Recent development in transition metal-catalysed C-H olefination

Transition metal-catalysed functionalizations of inert C-H bonds to construct C-C bonds represent an ideal route in the synthesis of valuable organic molecules. Fine tuning of directing groups, catalysts and ligands has played a crucial role in selective C-H bond (sp2 or sp3) activation. Recent developments in these areas have assured a high level of regioselectivity in C-H olefination reactions. In this review, we have summarized the recent progress in the oxidative olefination of sp2 and sp3 C-H bonds with special emphasis on distal, atroposelective, non-directed sp2 and directed sp3 C-H olefination. The scope, limitation, and mechanism of various transition metal-catalysed olefination reactions have been described briefly.

Evaluation of intrastromal injection of voriconazole as a therapeutic adjunctive for the management of deep recalcitrant fungal keratitis

PURPOSE

To evaluate the role of intrastromal injection of voriconazole in the management of deep recalcitrant fungal keratitis.

DESIGN

Interventional case series.

METHODS

SETTING

Cornea services at a tertiary care teaching hospital.

PATIENTS

Three eyes of three patients with deep stromal recalcitrant fungal keratitis not responding to topical antifungal medications. Intervention Procedure: Voriconazole 50 micrograms/0.1 ml was injected circumferentially around the fungal abscess in the corneal stroma as an adjunctive to the topical antifungal therapy.

MAIN OUTCOME MEASURE

Main outcome measure was a reduction in size of the abscess and resolution of the infection.

RESULTS

Before the intracorneal injection, all three eyes had gradually worsening lesions on topical medications. After the intervention, a faster reduction in the size of corneal infiltration was documented and a complete resolution of the ulcers was seen within three weeks in all cases.

CONCLUSION

Targeted delivery of voriconazole by intracorneal injection may be a safe and effective way to treat cases of deep-seated recalcitrant fungal keratitis responding poorly to conventional treatment modalities.

C-H deuteration of organic compounds and potential drug candidates

C-H deuteration has been intricately developed to satisfy the urgent need for site-selectively deuterated organic frameworks. Deuteration has been primarily used to study kinetic isotope effects of reactions but recently its significance in pharmaceutical chemistry has been discovered. Deuterium labelled compounds have stolen the limelight since the inception of the first FDA-approved deuterated drug, for the treatment of chorea-associated Huntington's disease, and their pharmacological importance was realised by chemists, although surprisingly very late. Various approaches were developed to carry out site-selective deuteration. However, the most common and efficient method is hydrogen isotope exchange (HIE). This review summarises deuteration methods of various organic motifs containing C(sp²)-H and C(sp³)-H bonds utilizing C-H bond functionalisation as a key step along with a variety of catalysts, and exemplifies their biological relevance.

Predictive factor and kappa angle analysis for visual satisfactions in patients with multifocal IOL implantation

PURPOSE

To evaluate the visual acuity and quality-related satisfaction of patients implanted with a refractive design multifocal intraocular lens (IOL), and evaluate the factors predicting it including angle kappa.

SETTING

Dr Agarwal's Eye Hospital and Eye Research Centre, Chennai.

METHODS

In this prospective trial, 50 eyes of 44 consecutive patients were included. All patients underwent phacoemulsification with multifocal IOL implantation (Rezoom IOL, Abbott Medical Optics). The preoperative and postoperative assessment included slit lamp biomicroscopy, uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA) and kappa angle assessment. At 1 year, 37 patients (43 eyes), who finished follow-up, were asked to rate their symptoms on a graded questionnaire (0-5 for five queries).

RESULTS

The decimal scores for UCVA and BCVA were 0.38±0.21 and 0.47±0.17 (preoperative), and 0.75±0.22 and 0.99±0.11 (postoperative), respectively. Symptom scores were haloes 0.98±1.7, glare 0.69±1.48, blurred distance 1.0±1.7, intermediate 1.34±1.6, near 1.06±1.8. On regression analysis haloes depended on angle kappa and distance UCVA (R (2)=0.26, P=0.029), and glare on angle kappa (R (2)=0.26, P=0.033). Poor satisfactions with distance, intermediate, and near vision were linked with distance UCVA (R (2)=0.17, P=2.3 × 10(-4)), distance UCVA (R (2)=0.1, P=0.04), and near UCVA (R (2)=0.12, P=0.03), respectively. The strongest predictor, however, for overall visual discomfort was distance UCVA (R (2)=0.1, P=0.04).

