Identification of potential anti-mucor agents by targeting endothelial cell receptor glucose-regulated protein-78 using in silico approach

Mucormycosis is a fungal infection of the sinuses, brain and lungs that is the cause of approximately 50% mortality rate despite the available first-line therapy. Glucose-Regulated Protein 78 (GRP78) is already reported to be a novel host receptor that mediates invasion and damage of human endothelial cells by Rhizopus oryzae and Rhizopus delemar, the most common etiologic species of Mucorales. The expression of GRP78 is also regulated by the levels of iron and glucose in the blood. There are several antifungal drugs in the market but they pose a serious side effect to the vital organs of the body. Therefore, there is an immediate need to discover effective drug molecules having increased efficacy with no side effects. With the help of various computational tools, the current study was attempted to determine potential antimucor agents against GRP78. The receptor molecule GRP78 was screened against 8820 known drugs deposited in DrugBank library using high-throughput virtual screening method. Total top 10 compounds were selected based on the binding energies greater than the reference co-crystal molecule. Furthermore, molecular dynamic (MD) simulations using AMBER were performed to calculate the stability of the top-ranked compounds in the active site of GRP78. After extensive computational studies, we propose that two compounds (CID439153 and CID5289104) have inhibitory potency against mucormycosis and can serve as potential drugs that can form the basis of treating mucormycosis disease.Communicated by Ramaswamy H. Sarma.

Probing the Nucleic Acid Flexibility to Disarm the Viral Counter-Defense Machinery: Design and Characterization of Potent p19 Inhibitors

Plant viruses are highly destructive and significant contributors to several global pandemics and epidemics in plants. A viral disease outbreak in plants can cause a scarcity of food supply and is a severe concern to humanity. The siRNA (small interfering RNA)-mediated RNA-induced silencing complex (RISC) formation is a primary defense mechanism in plants against viruses, where the RISC binds and degrades viral mRNAs. As a counter-defense, many viruses encode RNA-silencing suppressor proteins (e.g., the p19 protein from the Tombusviridae family) for viral proliferation in plants. The functional form of p19 (homodimer) binds to plant siRNA with high affinities, thereby interrupting the RISC formation and thus preventing the viral mRNA silencing in plants. By altering the RISC formation, the p19 protein helps the virus invasion in the plant and ultimately stunts host growth. In this study, we designed several modified siRNA-based molecules for p19 inhibition. The viral p19 protein is known to interact predominantly through H-bonds with 2'-OH and phosphates of the plant siRNA. We utilized this information and in silico-designed flexible substituents of siRNA, where we removed the C2'-C3' bond in each nucleotide unit. We performed all-atom explicit-solvent molecular dynamics simulations (400 ns, 3 replicates each) for control/modified siRNA─p19 complexes (8 in total) followed by energetic estimations. Strikingly, in a few modified complexes, the siRNA not only retained the double-helical structural integrity but also displayed remarkably enhanced p19 binding compared to the control siRNA; hence, we consider it important to perform biological and chemical in vitro and in vivo studies on proposed flexible nucleic acids as p19 inhibitors for crop protection.

The C-terminal 32-mer fragment of hemoglobin alpha is an amyloidogenic peptide with antimicrobial properties

Antimicrobial peptides (AMPs) are major components of the innate immune defense. Accumulating evidence suggests that the antibacterial activity of many AMPs is dependent on the formation of amyloid-like fibrils. To identify novel fibril forming AMPs, we generated a spleen-derived peptide library and screened it for the presence of amyloidogenic peptides. This approach led to the identification of a C-terminal 32-mer fragment of alpha-hemoglobin, termed HBA(111-142). The non-fibrillar peptide has membranolytic activity against various bacterial species, while the HBA(111-142) fibrils aggregated bacteria to promote their phagocytotic clearance. Further, HBA(111-142) fibrils selectively inhibited measles and herpes viruses (HSV-1, HSV-2, HCMV), but not SARS-CoV-2, ZIKV and IAV. HBA(111-142) is released from its precursor by ubiquitous aspartic proteases under acidic conditions characteristic at sites of infection and inflammation. Thus, HBA(111-142) is an amyloidogenic AMP that may specifically be generated from a highly abundant precursor during bacterial or viral infection and may play an important role in innate antimicrobial immune responses.

Ceftriaxone induces glial EAAT-2 promotor region via NF-kB conformational changes: An interaction analysis using HADDOCK

Excitotoxicity, depletion of energy metabolites, and ionic imbalance are the major factors involved in neurodegeneration mediated through excitatory amino acid transporter-2 (EAAT-2) dysfunction in ischemic insult. Recent studies have revealed that ceftriaxone expresses EAAT-2 via nuclear transcription factor kappa-B (NF-kB) signaling pathway, stimulation of EAAT-2 expression in the ischemic, and excitotoxic conditions that could provide potential benefits to control neurodegeneration. In this study, we have predicted the in silico model for interaction between NF-kB and EAAT-2 promoter region to rule out the conformational changes for the expression of EAAT-2 protein. Using homology-built model of NF-kB, we identified ceftriaxone-induced conformational changes in gene locus -272 of DNA where NF-kB binding with EAAT-2 promoter region through protein-DNA docking calculation. The interaction profile and conformational dynamics occurred between ceftriaxone predocked and postdocked conformations of NF-kB with DNA employing HADDOCK 2.2 web server followed by 250 ns long all atom explicit solvent molecular dynamics simulations. Both the protein and DNA exhibited modest conformational changes with respect to HADDOCK score, energy terms (desolvation energy [E_desolv ]), van der waal energy (E_vdw ), electrostatic energy (E_elec ), restraints energy (E_air ), buried surface area, root mean square deviation, RMSF, radius of gyration, total hydrogen bonds when ceftriaxone pre- and postdocked NF-kB conformations were bound to DNA. Hence, the conformational changes in the C-terminal domain could be the reason for EAAT-2 expression through ceftriaxone specific binding pocket of -272 of DNA.

Structure prediction and discovery of inhibitors against phosphopantothenoyl cysteine synthetase of Acinetobacter baumannii

Acinetobacter baumannii is an extremely dangerous multidrug-resistant (MDR) gram-negative pathogen which poses a serious life-threatening risk in immunocompromised patients. Phosphopantothenoyl cysteine synthetase (PPCS) catalyzes the formation of an amide bond between L-cysteine and phosphopantothenic acid (PPA) to form 4'- Phosphopantothenoylcysteine during Coenzyme A (CoA) biosynthesis. CoA is a crucial cofactor for cellular survival and inhibiting its synthesis will result in cell death. Bacterial PPCS differs from eukaryotic PPCS in a number of ways like it exists as a C-terminal domain of a PPCDC/PPCS fusion protein whereas eukaryotic PPCS exists as an independent protein. This difference makes it an attractive drug target. For which a conventional iterative approach of SBDD (structure-based drug design) was used, which began with three-dimensional structure prediction of AbPPCS using PHYRE 2.0. A database of FDA-approved compounds (Drug Bank) was then screened against the target of interest by means of docking score and glide energy, leading to the identification of 6 prominent drug candidates. The shortlisted 6 molecules were further subjected to all-atom MD simulation studies in explicit-solvent conditions (using AMBER force field). The MD simulation studies revealed that the ligands DB65103, DB449108 and DB443210, maintained several H-bonds with intense van der Waals contacts at the active site of the protein with high binding free energies: -11.42 kcal/mol, -10.49 kcal/mol and -10.98 kcal/mol, respectively, calculated via MM-PBSA method. Overall, binding of these compounds at the active site was found to be the most stable and robust highlighting the potential of these compounds to serve as antibacterials.Communicated by Ramaswamy H. Sarma.

