 13.68 ± 3.33 min. WIT in the traditional technique group was 28.73 ± 7.89 min, while in the PAN suture group was 20.64 ± 5.04 min, P = 0.0028. The BL in entirety in the traditional technique group was 141.56 ± 155.23 mL, and in the PAN suture group was 43.18 ± 31.17 mL (P = 0.0017). BL in patients without massive bleeding in the traditional technique group was significantly greater than in the PAN suture group at 101.03 ± 68.73 mL versus 43.18 ± 31.17 mL (P = 0.0008). The open conversion rate was 0 % in both groups. There was no significant difference between the two groups in postoperative discharge time, post-op bleeding, post-op DVT, ΔGFR (affected side, 3 months post-op).

CONCLUSIONS

The NAF running suture technique, or PAN suture, leading to less ST, WIT and BL, which was shown to be more effective and safer than the traditional technique used for LPN. A further expanded research with larger sample size is needed.

Simultaneous transthoracic intervention for multiple cardiac defects in children

BACKGROUND

Transthoracic intervention for isolated congenital heart disease (CHD) has been well tested for its technological feasibility and is increasingly used in clinical practice. We aimed to present our experience in simultaneous transthoracic intervention for multiple cardiac lesions in a series of pediatric patients.

METHODS

Between March 2015 and December 2019, 20 patients with multiple CHD were referred to this study; mean age was 18.8±8.6 (range, 4-36) months. The transthoracic echocardiography (TTE) diagnosis was atrial septal defect (ASD) and perimembranous ventricular septal defect (pmVSD) in 7 patients, patent ductus arteriosus (PDA) and ASD in 6, pmVSD and PDA in 2, pmVSD and valvular pulmonary stenosis (PS) in 2, ASD and PS in 2, and doubly committed subarterial VSD (dcsVSD) and PS in 1 patient. These patients underwent simultaneous transthoracic interventions with transesophageal echocardiography guidance. The procedure sequence was PS→VSD→PDA→ASD. Electrocardiography and TTE were scheduled at discharge and follow-ups.

RESULTS

All patients were occluded successfully without any thoracotomy conversion. Operation time was 56-120 (mean, 75±13) minutes. A 1.5-2.0-cm median sternum incision was performed in 6 ASD&PDAs, 2 ASD&PSs, and 1 dcsVSD&PS. In 11 other patients, a 1.5-2.0-cm incision in the inferior sternum was made and the chest closed with a drain. There were no serious complications before discharge and at follow-up.

CONCLUSIONS

Simultaneous transthoracic intervention for multiple cardiac defects in children is feasible with good short-term outcomes. For different lesions, the appropriate surgical incision and operational sequence can render the intervention minimally invasive and safer.

Hypoxic Preconditioning Enhances Cellular Viability and Pro-angiogenic Paracrine Activity: The Roles of VEGF-A and SDF-1a in Rat Adipose Stem Cells

To achieve the full therapeutic potential of implanted adipose stem cells (ASCs) in vivo, it is crucial to improve the viability and pro-angiogenic properties of the stem cells. Here, we first simulated the conditions of ischemia and hypoxia using the in vitro oxygen-glucose deprivation (OGD) model and confirmed that hypoxic preconditioning of ASCs could provide improved protection against OGD and enhance ASC viability. Second, we assessed the effect of hypoxic preconditioning on pro-angiogenic potential of ASCs, with a particular focus on the role of vascular endothelial growth factor-A (VEGF-A) and stromal derived factor-1a (SDF-1a) paracrine activity in mediating angiogenesis. We found that the conditioned medium of ASCs (ASC^CM) with hypoxic preconditioning enhanced angiogenesis by a series of angiogenesis assay models in vivo and in vitro through the upregulation of and a synergistic effect between VEGF-A and SDF-1a. Finally, to investigate the possible downstream mechanisms of VEGF/VEGFR2 and SDF-1a/CXCR4 axes-driven angiogenesis, we evaluated relevant protein kinases involved the signal transduction pathway of angiogenesis and showed that VEGF/VEGFR2 and SDF-1a/CXCR4 axes may synergistically promote angiogenesis by activating Akt. Collectively, our findings demonstrate that hypoxic preconditioning may constitute a promising strategy to enhance cellular viability and angiogenesis of transplanted ASCs, therein improving the success rate of stem cell-based therapies in tissue engineering.

