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1.
Indian Heart J ; 73(5): 617-621, 2021.
Article in English | MEDLINE | ID: mdl-34627579

ABSTRACT

OBJECTIVES: -This prospective study with a sizable cohort was undertaken to assess changes in left and right ventricle systolic and diastolic functions after percutaneous patent ductus arteriosus device closure with appropriate follow up evaluation. METHODS: - It is an observational analytical prospective study. Ninety-eight patients were recruited out of which sixty-eight patients underwent percutaneous PDA device closure and were taken for final analysis. The primary objective was to study the left and right ventricular systolic and diastolic functions pre- and post-procedure at 48 h with follow up analysis at six months. RESULTS: - The mean age of the patients was 7.88 ± 5.05 years with the female to male ratio was 3.85:1. Thirty-three (48.52%) of the patients had immediate post PDA device closure LV systolic dysfunction. It was more common in those having pre-procedure mean low LVEF and those having a significant reduction in mitral A velocity. It became normal at six months follow up. The study reported immediate decrease in mea/n LVEF from 63.55 ± 8.11% to 48.19 ± 7.9%. The changes in LVEDD, LVEF, LVFS and LVEDV were statistically significant (p < 0.0001). In diastolic functions, there were significant reductions in peak early and late diastolic velocities. There was no statistically significant difference in right chamber functional assessment. CONCLUSION: Asymptomatic LV systolic and diastolic dysfunction in immediate post PDA closure period is a common complication and reported in around 48.5% cases. It was more common in those having pre-procedure mean low LVEF and those having a significant reduction in mitral A velocity.


Subject(s)
Ductus Arteriosus, Patent , Child , Child, Preschool , Diastole , Echocardiography , Female , Humans , Male , Prospective Studies , Systole
2.
Indian Heart J ; 73(4): 470-475, 2021.
Article in English | MEDLINE | ID: mdl-34474760

ABSTRACT

OBJECTIVES: Though invasive monitoring is the most accurate to estimate diastolic dysfunction but it has its own risk. The purpose of this study was to find out any standardized correlation between invasive and non -invasive parameters. METHODS: It is an observational, descriptive study comprising of a total of 500 patients. The primary objective of the study was to determine the correlation between echocardiographic diastolic parameters and invasively measured left ventricular end diastolic pressure (LVEDP). RESULTS: On studying correlation of different invasive and non-invasive data it was reported that there was a weak correlation between peak E velocity (r = 0.14, p = 0.631), Peak A velocity (r = 0.67, p = 0.59), IVRT (r = -0.35, p = 0.178), Mitral deceleration time (DT) (r = -0.06, p = 0.842), pulmonary venous peak systolic (r = -0.02, p = 0.966) and diastolic flows (r = 0.47, p = 0.201) to LVEDP. There was a good positive correlation between elevated LVEDP and difference in duration of pulmonary venous and mitral flow at atrial contraction (A-Ard) and E/Ea at all four longitudinal segments of the left ventricle. The sensitivity and specificity for detecting an elevated LVEDP of more than 12 mm Hg, using a cut off value of E/Ea< 8, were 89% and 90%.Lateral E/Ea ≥ 12, LAVI ≥34 mL/m2, and Ard-Ad > 30 msec have the greatest diagnostic value for diagnosing diastolic dysfunction in HFpEF patients. CONCLUSION: Lateral E/Ea ≥ 12, LAVI ≥34 mL/m2, and Ard-Ad > 30 msec have the greatest diagnostic value for diagnosing diastolic dysfunction in HFpEF patients and have good correlation with invasively measured LVEDP.