CONCLUSIONS

Our study suggests that there may be a role of misalignment between the visual and pupillary axis (angle kappa) in the occurrence of photic phenomenon after refractive multifocal IOL implantation.

Glued posterior chamber IOL in eyes with deficient capsular support: a retrospective analysis of 1-year post-operative outcomes

PURPOSE

To evaluate the post-operative outcome of fibrin glue-assisted posterior chamber intraocular lens (IOL) implantation in eyes with deficient capsular support after 1 year.

METHODS

Eyes operated with fibrin glue-assisted posterior chamber IOL implantation from December 2007 to May 2008 were included. The post-operative best spectacle-corrected visual acuity (BCVA), uncorrected visual acuity (UCVA), intraocular pressure (IOP), central macular thickness, and specular count were evaluated. IOL position and centration at 1 year was determined. The 1-year post-operative complications were analysed.

RESULTS

A total of 53 eyes of 53 patients were analysed. There was significant improvement in UCVA (P=0.000) and BCVA (P=0.000). There was no significant change (P=0.447) in IOP from the pre-operative value. The early post-operative complication was decentration (5.6%). The late complication was pigment dispersion (3.7%) and healed macular oedema (7.5%). No vision threatening complications such as retinal break, retinal detachment, or endophthalmitis were seen. The percentage (%) loss of endothelial cells was 5.23+/-3.4% at 1-year follow-up. No pseudophakodonesis was seen in the follow-up visits.

CONCLUSION

Results obtained at 1 year after fibrin glue-assisted posterior chamber IOL implantation showed a good visual outcome with minimal complications in eyes with deficient capsular support.

The Diagnostic Dilemma of Neurolymphomatosis

Neurolymphomatosis (NL) defined as infiltration of the central nervous system or the peripheral nervous system (PNS) by malignant lymphoma cells is a rare clinical entity. However, the increasing use of fluorodeoxyglucose positron-emission tomography (FDG-PET) and magnetic resonance imaging in evaluating PNS disorders is resulting in; this condition being recognized more frequently. Here; we report five NL patients and review the current literature. We report five patients with non-Hodgkin's lymphoma (NHL) and NL, all of whom were men aged 47–69 years. The clinical presentation varied from symmetrical peripheral neuropathy to mononeuropathy. Peripheral neuropathy was the presenting manifestation of a systemic lymphoma in two patients (40%). Neuroimaging as well as whole-body FDG-PET helped in determining the correct diagnosis in all of the patients. NL is an unusual presentation of NHL resulting from infiltration of the PNS by malignant lymphomatous cells. While evaluating peripheral neuropathy, a high degree of suspicion of NL is required since the presenting symptoms vary, conventional radiology has only modest sensitivity, and a pathological diagnosis is often difficult. FDG-PET helps in the early diagnosis and treatment of this condition.

Evaluation of intraocular lens tilt with anterior segment optical coherence tomography

PURPOSE

To determine the ability of anterior segment optical coherence tomography (OCT) to detect intraocular lens (IOL) tilt evaluation in relation to the limbus.

DESIGN

Observational case series.

METHODS

The IOL position of 123 eyes of 92 patients was examined with anterior segment OCT (Carl Zeiss Meditec, Dublin, California, USA). All eyes underwent uneventful phacoemulsification with the IOL in the bag. Images were obtained in 4 axes (180 to 0 degrees, 225 to 45 degrees, 315 to 135 degrees, and 270 to 90 degrees). Using MatLab software version 7.1 (Mathworks), the OCT images were analyzed. The distance between the iris margin and the anterior surface of IOL, the slope ratio between IOL and limbus, and the angle (θ; position of IOL with reference to the limbus) were determined and were correlated with the astigmatism and vision.

