Dendrimer toxicity: Let's meet the challenge

Dendrimers are well-defined, versatile polymeric architecture with properties resembling biomolecules. Dendritic polymers emerged as outstanding carrier in modern medicine system because of its derivatisable branched architecture and flexibility in modifying it in numerous ways. Dendritic scaffold has been found to be suitable carrier for a variety of drugs including anticancer, anti-viral, anti-bacterial, antitubercular etc., with capacity to improve solubility and bioavailability of poorly soluble drugs. In spite of extensive applicability in pharmaceutical field, the use of dendrimers in biological system is constrained because of inherent toxicity associated with them. This toxicity is attributed to the interaction of surface cationic charge of dendrimers with negatively charged biological membranes in vivo. Interaction of dendrimers with biological membranes results in membrane disruption via nanohole formation, membrane thinning and erosion. Dendrimer toxicity in biological system is generally characterized by hemolytic toxicity, cytotoxicity and hematological toxicity. To minimize this toxicity two strategies have been utilized; first, designing and synthesis of biocompatible dendrimers; and second, masking of peripheral charge of dendrimers by surface engineering. Biocompatible dendrimers can be synthesized by employing biodegradable core and branching units or utilizing intermediates of various metabolic pathways. Dendrimer biocompatibility has been evaluated in vitro and in vivo for efficient presentation of biological performance. Surface engineering masks the cationic charge of dendrimer surface either by neutralization of charge, for example PEGylation, acetylation, carbohydrate and peptide conjugation; or by introducing negative charge such as half generation dendrimers. Neutral and negatively charged dendrimers do not interact with biological environment and hence are compatible for clinical applications as elucidated by various studies examined in this review. Chemical modification of the surface is an important strategy to overcome the toxicity problems associated with the dendrimers. The present review emphasizes on the approaches available to overcome the cationic toxicity inherently associated with the dendrimers.

A PEGylated dendritic nanoparticulate carrier of fluorouracil

The present study was aimed at developing and exploring the use of uncoated and PEGylated newer PAMAM dendrimers for delivery of anti-cancer drug 5-fluorouracil. For this study, successive Michael addition and exhaustive amidation reactions were used to synthesize 4.0 G PAMAM dendrimers, using ethylenediamine as core and methylmethacrylate as propagating agent. The dendrimer was PEGylated using N-hydroxysuccinimide-activated carboxymethyl MPEG-5000. IR and NMR data proved the synthesis. Various physicochemical parameters, SEM, TEM, lambda(max) values, hemolytic toxicity, drug entrapment, drug release and blood-level studies of both PEGylated and non-PEGylated systems were determined and compared. The PEGylation of the systems was found to have increased their drug-loading capacity, reduced their drug release rate and hemolytic toxicity. TEM study revealed surface properties of the systems. Stability studies had shown its stability at room temperature in dark. The systems were found suitable for prolonged delivery of an anti-cancer drug by in vitro and blood-level studies in albino rats, without producing any significant hematological disturbances. PEGylation has been found to be suitable for modification of PAMAM dendrimers for reduction of drug leakage and hemolytic toxicity. This, in turn, could improve drug-loading capacity and stabilize such systems in body. The study suggests use of such PEGylated dendrimeric systems as nanoparticulate depot type of system for drug administration.

Convergent functional genomics of schizophrenia: from comprehensive understanding to genetic risk prediction

We have used a translational convergent functional genomics (CFG) approach to identify and prioritize genes involved in schizophrenia, by gene-level integration of genome-wide association study data with other genetic and gene expression studies in humans and animal models. Using this polyevidence scoring and pathway analyses, we identify top genes (DISC1, TCF4, MBP, MOBP, NCAM1, NRCAM, NDUFV2, RAB18, as well as ADCYAP1, BDNF, CNR1, COMT, DRD2, DTNBP1, GAD1, GRIA1, GRIN2B, HTR2A, NRG1, RELN, SNAP-25, TNIK), brain development, myelination, cell adhesion, glutamate receptor signaling, G-protein-coupled receptor signaling and cAMP-mediated signaling as key to pathophysiology and as targets for therapeutic intervention. Overall, the data are consistent with a model of disrupted connectivity in schizophrenia, resulting from the effects of neurodevelopmental environmental stress on a background of genetic vulnerability. In addition, we show how the top candidate genes identified by CFG can be used to generate a genetic risk prediction score (GRPS) to aid schizophrenia diagnostics, with predictive ability in independent cohorts. The GRPS also differentiates classic age of onset schizophrenia from early onset and late-onset disease. We also show, in three independent cohorts, two European American and one African American, increasing overlap, reproducibility and consistency of findings from single-nucleotide polymorphisms to genes, then genes prioritized by CFG, and ultimately at the level of biological pathways and mechanisms. Finally, we compared our top candidate genes for schizophrenia from this analysis with top candidate genes for bipolar disorder and anxiety disorders from previous CFG analyses conducted by us, as well as findings from the fields of autism and Alzheimer. Overall, our work maps the genomic and biological landscape for schizophrenia, providing leads towards a better understanding of illness, diagnostics and therapeutics. It also reveals the significant genetic overlap with other major psychiatric disorder domains, suggesting the need for improved nosology.