Beforehand transection and suturing (BTS) of the dorsal vascular complex: a novel technique in laparoscopic radical prostatectomy

Background

Beforehand transection and suturing (BTS) of the dorsal vascular complex (DVC), a novel technique in non-neurovascular bundle sparing (NVB-sparing) extraperitoneal laparoscopic radical prostatectomy (eLRP), had been proposed; this study aimed to evaluate this technique in clinical laparoscopic procedures.

Methods

Using this new technique, the DVC was transected and sutured after dissection of the pelvic fascia and before dissection of the prostate, especially before ligation of the bilateral prostatic pedicles. This study retrospectively analyzed the data of 90 non NVB-sparing eLRP patients [traditional technique (n=60) and BTS technique (n=30)].

Results

The surgical time in the BTS technique group was 121.73±24.53 min, which was significantly shorter (P=0.0015) than the traditional technique group (144.12±39.68 min). The calculated blood loss in the traditional technique group was 388.45±232.78 mL, and 264.16±130.70 mL in the BTS technique group (P=0.0016). The estimated blood loss in the traditional technique group was 350.34±311.80 mL, which was significantly greater than the BTS technique group (250.33±145.31 mL, P=0.0422). The transfusion rate in the traditional technique group was significantly greater than the BTS technique group (15.00% vs. 0.00%; P=0.0266). The biochemical recurrence rate in traditional technique group was 48.33%, which was higher than in the BTS group (30.00%) (P=0.0465). There was no significant difference between the 2 groups with respect to the pre-operative hemoglobin (Hb) concentration, pre-operative hematocrit (HCT), post-operative Hb concentration, post-operative HCT, ΔHCT, pre-operative blood volume, rectal perforation, open conversion, apical capsule residue, false suture, post-operative bleeding, urinary leakage, re-operation, surgical site infection, post-operative stay, and emission time of urinary incontinence.

Conclusions

In managing the relationship between the DVC and prostate in patients undergoing non NVB-sparing eLRP, the BTS technique was shown to be more effective and safer than the traditional technique.

Beforehand transection and suturing (BTS) of the dorsal vascular complex: a novel technique in laparoscopic radical prostatectomy

BACKGROUND

Beforehand transection and suturing (BTS) of the dorsal vascular complex (DVC), a novel technique in non-neurovascular bundle sparing (NVB-sparing) extraperitoneal laparoscopic radical prostatectomy (eLRP), had been proposed; this study aimed to evaluate this technique in clinical laparoscopic procedures.

METHODS

Using this new technique, the DVC was transected and sutured after dissection of the pelvic fascia and before dissection of the prostate, especially before ligation of the bilateral prostatic pedicles. This study retrospectively analyzed the data of 90 non NVB-sparing eLRP patients [traditional technique (n=60) and BTS technique (n=30)].

RESULTS

The surgical time in the BTS technique group was 121.73±24.53 min, which was significantly shorter (P=0.0015) than the traditional technique group (144.12±39.68 min). The calculated blood loss in the traditional technique group was 388.45±232.78 mL, and 264.16±130.70 mL in the BTS technique group (P=0.0016). The estimated blood loss in the traditional technique group was 350.34±311.80 mL, which was significantly greater than the BTS technique group (250.33±145.31 mL, P=0.0422). The transfusion rate in the traditional technique group was significantly greater than the BTS technique group (15.00% vs. 0.00%; P=0.0266). The biochemical recurrence rate in traditional technique group was 48.33%, which was higher than in the BTS group (30.00%) (P=0.0465). There was no significant difference between the 2 groups with respect to the pre-operative hemoglobin (Hb) concentration, pre-operative hematocrit (HCT), post-operative Hb concentration, post-operative HCT, ΔHCT, pre-operative blood volume, rectal perforation, open conversion, apical capsule residue, false suture, post-operative bleeding, urinary leakage, re-operation, surgical site infection, post-operative stay, and emission time of urinary incontinence.

CONCLUSIONS

In managing the relationship between the DVC and prostate in patients undergoing non NVB-sparing eLRP, the BTS technique was shown to be more effective and safer than the traditional technique.

