Synthesis and Photophysical Studies on Naphthalimide Derived Fluorophores as Markers in Drug Delivery

Derivatives of 4-amino-1,8-naphthalimide containing a free alkyl chain bearing carboxyl group as linker and different substituents at 4-amino function have been synthesized, characterized and studied for their photophysical properties. Steady state fluorescence studies showed quantum yield varied from 0.45 to 0.65 with Stokes shift in the range of 5824-8558 cm(-1). Spectroscopic and physicochemical parameters, like electronic absorption, emission, and extinction coefficient were investigated in order to explore the analytical potential of compounds. Solvatochromic studies demonstrated that all compounds were sensitive towards the polarity of different solvents showing the highest degree of fluorescence in acetonitrile. In addition, the compounds in the presence of ions, viz. Na(+), K(+) and Mg(2+) at concentration of 0.1-2 equivalents, showed a decreasing trend in fluorescence with increasing ionic concentration. TCSPC set - up was used to measure the fluorescence lifetime of compounds, which was found to be bi-exponential with longer and shorter component at their respective amplitudes. The average lifetime of compounds was observed to be 5.76-9.96 ns indicating the possibility of their greater utilization in research and diagnosis.

A 10(9) neutrons/pulse transportable pulsed D-D neutron source based on flexible head plasma focus unit

A 17 kJ transportable plasma focus (PF) device with flexible transmission lines is developed and is characterized. Six custom made capacitors are used for the capacitor bank (CB). The common high voltage plate of the CB is fixed to a centrally triggered spark gap switch. The output of the switch is coupled to the PF head through forty-eight 5 m long RG213 cables. The CB has a quarter time-period of 4 μs and an estimated current of 506 kA is delivered to the PF device at 17 kJ (60 μF, 24 kV) energy. The average neutron yield measured using silver activation detector in the radial direction is (7.1 ± 1.4) × 10(8) neutrons/shot over 4π sr at 5 mbar optimum D2 pressure. The average neutron yield is more in the axial direction with an anisotropy factor of 1.33 ± 0.18. The average neutron energies estimated in the axial as well as in the radial directions are (2.90 ± 0.20) MeV and (2.58 ± 0.20) MeV, respectively. The flexibility of the PF head makes it useful for many applications where the source orientation and the location are important factors. The influence of electromagnetic interferences from the CB as well as from the spark gap on applications area can be avoided by putting a suitable barrier between the bank and the PF head.

Adiponectin correlates with obesity: A study of 159 childhood acute leukemia survivors from India

BACKGROUND

Acute lymphoblastic leukemia survivors are predisposed to obesity. However, the exact underlying mechanisms are not known.

AIMS

The study was done to assess the role of biomarkers of obesity in acute leukemia survivors.

SETTINGS AND DESIGNS

This is a cross-sectional study conducted at All India Institute of Medical Sciences in survivors of acute leukemia who had completed treatment at least 1 year before enrollment in this study.

MATERIALS AND METHODS

Obesity was studied by determining the body mass index. Potential biomarkers were studied by assessing serum leptin, resistin, and adiponectin by enzyme-linked immunosorbant assay, and the results were compared in obese versus nonobese survivors.

STATISTICAL ANALYSIS

Descriptive analysis for baseline demographic factors and Student's t-test for comparing the mean levels of biomarkers among the obese and nonobese survivors.

RESULTS

One hundred and fifty-nine acute leukemia patients were enrolled in this study with a median follow-up of 36.8 months. The median age was 10 (range: 3-18) years, and 123 (77.3%) patients were males. The overall prevalence of overweight/obesity was 26.4%, and this was similar in acute myeloid leukemia and acute lymphoblastic leukemia sub-groups (26.2% vs. 27.3%, P = 0.9). Mean serum leptin and resistin were similar in obese and nonobese leukemia survivors (3.7 vs. 2.85 pg/mL, P = 0.064; 8.01 vs. 9.33 ng/mL, P = 0.36). However, mean serum adiponectin was significantly lower in obese leukemia survivors (7.97 vs. 11.5 μg/mL, P = 0.023).

CONCLUSIONS

Obese leukemic survivors had lower serum adiponectin levels than nonobese survivors. However, serum resistin and leptin levels were similar in the two groups.