Harmonizing Interstrand Electrostatic Repulsion by Conformational Rigidity in Counterion-Deprived Z-DNA: A Molecular Dynamics Study

Deoxyribonucleic acid (DNA) is a vital biomacromolecule. Although the right-handed B-DNA type helical structure is the most abundant and extensively studied form of DNA, several noncanonical forms, such as triplex, quadruplex, Z-DNA, A-DNA, and ss-DNA, have been probed from time to time to gain insights into the DNA's function. Z-DNA was recently found to be involved in cancer and several autoimmune diseases. In the present Article, we evaluated the conformational stability of locked-sugar-based Z-DNA via all-atom explicit-solvent molecular dynamics simulations and found that the modified DNA maintained the left-handed conformation even in the absence of counterions, wherein the structural rigidity dominates over the electrostatic repulsion between the complementary strands. The control Z-DNA without counterions, as expected, instantaneously resulted in unfolded states. The remarkable stability of the conformationally locked model system was thoroughly investigated via structural and energetic perspectives and was probably the result of the backbone widening in tandem with enhanced electrostatics between complementary strands. We believe that the design of the proposed modified Z-DNA construct could help understand the otherwise delicate Z-DNA conformation even in salt-deprived conditions. The design could also motivate the medicinal use of short segments of such modified nucleotides and could be utilized in more advanced modeling techniques, such as DNA origami which has gained popularity in recent years.

Bicyclo-DNA mimics with enhanced protein binding affinities: insights from molecular dynamics simulations

DNA-protein interactions occur at all levels of DNA expression and replication and are crucial determinants for the survival of a cell. Several modified nucleotides have been utilized to manipulate these interactions and have implications in drug discovery. In the present article, we evaluated the binding of bicyclo-nucleotides (generated by forming a methylene bridge between C1' and C5' in sugar, leading to a bicyclo system with C2' axis of symmetry at the nucleotide level) to proteins. We utilized four ssDNA-protein complexes with experimentally known binding free energies and investigated the binding of modified nucleotides to proteins via all-atom explicit solvent molecular dynamics (MD) simulations (200 ns), and compared the binding with control ssDNA-protein systems. The modified ssDNA displayed enhanced binding to proteins as compared to the control ssDNA, as seen by means of MD simulations followed by MM-PBSA calculations. Further, the Delphi-based electrostatic estimation revealed that the high binding of modified ssDNA to protein might be related to the enhanced electrostatic complementarity displayed by the modified ssDNA molecules in all the four systems considered for the study. The improved binding achieved with modified nucleotides can be utilized to design and develop anticancer/antisense molecules capable of targeting proteins or ssRNAs.Communicated by Ramaswamy H. Sarma.

Discovery of the Lead Molecules Targeting the First Step of the Histidine Biosynthesis Pathway of Acinetobacter baumannii

Acinetobacter baumannii is a multidrug-resistant, opportunistic, nosocomial pathogen for which a new line of treatments is desperately needed. We have targeted the enzyme of the first step of the histidine biosynthesis pathway, viz., ATP-phosphoribosyltransferase (ATP-PRT). The three-dimensional structure of ATP-PRT was predicted on the template of the known three-dimensional structure of ATP-PRT from Psychrobacter arcticus (PaATPPRT) using a homology modeling approach. High-throughput virtual screening (HTVS) of the antibacterial library of Life Chemicals Inc., Ontario, Canada was carried out followed by molecular dynamics simulations of the top hit compounds. In silico results were then biochemically validated using surface plasmon resonance spectroscopy. We found that two compounds, namely, F0843-0019 and F0608-0626, were binding with micromolar affinities to the ATP-phosphoribosyltransferase from Acinetobacter baumannii (AbATPPRT). Both of these compounds were binding in the same way as AMP in PaATPPRT, and the important residues of the active site, viz., Val4, Ser72, Thr76, Tyr77, Glu95, Lys134, Val136, and Tyr156, were also interacting via hydrogen bonds. The calculated binding energies of these compounds were -10.5 kcal/mol and -11.1 kcal/mol, respectively. These two compounds can be used as the potential lead molecules for designing antibacterial compounds in the future, and this information will help in drug discovery programs against Acinetobacter worldwide.

Identification of potential drug candidates to combat COVID-19: a structural study using the main protease (mpro) of SARS-CoV-2

The recent outbreak of the SARS-CoV-2 virus leading to the disease COVID 19 has become a global pandemic that is spreading rapidly and has caused a global health emergency. Hence, there is an urgent need of the hour to discover effective drugs to control the pandemic caused by this virus. Under such conditions, it would be imperative to repurpose already known drugs which could be a quick and effective alternative to discovering new drugs. The main protease (Mpro) of SARS-COV-2 is an attractive drug target because of its essential role in the processing of the majority of the non-structural proteins which are translated from viral RNA. Herein, we report the high-throughput virtual screening and molecular docking studies to search for the best potential inhibitors against Mpro from FDA approved drugs available in the ZINC database as well as the natural compounds from the Specs database. Our studies have identified six potential inhibitors of Mpro enzyme, out of which four are commercially available FDA approved drugs (Cobicistat, Iopromide, Cangrelor, and Fortovase) and two are from Specs database of natural compounds (Hopeaphenol and Cyclosieversiodide-A). While Cobicistat and Fortovase are known as HIV drugs, Iopromide is a contrast agent and Cangrelor is an anti-platelet drug. Furthermore, molecular dynamic (MD) simulations using GROMACS were performed to calculate the stability of the top-ranked compounds in the active site of Mpro. After extensive computational studies, we propose that Cobicistat and Hopeaphenol show potential to be excellent drugs that can form the basis of treating COVID-19 disease.Communicated by Ramaswamy H. Sarma.

Cdc4 phospho-degrons allow differential regulation of Ame1CENP-U protein stability across the cell cycle

Kinetochores are multi-subunit protein assemblies that link chromosomes to microtubules of the mitotic and meiotic spindle. It is still poorly understood how efficient, centromere-dependent kinetochore assembly is accomplished from hundreds of individual protein building blocks in a cell cycle-dependent manner. Here, by combining comprehensive phosphorylation analysis of native Ctf19^CCAN subunits with biochemical and functional assays in the model system budding yeast, we demonstrate that Cdk1 phosphorylation activates phospho-degrons on the essential subunit Ame1^CENP-U, which are recognized by the E3 ubiquitin ligase complex SCF-Cdc4. Gradual phosphorylation of degron motifs culminates in M-phase and targets the protein for degradation. Binding of the Mtw1^Mis12 complex shields the proximal phospho-degron, protecting kinetochore-bound Ame1 from the degradation machinery. Artificially increasing degron strength partially suppresses the temperature sensitivity of a cdc4 mutant, while overexpression of Ame1-Okp1 is toxic in SCF mutants, demonstrating the physiological importance of this mechanism. We propose that phospho-regulated clearance of excess CCAN subunits facilitates efficient centromere-dependent kinetochore assembly. Our results suggest a novel strategy for how phospho-degrons can be used to regulate the assembly of multi-subunit complexes.