Synthesis and structure-activity relationships for tetrahydroisoquinoline-based inhibitors of Mycobacterium tuberculosis

A series of 5,8-disubstituted tetrahydroisoquinolines were shown to be effective inhibitors of M. tb in culture and modest inhibitors of M. tb ATP synthase. There was a broad general trend of improved potency with higher lipophilicity. Large substituents (e.g., Bn) at the tetrahydroquinoline 5-position were well-tolerated, while N-methylpiperazine was the preferred 8-substituent. Structure-activity relationships for 7-linked side chains showed that the nature of the 7-linking group was important; –CO– and –COCH₂– linkers were less effective than –CH₂– or –CONH– ones. This suggests that the positioning of a terminal aromatic ring is important for target binding. Selected compounds showed much faster rates of microsomal clearance than did the clinical ATP synthase inhibitor bedaquiline, and modest inhibition of mycobacterial ATP synthase.

Preformulation studies of l-glutathione: physicochemical properties, degradation kinetics, and in vitro cytotoxicity investigations

Objectives: l-Glutathione (GSH) is an endogenous tripeptide with super antioxidant properties. In this study, preformulation parameters of GSH and its degradation products were fully investigated.Significance: To date, no experimental preformulation data is available for GSH. Therefore, to the author's knowledge, this is the first study to experimentally determine the preformulation parameters of GSH, which can be considered more reliable for further studies.Methods: An HPLC method for GSH was optimized and validated to accurately quantify the GSH amount in solution, used to investigate GSH's solubility and Log P. Differential Scanning Calorimeter and Thermogravimetric Analyzer were used to evaluate the thermal properties of GSH. Polarized microscope and Fourier-transform Infrared Spectroscopy were used to determine GSH's crystal habits and functional groups, respectively. Forced degradation kinetics and the degradation products were investigated and identified by LC-MS, respectively. GSH's cellular cytotoxicity on fibroblasts was investigated by MTT assay.Results: It was determined that GSH has high aqueous solubility (252.7 mg/mL), low Log P (-3.1), a melting endotherm of 195 °C and decomposition at 210°C, negligible moisture content, and a rectangular/cylindrical-shaped crystalline form. Seven degradation products were identified; one of the major degradation products of GSH under different conditions is first order kinetic oxidation into glutathione disulfide. No cytotoxicity was observed when fibroblasts were treated with GSH (0.005-10.000 mg/mL).Conclusions: Precise preformulation parameters of GSH were obtained, and these are imperative for the development and optimization of advanced GSH formulations.

Aerobic oxidation of primary benzylic amines to amides and nitriles catalyzed by ruthenium carbonyl clusters carrying N,O-bidentate ligands

Four trinuclear ruthenium carbonyl clusters, (6-BrPyCHRO)₂Ru₃(CO)₈ (R = 4-OCH₃C₆H₄, 1a; R = 4-BrC₆H₄, 1b) and (2-OC₆H₄-HC[double bond, length as m-dash]N-C₆H₄R)₂Ru₃(CO)₈ (R = 4-OCH₃, 2a; R = 4-Br, 2b), were synthesized from the reactions of Ru₃(CO)₁₂ with the corresponding N,O-bidentate ligands (two pyridyl alcohols and two Schiff bases) respectively in a ratio of 1 : 2. Three new complexes 1b, 2a and 2b have been fully characterized by elemental analysis, FT-IR, NMR and X-ray crystallography. The catalytic activity of these ruthenium complexes for the aerobic oxidation of primary benzylic amines to amides and nitriles in the presence of t-BuOK was investigated, of which the Schiff base complex 2a was found to exhibit the highest activity.

Ruthenium carbonyl complexes supported by pyridine-alkoxide ligands: synthesis, structure and catalytic oxidation of secondary alcohols

Five novel trinuclear ruthenium carbonyl complexes were synthesized and their application in oxidation of secondary alcohols was also researched.

[Study on the super-antigen genes of group A Streptococcus pyogenes strains isolated from patients with scarlet fever and pharyngeal infection, in Beijing, 2015-2017]