Subject(s)
Heart Failure , Ventricular Dysfunction, Left , Blood Pressure , Cardiac Catheterization , Echocardiography , Heart Failure/diagnosis , Humans , Stroke Volume , Ventricular Dysfunction, Left/diagnosis , Ventricular Function, Left , Ventricular Pressure
3.
Indian Heart J ; 72(5): 435-441, 2020.
Article in English | MEDLINE | ID: mdl-33189208

ABSTRACT

OBJECTIVES: This is an open-label randomized control trial with a parallel assignment with single masking comparing patients undergoing coronary angiography via dorsal radial and classical radial access. METHODS: Study done at three tertiary cardiac care centers for two years. A total of 970 patients were finally recruited for the study. Patients were randomly selected for dorsal radial artery access Group A (485 patients) and classical radial artery access Group B (485 patients) without any bias for age & sex. RESULTS: On comparative assessment both techniques are found to be equal in terms of procedural success rate. While dorsal access was superior in terms of fewer incidences of forearm radial artery occlusion, radial artery spasm, less post-procedure persistence of pain, and hand clumsiness. In comparison to this, the number of puncture attempts and time to achieve post-procedure hemostasis is less in classical radial access. CONCLUSION: So both techniques have pros and coins and it is the discretion of interventionists to adopt which technique.


Subject(s)
Catheterization, Peripheral/methods , Coronary Angiography/methods , Coronary Artery Disease/diagnosis , Female , Follow-Up Studies , Humans , Male , Middle Aged , Radial Artery , Time Factors
4.
J Neonatal Perinatal Med ; 13(1): 143-148, 2020.
Article in English | MEDLINE | ID: mdl-31771078

ABSTRACT

With improved and prolonged survival of very and extremely low birth weight infants, invasive fungal infection has emerged as an important concern in the neonatal intensive care units. Candidiasis is the third leading cause of late onset sepsis in these neonates and is associated with 20-30% mortality. Extreme prematurity, central venous catheters, prolonged antibiotic exposure, parenteral nutrition are important risk factors. Various forms of cutaneous manifestations of candidiasis have been described ranging from local diaper dermatitis and oral thrush to widespread erosive and ulcerative lesions with extensive crusting in invasive fungal dermatitis. We report a series of four cases with cutaneous hyperpigmentation as manifestation of systemic candidiasis.


Subject(s)
Candidemia/physiopathology , Hyperpigmentation/pathology , Neonatal Sepsis/physiopathology , Amphotericin B/therapeutic use , Anti-Bacterial Agents/therapeutic use , Antifungal Agents/therapeutic use , Candidemia/complications , Candidemia/drug therapy , Candidiasis, Invasive/complications , Candidiasis, Invasive/drug therapy , Candidiasis, Invasive/physiopathology , Female , Humans , Hyperpigmentation/etiology , Infant, Newborn , Infant, Premature , Intensive Care Units, Neonatal , Male , Neonatal Sepsis/complications
5.
Comput Biol Chem ; 71: 161-169, 2017 Dec.
Article in English | MEDLINE | ID: mdl-29096382

ABSTRACT

This paper proposes a new hybrid search technique for feature (gene) selection (FS) using Independent component analysis (ICA) and Artificial Bee Colony (ABC) called ICA+ABC, to select informative genes based on a Naïve Bayes (NB) algorithm. An important trait of this technique is the optimization of ICA feature vector using ABC. ICA+ABC is a hybrid search algorithm that combines the benefits of extraction approach, to reduce the size of data and wrapper approach, to optimize the reduced feature vectors. This hybrid search technique is facilitated by evaluating the performance of ICA+ABC on six standard gene expression datasets of classification. Extensive experiments were conducted to compare the performance of ICA+ABC with the results obtained from recently published Minimum Redundancy Maximum Relevance (mRMR) +ABC algorithm for NB classifier. Also to check the performance that how ICA+ABC works as feature selection with NB classifier, compared the combination of ICA with popular filter techniques and with other similar bio inspired algorithm such as Genetic Algorithm (GA) and Particle Swarm Optimization (PSO). The result shows that ICA+ABC has a significant ability to generate small subsets of genes from the ICA feature vector, that significantly improve the classification accuracy of NB classifier compared to other previously suggested methods.