Dendrimers: Novel Polymeric Nanoarchitectures for Solubility Enhancement

Poor solubility and hydrophobicity of drugs/bioactives limit their possible applications in drug delivery and formulation development. Apart from conventional methods of solubility enhancement, there are some novel methods which can be used in solubilization. Dendrimers represent a novel type of polymeric material that has generated much interest in many diverse areas due to their unique structure and properties. Dendrimer-mediated solubility enhancement mainly depends on factors such as generation size, dendrimer concentration, pH, core, temperature, and terminal functionality. Added advantage in solubilization can be achieved considering these factors. Available literature suggests that ionic interaction, hydrogen bonding, and hydrophobic interactions are the possible mechanisms by which a dendrimer exerts its solubilizing property. This review presents various mechanisms and reports relating to solubility enhancement using dendrimers. Also, micellar behavior and future possibilities in relation to solubilization via dendrimers are included.

Transfersomes—A Novel Vesicular Carrier for Enhanced Transdermal Delivery: Development, Characterization, and Performance Evaluation

This work describes the use of a novel vesicular drug carrier system called transfersomes, which is composed of phospholipid, surfactant, and water for enhanced transdermal delivery. The transfersomal system was much more efficient at delivering a low and high molecular weight drug to the skin in terms of quantity and depth. In the present study transfersomes and liposomes were prepared by using dexamethasone as a model drug. The system was evaluated in vitro for vesicle shape and size, entrapment efficiency, degree of deformability, number of vesicles per cubic mm, and drug diffusion across the artificial membrane and rat skin. The effects of surfactant type, composition, charge, and concentration of surfactant were studied. The in vivo performance of selected formulation was evaluated by using a carrageenan-induced rat paw edema model. Fluorescence microscopy by using rhodamine-123 and 6-carboxyfluorescein as fluorescence probe was performed. The stability study was performed at 4 degrees C and 37 degrees C. An in vitro drug release study has shown a nearly zero order release of drug and no lag phase. The absence of lag phase in comparison to liposomes and ointment is attributed to the greater deformability, which may account for better skin permeability of transfersomes. In vivo studies of transfersomes showed better antiedema activity in comparison to liposomes and ointment, indicating better permeation through the penetration barrier of the skin. This was further confirmed through a fluorescence microscopy study. Finally, it may be concluded from the study that complex lipid molecules, transfersomes, can increase the transdermal flux, prolong the release, and improve the site specificity of bioactive molecules.

Estimation of the aqueous solubility I: application to organic nonelectrolytes

The estimation of aqueous solubilities of organic nonelectrolytes by the General Solubility Equation (GSE) as proposed by Valvani and Yalkowsky (1980) is used in this study. The data and assumptions on which the GSE are based are reevaluated, and the equation is revised. The revised GSE is validated on a set of 580 pharmaceutically, environmentally, and industrially relevant nonelectrolytes. The revised equation has a stronger theoretical background and provides a more accurate estimation of aqueous solubility.

Biosorption of chromium(VI) from aqueous solutions by green algae Spirogyra species

Biosorption of heavy metals is an effective technology for the treatment of industrial wastewaters. Results are presented showing the sorption of Cr(VI) from solutions by biomass of filamentous algae Spirogyra species. Batch experiments were conducted to determine the adsorption properties of the biomass and it was observed that the adsorption capacity of the biomass strongly depends on equilibrium pH. Equilibrium isotherms were also obtained and maximum removal of Cr(VI) was around 14.7 x 10(3) mg metal, kg of dry weight biomass at a pH of 2.0 in 120 min with 5 mg/l of initial concentration. The results indicated that the biomass of Spirogyra species is suitable for the development of efficient biosorbent for the removal and recovery of Cr(VI) from wastewater.