Objective: To analyze the characteristics of super-antigen (SAg) of group A Streptococcus pyogenes (GAS), isolated from patients with scarlet fever or pharyngeal infections in Beijing between 2015-2017. Methods: Throat swab specimens from patients with scarlet fever or pharyngeal infections were collected and tested for GAS. Eleven currently known SAg genes including SpeA, speC, speG, speH, speI, speJ, speK, speL, speM, smeZ and ssa were tested by real-time PCR while M protein genes (emm genes) were amplified and sequenced by PCR. Results: A total of 377 GAS were isolated from 6 801 throat swab specimens, with the positive rate as 5.5%. There were obvious changes noticed among speC, speG, speH and speK in three years. A total of 45 SAg genes profiles were observed, according to the SAgs inclusion. There were significant differences appeared in the frequencies among two of the highest SAg genes profiles between emm1 and emm12 strains (χ(2)=38.196, P<0.001; χ(2)=72.310, P<0.001). There also appeared significant differences in the frequencies of speA, speH, speI and speJ between emm1 and emm12 strains (χ(2)=146.154, P<0.001; χ(2)=52.31, P<0.001; χ(2)=58.43, P<0.001; χ(2)=144.70, P<0.001). Conclusions: Obvious changes were noticed among SAg genes including speC, speG, speH and speK from patients with scarlet fever or pharyngeal infections in Beijing between 2015-2017. SAg genes including speA, speH, speI and speJ appeared to be associated with the emm 1 and emm 12 strains. More kinds of SAg genes profiles were isolated form GAS but with no significant differences seen in the main SAg genes profiles, during the epidemic period.

CAMK4 gene variation is associated with hypertension in a Uygur population

Considering that calcium/calmodulin-dependent kinase 4 (CAMK4) plays a pivotal role in blood pressure regulation, we investigated the association between a CAMK4 polymorphism (rs10491334) and hypertension in the Han, Kazak, and Uygur ethnic groups. We studied 1224 patients with hypertension and 967 normotensive controls classified into three ethnic groups (Han, Kazak, and Uygur). The rs10491334 polymorphism was genotyped using a TaqMan® 5'-nuclease assay. In the Uygur group, the T-allele frequency in patients with hypertension was twice that of the controls (12.5 vs 6.38%), and T-allele carriers had a significantly increased risk of hypertension compared with non-carriers (odds ratio = 2.200; 95% confidence interval = 1.473-3.285, P < 0.001). However, no significant correlation was found in the Han and Kazak groups. The T-allele of rs10491334 in CAMK4 was associated with hypertension in the Uygur group.

Abstract B278: PR610: A novel hypoxia-selective tyrosine kinase inhibitor in phase I clinical trial

PR610 is a hypoxia-selective irreversible Human Epidermal Growth Factor Receptor (HER) family inhibitor currently in phase I clinical trials in New Zealand and the USA (clinical trial ID NCT01631279). The prodrug PR610 releases the TKI (Tyrosine Kinase Inhibitor) PR610E, a picomolar irreversible inhibitor of EGFR (HER1), under oxygen-limiting conditions typically found in solid tumors. Human neoplastic cell lines exposed to PR610 show an anoxia-selective anti-proliferative response that is associated with G1 arrest and induction of apoptosis arising from inhibition of EGFR auto-phosphorylation and downstream silencing of associated signal transduction pathways. PR610 is optimized for long tumor residency (T½ &gt;2 days); in a preclinical model of erlotinib-resistant NSCLC, a single injection of PR610 produces profound, global shutdown of signal transduction via EGFRT790M/L858R. Tumor PR610E concentrations were above cellular anti-proliferative IC50 concentrations for over 5 days, being more than sufficient to induce apoptosis via “oncogenic shock”.

Pharmacokinetic (PK) studies of PR610 show significant differences in species toxicokinetics. Both the rat and dog preclinical toxicology models display considerable systemic conversion of PR610 to PR610E (6% - 30% and 24% - 29% of prodrug AUC, respectively) with attendant symptoms of EGFR inhibition including acneiform skin rash and diarrhea. In contrast NIH-III nude mice display minimal circulating TKI (PR610E) relative to PR610 (1.5% - 1.7% of AUC) consistent with a substantially improved tolerance as judged by PR610 plasma AUCinf at the maximum tolerated dose (MTD). Human subjects from the phase I clinical trial consistently experience the lowest systemic levels of PR610E (Mean 1.06% ± 0.69%; range 0.34% - 2.7%; n=20) across dose levels ranging from 10 - 150 mg/m2. Notably, a dose of 150 mg/m2 in human subjects produces a PR610 plasma AUCinf equivalent to that measured for 30 mg/kg PR610 in NIH-III mice, a dose that is active in several HER-dependent subcutaneous tumor xenograft models. Collectively, these data indicate that PR610 has the desirable characteristics of a deactivated prodrug in human subjects and preclinical models predict that an active dose range has been reached in the phase I trial. PR610 is a first-in-class hypoxia-selective EGFR/HER2 inhibitor with exciting clinical potential.