Manipulation of BCG vaccine: a double-edged sword

Mycobacterium bovis Bacillus Calmette-Guérin (BCG), an attenuated vaccine derived from M. bovis, is the only licensed vaccine against tuberculosis (TB). Despite its protection against TB in children, the protective efficacy in pulmonary TB is variable in adolescents and adults. In spite of the current knowledge of molecular biology, immunology and cell biology, infectious diseases such as TB and HIV/AIDS are still challenges for the scientific community. Genetic manipulation facilitates the construction of recombinant BCG (rBCG) vaccine that can be used as a highly immunogenic vaccine against TB with an improved safety profile, but, still, the manipulation of BCG vaccine to improve efficacy should be carefully considered, as it can bring in both favourable and unfavourable effects. The purpose of this review is not to comprehensively review the interaction between microorganisms and host cells in order to use rBCG expressing M. tuberculosis (Mtb) immunodominant antigens that are available in the public domain, but, rather, to also discuss the limitations of rBCG vaccine, expressing heterologous antigens, during manipulation that pave the way for a promising new vaccine approach.

Synthesis, characterizations, in vitro and in vivo evaluation of Etoricoxib-loaded Poly (Caprolactone) microparticles--a potential Intra-articular drug delivery system for the treatment of Osteoarthritis

Intra-articular Drug delivery systems (IA-DDS) deliver the drug directly to the diseased joint space with significantly lowered systemic toxicities. In this work, we explored Etoricoxib (COX-2 inhibitor)-loaded Poly caprolactone (PCL) microparticles (MPs) as a potential IA-DDS. MPs were prepared by Oil/Water (O/W) emulsion-solvent evaporation method. Formulation parameters like polymer to drug ratio, stabilizer concentration were optimized to get the maximum encapsulation efficiency. The prepared particles were characterized using Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction studies (XRD), and Differential Scanning Calorimetry (DSC). The particles were found to be spherical and smooth-surfaced using SEM. FTIR studies proved that there was no chemical interaction between the drug and the polymer. XRD and DSC studies confirmed that Etoricoxib existed in its amorphous form while PCL had retained its semi-crystalline phase during the micro-encapsulation process. In vitro drug release studies proved that there was controlled release of the drug from the MPs for nearly 28 days. In vivo synovial drug clearance studies on SD rats proved that drug leach out rate from the joint region to the systemic circulation was slow which indicated that MPs had a good drug retention capacity. In vivo fluorescence imaging results confirmed that MPs could stay longer in the joint region for almost a month. Thus, PCL microparticles could be a potential IA-DDS for the treatment of the diseased joint regions especially for Osteoarthritis.

Thermoresponsive polymeric gel as an on-demand transdermal drug delivery system for pain management

The main aim of this work is to design a heat triggered transdermal drug delivery system (TDDS) using a thermoresponsive polymer, poly (N-vinyl caprolactam) [PNVCL] based gel, where in patients can themselves administer a pulse of drug on mere application of heat pad over the TDDS, whenever pain is experienced. The phase transition temperature of PNVCL was tuned to 35 °C by grafting it onto a pH sensitive biopolymer, Chitosan, to synthesize Chitosan-g-PNVCL (CP) co-polymer which render the gel both thermo- and pH-responsive property. The application of triggered delivery was explored by loading acetamidophenol (a model hydrophilic drug) and etoricoxib (a model hydrophobic drug). In vitro drug release experiments were performed at three different temperatures (25, 32 and 39 °C) at two different pH (5.5 and 7) to study its drug release with response to temperature and pH. Drug release profiles obtained were found to have enhanced release for both the drugs respectively at 39 °C (above LCST) and pH5.5 when compared to other release conditions. In vitro skin permeation of both the drugs performed in rat abdominal skin using Franz diffusion cell showed enhanced drug release when the skin was subjected to higher temperature (39 °C). Moreover, it was also found that skin permeation for hydrophobic drug was better than that of hydrophilic drug. The in vivo biocompatibility studies of the CP gel in rat skin proved that the gel is biocompatible. The results obtained demonstrated the potential use of the thermoresponsive CP gel as an on-demand localized drug delivery system.

Poly (caprolactone) microparticles and chitosan thermogels based injectable formulation of etoricoxib for the potential treatment of osteoarthritis

This study aimed to evaluate Poly (caprolactone) microparticles (MPs) loaded composite injectable Chitosan gel (CICGs) as a dual purpose (visco-supplement and intra articular drug delivery depot) therapeutic agent for the treatment of Osteoarthritis. Etoricoxib (COX-2 inhibitor), a highly hydrophobic drug was chosen as a model drug for the study. When administered orally, Etoricoxib poses severe cardiovascular toxicity issues. So, we have attempted to deliver this drug intra-articularly, which could retain the drug longer in the joint region and thus could ameliorate these toxicity issues. CICGs were prepared by dispersing MPs in the chitosan-Ammonium hydrogen phosphate solution and incubated at 37 °C. Rheology studies proved that gels were stable and had visco-elastic properties comparable to that of existing visco-supplements. The in vitro drug release profiles of CICGs were found to be more controlled when compared to MPs and bare chitosan gel (BCGs). In vitro and in vivo biocompatibility studies proved that the gels were biocompatible. In vivo synovial drug clearance studies proved that CICGs had a better drug retention capacity than BCGs and MPs. In vivo fluorescence imaging results confirmed that CICGs could stay longer in the joint region when compared to BCGs and MPs. Thus this novel CICGs could be a potential dual purpose gel for the treatment of diseased joint regions especially for Osteoarthritis.