Dermal and transdermal delivery of an anti-psoriatic agent via ethanolic liposomes

The aim of the current investigation is to evaluate the transdermal potential of novel vesicular carrier, ethosomes, bearing methotrexate (MTX), an anti-psoriatic, anti-neoplastic, highly hydrosoluble agent having limited transdermal permeation. MTX loaded ethosomes were prepared, optimized and characterized for vesicular shape and surface morphology, vesicular size, entrapment efficiency, stability, in vitro human skin permeation and vesicle-skin interaction. The formulation (EE(9)) having 3% phospholipid content and 45% ethanol showing the greatest entrapment (68.71+/-1.4%) and optimal nanometric size range (143+/-16 nm) was selected for further transdermal permeation studies. Stability profile of prepared system assessed for 120 days revealed very low aggregation and growth in vesicular size (8.8+/-1.2%). MTX loaded ethosomal carriers also provided an enhanced transdermal flux of 57.2+/-4.34 microg/cm(2)/h and decreased lag time of 0.9 h across human cadaver skin. Skin permeation profile of the developed formulation further assessed by confocal laser scanning microscopy (CLSM) revealed an enhanced permeation of Rhodamine Red (RR) loaded formulations to the deeper layers of the skin (170 microm). Also, the formulation retained its penetration power after storage. Vesicle skin interaction study also highlighted the penetration enhancing effect of ethosomes with some visual penetration pathways and corneocytes swelling, a measure of retentive nature of formulation. Our results suggests that ethosomes are an efficient carrier for dermal and transdermal delivery of MTX.

Dendrimer-mediated transdermal delivery: enhanced bioavailability of indomethacin

The transdermal delivery of aqueous formulations of indomethacin, a model drug, with different concentrations of three types of dendrimer showed a linear increase in flux with increasing concentration of each of the dendrimers. This result was in contrast to phase solubility studies, where Higuchi's A(N) profile was observed. The steady-state flux of the drug increased significantly and was highest with the G4-NH2 dendrimer at 0.2% w/v concentration, which showed an enhancement factor of 4.5 compared to the pure drug suspension. In vivo, a steady-state flux was achieved in 5 h, and the C(max) values were significantly higher with G4-NH2 and G4-OH dendrimer formulations. The [AUC](0-24h) of G4-NH2 (2.27 times) and G4-OH (1.95 times) formulations were significantly higher than that of the pure drug, but was only marginally higher in the case of G-4.5 dendrimer formulation. The % inhibition of paw volume showed a trend comparable to the pharmacokinetic data and a maximum of 1.6- and 1.5-fold increase was found with G4-NH2 and G4-OH formulations, respectively, compared to the pure drug suspension.

Glycodendrimeric nanoparticulate carriers of primaquine phosphate for liver targeting

In the present study it was intended to deliver primaquine phosphate (PP), a liver schizonticide directly to liver cells using polypropyleneimine (PPI) dendrimers-coated peripherally with galactose. PPI dendrimers were synthesized by consecutive Michael double addition reaction (using ethyelenediamine as core), followed by hydrogenation reaction. Galactose conjugation was carried out by ring opening reactions, followed by Schiff's reaction and reduction to secondary amine in sodium acetate buffer (pH 4.0). IR, NMR, MASS spectroscopy were used for the confirmation of synthesis of uncoated and coated dendrimers. The formulations were made by equilibrium dialysis of dendrimers with the solution of PP. Then the formulations were characterized by TEM for size and shape. Release rate, hemolytic toxicity; bio-distribution and blood level studies were also performed on lyophilized formulations. The results obtained indicated that galactose coating of PPI systems increases the drug entrapment efficiency by 5-15 times depending upon generations. Galactose coating prolonged release up to 5-6 days as compared to 1-2 days for uncoated PPI systems. The hemolytic toxicity, blood level and hematological studies proved these systems to be safer and suitable for sustained drug delivery. Blood level studies proved the suitability of the systems for the prolonged circulations and delivery of PP to liver. The galactose coating of PPI dendrimers can therefore make the PPI systems more effective and suitable for targeted delivery of Primaquine phosphate to liver.