Citation Information: Mol Cancer Ther 2013;12(11 Suppl):B278.

Citation Format: Adam V. Patterson, Jagdish Jaiswal, Kendall Carlin, Maria R. Abbattista, Christopher P. Guise, Shevan Silva, Ho Lee, Guo-Liang Lu, Robert F. Anderson, Teresa J. Melink, John C. Gutheil, Jeff B. Smaill. PR610: A novel hypoxia-selective tyrosine kinase inhibitor in phase I clinical trial. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr B278.

Weight loss effects of quaternary salts of 5-amino-1-(chloromethyl)-1,2-dihydro-3H-benz[e]indoles; structure-activity relationships

Quaternary salt analogues based on the DNA minor groove binder and adenine N3 alkylating agent 5-amino-1-(chloromethyl)-1,2-dihydro-3H-benz[e]indole (aminoCBI) show remarkable effects on the body weight of mice (a long-term failure to gain weight relative to matched controls with no loss of appetite or perceptible deterioration in health) following administration of a single (non-toxic) dose between about 0.5-5 μmol/kg. The nature of the quaternizing group was not important, but a related hydroxyCBI analogue was much less effective. Compounds where the chloro group was replaced by a hydrogen or hydroxy group (thus abrogating DNA alkylating capability) showed no weight control activity. It is speculated, based on other studies, that the marked long-term weight control effect is due to inhibition of bile flow into the intestine and reduced absorption of triglycerides, together with accelerated cell death in spleen and white adipose tissues due to drug accumulation there. This class of compound may serve as interesting tools for further study of these phenomena.

Abstract A247: Mechanism of action of the hypoxia-activated irreversible pan-HER inhibitor SN29966

Hypoxia occurs in most human tumors and is associated with disease progression, treatment resistance and poor patient outcome. We have developed the hypoxia-activated prodrug SN29966, designed to release the irreversible pan-HER inhibitor SN29926, following one-electron reduction by hypoxic cells (Smaill et al, Mol Cancer Ther., 2009; 8(12 Suppl), C46). Pharmacokinetic (PK) studies in nude mice bearing A431 tumor xenografts indicated SN29966 has a long tumor half-life (&gt;3 days) and releases SN29926 in tumors. SN29966 demonstrated single agent activity in nude mice bearing A431 and SKOV3 xenografts, inducing striking tumor regressions in both models (Patterson et al, Mol Cancer Ther., 2009; 8(12 Suppl), B76). PR509 and PR610, clinical candidates developed from SN29966, are currently undergoing comparative evaluation with Phase I trials anticipated in early 2012.

The single-agent antitumor activity of SN29966 is arguably counter-intuitive given that it is designed to target hypoxic cells within tumors. This activity may arise from a number of contributing mechanisms including; (i) bioactivity of the unreduced prodrug; (ii) local redistribution of released inhibitor in the tumor; (iii) liver metabolism and circulating inhibitor and (iv) a long tumor half-life allowing for targeting of both chronic and cycling hypoxia. To critically assess the relative contribution of each to the mechanism of action of SN29966 we performed a number of studies. We prepared SN31950, a prodrug of SN29926 designed to be incapable of one-electron fragmentation. In target modulation and anti-proliferative assays SN31950 showed no hypoxia-dependent activity. The murine A431 tumor PK of SN29966 and SN31950 demonstrated that at an equimolar dose (20 μmol/kg, ip), both prodrugs gave comparable tumor exposures (AUC0–72h: SN31950, 50 μmol*h/kg; SN29966, 57 μmol*h/kg). In contrast, the tumor exposure of SN29926 released from each prodrug differed by 40-fold (AUC0–72h: SN29926 from SN31950, 0.3 μmol*h/kg; SN29926 from SN29966, 12 μmol*h/kg). Plasma exposure of each prodrug was comparable, as were levels of SN29926 in plasma (presumed mainly due to hepatic prodrug metabolism). Consistent with the observed lack of inhibitor release in A431 tumors, SN31950 was inactive against A431 tumors in growth delay assays. To confirm the hypoxia-dependent nature of SN29966 inhibitor release in A431 tumors we re-oxygenated tumors in mice breathing 100% oxygen at 2.5 atm in a hyperbaric chamber. Accordingly, mice showed a marked reduction (56%, p&lt;0.001) in the concentration of released inhibitor in tumor relative to air breathing controls, indicating SN29966 tumor metabolism is hypoxia-dependent. Conversely, post-mortem anoxia (2 h, 37 °C) in mice 24 hours after SN29966 administration doubled the concentration of released inhibitor in tumor, indicating SN29966 is bioavailable for metabolism to release inhibitor as de novo hypoxia arises. Collectively the data support the conclusion that the single-agent activity of SN29966 results primarily from hypoxia-dependent tumor metabolism and inhibitor release. Inhibitor bystander effect and exploitation of both chronic and cycling hypoxia, thereby increasing the target cell population, are likely to play important roles. Liver metabolism, circulating inhibitor and activity of unreduced prodrug appear to be less important.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2011 Nov 12-16; San Francisco, CA. Philadelphia (PA): AACR; Mol Cancer Ther 2011;10(11 Suppl):Abstract nr A247.