Clinical utility of neuronal cells directly converted from fibroblasts of patients for neuropsychiatric disorders: studies of lysosomal storage diseases and channelopathy

Methodologies for generating functional neuronal cells directly from human fibroblasts [induced neuronal (iN) cells] have been recently developed, but the research so far has only focused on technical refinements or recapitulation of known pathological phenotypes. A critical question is whether this novel technology will contribute to elucidation of novel disease mechanisms or evaluation of therapeutic strategies. Here we have addressed this question by studying Tay-Sachs disease, a representative lysosomal storage disease, and Dravet syndrome, a form of severe myoclonic epilepsy in infancy, using human iN cells with feature of immature postmitotic glutamatergic neuronal cells. In Tay-Sachs disease, we have successfully characterized canonical neuronal pathology, massive accumulation of GM2 ganglioside, and demonstrated the suitability of this novel cell culture for future drug screening. In Dravet syndrome, we have identified a novel functional phenotype that was not suggested by studies of classical mouse models and human autopsied brains. Taken together, the present study demonstrates that human iN cells are useful for translational neuroscience research to explore novel disease mechanisms and evaluate therapeutic compounds. In the future, research using human iN cells with well-characterized genomic landscape can be integrated into multidisciplinary patient-oriented research on neuropsychiatric disorders to address novel disease mechanisms and evaluate therapeutic strategies.

Enhanced cell apoptosis triggered by a multi modal mesoporous amphiphilic drug delivery system

Mesoporous magnetic nanoparticles (MMNPs) have been synthesized through a facile soft chemical route and are conjugated with multiple therapeutic agents. These MMNPs have the ability to contain and deliver both hydrophilic and hydrophobic drugs simultaneously with the mediation of an AC magnetic field (ACMF). Furthermore, the synthesis and characterization of doxorubicin hydrochloride:paclitaxel (DOX:TXL) and doxorubicin hydrochloride:cisplatin (DOX:Cis-Pt) conjugates are demonstrated. MMNPs show an excellent loading efficiency of ~96:83% (DOX:TXL) and ~93:83% (DOX:Cis-Pt) along with a loading capacity of ~0.002:0.002 mg mg(-1) (DOX:TXL) and ~0.002:0.002 mg mg(-1) (DOX:Cis-Pt), respectively. Over a period of 180 h, a sustained release of drugs is observed and shows a better efficiency at pH 4.3 (~85:63%-DOX:TXL and ~86:73%-DOX:Cis-Pt) compared to that under physiological pH conditions (~28:22%-DOX:TXL and ~26:22%-DOX:Cis-Pt). The MMNPs can release ~37:22% (DOX:TXL) and ~34:25% (DOX:Cis-Pt) within 30 min when triggered by an ACMF (at ~43 °C). The in vitro cytotoxic effect, the ROS generation level and cell cycle distribution analysis of DOX:TXL-MMNPs and DOX:Cis-Pt-MMNPs treated MDA-MB231, MCF-7 and PC3 cancer cells are demonstrated. Enhanced cell apoptosis is observed by thermo-chemotherapy which includes application of an ACMF for 15 min. Specifically, DOX:TXL-MMNPs are more effective than DOX:Cis-Pt-MMNPs towards the PC3 cell line. The internalization of multiple drug loaded MMNPs by cells and their morphological changes due to thermo-chemotherapy are confirmed through confocal microscopy. From the present results, it is observed that the DOX:TXL and DOX:Cis-Pt conjugated MMNPs, under an ACMF, can readily minimize drug resistance. This has significantly enhanced the cell apoptosis of target cancer cells.

