Incidence of Respiratory Virus-Associated Pneumonia in Urban Poor Young Children of Dhaka, Bangladesh, 2009–2011

Pneumonia is the leading cause of childhood death in Bangladesh. We conducted a longitudinal study to estimate the incidence of virus-associated pneumonia in children aged <2 years in a low-income urban community in Dhaka, Bangladesh.We followed a cohort of children for two years. We collected nasal washes when children presented with respiratory symptoms. Study physicians diagnosed children with cough and age-specific tachypnea and positive lung findings as pneumonia case-patients. We tested respiratory samples for respiratory syncytial virus (RSV), rhinoviruses, human metapneumovirus (HMPV), influenza viruses, human parainfluenza viruses (HPIV 1, 2, 3), and adenoviruses using real-time reverse transcription polymerase chain reaction assays.Between April 2009-March 2011, we followed 515 children for 730 child-years. We identified a total of 378 pneumonia episodes, 77% of the episodes were associated with a respiratory viral pathogen. The overall incidence of pneumonia associated with a respiratory virus infection was 40/100 child-years. The annual incidence of pneumonia/100 child-years associated with a specific respiratory virus in children aged < 2 years was 12.5 for RSV, 6 for rhinoviruses, 6 for HMPV, 4 for influenza viruses, 3 for HPIV and 2 for adenoviruses.Young children in Dhaka are at high risk of childhood pneumonia and the majority of these episodes are associated with viral pathogens. Developing effective low-cost strategies for prevention are a high priority

Synthesis, Characterization, and Biological Evaluation of 99mTc(CO)3-Labeled Peptides for Potential Use as Tumor Targeted Radiopharmaceuticals

During the past decade, several peptides containing Arg-Gly-Asp sequence have been conjugated with different chelating agents for labeling with various radionuclides for the diagnosis of tumor development. In this study, we report the synthesis of two tetrapeptides (Asp-Gly-Arg-His and Asp-Gly-Arg-Cys) and one hexapeptide [Asp-Gly-Arg-D-Tyr-Lys-His] by changing the amino acid sequence of the Arg-Gly-Asp motif. Peptide synthesis was initiated from aspartic acid. Aspartic acid placed at C-terminal end of the peptide chain can be conjugated with different drug molecules facilitating their transport to the site of action. The peptides were synthesized in excellent yield and labeled using freshly prepared [99mTc(CO)3(H2O)3]+ intermediate. A complexation yield of over 97% was achieved under mild conditions even at low ligand concentrations of 10�2 M. Radiolabeled peptides were characterized by HPLC and were found to be substantially stable in saline, in His solution as well as in rat serum and tissue (kidney, liver) homogenates. Internalization studies using Ehrlich ascites carcinoma cell line showed rapid and significant internalization (30–35% at 30 min of incubation attaining maximum value of about 40–60% after 2–4 h incubation). A good percentage of quick internalization was also observed in avb3-receptor-positive B16F10 mouse melanoma cell line (14–16% after 30 min of incubation and 25–30% after 2–4 h incubation). Imaging and biodistribution studies were performed in Swiss albino mice bearing Ehrlich ascites tumor in right thigh. Radiolabeled peptides exhibited fast blood clearance and rapid elimination through the urinary systems. 99mTc(CO)3-tetra-Pep2 exhibited remarkable localization at tumor site (1.15%, 1.17%, and 1.37% ID/g at 2, 4, and 6 h p.i., respectively) which could be due to slow clearance of the radiolabeled peptide from blood in comparison with the other two radiolabeled peptides. However, 99mTc(CO)3-hexa-Pep exhibited the highest tumor to muscle and tumor to blood ratios among the three. The preliminary results with these amino acid–based peptides are encouraging enough to carry out further experiments for targeting tumor

Development and Physical Characterization of Chloramphenicol Loaded Biodegradable Nanoparticles for Prolonged Release

The objectives of our study were to prepare a biodegradable nanoparticulate system of chloramphenicol (CHL) and to evaluate its ability to prolong in vitro release of CHL compared to free drug suspension (FDS). CHL-loaded polylactide-co-glycolide nanoparticles (CHL-PLGA-NPs) were prepared by an emulsion/solvent evaporation method using ethyl acetate and polyvinyl alcohol. CHL-PLGA-NPs were characterized by particle size, zeta potential, infrared spectra, drug entrapment efficiency and in vitro release kinetics measurement. Sonication was done with an ultrasound pulse sonicator at 70 W, 30 kHz for 60 s to produce stable NPs of mean size range from 277 nm to 433 nm. Drug to polymer ratio (D : P) was selected as formulation variable and significantly influenced entrapment efficiency (�30% to 66%) and release (p < 0.05). Entrapment of CHL in biodegradable NPs significantly prolonged drug release compared to FDS and thus implies potential antibiotic delivery system for ocular application

