90 results on '"Singh, Ranu"'
Search Results
52. Regulatory Controls in the United States Related To Manufacturers and Marketers of Medical Devices and Implants
- Author
-
Harcharan Singh Ranu
- Subjects
Biomaterials ,business.industry ,Biomedical Engineering ,Medicine ,Marketing ,business ,Biomedical engineering - Published
- 1991
53. Loading response of nucleus and annulus of the human vertebra
- Author
-
Harcharan Singh Ranu
- Subjects
Annulus (mycology) ,medicine.anatomical_structure ,Rehabilitation ,Biomedical Engineering ,Biophysics ,medicine ,Orthopedics and Sports Medicine ,Anatomy ,Nucleus ,Geology ,Vertebra - Published
- 1990
54. Studies on the immunochemistry ofStaphylococcus aureus cell wall: Antigenicity of pentaglycine bridges
- Author
-
Rajinder Singh Ranu
- Subjects
Microbiology (medical) ,Antigenicity ,Staphylococcus ,Immunology ,Glycine ,Heterologous ,Penicillins ,medicine.disease_cause ,Absorption ,Microbiology ,Cell wall ,Cell Wall ,Immunochemistry ,medicine ,Animals ,Immunology and Allergy ,Immunoassay ,Antigens, Bacterial ,biology ,Immune Sera ,Complement Fixation Tests ,Serum Albumin, Bovine ,Hemagglutination Tests ,General Medicine ,Hemagglutination Inhibition Tests ,Peptide Chain Termination, Translational ,Penicillin ,Biochemistry ,Mechanism of action ,Staphylococcus aureus ,biology.protein ,Cattle ,Rabbits ,Antibody ,medicine.symptom ,Peptides ,medicine.drug - Abstract
The specific antigenicity of pentaglycine bridges in cell walls ofS. aureus was investigated. The antistaphylococcal sera (against11 Oeding strains ofS. aureus) were found to contain antibodies of two different specificities against polyglycyl peptides; one type reacted with polyglycyl peptides with a free amino terminus and the other with polyglycyl peptides with a free carboxyl terminus. These antibodies were assayed by passive hemagglutination with tanned sheep red cells sensitized with N-polyglycyl-BSA (containing polyglycyl peptides with a free amino terminus) or with C-polyglycyl-BSA (containing polyglycyl peptides with a free carboxyl terminus). Only the antibodies against N-polyglycyl peptides were absorbed byS. aureus strains and byS. epidermidis. Heterologous bacterial species failed to absorb antibodies of either specificity. Antibodies against polyglycyl peptides were used to confirm the mechanism of action of penicillin onS. aureus cell wall.
- Published
- 1975
55. Vertebral response to laminectomy
- Author
-
Albert I. King, K. Balasubramanian, and Harcharan Singh Ranu
- Subjects
Lamina ,Vertebral endplate ,Materials science ,medicine.medical_treatment ,Rehabilitation ,Laminectomy ,Biomedical Engineering ,Biophysics ,Symmetric model ,Anatomy ,Models, Biological ,Spine ,Finite element method ,Vertebra ,medicine.anatomical_structure ,Tensile Strength ,Pars interarticularis ,medicine ,Humans ,Orthopedics and Sports Medicine ,Stress, Mechanical - Abstract
A finite element model of a complete vertebra was formulated from a previously developed bilaterally symmetric model. This model was verified by comparing its results to those of the previous model and by ensuring that the output was bilaterally symmetric. The applied nodal loads were checked against experimentally measured pressures on the vertebral endplate. Simulations of complete and partial laminectomies on one side of a vertebra were performed. High tensile stresses occurred in the pedicle and in the region of the pars interarticularis as a result of surgery, particularly when the superior half of the lamina was removed.