Lactosmart: A Novel Therapeutic Molecule for Antimicrobial Defense

The problem of antibiotic resistance has prompted researchers around the globe to search for new antimicrobial agents. Antimicrobial proteins and peptides are naturally secreted by almost all the living organisms to fight infections and can be safer alternatives to chemical antibiotics. Lactoferrin (LF) is a known antimicrobial protein present in all body secretions. In this study, LF was digested by trypsin, and the resulting hydrolysates were studied with respect to their antimicrobial properties. Among the hydrolysates, a 21-kDa basic fragment of LF (termed lactosmart) showed promise as a new potent antimicrobial agent. The antimicrobial studies were performed on various microorganisms including Shigella flexneri, Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli as well as fungal pathogens such as Candida albicans, Candida tropicalis, and Candida glabrata. In addition, the lipopolysaccharide (LPS)-binding properties of lactosmart were studied using surface plasmon resonance technique in vitro, along with docking of LPS and molecular dynamics (MD) simulation studies. The results showed that lactosmart had better inhibitory effects against pathogenic microorganisms compared to LF. The results of docking and MD simulation studies further validated the tighter binding of LPS to lactosmart compared to LF. The two LPS-binding sites have been characterized structurally in detail. Through these studies, it has been demonstrated that in native LF, only one LPS-binding site remains exposed due to its location being on the surface of the molecule. However, due to the generation of the lactosmart molecule, the second LPS-binding site gets exposed too. Since LPS is an essential and conserved part of the bacterial cell wall, the pro-inflammatory response in the human body caused by LPS can be targeted using the newly identified lactosmart. These findings highlight the immense potential of lactosmart in comparison to native LF in antimicrobial defense. We propose that lactosmart can be further developed as an antibacterial, antifungal, and antibiofilm agent.

Virtual screening of quinoline derived library for SARS-COV-2 targeting viral entry and replication

The COVID-19 pandemic infection has claimed many lives and added to the social, economic, and psychological distress. The contagious disease has quickly spread to almost 218 countries and territories following the regional outbreak in China. As the number of infected populations increases exponentially, there is a pressing demand for anti-COVID drugs and vaccines. Virtual screening provides possible leads while extensively cutting down the time and resources required for ab-initio drug design. We report structure-based virtual screening of a hundred plus library of quinoline drugs with established antiviral, antimalarial, antibiotic or kinase inhibitor activity. In this study, targets having a role in viral entry, viral assembly, and viral replication have been selected. The targets include: 1) RBD of receptor-binding domain spike protein S 2) M^pro Chymotrypsin main protease 3) P^pro Papain protease 4) RNA binding domain of Nucleocapsid Protein, and 5) RNA Dependent RNA polymerase from SARS-COV-2. An in-depth analysis of the interactions and G-score compared to the controls like hydroxyquinoline and remdesivir has been presented. The salient results are (1) higher scoring of antivirals as potential drugs (2) potential of afatinib by scoring as better inhibitor, and (3) biological explanation of the potency of afatinib. Further MD simulations and MM-PBSA calculations showed that afatinib works best to interfere with the the activity of RNA dependent RNA polymerase of SARS-COV-2, thereby inhibiting replication process of single stranded RNA virus.

Communicated by Ramaswamy H. Sarma

Symmetric Nucleosides as Potent Purine Nucleoside Phosphorylase Inhibitors

Nucleic acids are one of the most enigmatic biomolecules crucial to several biological processes. Nucleic acid-protein interactions are vital for the coordinated and controlled functioning of a cell, leading to the design of several nucleoside/nucleotide analogues capable of mimicking these interactions and hold paramount importance in the field of drug discovery. Purine nucleoside phosphorylase is a well-established drug target due to its association with numerous immunodeficiency diseases. Here, we study the binding of human purine nucleoside phosphorylase (PNP) to some bidirectional symmetric nucleosides, a class of nucleoside analogues that are more flexible due to the absence of sugar pucker restraints. We compared the binding energies of PNP-symmetric nucleosides to the binding energies of PNP-inosine/Imm-H (a transition-state analogue), by means of 200 ns long all-atom explicit-solvent Gaussian accelerated molecular dynamics simulations followed by energetics estimation using the MM-PBSA methodology. Quite interestingly, we observed that a few symmetric nucleosides, namely, ν3 and ν4, showed strong binding with PNP (-14.1 and -12.6 kcal/mol, respectively), higher than inosine (-6.3 kcal/mol) and Imm-H (-9.6 kcal/mol). This is rationalized by an enhanced hydrogen-bond network for symmetric nucleosides compared to inosine and Imm-H while maintaining similar van der Waals contacts. We note that the chemical structures of both ν3 and ν4, due to an additional unsaturation in them, resemble enzymatic transition states and fall in the category of transition-state analogues (TSAs), which are quite popular.

Structure-Based Virtual Screening and Biochemical Validation to Discover a Potential Inhibitor of the SARS-CoV-2 Main Protease

The recent pandemic caused by SARS-CoV-2 has led the world to a standstill, causing a medical and economic crisis worldwide. This crisis has triggered an urgent need to discover a possible treatment strategy against this novel virus using already-approved drugs. The main protease (Mpro) of this virus plays a critical role in cleaving the translated polypeptides that makes it a potential drug target against COVID-19. Taking advantage of the recently discovered three-dimensional structure of Mpro, we screened approved drugs from the Drug Bank to find a possible inhibitor against Mpro using computational methods and further validating them with biochemical studies. The docking and molecular dynamics study revealed that DB04983 (denufosol) showed the best glide docking score, -11.884 kcal/mol, and MM-PBSA binding free energy, -10.96 kcal/mol. Cobicistat, cangrelor (previous computational studies in our lab), and denufosol (current study) were tested for the in vitro inhibitory effects on Mpro. The IC50 values of these drugs were ∼6.7 μM, 0.9 mM, and 1.3 mM, respectively, while the values of dissociation constants calculated using surface plasmon resonance were ∼2.1 μM, 0.7 mM, and 1.4 mM, respectively. We found that cobicistat is the most efficient inhibitor of Mpro both in silico and in vitro. In conclusion, cobicistat, which is already an FDA-approved drug being used against HIV, may serve as a good inhibitor against the main protease of SARS-CoV-2 that, in turn, can help in combating COVID-19, and these results can also form the basis for the rational structure-based drug design against COVID-19.