Subject(s)
Algorithms , Bayes Theorem , Oligonucleotide Array Sequence Analysis , Gene Expression , Humans
6.
J Helminthol ; 91(2): 197-205, 2017 Mar.
Article in English | MEDLINE | ID: mdl-26984296

ABSTRACT

Three species of genus Bychowskyella Akhmerov (1952), i.e. B. fossilisi Majumdar & Agarwal, 1989, B. tchangi Gusev, 1976 and B. wallagonia (Jain, 1959a) Gusev, 1961, were found to parasitize the gill filaments of siluriform fish in India. This redescription based on light microscopic examination of B. fossilisi, B. tchangi and B. wallagonia provides detailed taxonomic data for these species. We also amplified the 18S ribosomal RNA gene to evaluate the phylogenetic relationships of these three species. The morphological and genetic profiles confirmed the validation and taxonomical relationships of the above-mentioned species belonging to the genus Bychowskyella.


Subject(s)
Catfishes/parasitology , Fish Diseases/parasitology , Platyhelminths/growth & development , Platyhelminths/genetics , Trematode Infections/veterinary , Animals , DNA, Helminth/genetics , DNA, Ribosomal/genetics , Gills/parasitology , India , Phylogeny , Platyhelminths/classification , Platyhelminths/isolation & purification , Trematode Infections/parasitology
7.
Protein Eng Des Sel ; 29(7): 253-61, 2016 07.
Article in English | MEDLINE | ID: mdl-27255759

ABSTRACT

To aid in the discovery and development of peptides and proteins as therapeutic agents, a virtual screen can be used to predict trends and direct workflow. We have developed the Parasol Protocol, a dynamic method implemented using the AMBER MD package, for computational site-directed mutagenesis. This tool can mutate between any pair of amino acids in a computationally expedient, automated manner. To demonstrate the potential of this methodology, we have employed the protocol to investigate a test case involving stapled peptides, and have demonstrated good agreement with experiment.


Subject(s)
Mutagenesis, Site-Directed , Proteins/chemistry , Proteins/genetics , Software , Amino Acid Sequence , Animals , Computer Simulation , Humans , Models, Molecular , Mutation , Peptides/chemistry , Peptides/genetics , Workflow
8.
Genom Data ; 8: 4-15, 2016 Jun.
Article in English | MEDLINE | ID: mdl-27081632

ABSTRACT

Feature (gene) selection and classification of microarray data are the two most interesting machine learning challenges. In the present work two existing feature selection/extraction algorithms, namely independent component analysis (ICA) and fuzzy backward feature elimination (FBFE) are used which is a new combination of selection/extraction. The main objective of this paper is to select the independent components of the DNA microarray data using FBFE to improve the performance of support vector machine (SVM) and Naïve Bayes (NB) classifier, while making the computational expenses affordable. To show the validity of the proposed method, it is applied to reduce the number of genes for five DNA microarray datasets namely; colon cancer, acute leukemia, prostate cancer, lung cancer II, and high-grade glioma. Now these datasets are then classified using SVM and NB classifiers. Experimental results on these five microarray datasets demonstrate that gene selected by proposed approach, effectively improve the performance of SVM and NB classifiers in terms of classification accuracy. We compare our proposed method with principal component analysis (PCA) as a standard extraction algorithm and find that the proposed method can obtain better classification accuracy, using SVM and NB classifiers with a smaller number of selected genes than the PCA. The curve between the average error rate and number of genes with each dataset represents the selection of required number of genes for the highest accuracy with our proposed method for both the classifiers. ROC shows best subset of genes for both the classifier of different datasets with propose method.

9.
J Helminthol ; 90(5): 596-606, 2016 Sep.
Article in English | MEDLINE | ID: mdl-26373618

ABSTRACT

Species of the genus Mizelleus Jain (1957) have always been controversial regarding identification and validity. Members of this group of species differ from each other in the morphology of their hard parts, which can be misleading and subject to differing interpretation among scientists. Therefore, the main objective of present study was to identify Mizelleus worms by morphological methods and molecular analysis on the basis of 18S ribosomal DNA to clarify their phylogenetic status. In this study, specimens were isolated from the gill filaments of Wallago attu (Siluriformes) and studied morphologically. In accordance with morphological characters, the specimens were found to be Mizelleus indicus and Mizelleus longicirrus. Partial sequences of nuclear 18S rDNA of these two species were amplified. The results confirm the phylogenetic relationships and taxonomic validation of M. indicus and M. longicirrus in India.