Glycoconjugated peptide dendrimers-based nanoparticulate system for the delivery of chloroquine phosphate

Dendrimers consisting of different molecules of metabolic pathways such as amino acids can greatly reduce the toxicity associated with amine-terminated dendrimers e.g. polyamidoamine (PAMAM) and polypropylene imine (PPI) dendrimers. In the present study, poly-L-lysine dendrimers having polyethyleneglycol (PEG-1000) as core, were synthesized upto fourth generation. Dendrimers were synthesized by alternating protection and deprotection steps of L-lysine by di-BOC (di-tertiary butyl pyrocarbonate) till the formation of 4.0 G peptide dendrimer took place. D-galactose was selected as model sugar for peripheral conjugation (coating) of these peptide dendrimer. The complete formation of uncoated and galactose-coated poly-L-lysine dendrimers was characterized by transmission electron microscopy (TEM), IR, NMR and MALDI TOF mass spectroscopic studies. Chloroquine phosphate (CP)-loaded uncoated and coated dendrimers were evaluated for in vitro drug release rate, hemolytic toxicity and stability studies. Ex vivo cellular uptake studies of uncoated and coated drug dendrimer formulations in macrophages revealed almost 5 times reduced phagocytosis due to galactose coating (p<0.0001). In vitro-in vivo release behavior indicated possibilities of galactose-coated drug dendrimers formulation in controlled drug delivery of CP. Galactose coated formulations drastically reduced hemolytic toxicity compared to uncoated poly-L-lysine formulation as well as plain drug. Hematological data suggests that galactose-coated formulations are less immunogenic compared to uncoated formulations. Finally, it can be concluded that galactose-coated polylysine dendrimers can be utilized for controlled delivery of CP more safely compared to its uncoated formulation both in vitro and in vivo.

Antibiotic prophylaxis for percutaneous endoscopic gastrostomy. A prospective, randomized, double-blind clinical trial

Study Objective. To determine if prophylactic use of cefazolin reduces peristomal wound infection associated with percutaneous endoscopic gastrostomy. Design. Prospective, randomized, double-blind, placebo-controlled clinical trial. Setting. Academic medical center, referral-based, gastroenterology service. Patients. One hundred thirty hospitalized patients, 23 of whom were excluded. Of the remaining 107 patients, 52 (group I) were already using antibiotics at the time of randomization for gastrostomy, whereas 55 (group II) were not. Interventions. Patients received either intravenous saline as a placebo or intravenous cefazolin (1 g) 30 minutes before gastrostomy. Measurements and Main Results. For 1 week after gastrostomy, the peristomal area was evaluated and a score assigned each day for erythema (0 to 4), induration (0 to 3), and exudate (0 to 4). A maximum combined score of 8 or more or the development of pus was a criterion for infection. None of the patients in group I developed a wound infection. Only 2 of 27 group II patients given prophylaxis developed a wound infection, compared with 9 of 28 patients not given prophylaxis, a difference of 25% (95% confidence interval, 4.8 to 44.6%; p less than 0.025). The number of patients who developed a wound infection was 0 of 52 in group I and 2 of 27 in group II patients who received cefazolin, a difference of 7.4% (95% confidence interval, -2.5 to 17.3%; p = 0.07). Conclusion. Cefazolin prophylaxis significantly reduces the risk for peristomal wound infection associated with percutaneous endoscopic gastrostomy. It is needed, however, only for patients not already receiving antibiotic treatment at the time of gastrostomy.

Protein kinase C delta associates with and phosphorylates Stat3 in an interleukin-6-dependent manner

Stat3 is activated by phosphorylation on Tyr-705, which leads to dimer formation, nuclear translocation, and regulation of gene expression. Serine phosphorylation of Stat3 by mitogen-activated protein kinase has also been observed in cells responding to epidermal growth factor and shown to affect its tyrosine phosphorylation and transcriptional activity. Serine phosphorylation of Stat3 is also induced by interleukin-6 (IL-6) stimulation, which is shown to be independent of mitogen-activated protein kinase and sensitive to the Ser/Thr kinase inhibitor H7. In this study, we investigated whether protein kinase C (PKC) is the kinase that is induced and responsible for Stat3 serine phosphorylation by IL-6 stimulation and which isoform of PKCs is likely to be involved. Here, we report that Stat3 was specifically associated with PKC delta in vivo in an IL-6-dependent manner in several cell types. Furthermore, Stat3 was phosphorylated by PKC delta in vivo on Ser-727, which could be inhibited either by a specific PKC delta inhibitor or by a dominant-negative mutant of PKC delta. Finally, we showed that the phosphorylation of Stat3 by PKC delta led to a negative regulation of Stat3 DNA binding and transcriptional activity. These results indicate that PKC delta is likely to be the kinase that phosphorylates Stat3 in response to IL-6 stimulation and suggest a possible regulatory role of PKC delta on Stat3 function.