Marshall's nucleic acid: From double-helical structure to a potent intercalator

Deoxyribonucleic acid (DNA) not only stores genetic information but also emerged as a popular drug target. Modified nucleotides/nucleosides have been extensively studied in recent years wherein the sugar/nucleobase/phosphate-backbone has been altered. Several such molecules are FDA approved, capable of targeting nucleic acids and proteins. In this article, we modified negatively charged phosphate backbone to marshall's acid-based neutral backbone and analyzed the resultant structures by utilizing Gaussian accelerated molecular dynamics simulations (1 μs) in aqueous media at 150 mM salt concentration. We noted that the double-helical marshall's nucleic acid structure was partially denatured during the course of simulations, however, after using conformationally locked sugar, the marshall's nucleic acid (hereby called MNA) maintained the double-helical structure throughout the simulations. Despite the fact that MNA has a more extended backbone than the regular DNA, surprisingly, both showed similar helical rise (~3.4 Å) along with a comparable Watson-Crick hydrogen bond profile. The backbone difference was majorly compensated in terms of helical twist (~56° (MNA) and ~ 35° (control DNA)). Further, we examined a few MNA based ss-dinucleotides as intercalating ligands for a regular B-DNA. Quite strikingly, the ligands unwinded the DNA and showed intercalating properties with high DNA binding affinities. Hence, the use of small fragments of MNA based molecules in DNA targeted drug discovery is foreseen.

5-HT1A targeting PARCEST agent DO3AM-MPP with potential for receptor imaging: Synthesis, physico-chemical and MR studies

Contrast enhancement in MRI using magnetization or saturation transfer techniques promises better sensitivity, and faster acquisition compared to T₁ or T₂ contrast. This work reports the synthesis and evaluation of 5-HT_1A targeted PARACEST MRI contrast agent using 1,4,7,10-tetraazacycloDOdecane-4,7,10-triacetAMide (DO3AM) as the bifunctional chelator, and 5-HT_1A-antagonist methoxyphenyl piperazine (MPP) as a targeting unit. The multi-step synthesis led to the MPP conjugated DO3AM with 60% yield. CEST-related physicochemical parameters were evaluated after loading DO3AM-MPP with paramagnetic MRI active lanthanides: Gadolinium (Gd-DO3AM-MPP) and Europium (Eu-DO3AM-MPP). Luminescence lifetime measurements with Eu-DO3AM-MPP and computational DFT studies using Gd-DO3AM-MPP revealed the coordination of one water molecule (q = 1.43) with metal-water distance (r_M-H₂O) of 2.7 Å and water residence time (τ_m) of 0.23 ms. The dissociation constant of K_d 62 ± 0.02 pM as evaluated from fluorescence quenching of 5-HT_1A (protein) and docking score of -4.81 in theoretical evaluation reflect the binding potential of the complex Gd-DO3AM-MPP with the receptor 5-HT_1A. Insights of the docked pose reflect the importance of NH₂ (amide) and aromatic ring in Gd-DO3AM-MPP while interacting with Ser 374 and Phe 370 in the antagonist binding pocket of 5-HT_1A. Gd-DO3AM-MPP shows longitudinal relaxivity 5.85 mM^-1s^-1 with a water residence lifetime of 0.93 ms in hippocampal homogenate containing 5-HT_1A. The potentiometric titration of DO3AM-MPP showed strong selectivity for Gd³⁺ over physiological metal ions such as Zn²⁺ and Cu²⁺. The in vitro and in vivo studies confirmed the minimal cytotoxicity and presential binding of Gd-DO3AM-MPP with 5-HT_1A receptor in the hippocampus region of the mice. Summarizing, the complex Gd-DO3AM-MPP can have a potential for CEST imaging of 5-HT_1A receptors.

Risk Factors Associated with Ninety Day Readmission in Chronic Obstructive Pulmonary Disease Exacerbation at a Tertiary Care Hospital: A retrospective cohort study

Background Chronic obstructive pulmonary disease (COPD) exacerbation is a leading cause of frequent hospital admission. Globally, several studies have reported potential risk factors associated with COPD exacerbations which are largely unknown in Nepalese health care setting. Objective To identify the risk factors associated with hospital readmission within ninety days of discharge in acute COPD exacerbation. Method This is a hospital based retrospective cohort study conducted at Tribhuvan University Teaching Hospital. COPD patients admitted in respiratory ward from August 2019 to November 2019 were followed up till 90 days after discharge. Logistic regression analysis was performed at 95% Confidence Interval (CI) to identify risk factors for readmission in COPD exacerbation. Statistical analysis was performed using SPSS version 20.0. Result Of total 86 patients hospitalized for COPD, 42 (48.8%) had at least one subsequent readmission during post-discharge follow-up period of 90 days. Mean age of patients was 70.55±10.98 years. There were 45 (52.3%) males. Logistic regression analysis revealed preadmission domiciliary oxygen use (Odds Ratio (OR) 2.93; 95% CI 1.195- 7.202; p=0.019), admission in intensive care unit (ICU) (OR 3.060; 95% CI 1.145- 8.179; p=0.026), previous hospital admission for COPD exacerbation (OR 3.230; 95% CI 1.219-8.556; p=0.018), age (OR 0.946; 95% CI 0.905-0.988; p=0.012) and duration of hospital stay (OR 0.901; 95% CI 0.819-0.992; p=0.034) were independently associated with ninety day readmission in COPD patients. Conclusion Five clinical factors were found to be independently associated with COPD readmission in this study. Large multi-centre study at various health care levels is recommended to validate the potential risk factors in different populations and health care settings in Nepal.

C5' omitted DNA enhances bendability and protein binding

Protein-DNA interactions are of great biological importance. The specificity and strength of these intimate contacts are crucial in the proper functioning of a cell, wherein the role of DNA dynamic bendability has been a matter of discussion. We relate DNA bendability to protein binding by introducing some simple modifications in the DNA structure. We removed C5' carbon in first modified structure and the second has an additional carbon between C3' and 3'-OH, hereby pronounced as C(-) and C(+) nucleic acids respectively. We observed that C(+) nucleic acid retains B-DNA duplex as seen by means of 500 ns long molecular dynamics (MD) simulations, structural and energetic calculations, while C(-) nucleic acid attains a highly bend structure. We transferred these observations to a protein-DNA system in order to monitor as to what extent the bendability enhances the protein binding. The energetics of binding is explored by performing 100 ns long MD simulations on control and modified DNA-protein complexes followed by running MM-PBSA/GBSA calculations on the resultant structures. It is observed that C(+) nucleic acid has protein binding in close correspondence to the control system (∼-14 kcal/mol) due to their relatable structure, while the C(-) nucleic acid displayed high binding to the protein (∼-18 kcal/mol). DelPhi based calculations reveal that the high binding could be the result of enhanced electrostatic interactions caused by exposed bases in the bend structure for protein recognition. Such modified oligonucleotides, due to their improved binding to protein and resistance to nuclease degradation, have a great therapeutic value.