Subject(s)
Catfishes/parasitology , Platyhelminths/anatomy & histology , Platyhelminths/genetics , Animals , Cluster Analysis , DNA, Helminth/chemistry , DNA, Helminth/genetics , DNA, Ribosomal/chemistry , DNA, Ribosomal/genetics , Gills/parasitology , India , Microscopy , Phylogeny , Platyhelminths/classification , Platyhelminths/isolation & purification , RNA, Ribosomal, 18S/genetics , Rivers , Sequence Analysis, DNA
10.
J Antimicrob Chemother ; 69(12): 3244-7, 2014 Dec.
Article in English | MEDLINE | ID: mdl-25125676

ABSTRACT

OBJECTIVES: Voriconazole, itraconazole and posaconazole are members of the azole family and widely used for the treatment of aspergillosis. They act by inhibiting the activity of the fungal Cyp51A enzyme. The emergence of environmental azole-resistant Aspergillus fumigatus strains raises major concerns for human health. METHODS: Recently, a new cyp51A-mediated resistance mechanism (namely TR46/Y121F/T289A) was described in clinical samples and patient-frequented environmental sites. In an azole-naive patient, we isolated an A. fumigatus strain that was not susceptible to voriconazole but was susceptible to itraconazole and posaconazole. RESULTS: A molecular analysis indicated a single Y121F substitution without the TR46 or T289A alterations, which to our knowledge has never been reported. Structure modelling and molecular dynamics offered an explanation for the resistance profile consistent with the structural differences between the three azoles. CONCLUSIONS: Taken together, these observations suggest an original mechanism conferring resistance to azoles mediated by cyp51A of environmental origin. This uncommon susceptibility pattern might represent a 'missing link' between the wild-type A. fumigatus and the fully azole-resistant strain harbouring the TR46/Y121F/T289A mutations.


Subject(s)
Antifungal Agents/pharmacology , Aspergillus fumigatus/drug effects , Cytochrome P-450 Enzyme System/genetics , Fungal Proteins/genetics , Itraconazole/pharmacology , Mutation, Missense , Triazoles/pharmacology , Voriconazole/pharmacology , Aspergillus fumigatus/genetics , Aspergillus fumigatus/isolation & purification , DNA, Fungal/chemistry , DNA, Fungal/genetics , Drug Resistance, Fungal , Molecular Sequence Data , Sequence Analysis, DNA
11.
Indian J Lepr ; 86(3): 105-10, 2014.
Article in English | MEDLINE | ID: mdl-26118222

ABSTRACT

A multistage representative random sample of women and men from each of the 3 states of Bihar, Uttar Pradesh and West Bengal, from the rural blocks where the Leprosy Mission Hospitals were located were selected during 2010 to identify relevant factors that are preventing active participation of women and suggest corrective steps. Adult men and women were interviewed in depth, using a detailed checklist by the first author. A total of 1239 respondents 634 women and 605 men, were interviewed, only 44 women (7%) claimed that they had earlier participated in leprosy work, about 92% of the women felt that they had the potential to take part in leprosy work, and 70% showed willingness to participate. Factors that would encourage and facilitate more women to participate in leprosy work, included financial support (32.8%), convincing the family to grant permission (88%), and delegating them to work in proximity to their residences (15%). Some women respondents (11.0%) felt that they would provide their services voluntarily for social good. Women suggested that work should be delegated as per their capabilities and skills, and they should be given proper orientation, training and guidance. Hardly 5% of ASHA's in the clusters examined participated in leprosy related work, which needs stringent steps to re-orient and encourage them to undertake leprosy related work. It is concluded that rural Indian women are keen to play an important role in the national leprosy eradication program, with minimal support from the government and nongovernmental agencies in a truly community-based approach. This will benefit vast numbers of leprosy affected women as well as others.