Repression of Stat3 activity by activation of mitogen-activated protein kinase (MAPK)

STAT proteins are activated by phosphorylation at specific tyrosine residue at the carboxy-terminus which is required for dimer-formation, nuclear translocation, DNA binding and transcriptional activity in cells treated with cytokines and growth factors. Recent studies have indicated that STATs are also phosphorylated by MAPK, or extracellular signal-regulated kinase (ERK) on serine. We investigated the role of ERK on the regulation of STAT activity. Here, we report that ERK2 activated by its upstream kinase, MEK1, represses Stat3 transcriptional activity induced by Src or Jak-2. To unravel the mechanism of repression, we further showed that Stat3 DNA binding activity and its tyrosine phosphorylation are also inhibited under the same conditions. ERK2 phosphorylates Stat3 on three serine-containing peptides and decreases its tyrosine phosphorylation induced by EGF treatment. We also detected an association of ERK2 and Stat3 in vivo which is modulated positively by activation of ERK2, but negatively by Jak2. We propose that MAP kinase cascade may negatively regulate Stat3 activities by decreasing its tyrosine phosphorylation and also possibly by association.

Proniosome based transdermal delivery of levonorgestrel for effective contraception

A proniosome based transdermal drug delivery system of levonorgestrel (LN) was developed and extensively characterized both in vitro and in vivo. The proniosomal structure was liquid crystalline-compact niosomes hybrid which could be converted into niosomes upon hydration. The system was evaluated in vitro for drug loading, rate of hydration (spontaneity), vesicle size, polydispersity, entrapment efficiency and drug diffusion across rat skin. The effect of composition of formulation, amount of drug, type of Spans, alcohols and sonication time on transdermal permeation profile was observed. The stability studies were performed at 4 degrees C and at room temperature. The biological assay for progestational activity included endometrial assay and inhibition with the formation of corpora lutea. The study demonstrated the utility of proniosomal transdermal patch bearing levonorgestrel for effective contraception.

Deactivation and reactivation of somatosensory cortex after dorsal spinal cord injury

Sensory stimuli to the body are conveyed by the spinal cord to the primary somatosensory cortex. It has long been thought that dorsal column afferents of the spinal cord represent the main pathway for these signals, but the physiological and behavioural consequences of cutting the dorsal column have been reported to range from mild and transitory to marked. We have re-examined this issue by sectioning the dorsal columns in the cervical region and recording the responses to hand stimulation in the contralateral primary somatosensory cortex (area 3b). Following a complete section of the dorsal columns, neurons in area 3b become immediately and perhaps permanently unresponsive to hand stimulation. Following a partial section, the remaining dorsal column afferents continue to activate neurons within their normal cortical target territories, but after five or more weeks the area of activation is greatly expanded. After prolonged recovery periods of six months or more, the deprived hand territory becomes responsive to inputs from the face (which are unaffected by spinal cord section). Thus, area 3b of somatosensory cortex is highly dependent on dorsal spinal column inputs, and other spinal pathways do not substitute for the dorsal columns even after injury.

Growth of new brainstem connections in adult monkeys with massive sensory loss

Somatotopic maps in the cortex and the thalamus of adult monkeys and humans reorganize in response to altered inputs. After loss of the sensory afferents from the forelimb in monkeys because of transection of the dorsal columns of the spinal cord, therapeutic amputation of an arm or transection of the dorsal roots of the peripheral nerves, the deprived portions of the hand and arm representations in primary somatosensory cortex (area 3b), become responsive to inputs from the face and any remaining afferents from the arm. Cortical and subcortical mechanisms that underlie this reorganization are uncertain and appear to be manifold. Here we show that the face afferents from the trigeminal nucleus of the brainstem sprout and grow into the cuneate nucleus in adult monkeys after lesions of the dorsal columns of the spinal cord or therapeutic amputation of an arm. This growth may underlie the large-scale expansion of the face representation into the hand region of somatosensory cortex that follows such deafferentations.

Controlling a possible outbreak of Candida auris infection: lessons learnt from multiple interventions

BACKGROUND

Multidrug-resistant Candida auris infection has been reported from five continents in recent years. The prevalence of C. auris invasive infection has been estimated at 5.3% for intensive-care-acquired candidaemia in India. The transmission of the organism between the patients and from environment to patients is rapid.

AIM

To understand the intra-hospital dynamics of C. auris transmission and to determine the possible interventions to prevent its spread.

METHODS

Surveillance of intensive care units was carried out to assess patient colonization, environmental contamination and hand carriage of the yeast among healthcare workers. Interventions including chlorhexidine washing of patients and decontamination of environmental surfaces with stabilized hydrogen peroxide disinfectant (Ecoshield) were undertaken. We further evaluated the effectiveness of frequently used disinfectants in the hospital against C. auris on various inanimate surfaces, and its persistence on hospital fabrics.