Direct conversion of carbon nanofibers and nanotubes into diamond nanofibers and the subsequent growth of large-sized diamonds

We report a pulsed laser annealing method to convert carbon fibers and nanotubes into diamond fibers at ambient temperature and pressure in air. The conversion of carbon nanofibers and nanotubes into diamond nanofibers involves melting in a super undercooled state using nanosecond laser pulses, and quenching rapidly to convert into phase-pure diamond. The conversion process occurs at ambient temperature and pressure, and can be carried out in air. The structure of diamond fibers has been confirmed by selected-area electron diffraction in transmission electron microscopy, electron-back-scatter-diffraction in high-resolution scanning electron microscopy, all showing characteristic diffraction lines for the diamond structure. The bonding characteristics were determined by Raman spectroscopy with a strong peak near 1332 cm-1, and high-resolution electron-energy-loss spectroscopy in transmission electron microscopy with a characteristic peak at 292 eV for σ* for sp3 bonding and the absence of π* for sp2 bonding. The Raman peak at 1332 cm-1 downshifts to 1321 cm-1 for diamond nanofibers due to the phonon confinement in nanodiamonds. These laser-treated carbon fibers with diamond seeds are used to grow larger diamond crystallites further by using standard hot-filament chemical vapor deposition (HFCVD). We compare these results with those obtained without laser treating the carbon fibers. The details of diamond conversion and HFCVD growth are presented in this paper.

Design, synthesis and glycosidase inhibition studies of novel triazole fused iminocyclitol-δ-lactams

Synthesis of novel triazole fused iminocyclitol-δ-lactams, from tri-O-benzyl-d-glucal, involving intermolecular [3 + 2]cycloaddition and intramolecular lactamisation reactions as key steps is described.

Design, physico-chemical and pre-clinical evaluation of a homo-bivalent 99mTc-(BTZ)2DTPA radioligand for targeting dimeric 5-HT1A/5-HT7 receptors

A ^99mTc-labelled bis-benzothiazolone-DTPA radio-complex as a SPECT neuroimaging agent.

A computational protocol for the discovery of lead molecules targeting DNA unique to pathogens

With the rapid emergence of drug resistant pathogens, it has become imperative to develop alternative medications as well as find new drug targets to overcome this crisis. Hence, this has become prime focus of several academic laboratories and pharmaceutical companies. Here, we report a computational protocol for identifying unique DNA sequence(s) in the pathogen which is absent in human and related non-pathogenic strains of the microbe. In order to use the unique sequence as drug target, the protocol, in the second step, uses virtual screening against a million compound library to identify candidate small molecules which can bind to these unique DNA targets in the pathogen only. Theoretically the molecules identified after screening should not bind to human DNA. This methodology is demonstrated on Mycobacterium tuberculosis H37Rv, wherein a new octamer sequence present only in H37Rv has been identified and a few candidate small molecules as potential drug have been proposed. Being fast and cost effective, this protocol could be of importance in generating new potential drug candidates against infectious organisms for further experimental studies. This methodology is freely available at http://www.scfbio-iitd.res.in/PSDDF/.

Unresolving Pneumonia with Pleural effusion: Pulmonary Paragonimiasis

Paragonimiasis is a zoonosis caused by many species of Paragonimus commonly P. westermani. Human get infected by eating raw, salted, pickled, smoked, partially cooked crustaceans (crayfish or crabs). Clinical manifestations ranges from non-specific symptoms like pain abdomen, diarrhea, urticarial rashes, fever to pleuropulmonary symptoms like cough, hemoptysis, chest pain and dyspnea. A 48 years, female presented at TUTH emergency with fever on and off for nine months, cough and shortness of breath for three months, lethargy, malaise and urticaria with history of raw crab intake one month prior to the onset of symptoms. Blood and pleural fluid analysis revealed raised total counts with eosinophilia and x-ray showed bilateral infiltration of lower lobes with pleural effusion. Diagnosis was confirmed by microscopic examination of sputum for Paragonimus. She responded well to Praziquantel. Pulmonary paragonimiasis must be considered in the differential diagnosis of unresolving pneumonia and unexplained hypereosinophilia.

Design and characterization of symmetric nucleic acids via molecular dynamics simulations

Asymmetry (5'→3') associated with each strand of the deoxyribonucleic acid (DNA) is inherent in the sugar-phosphate backbone connectivity and is essential for replication and transcription. We note that this asymmetry is due to one single chemical bond (C_3' to C_2' ) in each nucleotide unit, and the absence of this bond results in directionally symmetric nucleic acids. We also discovered that creation of an extra chemical bond (C_5' to C_2' ) can lead to a symmetric backbone. Keeping their potential synthetic and therapeutic interest in mind, we designed a few novel symmetric nucleic acids. We investigated their conformational stability and flexibility via detailed all atom explicit solvent 100-ns long molecular dynamics simulations and compared the resulting structures with that of regular B-DNA. Quite interestingly, some of the symmetric nucleic acids retain the overall double helical structure indicating their potential for integration in physiological DNA without causing major structural perturbations.

Changing picture of acute kidney injury in pregnancy: Study of 259 cases over a period of 33 years

The incidence of acute kidney injury (AKI) in pregnancy is declining in developing countries but still remains a major cause of maternal and fetal morbidity and mortality. The aim of the study was to analyze the changing trends in pregnancy related AKI (PR-AKI) over a period of thirty-three years. Clinical characteristics of PR-AKI with respect to incidence, etiology and fetal and maternal outcomes were compared in three study periods, namely 1982-1991,1992-2002 and 2003-2014. The incidence of PR-AKI decreased to 10.4% in 1992-2002, from 15.2% in 1982-1991, with declining trend continuing in 2003-2014 (4.68%).Postabortal AKI decreased to 1.49% in 2003-2014 from 9.4% in 1982-1991of total AKI cases. The AKI related to puerperal sepsis increased to 1.56% of all AKI cases in 2003-2014 from 1.4% in 1982-1991. Preeclampsia/eclampsia associated AKI decreased from 3.5% of total AKI cases in 1982-1991 to 0.54% in 2003-2014. Pregnancy associated – thrombotic microangiopathy and acute fatty liver of pregnancy were uncommon causes of AKI. Hyperemesis gravidarum associated AKI was not observed in our study. Incidence of renal cortical necrosis (RCN) decreased to 1.4% in 2003-2014 from 17% in 1982-1991.Maternal mortality reduced to 5.79% from initial high value 20% in 1982-1991. The progression of PR-AKI to ESRD decreased to1.4% in 2003-2014 from 6.15% in 1982-1991. The incidence of PR-AKI has decreased over last three decades, mainly due to decrease in incidence of postabortal AKI. Puerperal sepsis and obstetric hemorrhage were the major causes of PR-AKI followed by preeclampsia in late pregnancy. Maternal mortality and incidence and severity of RCN have significantly decreased in PR-AKI. The progression to CKD and ESRD has decreased in women with AKI in pregnancy in recent decade. However, the perinatal mortality did not change throughout study period.