RESULTS

The mean slope of the limbus and the IOL in all axes was 0.003 ± 0.09 and -0.002 ± 0.12, respectively. The average slope ratio was 1.1 ± 1 (range, -2.09 to 3.82) and the angle (θ) was 1.52 ± 0.9 degrees (range, 0.04 to 3.6 degrees). The mean ocular residual astigmatism was 0.2379 ± 0.469 diopters. There was no significant correlation of ocular residual astigmatism with slope ratio (r = -0.171; P = .060) and slope angle (r = -0.132; P = .147). There was significant correlation of ocular residual astigmatism with total astigmatism (r=0.602, p=0.000). The mean distances between the iris margin and the anterior surface of IOL at the pupillary plane were 0.80 ± 0.6 mm and 0.83 ± 0.57 mm, respectively.

CONCLUSIONS

The normal in-the-bag IOL maintains an angle with reference to the limbus and a slope ratio without causing a significant tilt. Anterior segment OCT can be used as an alternative in IOL tilt evaluation by the analysis of its position in relation to the limbus.

A direct route to six and seven membered lactones via γ-C(sp3)-H activation: a simple protocol to build molecular complexity

Lactones comprise a class of valuable compounds having biological as well as industrial importance. Development of a methodology to synthesize such molecules directly from readily available materials such as aliphatic carboxylic acid is highly desirable. Herein, we have reported synthesis of δ-lactones and ε-lactones via selective γ-C(sp³)–H activation. The γ-C–H bond containing aliphatic carboxylic acids provide six or seven membered lactones depending on the olefin partner in the presence of a palladium catalyst. A mechanistic investigation suggests that C–H activation is the rate-determining step. Further transformations of the lactones have been carried out to showcase the applicability of the present strategy.

Six and seven membered lactones have been synthesized directly from readily available aliphatic acids.

Silicon-Based Reagents for Difluoromethylation and Difluoromethylenation Reactions

There have been significant developments in the area of perfluoroalkyl group transfer using silicon reagents, specifically in nucleo­philic trifluoromethylation. The mild and versatile activation conditions bestow significant synthetic prowess to the silicon reagents in the area of fluoroalkylations. Owing to the importance of difluoromethylene (CF2) containing compounds in pharmaceuticals, materials, and agrochemicals, several CF2 group transfer methods using related silicon reagents have been developed and studied in detail. This review summarizes the recent developments and trends in this area.

1 Introduction

2 Trimethyl(trifluoromethyl)silane (Me3SiCF3)

3 (Difluoromethyl)trimethylsilane (Me3SiCF2H)

3.1 Nucleophilic Addition

3.2 Nucleophilic Substitution

3.3 Nucleophilic Difluoromethylation of Electron-Deficient Hetero­cycles

3.4 Metal-Mediated Cross Coupling

3.5 Oxidative Coupling of Terminal Alkynes

4 Post-functionalizable Difluoromethyl Transfer Reagents

4.1 (Chlorodifluoromethyl)trimethylsilane (Me3SiCF2Cl)

4.2 (Bromodifluoromethyl)trimethylsilane (Me3SiCF2Br)

4.3 [Difluoro(iodo)methyl]trimethylsilane (Me3SiCF2I)

4.4 [Difluoro(phenylthio)methyl]trimethylsilane (Me3SiCF2SPh)

4.5 [Difluoro(phenylsulfonyl)methyl]trimethylsilane (Me3SiCF2SO2Ph)

4.6 Diethyl [Difluoro(trimethylsilyl)methyl]phosphonate [Me3SiCF2P(O)(OEt)2]

4.7 Ethyl Difluoro(trimethylsilyl)acetate (Me3SiCF2CO2Et)

4.8 Difluoro(trimethylsilyl)acetamides (Me3SiCF2CONR2)

4.9 Difluoro(trimethylsilyl)acetonitrile (Me3SiCF2CN)

5 Others

6 Conclusions

Pediatric keratoplasty in India: indications and outcomes

PURPOSE

To analyze the indications and outcomes of pediatric corneal transplantation surgery in a tertiary eye care center in the developing world.

METHODS

In this longitudinal, retrospective study involving continuous cases, the records of 168 eyes of 154 children undergoing keratoplasty at a tertiary care center's specialized keratoplasty clinic during a 7-year period (1998-2004) were reviewed. The demography, etiology of opacification, visual acuity, and other findings were recorded. Intraoperative and postoperative details were reviewed. Major postoperative outcomes analyzed were visual acuity, graft survival, causes of graft failure, and follow-up duration.