FINDINGS

Three cases of C. auris bloodstream infection were detected over a period of three months. Many patients admitted at the same time, in the same area, were colonized by C. auris. Surveillance detected C. auris contamination of environmental surfaces and hands of healthcare workers. Interventions such as chlorhexidine washing and appropriate use of disinfectants could eradicate C. auris from patients and hospital environment.

CONCLUSION

The frequently used disinfectants in our hospital and current hand hygiene practices were efficient against C. auris if proper contact time and procedures were followed. Evaluation of possible persistence of C. auris on dry fabrics showed that they can persist for up to seven days.

Melatonin loaded ethanolic liposomes: physicochemical characterization and enhanced transdermal delivery

The current investigation aims to evaluate the transdermal potential of novel ethanolic liposomes (ethosomes) bearing Melatonin (MT), an anti-jet lag agent associated with poor skin permeation and long lag time. MT loaded ethosomes were prepared and characterized for vesicular shape and surface morphology, vesicular size, entrapment efficiency, stability, in vitro skin permeation and in vivo skin tolerability. Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), and Dynamic Light Scattering (DLS) defined ethosomes as spherical, unilamellar structures having low polydispersity (0.032+/-0.011) and nanometric size range (122+/-3.5 nm). % Entrapment efficiency of MT in ethosomal carrier was found to be 70.71+/-1.4. Stability profile of prepared system assessed for 120 days revealed very low aggregation and growth in vesicular size (7.6+/-1.2%). MT loaded ethosomal carriers also provided an enhanced transdermal flux of 59.2+/-1.22 microg/cm2/h and decreased lag time of 0.9 h across human cadaver skin. Fourier Transform-Infrared (FT-IR) data generated to assess the fluidity of skin lipids after application of formulation revealed a greater mobility of skin lipids on application of ethosomes as compared to that of ethanol or plain liposomes. Skin permeation profile of the developed formulation further assessed by confocal laser scanning microscopy (CLSM) revealed an enhanced permeation of Rhodamine Red (RR) loaded formulations to the deeper layers of the skin (240 microm). Further, a better skin tolerability of ethosomal suspension on rabbit skin suggested that ethosomes may offer a suitable approach for transdermal delivery of melatonin.

Interstitial Lung Disease in India. Results of a Prospective Registry

RATIONALE

Interstitial lung disease (ILD) is a heterogeneous group of acute and chronic inflammatory and fibrotic lung diseases. Existing ILD registries have had variable findings. Little is known about the clinical profile of ILDs in India.

OBJECTIVES

To characterize new-onset ILDs in India by creating a prospective ILD using multidisciplinary discussion (MDD) to validate diagnoses.

METHODS

Adult patients of Indian origin living in India with new-onset ILD (27 centers, 19 Indian cities, March 2012-June 2015) without malignancy or infection were included. All had connective tissue disease (CTD) serologies, spirometry, and high-resolution computed tomography chest. ILD pattern was defined by high-resolution computed tomography images. Three groups independently made diagnoses after review of clinical data including that from prompted case report forms: local site investigators, ILD experts at the National Data Coordinating Center (NDCC; Jaipur, India) with MDD, and experienced ILD experts at the Center for ILD (CILD; Seattle, WA) with MDD. Cohen's κ was used to assess reliability of interobserver agreement.

MEASUREMENTS AND MAIN RESULTS

A total of 1,084 patients were recruited. Final diagnosis: hypersensitivity pneumonitis in 47.3% (n = 513; exposure, 48.1% air coolers), CTD-ILD in 13.9%, and idiopathic pulmonary fibrosis in 13.7%. Cohen's κ: 0.351 site investigator/CILD, 0.519 site investigator/NDCC, and 0.618 NDCC/CILD.

CONCLUSIONS

Hypersensitivity pneumonitis was the most common new-onset ILD in India, followed by CTD-ILD and idiopathic pulmonary fibrosis; diagnoses varied between site investigators and CILD experts, emphasizing the value of MDD in ILD diagnosis. Prompted case report forms including environmental exposures in prospective registries will likely provide further insight into the etiology and management of ILD worldwide.