Pulmonary azygous lobe--an anatomical variant

Pulmonary azygous lobe is one of the common lung malformations. There is only few article about azygous lobe. Its a small accessory lobe sometimes found on the upper part of the right lung, separated from the rest of the upper lobe by a deep groove lodging the ayzygous vein. This reports decribes the presence of azygous lobe, a rare anatomical variant, encounted during chest x-ray discussion. We describe here the anatomical basis and the clinical significance of azygous lobe.

Pd/mannose promoted tandem cross coupling-nitro reduction: expedient synthesis of aminobiphenyls and aminostilbenes

d-Mannose as a ligand for Pd catalyzed cross-coupling, and as a hydrogen source for nitro reduction in a modular one-pot cross coupling-nitro reduction sequence.

Ritual scalp shaving-a risk factor for community acquired late onset neonatal sepsis

Background Neonatal sepsis is one of the major causes of morbidity and mortality at the community and hospital levels in India. There are several community practices associated with and contributing to Neonatal sepsis, especially late onset variety.Objective To analyze whether scalp shaving is an independent risk factor associated with community acquired late onset neonatal sepsis and the causative organism responsible.Methods This was a prospective, non-interventional, observational study. The study was conducted at two tertiary teaching hospitals in Eastern India from 1st May 2010 to 30th April 2011. A total of 382 babies were diagnosed as Late Onset Neonatal Sepsis and 410 , age and sex matched controls were taken from the Well Baby and Immunization clinics. The patients were clinically screened for sepsis and "septic screen" and blood, urine and CSF cultures sent, as needed.Results History of scalp shaving was present in 46(12.04%) out of 382 cases of Late Onset Neonatal Sepsis as compared to 20(4.87%) of 410 matched community controls, the difference was statistically significant (p<0.005). Positive blood cultures were obtained in 20(43.48%) out of 46 scalp shaven babies as compared to 118(35.11%) out of 336 non scalp shaven babies. The commonest organism in babies with scalp shaving was found to be methicillin resistant Staphylococcus aureus(MRSA), whereas the most common organism in non scalp shaven babies was Klebsiella pnuemoniae.Conclusion Scalp shaving appears to be an independent variable associated with community acquired Late Onset Neonatal Sepsis.Journal of College of Medical Sciences-Nepal, 2013, Vol-9, No-3, 35-44

Prevalence and correction of near vision impairment at Kaski, Nepal

INTRODUCTION

Presbyopia is an important cause of avoidable visual disability.

OBJECTIVE

To estimate the prevalence of near vision impairment and spectacle coverage among middle and older-aged adults in rural Nepal.

MATERIALS AND METHODS

The surveys was carried out among the people of age 35 and over in randomly-selected cluster samples in rural settings of Kaski district of western Nepal, Near visual acuity, with and without presenting near correction, was measured at 40 cm using a LogMAR near vision tumbling E chart under ambient indoor lighting. Subjects with uncorrected binocular distance vision of 20/40 or worse were refracted and those with near vision of 20/40 or worse tested with plus sphere to obtain the best-corrected binocular near visual acuity.

RESULTS

A total of 2,360 persons aged 35 years and over were enumerated and 2,156 (91.3%) were examined. The age- and gender-standardized prevalence of uncorrected near visual impairment (vision of 20/40 or worse) in study population was found to be 66.1 %. Near vision could not be corrected (>20/40) even after distance and near vision correction in 6.4 % . Using the multiple logistic regression models, uncorrected visual impairment was associated with an older age (odds ratio [OR] = 1.13, P less than 0.001) and a lower educational level (OR = 1.11, P = 0.01) was less associated with female gender (OR = 0.72, P = 0.038). Over 90 % of people with near visual impairment did not have spectacles.

CONCLUSION

The prevalence of presbyopia appears to be higher with an earlier onset and over 90 % of people in need of near correction do not have spectacles in this setting.

A fatal presentation of dermatomyositis

Dermatomyositis (DM) is an autoimmune disease that mainly affects the skin, muscle, and lung. The pathogenesis of skin inflammation in DM is not well understood. We present a 40-year-old male who presented with four months history of generalized skin lesion, pain and weakness. He had elevated transaminases with detectable muscle weakness. This case highlights the need to consider dermatomyositis with skin lesion and weakness; and the use of aggressive immunosuppressive therapies due to its associated vasculopathies.

Spectrum of diseases in a medical ward of a teaching hospital in a developing country

Communicable and respiratory tract diseases especially chronic obstructive pulmonary diseases are the main reasons of admission in medical ward of low and middle income countries. This is different from the developed countries where non communicable diseases are the main reasons of hospital admission. In developing countries the data of hospital admission are still lacking. Therefore this study will help us to assess the common patterns of diseases admitted in a medical ward, the average length of hospital stay etc. The record of 1040 hospitalized patients in medical ward was analyzed for the period of six months from Jan 2010 to Jun 2010. Patient’s medical records were retrieved and data analysis was done to obtain age, sex, common diagnosis, the affected system and the duration of the hospital stay. The data was analyzed by using SPSSV 16. After reviewing the data the most common age of patients being admitted were between 46-65 years (31.5%) followed by more than 65 years (25%) between 26-45 years (21.28%) and less than 25 years (21.28%). Among the admitted patients females were more than the males except in neurolog ward. The most effected system was respiratory (31.73 %),and the most common diagnosis was Chronic obstructive pulmonary diseases (23.17%). The next common system involved was gastroenterology including liver (18.64%) ,genitourinary (12.01%), cardiovascular ( 11.34%), neurology (9.23%), endocrine (4.80%) hematology (2.30%). The cause for hospital admission by infection in different system was (30.08%) The average duration of hospital stay of the patients was less than 7 days. The respiratory diseases and the infectious disease are the most common disease in Nepal. The communicable diseases still hold a greater position, while non communicable diseases are main reasons for admission to the medical wards in developed countries. Journal of College of Medical Sciences-Nepal,2012,Vol-8,No-2, 7-11 DOI: http://dx.doi.org/10.3126/jcmsn.v8i2.6831

Study of clinical profile of megaloblastic anemia: An experience of six year at Kathmandu University Hospital, Dhulikhel

Megaloblastic anemia is not uncommon, however varied of presentation makes difficult to come to conclusion. It’s more difficult when resources are limited. In this back ground clinical features of megaloblastic anemia are very important for diagnosis and treatment. It is a retrospective analysis of data from December 2003 to September 2009. During the period, bone marrow aspiration was done for analysis of cause and type of anemia.A total of 14 cases bone marrow findings was consistent with megaloblastic anemia. These reports were taken into consideration after pathologist impression. Serum Vitamin B12 and RBC folate were not done in view of limited resources and financial constrain. In the analysis 14 (11.96%) bone marrow findings were consistent with megaloblastic anemia. Regarding clinical presentation; pallor was 13 (92.85%) followed by glossitis 5 (35.71%) and Jaundice 5 (35.71%), paresthesia 3 (21.42%), and pigmentation, ataxia, confusion each case (7.14 %). Mostly the patients were between the 21- 40 years of age. Megloblastic anemia is common clinical problem with pallor and glossitis as major presentation. However some had neurological features. This disease can be diagnosed and treated on the basis of bone marrow aspiration when resources are limited.Journal of College of Medical Sciences-Nepal, 2011, Vol-7, No-2, 41-44DOI: http://dx.doi.org/10.3126/jcmsn.v7i2.6679

Understanding of tobacco and lung cancer among medical students in Kathmandu University School of Medical Sciences (KUSMS)

BACKGROUND

Often, lung cancer is diagnosed at terminal stages. Poor awareness about the symptoms or risk factors of lung cancer among medics may be one of the factors for delayed diagnosis.