- Published
- 1979
56. Pressure distribution under an intervertebral disc—An experimental study
- Author
-
Albert I. King, R.A. Denton, and Harcharan Singh Ranu
- Subjects
Materials science ,Distribution (number theory) ,Rehabilitation ,Biomedical Engineering ,Biophysics ,Intervertebral disc ,Mechanics ,Biomechanical Phenomena ,medicine.anatomical_structure ,Pressure ,medicine ,Humans ,Orthopedics and Sports Medicine ,Stress, Mechanical ,Intervertebral Disc - Published
- 1979
57. Regulation of protein synthesis in rabbit reticulocyte lysates: characteristics of inhibition of protein synthesis by a translational inhibitor from heme-deficient lysates and its relationship to the initiation factor which binds Met-tRNAf
- Author
-
Vivian Ernst, Daniel H. Levin, Rajinder Singh Ranu, Jean Delaunay, and Irving M. London
- Subjects
Reticulocytes ,GTP' ,Heme ,Biology ,chemistry.chemical_compound ,Reticulocyte ,Peptide Initiation Factors ,Polysome ,medicine ,Protein biosynthesis ,Initiation factor ,Ternary complex ,Multidisciplinary ,Cell-Free System ,Temperature ,Molecular biology ,Kinetics ,medicine.anatomical_structure ,Mechanism of action ,chemistry ,Biochemistry ,Polyribosomes ,Protein Biosynthesis ,medicine.symptom ,Research Article ,Hemin - Abstract
In heme-deficient reticulocyte lysates a translational inhibitor which regulates protein synthesis is formed or activated. To define the mechanism of action of the translational inhibitor (RI), RI was partially purified. We have utilized the isolated RI to examine its relationship to the translational inhibitor formed in situ in heme-deficiency, some quantitative aspects of inhibition of protein synthesis, and the relationship of RI concentration to the initiation factor (IF-MP) which forms a ternary complex with Met-tRNAf and GTP (IF-MP-Met-tRNAf-GTP). The results demonstrate that the activity of isolated RI is related to the in situ heme-deficiency inhibitor by several criteria: (a) the biphasic kinetics of inhibition manifested by RI in lysates containing optimal levels of hemin are very similar to those observed in heme-deficiency, i.e., an initial period in which several rounds of protein synthesis proceed at the control rate followed by an abrupt decline in the rate of protein synthesis. (b) Both inhibitions are accompanied by the disaggreagation of polyribosomes with a concomitant increase in 80S ribosomes. (c) Both inhibitions are reversed by IF-MP. The isolated RI blocked protein synthesis in lysates at temperatures ranging from 15 degrees to 30 degrees. Although the rate of protein synthesis was a function of the temperature of incubation, the number of rounds of protein synthesis prior to shut-off was essentially the same at various temperatures. When RI was added to lysates, at increasing intervals after the start of incubation, the period of synthesis before shut-off (lag) progressively decreased. The inhibition of protein synthesis by RI was immediately reversed by the addition of IF-MP. The extent of reversal increased with increasing concentrations of IF-MP; at low levels of RI almost complete reversal of inhibition by IF-MP was obtained. However, at high levels of RI which did not appreciably increase the degree of inhibition of protein synthesis, equivalent amounts of IF-MP were less effective in reversing inhibition. These results suggest that the inhibition of protein synthesis by the isolated inhibitor involves the initiation factor IF-MP.
- Published
- 1976
58. Regulation of protein synthesis in rabbit reticulocyte lysates: purification and initial characterization of the cyclic 3':5'-AMP independent protein kinase of the heme-regulated translational inhibitor
- Author
-
Irving M. London and Rajinder Singh Ranu
- Subjects
Reticulocytes ,Multidisciplinary ,GTP' ,Heme ,Chromatography, Ion Exchange ,chemistry.chemical_compound ,Biochemistry ,chemistry ,Ammonium Sulfate ,Peptide Initiation Factors ,Chromatography, Gel ,Protein biosynthesis ,Animals ,Initiation factor ,Phosphorylation ,Rabbits ,Isoelectric Focusing ,Peptide Chain Initiation, Translational ,Protein kinase A ,Protein Kinases ,Ternary complex ,Polyacrylamide gel electrophoresis ,Research Article - Abstract
The heme-regulated translational inhibitor (HRI) has been purified 4800-fold. On electrophoresis in sodium dodecyl sulfate/polyacrylamide gel, the purified HRI showed one major polypeptide band. The purified HRI inhibits protein synthesis in lysates containing optimal levels of hemin with inhibition kinetics which parallel those observed in heme-deficiency. Data are presented which are consistent with an enzymatic function of HRI in the inhibition of protein synthesis. The HRI is an adenosine 3':5'-cyclic monophosphate independent protein kinase which phosphorylates the small subunit (38,000) but not the large subunits (52,000 and 50,000) of the initiation factor which forms a ternary complex with Met-tRNAf and GTP. This evidence supports the hypothesis that inhibition of protein synthesis by HRI involves the phosphorylation of the initiation factor. These findings are discussed in relation to various models for the regulation of protein kinase activity by heme. (see article).