Abstract LB-297: Characterization of novel hypoxia-activated prodrugs of irreversible pan-HER inhibitors

Reversible HER1 (EGFR) inhibitors erlotinib and gefitinib are approved for use in non-small cell lung cancer (NSCLC), particularly demonstrating activity against tumors expressing mutant forms of HER1. Unfortunately, relapse invariably occurs in this patient population, with approximately half of patients having acquired an additional T790M mutation in HER1. Irreversible pan-HER inhibitors (BIBW2992, PF00299804) are under clinical evaluation in the context of NSCLC that has relapsed post-erlotinib/gefitinib treatment. However it is currently unclear whether these agents possess the therapeutic index in man necessary to gain approval in this setting (Regales et al., J. Clin. Invest. 2009, 119:3000-10), prompting the development of HER1T790M mutant-selective irreversible inhibitors (Zhou et al., Nature. 2009, 462: 1070-74).

Hypoxia occurs in most human tumors and is associated with disease progression, resistance to conventional therapies and poor patient outcome. It can however be considered as an exploitable physiological target, as it supports tumor-selective bioreduction of prodrugs. We have developed hypoxia-activated prodrugs of irreversible pan-HER inhibitors as a strategy to broaden their therapeutic index. SN29966 is a prototype nitromethylaryl quaternary (NMQ) ammonium salt prodrug of an irreversible pan-HER inhibitor (SN29926), with masked cellular activity. Radiolytic reduction of SN29966 demonstrated fragmentation of the one-electron adduct to release SN29926 [kfrag 130 ± 10 s-1], and hypoxia-selective metabolism to SN29926 has been confirmed in all cell lines tested.

SN32807 is the lead prodrug of this series, releasing the irreversible pan-HER inhibitor SN32793 in a hypoxia-dependent manner. In a panel of HER1/HER1T790M/HER2-expressing cell lines SN32807 showed hypoxia-dependent inhibition of proliferation (hypoxic/oxic IC50 ratios of 60, 11 and 20 in A431, H1975 and SKOV3 cells, respectively), a property SN32793 lacked (IC50 ratios 0.8-1.6). Tumor growth delay experiments (NIH-III nude mice) in large (500 mm3) HER1T790M-expressing H1975 tumor xenografts showed BIBW2992 (20 mg/kg, p.o. daily) failed to control tumor growth (i.e. progressive disease), with only a modest Tumor Growth Delay value of 35% [TGD % = [(T-C)/C]x100 where T and C are time to 4-fold increase in tumor volume from treatment day-1 for treated and control tumors, respectively]. In contrast, single-agent SN32807 (88 mg/kg; ip, q3dx8) demonstrated complete tumor responses in all animals during the treatment period (TGD value 246%; P&lt;0.0005 vs controls; P&lt;0.0005 vs BIBW-2992; log-rank test). Collectively the data indicates that SN32807 possesses a much improved therapeutic index relative to existing HER-family inhibitors, demonstrating marked activity against a HER1T790M-expressing erlotinib, gefitinib and BIBW2992 resistant tumor xenograft model.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-297.