OBJECTIVE

We explored the knowledge of medical students and their behavior with the patients of lung cancer.

METHOD

Qualitative and quantitative approaches were used for data collection from 153 medical student of Kathmandu University School of Medical Sciences from December 2011 to May 2012.

RESULTS

Among the results, eighty-nine students had over 80% knowledge of the 14 cancer warning signs, among them 83% knew the nine risk factors for lung cancer. Twenty-three students told lung cancer can be hereditary. Sixty five percent of all participants believed that lung cancer can be detected at early stage; of them 81% told that it can be treated. About 24% of the total students were current or exsmokers and about half of them believed that lung cancer does not occur in light smokers. Only 10% have heard of Framework Convention on Tobacco Control in Nepal.

CONCLUSION

Study finds that all medical students who know about any cancers may not necessarily have knowledge about lung cancers. Their perception about the cause of lung cancer may be influenced by their smoking behavior and there was little knowledge of public health measures for smoking control. Awareness about national policies needs to be increased.

Spatial and temporal diversity of begomoviral complexes in papayas with leaf curl disease

Old World, monopartite begomoviruses associated with satellite DNA β were observed in papaya showing symptoms of leaf curl disease sampled randomly over five years from within a radius of 250 km in north-central India. Three groups of DNA A sequences were evident. One group resembled chili leaf curl virus infecting tomatoes (ChiLCuV). Another group resembled tomato leaf curl New Delhi virus (ToLCuNDV). The third group was novel (tentatively named papaya leaf crumple virus, PaLCrV), with less than 89% identity to known begomovirus sequences in the GenBank database. At least seven DNA A sequences were putative recombinants. The AC4-encoding regions exhibited highest numbers of non-synonymous substitutions. Most DNA β sequences resembled tomato leaf curl virus-associated DNA βs. A few DNA β sequences were similar to that of croton yellow vein mosaic virus-associated DNA β (CroYVMVβ). One DNA β sequence was novel and showed <65% similarity to its counterparts. Mixed infections and sequence diversity among 25 cloned av1 genes indicated that papayas grown in plantations, kitchen gardens and feral patches in the region are vulnerable to disease outbreak. No geographic or temporal patterns were discernable in the distribution of these viruses.

Microalbuminuria in diabetes mellitus: Association with age, sex, weight, and creatinine clearance

Studies in the Western literature show a linear relationship between degree of microalbuminuria and body mass index (BMI), blood pressure, and duration of diabetes. This study was aimed to determine the correlation of microalbuminuria with age, sex, duration of diabetes, BMI, and creatinine clearance in type-2 diabetics in Indian population. One hundred patients (59 males and 41 females) with type-2 diabetes mellitus of duration six months or more and negative for albumin in urine by albustic method were included in the study. Detailed clinical history was taken followed by a thorough physical examination that included neurological examination in the selected patients. Micral test was used for estimation of microalbuminuria. Overall prevalence of microalbuminuria in the present study was 37%. Among the patients with microalbuminuria, 20 were males and 17 were females. Pearson correlation of microalbuminuria with age showed statistically significant linear relationship. Gender-wise correlation analysis of microalbuminuria failed to show any statistical significance. Correlation of microalbuminuria with BMI was also not significant (r = 0.063, P > 0.05). Creatinine clearance negatively correlated with microalbuminuria, but this was statistically insignificant. There was a statistically significant correlation of microalbuminuria with duration of diabetes. Prevalence of microalbuminuria is around 37% in type-2 diabetes mellitus. Incidence of microalbuminuria increases with age as well as with increased duration of diabetes mellitus. There is no effect of BMI and sex on the prevalence of microalbuminuria.

Upper gastro-intestinal bleeding: aetiology and demographic profile based on endoscopic examination at Dhulikhel Hospital, Kathmandu University Hospital

BACKGROUND

The upper gastrointestinal bleeding (UGIB) is defined as bleeding within the intraluminal gastrointestinal tract from any location between the upper oesophagus to the duodenum at the ligament of Treitz. It is one of the important medical emergencies worldwide.

OBJECTIVE

The objective of this study is to study the aetiology of upper gastrointestinal bleeding based on endoscopic examination findings in patients of various demographic characteristics.

MATERIALS AND METHODS

This is a retrospective observational study. The endoscopic record book from 2007 January to 2009 October was reviewed for all the cases who underwent oesophago-gastro-duodenoscopic examination for upper GI bleeding. The clinico-epidemiological data of all the patients was reviewed and analyzed in concert with the aetiology of bleeding.

RESULTS

A total of 90 patients (58 males, 32 females; mean age 45.32+ 18.47 years) of upper gastrointestinal bleeding was studied and analyzed in terms of aetiology of bleeding and demographic profile. Among the ethnic groups, Aryan 46 (51%) was the most common ethnic group to have upper GI bleeding followed by Newars 24 (27%), Mongolians 16 (18%), Dalits 3 (3%) and others 1 (1%). Out of 90 patients, 47( 52.2%) cases was less than 45 years of age, 30(33.3%) of 46 to 65 age ; and 13(14.4 %) more than 65 years of age. Gastric ulcer 23(25.6%) was the most common endoscopic finding, followed by oesophageal varices 14 (15.6%), acute erosive/haemorrhagic gastropathy 11 (12.2%), duodenal ulcer 9(10%), growth 7(7.8%), vascular lesions 3(3.3%), Mallory-Weiss tear 1(1.1%), fundal varices 1(1.1%) and, no cause was identified in 21(23.3%) cases. The peptic ulcer bleeding was the most common finding in Aryan 22(47.9%), whereas oesophageal varices and growth were more common in Newar 7(29.2%) and 3 (12.5%) respectively.

CONCLUSION

Peptic ulcer disease is the most common cause of upper GI bleeding which was most commonly found in Aryan population; followed by oesophageal varices and growth as second and third most common causes and were more prevalent in Newar and Mongolian people.

Mercury contamination in the riparian zones along the East Fork Poplar Creek at Oak Ridge

Oak Ridge (Tennessee, USA) has a history of mercury (Hg) contamination in its aquatic and soil environment associated with past nuclear-weapons production activities at its Department of Energy (DOE) sites. Three different riparian zones along the Lower East Fork Poplar Creek were investigated in order to study Hg distribution and transformation in surface soils. The surface soil samples collected from these areas showed higher total Hg on an average (129.08 mg/kg) and higher total organic carbon (5.50%) in the upstream soils compared to the other two downstream locations that contained only 31.78 and 19.98 mg/kg total Hg and 2.88% and 1.65% of TOC on average, respectively. Further, methyl Hg concentrations were also comparatively higher in case of the upstream soils (30.10 μg/kg) than that of the downstream sites (5.69 and 4.05 μg/kg). The study showed a plume-like dispersion of Hg in the terrestrial environment along the creek, with decreasing Hg concentrations with distance from the Hg source zone. Also, the transformation of Hg in the soils was found to have been influenced by the soil TOC contents.