RESULTS

Infectious keratitis (43%) was the most common indication for keratoplasty, followed by congenital glaucoma (16.6%) and corneal trauma (11.2%). Overall 77% graft survival was seen at 36 months, and better graft outcome was associated with younger age and longer regular follow-up. Postoperatively, a best-corrected visual acuity (BCVA) > 20/200 could be achieved in only 30.1% of eyes at the last follow-up. Graft failure was seen in 18.4% of eyes, with graft infection being the most frequent cause (50%). Moreover, graft infection was the most common cause of graft failure in all age groups.

CONCLUSIONS

In the developing world, infectious keratitis is the most common indication for pediatric keratoplasty and the most frequent cause of its failure.

Reliability and reproducibility of assessment of corneal epithelial thickness by fourier domain optical coherence tomography

PURPOSE

To analyze the intra-user reliability and inter-user reproducibility of assessment of corneal epithelial thickness by Fourier domain optical coherence tomography.

METHODS

In this consecutive cross-sectional case series performed at a tertiary ocular care institution, 210 eyes of 210 subjects underwent anterior segment Fourier domain optical coherence tomography (FDOCT). A caliper tool software was used to measure the corneal thickness. For the reproducibility measures, the examination was done by 2 examiners (user 1, user 2) within 30 minutes of each other. For the reliability measure, the retest was done by user 1 on the next day, within 30 minutes of the previous test's time. The total corneal thickness, epithelial thickness, and corneal thickness excluding the epithelium were measured.

RESULTS

The mean corneal thickness of the population measured by user 1 was 519.5 ± 31.1 μm, 58.6 ± 4.2 μm, and 460.95 ± 31.4 μm for total cornea, epithelium, and non-epithelial cornea, respectively. The difference in results between user 2 and user 1 was 0.8 ± 7.2 μm, 0.23 ± 3.3 μm, and 0.7 ± 8.2 μm for total, epithelium, and non-epithelial cornea, respectively, and the difference in results between the repeated series by user 1 was 0.49 ± 5.7 μm, -0.13 ± 2.7 μm, 0.61 ± 5.4 μm total, epithelium, and non-epithelial cornea, respectively (paired t-test, P > 0.05). Intraclass correlations ranged from 0.87 to 0.99, coefficients of repeatability from 4.5 to 14.11, and coefficient of variation from 2.3% to 11.1%.

CONCLUSIONS

Fourier domain anterior segment optical coherence tomography is reproducible and reliable for the measurement of epithelial thickness at vertex.

Traditional and sustainable approaches for the construction of C–C bonds by harnessing C–H arylation

Biaryl scaffolds are found in natural products and drug molecules and exhibit a wide range of biological activities. In past decade, the transition metal-catalyzed C–H arylation reaction came out as an effective tool for the construction of biaryl motifs. However, traditional transition metal-catalyzed C–H arylation reactions have limitations like harsh reaction conditions, narrow substrate scope, use of additives etc. and therefore encouraged synthetic chemists to look for alternate greener approaches. This review aims to draw a general overview on C–H bond arylation reactions for the formation of C–C bonds with the aid of different methodologies, majorly highlighting on greener and sustainable approaches.

Transition-metal-catalyzed C–H arylations are an effective tool for the construction of biaryl motifs in an efficient and selective manner. Here the authors provide an overview of the state-of-the-art of the field and perspectives on emerging directions toward increased sustainability.

Early Results of Extreme Hypofractionation Using Stereotactic Body Radiation Therapy for High-risk, Very High-risk and Node-positive Prostate Cancer

AIMS

Stereotactic body radiotherapy (SBRT) in low- and intermediate-risk prostate cancer has shown encouraging results. However, its use in high-risk patients is limited due to lack of data regarding adequate radiotherapy dose, need for pelvic nodal treatment and androgen deprivation therapy. Herein we report our experience of SBRT in this subgroup.