Subject(s)
Community Health Services , Leprosy/prevention & control , Leprosy/psychology , Adult , Female , Humans , India , Male , Middle Aged , Rural Population , Socioeconomic Factors , Young Adult
12.
Indian J Lepr ; 83(2): 95-100, 2011.
Article in English | MEDLINE | ID: mdl-21972662

ABSTRACT

Leprosy services were integrated into the general health a decade ago but it seems that a majority of public are still ignorant of this development. Hence, a study was done in Uttar Pradesh, India to determine the awareness about integration and its relationships to various socio-demographic factors. A multistage representative random sample of 3000 persons was chosen in Faizabad district, selecting a sample of 3 villages each situated within 1 km, 1-3 km and beyond 3 km of a PHC. A systematic random sample of 10% of households was chosen from selected villages and an adult male and an adult female from each household interviewed by a qualified investigator. Data were computerized and cross- tabulated against distance from the PHC, sex, age, education and occupational status. Only 45.7% in Uttar Pradesh are aware of the availability of leprosy treatment facilities at PHC but most knew that MDT was free. A smaller proportion was also aware of other facilities such as ulcer dressing and treatment of complications. Family members and health workers and PHC were the main source of information. It is concluded that massive efforts are urgently needed to educate the rural public on integration.


Subject(s)
Delivery of Health Care, Integrated/organization & administration , Health Knowledge, Attitudes, Practice , Leprosy/therapy , Primary Health Care/organization & administration , Adolescent , Adult , Female , Health Care Surveys , Health Services Accessibility , Humans , India , Leprostatic Agents/therapeutic use , Male , Middle Aged , Patient Acceptance of Health Care , Rural Population , Socioeconomic Factors , Young Adult
13.
Amino Acids ; 40(1): 123-33, 2011 Jan.
Article in English | MEDLINE | ID: mdl-20397033

ABSTRACT

Understanding the molecular mechanisms of antimicrobial peptide-membrane interactions is crucial in predicting the design of useful synthetic antimicrobial peptide analogues. Defensins are small (3-5 kDa) cysteine-rich cationic proteins which constitute the front line of host innate immunity. In this study, a series of eight 10 AA C-terminal analogues of hBD3 [sequence: RGRKXXRRKK, X = W, F, Y, V, L, I, H, C(Acm); net charge = +7, coded as W2, F2, Y2, V2, L2, I2, H2, and C2] and covalent V2-dimer [(RGRKVVRR)(2)KK] (18 AA, net charge = +11) were synthesized using solid phase peptide synthesis (SPPS) in Fmoc chemistry. Wild-type hBD3 was used as a control in all analyses. W2, V2, and especially Y2 showed high activity selectively against Gram-negative bacteria Pseudomonas aeruginosa in the concentration range of 4.3-9.7 microM. The covalent dimeric form of V2-monomer, V2-dimer, showed increased antibacterial killing compared to the monomeric form, V2-monomer. Cytotoxicity assays on a human conjunctival epithelial cell line (IOBA-NHC cells) showed that no change in viable cell number 24 h after constant exposure to all the eight peptide analogues even at concentrations up to 200 microg/ml. Fluorescence correlation spectroscopy (FCS) was used to study the interaction of these peptides against POPC vesicles (neutral; mammalian cell membrane mimic) and POPG vesicles (negatively charged; bacterial cell membrane mimic). Using FCS, significant aggregation and some leakage of Rhodamine dye were observed with POPG with Y2, W2 and V2 at the concentration of 5-10 mmicroM and no significant aggregation or disruption of vesicles was observed for all peptide analogues tested against POPC. V2-dimer induced more leakage and aggregation than the monomeric form. Overall, V2-dimer is the most effective antimicrobial peptide, with aggregation of POPG vesicles observed at concentrations as low as 1 microM. The concentration of 5-10 microM for Y2 from FCS correlated with the concentration of 5 microM (6.25 microg/ml), at which Y2 showed a cooperative increase in the activity. This suggests a structural transition of Y2 in the 2.5-5 microM concentration range resulting in the correlated increased antimicrobial activity. These results and the FCS together with previous NMR and molecular dynamics (MD) suggested that the charge density-based binding affinity, stable covalent dimerization, the ability to dimerize or even oligomerize and adopt a well-defined structure are important physicochemical properties distinguishing more effective cationic antimicrobial peptides.