Mercury uptake and translocation in Impatiens walleriana plants grown in the contaminated soil from Oak Ridge

Mercury (Hg) contaminated soils from Oak Ridge, Tennessee were investigated for phytoavailability of mercury as measured by degree of Hg translocation in aboveground biomass of Impatiens walleriana plants grown in the soils. After 90 days of incubation, results revealed a higher concentration of total Hg in the leaves than in the flowers or the stems. Plants that were grown in the soils with higher Hg concentrations showed significantly higher Hg uptake and translocation in the aboveground plant-biomass, and the correlation with the initial soil-Hg was significant for the leaves and the stems in the plants that were tested. On an average, only 4.06 microg of Hg could be found in the above ground plant biomass of all the plants, compared to an average 3673.50 microg of initial total Hg concentrations in these soils. Statistical analysis revealed a greater affinity of Hg for the soil carbon, which supported the finding of this study on low soil Hg bioavailability.

Unusual site of metastasis of bronchogenic carcinoma

Metastasis of bronchogenic carcinoma to the chest wall and axillary lymphnodes is a rare occurrence. This study reports the case of a patient presenting with chest wall swelling as initial symptom which on evaluation was found to be a lymphnode metastasis. The patient also had axillary lymphnode metastasis on the same side as the chest swelling with a contralateral pleural effusion. Here, we discuss the pathways and possible mechanisms of contra lateral axillary and chest wall lymphnode involvement without ispilateral nodal involvement in bronchogenic carcinoma.

Young people's knowledge, attitude, and behaviour on STI/HIV/AIDS in the context of Nepal: a systematic review

BACKGROUND

Sexual and reproductive health of young people has become a major health problem in recent decades. Recent and rapidly increasing Human Immune Deficiency Virus (HIV) rates show an urgent need for Sexually Transmitted Infections (STIs) and HIV prevention interventions in Nepal.

OBJECTIVES

This paper attempts to assess knowledge, attitude and behaviour on STIs/HIV/AIDS in the context of young peoples of Nepal.

METHOD AND MATERIAL

A systematic review based on the available literature was carried out including both qualitative and quantitative studies.

RESULTS

Our findings indicate that the overall knowledge regarding STIs and HIV/AIDS is high although the level of knowledge seems to differ according to education, gender, and area of residence. Knowledge about condoms was also very high but practice of correct and consistent use in premarital and extramarital sexual relations with non-regular partners seems to be lower. The overall sexual behaviour among young people is unsafe.

CONCLUSION

This suggests that young people's sexual and reproductive health issues need to be further addressed and explored in order to promote safer and responsible sexual behaviour.

Lipid Profile in a Tertiary Care Center

INTRODUCTION: Lipid profile is changing with changing developmental status and lifestyle in less developed countries and coronary artery disease risk factor is rising. The aim of the study is to find the lipid pattern in Department of Medicine in tertiary care hospital. METHODS: An observational prospective study was conducted in 408 subjects from January 2009 to February 2010. Study subjects were selected irrespective of co-morbid condition and coronary risk factors. RESULTS: The mean triglycerides, cholesterol, LDL, HDL were 138.3 +/- 78.3 mg/dl, 180.2 +/- 53.7 mg/dl, 113.8 +/- 41.2 mg/dl, 40.1 +/- 10.1 mg/dl respectively. The Triglycerides (>140 mg/dl), Cholesterol (>250 mg/dl), LDL (>92 mg/dl), HDL (<45mg/dl) were 35.5%, 7.6%, 67.9%, 76% respectively. CONCLUSIONS: Lipid profile is becoming atherogenic with high triglyceride, high LDL and low HDL being the most common abnormality. An epidemiological study is recommended to understand the true burden of the disease in the community.  KEYWORDS: atherogenic, cholestrol, coronary artery diseases, lipid profile, triglyceride. 

Lipid profile in a tertiary care center

INTRODUCTION

Lipid profile is changing with changing developmental status and lifestyle in less developed countries and coronary artery disease risk factor is rising. The aim of the study is to find the lipid pattern in Department of Medicine in tertiary care hospital.

METHODS

An observational prospective study was conducted in 408 subjects from January 2009 to February 2010. Study subjects were selected irrespective of co-morbid condition and coronary risk factors.

RESULTS

The mean triglycerides, cholesterol, LDL, HDL were 138.3 +/- 78.3 mg/dl, 180.2 +/- 53.7 mg/dl, 113.8 +/- 41.2 mg/dl, 40.1 +/- 10.1 mg/dl respectively. The Triglycerides (>140 mg/dl), Cholesterol (>250 mg/dl), LDL (>92 mg/dl), HDL (<45mg/dl) were 35.5%, 7.6%, 67.9%, 76% respectively.

CONCLUSIONS

Lipid profile is becoming atherogenic with high triglyceride, high LDL and low HDL being the most common abnormality. An epidemiological study is recommended to understand the true burden of the disease in the community.

Comparative Raman and HRTEM study of nanostructured GaN nucleation layers and device layers on sapphire (0001)

Raman spectroscopy in conjunction with high-resolution transmission electron microscopy (HRTEM) has been used to study structural characteristics and strain distribution of the nanostructured GaN nucleation layer (NL) and the GaN device layer on (0001) sapphire substrates used for light-emitting diodes and lasers. Raman peaks corresponding to the cubic and the hexagonal phase of GaN are observed in the Raman spectrum from 15 nm and 45 nm NLs. A comparison of the peak intensities for the cubic and hexagonal phases of GaN in the NLs suggests that the cubic phase is dominant in the 15 nm NL and the hexagonal phase in the 45 nm NL. An increase in the density of stacking faults in the metastable cubic GaN (c-GaN) phase with increasing growth time lowers the system energy as well as locally converts c-GaN phase into hexagonal GaN (h-GaN). It also explains the observation of the more intense peaks of h-GaN in the 45 nm NL compared to c-GaN peaks. For the sample wherein an h-GaN device layer was grown at higher temperatures on the NL, narrow Raman peaks corresponding to only h-GaN were observed, confirming the high-quality of the films. The peak shift of the E2(H)(LO) mode of h-GaN in the NLs and the h-GaN film suggests the presence of a tensile stress in the NL which is attributed to defects such as stacking faults and twins, and a compressive stress in high-temperature grown h-GaN film which is attributed to the thermal-expansion mismatch between the film and the substrate. The peak shifts of the substrate also reveal that during the low temperature growth of the NL the substrate is under a compressive stress which is attributed to defects in the NL and during the high temperature growth of the device layer, there is a tensile strain in the substrate as expected from differences in coefficients of thermal expansion of the film and the substrate during the cooling cycle.