- Published
- 1976
59. Dissociation of skeletal muscle ribosomes from normal and diabetic animals by initiation factor EIF-3
- Author
-
Ira G. Wool, Rajinder Singh Ranu, and Kazuyasu Nakaya
- Subjects
Male ,medicine.medical_specialty ,Protein subunit ,Biophysics ,Biochemistry ,Ribosome ,Dissociation (chemistry) ,Diabetes Mellitus, Experimental ,Mice ,Drug Stability ,Peptide Initiation Factors ,Internal medicine ,Centrifugation, Density Gradient ,medicine ,Animals ,Initiation factor ,Peptide Chain Initiation, Translational ,Molecular Biology ,Binding Sites ,Eukaryotic Large Ribosomal Subunit ,Chemistry ,Muscles ,Skeletal muscle ,Cell Biology ,Rats ,Endocrinology ,medicine.anatomical_structure ,Glutaral ,RNA, Ribosomal ,Polyribosomes ,Spectrophotometry, Ultraviolet ,Eukaryotic Ribosome ,Ribosomes - Abstract
Summary 80S ribosomes from skeletal muscle of diabetic rats were more susceptible than normal to dissociation by the initiation factor EIF-3; the increased sensitivity to dissociation was a property of the 60S subunit. Increased dissociation may be a reflection of the instability of diabetic 80S couples resulting from a change in the structure of the large subunit.
- Published
- 1974
60. Association of a cyclic AMP-dependent protein kinase with a purified translational inhibitor isolated from hemin-deficient rabbit reticulocyte lysates
- Author
-
L M London, Daniel H. Levin, Vivian Ernst, Rajinder Singh Ranu, and Michael A. Fifer
- Subjects
Reticulocytes ,Macromolecular Substances ,Heme ,Biology ,Mitogen-activated protein kinase kinase ,Enzyme activator ,chemistry.chemical_compound ,Reticulocyte ,Cyclic AMP ,Protein biosynthesis ,medicine ,Animals ,Kinase activity ,Protein kinase A ,Cyclic GMP ,Binding Sites ,Multidisciplinary ,Blood Proteins ,Molecular biology ,Enzyme Activation ,Isoenzymes ,Kinetics ,medicine.anatomical_structure ,chemistry ,Biochemistry ,Protein Biosynthesis ,Hemin ,Phosphorylation ,Rabbits ,Protein Kinases ,Research Article ,Protein Binding - Abstract
In the absence of added hemin, protein synthesis in rabbit reticulocyte lysates proceeds at maximal linear rates for several minutes and then ceases abruptly. Inhibition involves the action of a translational inhibitor whose formation is regulated by hemin. Addition of the isolated inhibitor to hemin-supplemented lysates produces an inhibition of protein chain initiation similar to that observed in heme-deficiency. The inhibitor has been purified over 300-fold and contains a protein kinase activity that copurifies with the inhibitory function. With calf thymus histone II as the phosphate receptor, the inhibitor-associated protein kinase requires ATP as the phosphorylating agent. Cycle AMP stimulates kinase activity 5- to 8-fold; the concentration of cycle AMP required for halfmaximal activity is 4 X 10-8 M. Preincubation of the inhibitor in the presence of cyclic AMP significantly reduces cyclic AMP-dependent phosphorylation and inhibitory activity. The corresponding protein kinase activity from hemin-supplemented lysates displays reduced cyclic AMP-dependency and little or no inhibitory activity. These findings suggest that the protein kinase activity associated with the purified translational inhibitor is involved in the mechanism of inhibition of initiation observed in hemedeficient reticulocyte lysates.