MATERIALS AND METHODS

Analysis of a prospectively maintained database of 68 consecutive patients of the National Comprehensive Cancer Network (NCCN) high-risk, very high-risk and node-positive adenocarcinoma prostate treated with SBRT was undertaken. All patients were treated with rotational intensity-modulated radiotherapy with daily image guidance. The dose delivered to the prostate and gross node was 35-37.5 Gy in 5 alternate day fractions. Node-positive patients received 25 Gy to pelvic nodal regions until the common iliac nodes. Treatment was delivered in 7-10 days. All patients received long-term androgen deprivation therapy (79% medical and 21% surgical).

RESULTS

Most patients (65%) had a Gleason score ≥ 8. The median prostate-specific antigen was 42. Twenty patients were high risk (30%), 11 (16%) very high risk and 37 (54%) node positive. No acute Radiation Therapy Oncology Group grade ≥ 3 genitourinary or gastrointestinal toxicity was noted. Acute grade 2 genitourinary and gastrointestinal toxicity were 12% and 3%, respectively. Late grade 3 genitourinary and gastrointestinal toxicity was 3% and 0%, respectively. There was no increase in acute or late gastrointestinal toxicity with prophylactic pelvic nodal radiotherapy. Prior transurethral resection of prostate (n = 11) did not increase toxicity. At a median follow-up of 18 months, 97% patients were alive and 94% were biochemically controlled.

CONCLUSION

SBRT is safe in the treatment of high-risk, very high-risk and node-positive prostate cancer, even with prophylactic pelvic radiotherapy or prior transurethral resection of prostate. Longer follow-up is required to determine efficacy.

Discriminant analysis and structure-activity relationships. 1. Naphthoquinones

Discriminant analysis has been used to study the data for naphthoquinones as antitumor agents in three different animal tumor systems. In each case the most significant variables for classifying the compounds into two groups according to their antitumor activities were determined by a stepwise procedure. The usefulness of discriminant analysis in the design of drugs is discussed.

Outcomes of transurethral resection and holmium laser enucleation in more than 60 g of prostate: A prospective randomized study

AIM

Transurethral resection of prostate (TURP) is considered a gold standard surgical procedure. The management of benign prostatic hyperplasia (BPH) has undergone tremendous change in recent years and shifted from open to minimal invasive procedure. With the advancement in technology and skills of surgeons, lasers have been used more liberally, particularly holmium laser. Holmium laser enucleation of prostate (HoLEP) is seen as close rival of TURP. The objective if this study is to observe long- and short-term outcomes of transurethral resection and holmium laser enucleation in the prostate of more than 60 g.

MATERIALS AND METHODS

This prospective randomized study includes 164 patients. Inclusion criteria were age <75 years after failed or poor response to medical therapy, prostatic size >60 g, gross hematuria secondary to BPH, recurrent urinary tract infection, acute urinary retention, postvoid residual >150 ml, and Schafer Grade II or more. BPH associated with neurogenic bladder, stricture urethra, and carcinoma prostate were excluded from the study. Group 1 comprises patients who underwent TURP and Group 2 comprises who underwent HoLEP. Follow-up was done at 1, 3, 6, 12, and 24 months after the surgery.

RESULTS

Data of 144 patients were analyzed. The mean age of patients in TURP and HoLEP group was 66.78 ± 7.81 and 67.70 ± 7.44 years, respectively (P = 0.47), mean prostatic volume was 74.5 ± 12.56 and 75.6 ± 12.84 g, respectively (P = 0.60), operative time was 73.10 ± 10.49 and 89.56 ± 13.81 min, respectively (P = 0.0001). Mean resected tissue was 44.80 ± 9.87 and 48.49 ± 10.87, respectively (P = 0.03). The sexual function did not changed significantly in postoperative follow-up.

CONCLUSION

HoLEP is associated with less blood loss, lower transfusion rates, and a shorter hospital stay. The disadvantage of HoLEP is longer operative time and postoperative dysuria.

Glued intraocular lens implantation for eyes with defective capsules: A retrospective analysis of anatomical and functional outcome

PURPOSE

To analyze the anatomical and functional outcome of glued intra ocular lens (IOL) implantation technique and its modifications.

DESIGN

Retrospective observational case series.