Subject(s)
Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Cytotoxins/chemistry , Cytotoxins/pharmacology , Epithelial Cells/drug effects , beta-Defensins/chemistry , beta-Defensins/pharmacology , Amino Acid Sequence , Cell Line , Cytotoxins/chemical synthesis , Dimerization , Gram-Negative Bacteria/drug effects , Humans , Molecular Structure , beta-Defensins/chemical synthesis
14.
J Mol Biol ; 405(3): 736-53, 2011 Jan 21.
Article in English | MEDLINE | ID: mdl-21094167

ABSTRACT

Eukaryotic initiation factor (eIF)4E is overexpressed in many types of cancer such as breast, head and neck, and lung. A consequence of increased levels of eIF4E is the preferential translation of pro-tumorigenic proteins such as c-Myc, cyclin D1, and vascular endothelial growth factor. Inhibition of eIF4E is therefore a potential therapeutic target for human cancers. A novel peptide based on the eIF4E-binding peptide eIF4G1, where the α-helix was stabilized by the inclusion of α-helix inducers as shown by CD measurements, was synthesized. The helically stabilized peptide binds with an apparent K(d) of 9.43±2.57 nM, which is ∼15.7-fold more potent than the template peptide from which it is designed. The helically stabilized peptide showed significant biological activity at a concentration of 400 µM, unlike the naturally occurring eIFG1 peptide when measured in cell-based cap-dependent translational reporter and WST-1 (4-[3-(4-iodophenyl)-2-(4-nitrophenyl)-2H-5-tetrazolio]-1,3-benzene disulfonate) assays. Fusion of the template peptide and the stabilized peptide to the cell-penetrating peptide TAT produced more active but equally potent inhibitors of cap-dependent translation in cell lines. They also equally disrupted cell metabolism as measured in a WST-1 assay. Propidium iodide staining revealed that the TAT-fused, helically stabilized peptide caused more cell death than the TAT-fused eIF4G1 template peptide with substantial decreases in the G1 and G2 cell populations. Annexin-staining experiments also indicated that the TAT-fused eIF4G1 derivative peptides caused cell death by apoptosis. The results presented should offer further insight into peptidomimetics development for eIF4E.


Subject(s)
Antineoplastic Agents/chemistry , Drug Design , Eukaryotic Initiation Factor-4E/chemistry , Eukaryotic Initiation Factor-4G/chemistry , Peptidomimetics/chemistry , Recombinant Fusion Proteins/chemistry , Amino Acid Sequence , Antineoplastic Agents/metabolism , Apoptosis , Cell Line, Tumor , Eukaryotic Initiation Factor-4E/genetics , Eukaryotic Initiation Factor-4G/genetics , Gene Products, tat/chemistry , Gene Products, tat/genetics , Gene Products, tat/metabolism , Humans , Molecular Sequence Data , Peptidomimetics/metabolism , Protein Binding , Protein Biosynthesis/drug effects , Protein Structure, Secondary , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/metabolism
15.
Oncogene ; 28(6): 803-14, 2009 Feb 12.
Article in English | MEDLINE | ID: mdl-19060928