Stress-induced immediate-early gene, egr-1, involves activation of p38/JNK1

The Ras/Raf/MAP kinase (ERK) pathway is a major signaling pathway induced by growth factors in mammalian cells. Two other types of mammalian MAP kinases, JNK (SAPK) and p38 (RK, CSBP), are induced by environmental stress. Although the immediate-early gene, egr-1, is induced by growth factors, cytokines, differentiation signals and DNA damaging agents, less is known about its induction by environmental stress and the mechanism involved. Here we report that in NIH3T3 cells, egr-1 is induced by various stress treatments such as heat shock, sodium arsenite, ultraviolet (U.V.) radiation, and anisomycin. p38 and JNK1, but not ERK2, were activated by these stress treatments. Induction of egr-1 by anisomycin is inhibited by a specific inhibitor of p38, SB 203580. We also show that p38 and JNK1 activated by their upstream kinases induce egr-1 promoter activity through activation of the ternary complex factor, Elk-1. The stress treatments also lead to an increase in Egr-1 protein phosphorylation and its DNA binding activity. Together, our data suggest that induction of egr-1 gene by growth factors and stress are mediated through different subgroups of MAP kinases which may also differentially affect egr-1 function on its target genes.

Investigations on the toxicological profile of functionalized fifth-generation poly(propylene imine) dendrimer

Dendrimers have generated tremendous interest in the field of drug delivery. Despite indications of their utility as drug carriers, the inherent cytotoxicity associated with polycationic dendrimers acts as a limiting factor to their clinical applications. Many functionalization strategies have been adopted to mask peripheral amines in order to overcome this limitation. The object of the present investigation was to evaluate the effect of functionalization on the toxicological profile of fifth-generation poly(propylene imine) dendrimer (PPI-5.0G). Four forms of functionalized dendrimers, including protected glycine and phenylalanine, and mannose and lactose functionalized poly(propylene imine) (PPI) dendrimer, were synthesized as prospective drug carriers. These dendrimeric systems were evaluated for haemolytic toxicity, cytotoxicity, immunogenicity and haematological parameters. PPI-5.0G demonstrated a positive charge-based time- and concentration-dependent toxicity profile. Functionalization greatly improved the toxicity profile of the parent dendrimer. Hence it is proposed that these functionalized forms of PPI dendrimer have great potential as bio-compatible drug vehicles.

Calcium silicate based microspheres of repaglinide for gastroretentive floating drug delivery: Preparation and in vitro characterization

Gastroretentive dosage forms have potential for use as controlled-release drug delivery systems. Multiple unit systems avoid the 'all-or-none' gastric emptying nature of single-unit systems. A controlled release system designed to increase its residence time in the stomach without contact with the mucosa was achieved through the preparation of floating microspheres by the emulsion solvent diffusion technique consisting of (i) calcium silicate (FLR) as porous carrier; (ii) repaglinide, an oral hypoglycemic agent; and (iii) Eudragit S as polymer. The effect of various formulation and process variables on the internal and external particle morphology, micromeritic properties, in vitro floating behavior, physical state of the incorporated drug, drug loading and in vitro drug release were studied. The microparticles were found to be regular in shape and highly porous. The release rate was determined in simulated gastro-intestinal fluids at 37 degrees C. The formulation demonstrated favorable in vitro floating and release characteristics. The drug encapsulation efficiency was high. Incorporation of FLR in the microspheres proved to be an effective method to achieve the desired release behavior and buoyancy. The designed system, combining excellent buoyant ability and suitable drug release pattern, could possibly be advantageous in terms of increased bioavailability of repaglinide.

BET protein proteolysis targeting chimera (PROTAC) exerts potent lethal activity against mantle cell lymphoma cells

Bromodomain extraterminal protein (BETP) inhibitors transcriptionally repress oncoproteins and nuclear factor-κB (NF-κB) target genes that undermines the growth and survival of mantle cell lymphoma (MCL) cells. However, BET bromodomain inhibitor (BETi) treatment causes accumulation of BETPs, associated with reversible binding and incomplete inhibition of BRD4 that potentially compromises the activity of BETi in MCL cells. Unlike BETi, BET-PROTACs (proteolysis-targeting chimera) ARV-825 and ARV-771 (Arvinas, Inc.) recruit and utilize an E3-ubiquitin ligase to effectively degrade BETPs in MCL cells. BET-PROTACs induce more apoptosis than BETi of MCL cells, including those resistant to ibrutinib. BET-PROTAC treatment induced more perturbations in the mRNA and protein expressions than BETi, with depletion of c-Myc, CDK4, cyclin D1 and the NF-κB transcriptional targets Bcl-xL, XIAP and BTK, while inducing the levels of HEXIM1, NOXA and CDKN1A/p21. Treatment with ARV-771, which possesses superior pharmacological properties compared with ARV-825, inhibited the in vivo growth and induced greater survival improvement than the BETi OTX015 of immune-depleted mice engrafted with MCL cells. Cotreatment of ARV-771 with ibrutinib or the BCL2 antagonist venetoclax or CDK4/6 inhibitor palbociclib synergistically induced apoptosis of MCL cells. These studies highlight promising and superior preclinical activity of BET-PROTAC than BETi, requiring further in vivo evaluation of BET-PROTAC as a therapy for ibrutinib-sensitive or -resistant MCL.