HLA-B27 subtypes in enthesitis-related arthritis category of juvenile idiopathic arthritis and ankylosing spondylitis in northern India

OBJECTIVES

Enthesitis-related arthritis (ERA) is the most common form of juvenile idiopathic arthritis (JIA) in the Asian and Indian populations. The presence of HLA-B27 has a strong association with JIA-ERA similar to that with adult ankylosing spondylitis (AS). The HLA-B27gene is highly polymorphic. Susceptibility to AS varies between different HLA-B27 subtypes; data on the relationship of susceptibility to JIA-ERA with HLA-B27 types are scant. In this study, we determined HLA-B27 subtypes in patients with JIA-ERA and AS to find out whether there is any difference in the HLA-B27 subtypes prevalent in these two diseases.

METHODS

Genomic DNA from 135 patients with JIA-ERA and 121 with AS was tested for the presence of HLA-B27. In patients testing positive, HLA-B27subtyping was done by sequencing a genomic region that contained second and third exons and the intervening intron of this gene; this method permitted identification of common HLA-B27 subtypes (HLA-B*27:01 to HLA-B*27:09).

RESULTS

One hundred and seven (79%) patients with JIA-ERA and 102 (84%) patients with AS tested positive for HLA-B27. In both groups, HLA-B*27:05 and HLA-B*27:04 were the common subtypes; some patients had HLA-B*27:07(7.4%) and HLA-B*27:18. Patients with JIA-ERA had a higher frequency of HLA-B*27:05 than those with AS (70% vs. 57%, p=0.047), and a lower frequency of HLA-B*27:04 (21% vs. 36%, p=0.018).

CONCLUSIONS

HLA-B*27:05 and HLA-B*27:04 were the most common HLA-27 subtypes in both JIA-ERA and AS. However, HLA-B*27:05 was more frequent and HLA-B*27:04 was less frequent in JIA-ERA. It is possible that HLA-B*27:05 being the ancestral HLA-27 subtype leads to expression of disease early in life.

A descriptive study of tuberculosis case finding in private health care facilities in a South Indian district

SETTING

A South Indian district providing anti-tuberculosis services through the Revised National TB Control Programme (RNTCP) and private health care facilities.

OBJECTIVE

To ascertain the profile of tuberculosis (TB) patients diagnosed and/or treated in private health care facilities.

METHODS

Data on TB cases diagnosed and/or treated in all clinical departments of the medical college, 83 nursing homes and RNTCP health care facilities were collected prospectively.

RESULTS

About 83% of new TB cases recorded in the private medical college, 47% in nursing homes and 24.5% in RNTCP TB registers were extra-pulmonary. The proportion of retreatment cases was respectively 5.5%, 9.6% and 19.8%. The proportion of males and those in the economically productive age group were similar in the three data sources. About 94% of cases diagnosed in the medical college and 55% in nursing homes were registered for treatment under the RNTCP. About 11% of the smear-positive patients diagnosed in RNTCP were initial defaulters.

CONCLUSION

The proportion of extra-pulmonary cases was higher in the medical college and nursing homes and that of retreatment cases was lower than in the RNTCP.

Forensic Application of Palatal Rugae in Dental Identification

INTRODUCTION

The palatal rugae are anatomical folds or wrinkles located on the anterior third of the palate behind the incisive papilla on each side of the palatal raphe. The rugae patterns have been studied for various purposes mainly in the field of anthropology, comparative anatomy, genetics, prosthodontics, orthodontics and forensic odontology. This study is aimed to determine the difference in number and pattern of palatal rugae in males and females.

METHODS

This is a prospective study in which maxillary impressions of 50 volunteers, 25 males and 25 females were taken and the casts prepared. The boundaries of the rugae were marked with a HB pencil and were observed with a magnifying glass following the classification used by Kapali, et al, (1997). Association between rugae number and sex and rugae shape and sex were tested using two sample unpaired t test.

RESULTS

The study revealed significant difference in the pattern of converge rugae which were found to be higher in females than males, however, no statistical significant difference was found in the number of rugae between the two sexes.

CONCLUSIONS

The rugae pattern can be an additional method of differentiation between the males and females in conjunction with the other methods used in forensic sciences.

Role of pre-Xpert® screening using chest X-ray in early diagnosis of smear-negative pulmonary tuberculosis

In a sub-district level hospital in South India, the proportion of patients with abnormal chest X-ray (CXR) was evaluated among smear-negative, Xpert® MTB/RIF (Xpert) positive individuals with pulmonary tuberculosis (PTB) symptoms; 384 smear-negative PTB individuals with PTB symptoms and without a history of anti-tuberculosis treatment underwent CXR and Xpert testing of one sputum specimen. Of 378 individuals with both Xpert and CXR results available, 14 were positive for Mycobacterium tuberculosis. Of these, 13 (92.9%) had an abnormal CXR and one was normal. This study highlights the usefulness of CXR before Xpert testing, which needs further validation.