Preparation, Characterization, and Biodistribution of Letrozole Loaded PLGA Nanoparticles in Ehrlich Ascites Tumor Bearing Mice

Letrozole (LTZ) incorporated PLGA nanoparticles were prepared by solvent displacement technique and characterized by transmission electron microscopy, poly-dispersity index and zeta potential measurement. Radiolabeling of free LTZ and LTZ-loaded PLGA NPs was performed with technetium-99m with high labeling efficiency. The labeled complex showed good in vitro stability as verified by DTPA challenge test. The labeled complexes also showed significant in vivo stability when incubated in rat serum for 24 h. Biodistribution studies of 99mTc-labeled complexes were performed after intravenous administration in normal mice and Ehrlich Ascites tumor bearing mice. Compared to free LTZ, LTZ-loaded PLGA NPs exhibited significantly lower uptake by the organs of RES. The tumor concentration of LTZ-loaded PLGA NPs was 4.65 times higher than that of free LTZ at 4 h post-injection. This study indicates the capability of PLGA nanopartcles in enhancing the tumor uptake of letrozole

Evaluation of 99mTc(I)-tricarbonyl complexes of fluoroquinolones for targeting bacterial infection

The aim of this study was to develop 99mTc(CO)3-labeled fluoroquinolones as novel SPECT radiopharmaceuticals for imaging bacterial infection. Fluoroquinolones, e.g., ofloxacin (OFX), levofloxacin (LVX), lomefloxacin (LMX) and norfloxacin (NFX) were labeled with a fac-[99mTc(CO)3(H2O)3]+ precursor. The radiochemical purity of the radiopharmaceuticals exceeded 97% as determined by thin layer chromatography and HPLC. No further purification was necessary before injection. The Re(CO)3 complex of one of the fluoroquinolones (levofloxacin) was synthesized using [Re(CO)3(H2O)3]OTf and Re(CO)5Br precursors in separate experiments and characterized by IR, NMR and mass spectroscopic analysis. These studies revealed the formation of a single species in which the piperazinyl nitrogen and the –COOH group attached to the benzoxazine ring system of quinolone were involved in co-ordination to the Re(CO)3 core. The HPLC elution pattern and retention time of the Re(CO)3-LVX complex were comparable to those of the corresponding 99mTc(CO)3-complex proving their similarity. When incubated in isotonic saline and serum up to 24 h 99mTc(CO)3-labeled fluoroquinolones exhibited good in vitro stability. Biodistribution studies performed at different time points on rats intramuscularly infected with S. aureus as well as on rats with sterile inflammation revealed a higher uptake in the infected area than the turpentine induced inflamed area. The uptake in infected thigh was significant with 99mTc(CO)3-OFX followed by 99mTc(CO)3-LVX. The mean ratios of the uptake in infected/non-infected thighs were 4.75 and 4.27 at 8 h and 24 h, respectively, for 99mTc(CO)3-OFX and 4.42 and 4.18 at 24 h and 8 h, respectively, for 99mTc(CO)3-LVX. The above abscess to muscle ratios were higher than reported for 99mTc-ciprofloxacin and other 99mTc-labeled fluoroquinolones. Scintigraphy studies also showed a significant uptake in the infectious lesions suggesting that 99mTc(CO)3-fluoroquinolones might be useful as diagnostic agents for targeted delivery in bacterial infection

Proceedings of International Conference on Emerging Trends in Engineering and Advanced Science

This conference proceedings contains articles on the various research ideas of the academic community and practitioners presented at the International Conference on Emerging Trends in Engineering and Advanced Science (ICETEAS-2021). ICETEAS-2021 was organized by the Department of Electrical and Electronic Engineering &amp; Department of Mechatronics Engineering, World University of Bangladesh, Dhaka, Bangladesh on July 4th-5th November 2021. Conference Title: International Conference on Emerging Trends in Engineering and Advanced ScienceConference Acronym: ICETEAS-2021Conference Date: 4-5 November 2021Conference Location: Online (Virtual Mode)Conference Organizers: World University of Bangladesh, Dhaka, Bangladesh