Understanding and predicting suicidality using a combined genomic and clinical risk assessment approach

Worldwide, one person dies every 40 seconds by suicide, a potentially preventable tragedy. A limiting step in our ability to intervene is the lack of objective, reliable predictors. We have previously provided proof of principle for the use of blood gene expression biomarkers to predict future hospitalizations due to suicidality, in male bipolar disorder participants. We now generalize the discovery, prioritization, validation, and testing of such markers across major psychiatric disorders (bipolar disorder, major depressive disorder, schizoaffective disorder, and schizophrenia) in male participants, to understand commonalities and differences. We used a powerful within-participant discovery approach to identify genes that change in expression between no suicidal ideation and high suicidal ideation states (n=37 participants out of a cohort of 217 psychiatric participants followed longitudinally). We then used a convergent functional genomics (CFG) approach with existing prior evidence in the field to prioritize the candidate biomarkers identified in the discovery step. Next, we validated the top biomarkers from the prioritization step for relevance to suicidal behavior, in a demographically matched cohort of suicide completers from the coroner's office (n=26). The biomarkers for suicidal ideation only are enriched for genes involved in neuronal connectivity and schizophrenia, the biomarkers also validated for suicidal behavior are enriched for genes involved in neuronal activity and mood. The 76 biomarkers that survived Bonferroni correction after validation for suicidal behavior map to biological pathways involved in immune and inflammatory response, mTOR signaling and growth factor regulation. mTOR signaling is necessary for the effects of the rapid-acting antidepressant agent ketamine, providing a novel biological rationale for its possible use in treating acute suicidality. Similarly, MAOB, a target of antidepressant inhibitors, was one of the increased biomarkers for suicidality. We also identified other potential therapeutic targets or biomarkers for drugs known to mitigate suicidality, such as omega-3 fatty acids, lithium and clozapine. Overall, 14% of the top candidate biomarkers also had evidence for involvement in psychological stress response, and 19% for involvement in programmed cell death/cellular suicide (apoptosis). It may be that in the face of adversity (stress), death mechanisms are turned on at a cellular (apoptosis) and organismal level. Finally, we tested the top increased and decreased biomarkers from the discovery for suicidal ideation (CADM1, CLIP4, DTNA, KIF2C), prioritization with CFG for prior evidence (SAT1, SKA2, SLC4A4), and validation for behavior in suicide completers (IL6, MBP, JUN, KLHDC3) steps in a completely independent test cohort of psychiatric participants for prediction of suicidal ideation (n=108), and in a future follow-up cohort of psychiatric participants (n=157) for prediction of psychiatric hospitalizations due to suicidality. The best individual biomarker across psychiatric diagnoses for predicting suicidal ideation was SLC4A4, with a receiver operating characteristic (ROC) area under the curve (AUC) of 72%. For bipolar disorder in particular, SLC4A4 predicted suicidal ideation with an AUC of 93%, and future hospitalizations with an AUC of 70%. SLC4A4 is involved in brain extracellular space pH regulation. Brain pH has been implicated in the pathophysiology of acute panic attacks. We also describe two new clinical information apps, one for affective state (simplified affective state scale, SASS) and one for suicide risk factors (Convergent Functional Information for Suicide, CFI-S), and how well they predict suicidal ideation across psychiatric diagnoses (AUC of 85% for SASS, AUC of 89% for CFI-S). We hypothesized a priori, based on our previous work, that the integration of the top biomarkers and the clinical information into a universal predictive measure (UP-Suicide) would show broad-spectrum predictive ability across psychiatric diagnoses. Indeed, the UP-Suicide was able to predict suicidal ideation across psychiatric diagnoses with an AUC of 92%. For bipolar disorder, it predicted suicidal ideation with an AUC of 98%, and future hospitalizations with an AUC of 94%. Of note, both types of tests we developed (blood biomarkers and clinical information apps) do not require asking the individual assessed if they have thoughts of suicide, as individuals who are truly suicidal often do not share that information with clinicians. We propose that the widespread use of such risk prediction tests as part of routine or targeted healthcare assessments will lead to early disease interception followed by preventive lifestyle modifications and proactive treatment.