METHODS

This is a retrospective analysis of the patients who underwent glued intra ocular lens implantation from December 2007 to August 2010. Post operative uncorrected vision, best corrected visual acuity (BCVA), intra ocular pressure, IOL position, endothelial cells and anterior chamber reaction at their last follow up are analyzed from their concerned case sheets documentation. Subjective changes are analyzed via individual questionnaire. Immediate and late postoperative complications are also evaluated. Surgical modifications and the difference in the operated eyes are analyzed.

RESULTS

Total 210 glued IOL eyes have been reviewed. Out of this 210, there are 152 (PMMA glued IOL), 21 (three piece foldable IOL), 5 (multifocal foldable IOL), 12 (pediatric glued IOL), 5 (20G sutureless vitrectomy), 2 (glued iris prosthesis) and 3 (transposition of posterior chamber IOL into anterior chamber). In combined surgeries there are, 5 (optical penetrating keratoplasty), 2 (descemet's stripping endothelial keratoplasty) and 3 (iridoplasty). The modifications in glued IOL are handshake technique, injectable or foldable glued IOL, Multifocal glued IOL and intraoperative 23/25G trocar cannula infusion. Decentration (1.97%), macular edema (1.97%) and optic capture (2.63%) are the post operative complications encountered in rigid glued IOL. Good patient satisfaction is seen in the eyes with IOL repositioning, IOL exchange and multifocal glued IOL. There is significant improvement in BCVA in PMMA IOL (p = 1.35 × 10(-5)) and foldable IOL (p = 0.000).

CONCLUSION

Glued IOL seems to be a good alternative in IOL implantation in eyes with deficient capsules. The modifications in the existing technique decrease the learning time and risk for complications.

Improvement of Basmati rice varieties for resistance to blast and bacterial blight diseases using marker assisted backcross breeding

Marker assisted backcross breeding was employed to incorporate the blast resistance genes, Pi2 and Pi54 and bacterial blight (BB) resistance genes xa13 and Xa21 into the genetic background of Pusa Basmati 1121 (PB1121) and Pusa Basmati 6. Foreground selection for target gene(s) was followed by arduous phenotypic and background selection which fast-tracked the recovery of recurrent parent genome (RPG) to an extent of 95.8% in one of the near-isogenic lines (NILs) namely, Pusa 1728-23-33-31-56, which also showed high degree of resemblance to recurrent parent, PB6 in phenotype. The phenotypic selection prior to background selection provided an additional opportunity for identifying the novel recombinants viz., Pusa 1884-9-12-14 and Pusa 1884-3-9-175, superior to parental lines in terms of early maturity, higher yield and improved quality parameters. There was no significant difference between the RPG recovery estimated based on SSR or SNP markers, however, the panel of SNPs markers was considered as the better choice for background selection as it provided better genome coverage and included SNPs in the genic regions. Multi-location evaluation of NILs depicted their stable and high mean performance in comparison to the respective recurrent parents. The Pi2+Pi54 carrying NILs were effective in combating a pan-India panel of Magnaporthe oryzae isolates with high level of field resistance in northern, eastern and southern parts of India. Alongside, the PB1121-NILs and PB6-NILs carrying BB resistance genes xa13+Xa21 were resistant against Xanthomonas oryzae pv. oryzae races of north-western, southern and eastern parts of the country. Three of NILs developed in this study, have been promoted to final stage of testing during the ​Kharif 2015 in the Indian National Basmati Trial.

Nitrogen analogues of 1,4-benzoquinones. Activities against the ascitic sarcoma 180 of mice

Compounds having the basic structure N-(R)-substituted ring-substituted 4-iminocyclohexadienone have been synthesized and tested as antitumor agents against the ascitic sarcoma 180 tumor in Swiss mice. Among these compounds, the dimethylindoanilines [R = 4-(CH3)2NC6H4] are most stable in water at pH 7.0 and at 25 degrees C, the oximes (R = oh) are less stable, and the N-halo compounds (R = Br and Cl) are least stable. The N-halo derivatives have the highest redox potentials under the conditions used, the greatest effect against ascitic sarcoma 180 in Swiss mice, and the greatest acute toxicity when injected ip in the Swiss mice. Discriminant analysis of the results indicates that substituents with positive values of F and negative values of pi increase the antitumor activities, whereas those with positive values of sigma and R should lower the toxicity. The redox potential, a molecular parameter, is the best single variable for discriminating between the groups based on antitumor activities.