ABSTRACT

Lapatinib is a human epidermal growth factor receptor 2 (HER2) tyrosine kinase inhibitor (TKI) that has clinical activity in HER2-amplified breast cancer. In vitro studies have shown that lapatinib enhances the effects of the monoclonal antibody trastuzumab suggesting partially non-overlapping mechanisms of action. To dissect these mechanisms, we have studied the effects of lapatinib and trastuzumab on receptor expression and receptor signaling and have identified a new potential mechanism for the enhanced antitumor activity of the combination. Lapatinib, given alone or in combination with trastuzumab to HER2-overexpressing breast cancer cells SKBR3 and MCF7-HER2, inhibited HER2 phosphorylation, prevented receptor ubiquitination and resulted in a marked accumulation of inactive receptors at the cell surface. By contrast, trastuzumab alone caused enhanced HER2 phosphorylation, ubiquitination and degradation of the receptor. By immunoprecipitation and computational protein modeling techniques we have shown that the lapatinib-induced HER2 accumulation at the cell surface also results in the stabilization of inactive HER2 homo- (HER2/HER2) and hetero- (HER2/EGFR and HER2/HER3) dimers. Lapatinib-induced accumulation of HER2 and trastuzumab-mediated downregulation of HER2 was also observed in vivo, where the combination of the two agents triggered complete tumor remissions in all cases after 10 days of treatment. Accumulation of HER2 at the cell surface by lapatinib enhanced immune-mediated trastuzumab-dependent cytotoxicity. We propose that this is a novel mechanism of action of the combination that may be clinically relevant and exploitable in the therapy of patients with HER2-positive tumors.


Subject(s)
Antibodies, Monoclonal/pharmacology , Breast Neoplasms/drug therapy , Drug Synergism , Protein Kinase Inhibitors/pharmacology , Quinazolines/pharmacology , Receptor, ErbB-2/antagonists & inhibitors , Animals , Antibodies, Monoclonal, Humanized , Breast Neoplasms/metabolism , Cell Line, Tumor , Cell Membrane/metabolism , Gene Expression Regulation, Neoplastic , Humans , Lapatinib , Mice , Neoplasm Transplantation , Remission Induction , Signal Transduction , Trastuzumab
16.
Br J Cancer ; 98(1): 4-8, 2008 Jan 15.
Article in English | MEDLINE | ID: mdl-18182973

ABSTRACT

The p53 pathway is aberrant in most human tumours with over 50% expressing mutant p53 proteins. The pathway is critically controlled by protein degradation. Here, we discuss the latest developments in the search for small molecules that can modulate p53 pathway protein stability and restore p53 activity for cancer therapy.


Subject(s)
Neoplasms/metabolism , Tumor Suppressor Protein p53/metabolism , Animals , Humans , Neoplasms/therapy , Proto-Oncogene Proteins c-mdm2/metabolism
17.
Cell Mol Life Sci ; 63(2): 207-19, 2006 Jan.
Article in English | MEDLINE | ID: mdl-16389462

ABSTRACT

Computer simulations at the atomic level have arrived at a stage where they provide realistic modeling of flexibility in proteins (and the mobility of their associated solvent) that is important in understanding the nature of molecular motions. This can now be extended to the molecular and atomic motions that are associated with protein mechanisms. Moreover, the derived data agree reasonably accurately with experimental measurements of several kinetic and thermodynamic parameters. Fundamental insights emerge on the roles that this intrinsic flexibility plays in the thermodynamic characteristics of macromolecules in solution; these equip the investigator to probe the consequences of cognate interactions and ligand binding on entropy and enthalpy. Thus simulations can now provide a powerful tool for investigating protein mechanisms that complements the existing and the emerging experimental techniques.


Subject(s)
Protein Structure, Secondary , Calmodulin/chemistry , Chaperonin 10/chemistry , Computer Simulation , Crystallography, X-Ray , Hydrogen Bonding , Hydrophobic and Hydrophilic Interactions , Ligands , Lipase/chemistry , Models, Molecular , Pliability , Prions/chemistry , Protein Conformation , Structure-Activity Relationship , Water/chemistry
18.
J Nanosci Nanotechnol ; 5(11): 1759-67, 2005 Nov.
Article in English | MEDLINE | ID: mdl-16433409

ABSTRACT

Design of thermally stable proteins is spurred by their applications in bionanotechnology. There are three major issues governing this: first, the upper limit on the temperature at which proteins remain physiologically active and are available for technological applications (answers may emerge from the discovery of new, natural hyperthermophilic enzymes that are active above 125 degrees C or from the selection of mutants of hyperthermophilic enzymes that are more stable); second, the use of hyperthermophilic enzymes as molecular templates to design highly stable enzymes that have high activity at low temperatures; third, the link between rigidity and flexibility to thermostability and activity, respectively. We review progress in these areas.