Abstract C46: Design and identification of the novel hypoxia-activated irreversible pan-HER inhibitor SN29966

Several irreversible pan-HER inhibitors (HKI-272, BIBW-2992, PF299) are under development and demonstrate encouraging activity against erlotinib resistant non-small cell lung cancer expressing mutant forms of HER1. However, dose limiting toxicities mirror that of erlotinib and are attributed to inhibition of HER1 in gastrointestinal and skin tissues. To introduce additional tumor selectivity to irreversible pan-HER inhibitors and thereby broaden their therapeutic index, we have sought to utilise tumor hypoxia as a physiological target that supports tumor-selective bioreduction. To achieve this we have developed a series of hypoxia-activated prodrugs of the known irreversible pan-HER inhibitor SN29926.

Five nitromethylaryl quaternary ammonium bromide (NMQ) prodrugs were synthesised by quaternizing the tertiary amine of SN29926 with five nitroheterocyclic alpha-methyl bromides. Three further quaternary salts were prepared as Chemical-Biology Tools (CBTs) designed as controls to probe aspects of the mechanism of action of the NMQ prodrugs. The NMQ prodrugs and CBTs were compared, relative to SN29926, in a range of assays to identify a lead compound that (i) is deactivated under oxic conditions with respect to A431 cellular HER1 target modulation and proliferation, (ii) efficiently fragments following one-electron reduction in an oxygen inhibited manner to release the irreversible pan-HER inhibitor, (iii) displays increased anti-proliferative activity against A431 cells under hypoxia.

All of the NMQ/CBT prodrugs were successfully deactivated with respect to inhibition of A431 HER1 autophosphorylation (62- to 201-fold) and proliferation under oxic conditions (12- to 294-fold). Pulse and steady-state radiolysis under nitrogen determined their one-electron reduction potentials (−388 to −493 mV) and demonstrated that only two of the NMQ prodrugs (SN29965, SN29966) efficiently fragment following one-electron reduction (first-order rate constants of 90 and 130 s−1, respectively). SN29966 alone demonstrated significant anti-proliferative activity against A431 cells under hypoxia (hypoxic/oxic IC50 ratio 38). Preliminary growth delay screening of SN29966 and the CBTs in advanced A431 xenografts (∼600 mm3; hypoxic fraction of 32% ± 13%) demonstrated that the CBTs lacked efficacy, while SN29966 induced tumor regressions, with greater than 30 days tumor control using a well tolerated three-dose schedule (133 umol/kg/dose, q4dx3). In summary, prodrug SN29966 is deactivated relative to the parent inhibitor, efficiently fragments following one-electron reduction, is selective against hypoxic A431 cells and has remarkable single-agent activity against hypoxic A431 xenografts using a conservative treatment schedule. We therefore identify SN29966 as a “first-in-class” hypoxia-activated irreversible pan-HER inhibitor that has significant clinical potential.

Citation Information: Mol Cancer Ther 2009;8(12 Suppl):C46.

Synthesis and Characterization of Some Metal Complexes of 4,5-Diazafluoren-9-one and their Biological Effects on Human Carcinoma Cells

Three new transition metal complexes of 4,5-diazafluoren-9-one, [(DAFO)PdCl2], [(DAFO)PtCl2], and [(DAFO)ZnCl2], were prepared in good yields by the reactions between appropriate metal chloride precursors and 4,5-diazafluoren-9-one under ambient conditions. The structures of these metal complexes were established by spectroscopic (Fourier-transform IR, NMR, and fast-atom bombardment mass spectrometry) techniques. The possible biological activity of these compounds on three human cancer cell lines including Hep3B, MDAMB-231, and SKHep-1 was investigated. The results obtained showed that both zinc- and platinum-containing compounds exhibit a similar growth inhibitory effect on these three cancer cell lines when compared with the prototypical cis-platin. In contrast, the corresponding palladium congener is virtually biologically inactive in these trials.

The synthesis and biological evaluation of novel series of nitrile-containing fluoroquinolones as antibacterial agents

Several novel series of nitrile-containing fluoroquinolones with weakly basic amines are reported which have reduced potential for hERG (human ether-a-go-go gene) channel inhibition as measured by the dofetilide assay. The new fluoroquinolones are potent against both Gram-positive and fastidious Gram-negative strains, including Methicillin resistant Staphylococcus aureus and fluoroquinolone-resistant Streptococcus pneumoniae. Several analogs also showed low potential for human genotoxicity as measured by the clonogenicity test. Compounds 22 and 37 (designated PF-00951966 and PF-02298732, respectively), which had good in vitro activity and in vitro safety profiles, also showed good pharmacokinetic properties in rats.