Delivery of mRNA to platelets using lipid nanoparticles

Platelets are natural delivery vehicles within the blood, carrying and releasing their contents at sites of vasculature damage. Investigating the biology of platelets, and modifying them for new therapeutic uses, is limited by a lack of methods for efficiently transfecting these cells. The ability of four different classes of lipid nanoparticles (LNPs) to deliver mRNA to platelets was compared using confocal microscopy, flow cytometry and quantitative PCR. The amount of mRNA delivered, mechanism of uptake, and extent of platelet activation depended on the LNP formulation and platelet storage conditions. Cationic LNPs (cLNPs) delivered mRNA to the largest percentage of platelets but induced platelet activation. Ionizable cationic LNPs (icLNPs) delivered mRNA to fewer platelets and did not induce activation. Furthermore, mRNA delivered using icLNPs and cLNPs was stable in resting platelets and was released in platelet microparticles under specific conditions. The results demonstrate that mRNA can be delivered to platelets using cLNPs and icLNPs without impairing platelet aggregation or spreading. Optimizing the LNP formulations used here may lead to a transfection agent for platelets that allows for de novo synthesis of exogenous proteins in the future.

Targeted therapy of gastrointestinal stromal tumours

Gastrointestinal stromal tumours (GISTs) are mesenchymal neoplasms originating in the gastrointestinal tract, usually in the stomach or the small intestine, and rarely elsewhere in the abdomen. The malignant potential of GISTs is variable ranging from small lesions with a benign behaviour to fatal sarcomas. The majority of the tumours stain positively for the CD-117 (KIT) and discovered on GIST-1 (DOG-1 or anoctamin 1) expression, and they are characterized by the presence of a driver kinase-activating mutation in either KIT or platelet-derived growth factor receptor α. Although surgery is the primary modality of treatment, almost half of the patients have disease recurrence following surgery, which highlights the need for an effective adjuvant therapy. Traditionally, GISTs are considered chemotherapy and radiotherapy resistant. With the advent of targeted therapy (tyrosine kinase inhibitors), there has been a paradigm shift in the management of GISTs in the last decade. We present a comprehensive review of targeted therapy in the management of GISTs.

Development and evaluation of near-isogenic lines for major blast resistance gene(s) in Basmati rice

A set of NILs carrying major blast resistance genes in a Basmati rice variety has been developed. Also, the efficacy of pyramids over monogenic NILs against rice blast pathogen Magnaporthe oryzae has been demonstrated. Productivity and quality of Basmati rice is severely affected by rice blast disease. Major genes and QTLs conferring resistance to blast have been reported only in non-Basmati rice germplasm. Here, we report incorporation of seven blast resistance genes from the donor lines DHMASQ164-2a (Pi54, Pi1, Pita), IRBLz5-CA (Pi2), IRBLb-B (Pib), IRBL5-M (Pi5) and IRBL9-W (Pi9) into the genetic background of an elite Basmati rice variety Pusa Basmati 1 (PB1). A total of 36 near-isogenic lines (NILs) comprising of 14 monogenic, 16 two-gene pyramids and six three-gene pyramids were developed through marker-assisted backcross breeding (MABB). Foreground, recombinant and background selection was used to identify the plants with target gene(s), minimize the linkage drag and increase the recurrent parent genome (RPG) recovery (93.5-98.6 %), respectively, in the NILs. Comparative analysis performed using 50,051 SNPs and 500 SSR markers revealed that the SNPs provided better insight into the RPG recovery. Most of the monogenic NILs showed comparable performance in yield and quality, concomitantly, Pusa1637-18-7-6-20 (Pi9), was significantly superior in yield and stable across four different environments as compared to recurrent parent (RP) PB1. Further, among the pyramids, Pusa1930-12-6 (Pi2+Pi5) showed significantly higher yield and Pusa1633-7-8-53-6-8 (Pi54+Pi1+Pita) was superior in cooking quality as compared to RP PB1. The NILs carrying gene Pi9 were found to be the most effective against the concoction of virulent races predominant in the hotspot locations for blast disease. Conversely, when analyzed under artificial inoculation, three-gene pyramids expressed enhanced resistance as compared to the two-gene and monogenic NILs.