Subject(s)
Enzymes/chemistry , Nanotechnology/methods , Bacteriorhodopsins/chemistry , Ferredoxins/chemistry , Hot Temperature , Mutation , Protein Conformation , Protein Denaturation , Protein Engineering , Rubredoxins/chemistry , Software , Temperature , Thermodynamics
19.
J Mol Biol ; 336(5): 1175-83, 2004 Mar 05.
Article in English | MEDLINE | ID: mdl-15037077

ABSTRACT

The prion protein PrP is a naturally occurring polypeptide that becomes transformed from a normal conformation to that of an aggregated form, characteristic of pathological states in fatal transmissible spongiform conditions such as Creutzfeld-Jacob Disease and Bovine Spongiform Encephalopathy. We report the crystal structure, at 2 A resolution, of residues 123-230 of the C-terminal globular domain of the ARQ allele of sheep prion protein (PrP). The asymmetric unit contains a single molecule whose secondary structure and overall organisation correspond to those structures of PrPs from various mammalian species determined by NMR. The globular domain shows a close association of helix-1, the C-terminal portion of helix-2 and the N-terminal portion of helix-3, bounded by the intramolecular disulphide bond, 179-214. The loop 164-177, between beta2 and helix-2 is relatively well structured compared to the human PrP NMR structure. Analysis of the sheep PrP structure identifies two possible loci for the initiation of beta-sheet mediated polymerisation. One of these comprises the beta-strand, residues 129-131 that forms an intra-molecular beta-sheet with residues 161-163. This strand is involved in lattice contacts about a crystal dyad to generate a four-stranded intermolecular beta-sheet between neighbouring molecules. The second locus involves the region 188-204, which modelling suggests is able to undergo a partial alpha-->beta switch within the monomer. These loci provide sites within the PrPc monomer that could readily give rise to early intermediate species on the pathway to the formation of aggregated PrPSc containing additional intermolecular beta-structure.


Subject(s)
Prions/chemistry , Animals , Binding Sites , Crystallization , Crystallography, X-Ray , Dimerization , Humans , Models, Molecular , Prion Diseases/etiology , Protein Structure, Secondary , Protein Structure, Tertiary , Sheep
20.
Indian J Exp Biol ; 40(1): 101-5, 2002 Jan.
Article in English | MEDLINE | ID: mdl-12561978

ABSTRACT

Batch studies were conducted on degradation of anaerobically digested distillery wastewater by three bacterial strains, viz. Xanthomonas fragariae, Bacillus megaterium and Bacillus cereus in free and immobilized form, isolated from the activated sludge of a distillery wastewater treatment plant. The removal of COD and colour with all the three strains increased with time up to 48 hr and only marginal increase in COD and colour removal efficiency was observed beyond this period up to 72 hr. After this period removal efficiency remained fairly constant up to 120 hr. The maximum COD and colour removal efficiency varied from 66 to 81% and 65 to 75%, respectively for both free and immobilized cells of all the three strains. The strain Bacillus cereus showed the maximum efficiency of COD (81%) and colour (75%) removal out of the three strains. An interrelationship between the percent COD and colour removal was carried out by correlation and regression analysis and was justified by high values of coefficient of correlation (r = 0.99) for all the cases. The first order removal rate kinetics was also applied and rate constants were evaluated for COD and colour removal efficiencies.


Subject(s)
Alcoholic Beverages , Bacillus cereus/metabolism , Bacillus megaterium/metabolism , Industrial Waste , Water Pollutants, Chemical/metabolism , Xanthomonas/metabolism , Alginates/chemistry , Alginates/metabolism , Bacillus cereus/isolation & purification , Bacillus megaterium/isolation & purification , Biodegradation, Environmental , Drug Carriers/chemistry , Drug Carriers/metabolism , Glucuronic Acid , Hexuronic Acids , Industrial Microbiology/methods , Potassium Dichromate/metabolism , Time Factors , Waste Disposal, Fluid/methods , Xanthomonas/isolation & purification
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