- Published
- 1975
61. Characterization of bone materials as ultrasonic transducers
- Author
-
Surendra Singh and Harcharan Singh Ranu
- Subjects
Materials science ,Biophysics ,Mineralogy ,Bioengineering ,Dielectric ,In Vitro Techniques ,Bone and Bones ,Biomaterials ,Apatites ,Animals ,Humans ,Ultrasonics ,Ceramic ,Composite material ,Electrical impedance ,Phase angle ,Temperature ,Resonance ,Piezoelectricity ,Models, Structural ,Transducer ,Mechanics of Materials ,visual_art ,Ceramics and Composites ,visual_art.visual_art_medium ,Ultrasonic sensor ,Collagen - Abstract
Physical, dielectric, piezoelectric and electromechanical parameters have been reported for bone and its two major constituents i.e. collagen and apatite, for their characterization as ultrasonic transducer materials. Collagen and apatite have been extracted from full bone using well known methods. These materials have been used to prepare simple disc-shaped test pieces (dimensions: diameter 10 mm and thickness 1.0 ± 0.01 mm). The variation of various electrical parameters with frequency in the region (1–108 MHz) is examined for these materials. These include impedance, phase angle, relative voltage output, quality factor ‘Q’, dielectric constant and resistivity. The data so obtained are compared with those for ceramic and quartz transducers. The observations on impedance, phase and relative voltage output for bone materials indicate that the first resonance peak falls around 56 MHz followed by second and third harmonics around 112 MHz and 168 MHz respectively. A low ‘Q’ value suggests a fairly wide band transducer, while other parameters compare favourably with ceramic and quartz materials. Bone material has also been used to obtain a transducer in the standard configuration and velocity dispersion in the frequency range 1–108 MHz is examined.
- Published
- 1986
62. Three dimensional surgical simulations of the spine
- Author
-
Harcharan Singh Ranu
- Subjects
Engineering ,Lamina ,business.industry ,medicine.medical_treatment ,Laminectomy ,Biophysics ,Anatomy ,Models, Biological ,Spine ,Vertebra ,medicine.anatomical_structure ,Harrington rod ,Pars interarticularis ,medicine ,Humans ,Stress, Mechanical ,business - Abstract
A finite element model of a complete vertebra has been formulated. It is used to simulate the laminectomy and Harrington rod procedures. The results indicate that high tensile stresses occurred on the affected side in the region of the pars interarticularis after laminectomy. High tensile stresses near the pars interarticularis and at the posterior junction of lamina and pedicles are predicted due to Harrington rod loading.
- Published
- 1982
63. Inhibition of eukaryotic protein chain initiation by vanadate
- Author
-
Rajinder Singh Ranu
- Subjects
Poly U ,eIF2 ,Reticulocytes ,Multidisciplinary ,Vanadium ,Biology ,Kinetics ,Biochemistry ,Polyribosomes ,Eukaryotic initiation factor ,Protein biosynthesis ,Animals ,Initiation factor ,Eukaryotic Small Ribosomal Subunit ,Vanadate ,RNA, Messenger ,Rabbits ,Vanadates ,Peptide Chain Initiation, Translational ,Eukaryotic Ribosome ,Ternary complex ,Research Article - Abstract
Vanadate inhibits protein chain initiation in rabbit reticulocyte lysates. The evidence that supports this conclusion is as follows: (i) the biphasic kinetics of inhibition in which protein synthesis is maintained at the control rate for 1-2 min is followed by an abrupt decline in the rate of synthesis; (ii) inhibition is associated with a marked disaggregation of polyribosomes and a concomitant increase in 80S ribosomes; and (iii) vanadate concentrations that inhibit protein chain initiation do not inhibit polypeptide chain elongation or the aminoacylation of tRNA. In partial reactions of protein chain initiation, vanadate concentrations that inhibit protein synthesis have no detectable effect on the formation of eukaryotic initiation factor eIF-2-promoted ternary complex with Met-tRNAf and GTP and on the assembly of 40S ribosomal subunit-Met-tRNAf complexes. On the addition of mRNA, the 40S ribosomal subunit-Met-tRNAf complexes also are transformed into 80S ribosome-mRNA-Met-tRNAf complexes, termed 80S initiation complexes. In vanadate-treated samples, however, these 80S initiation complexes are defective and unable to proceed beyond this step.
- Published
- 1983
64. Effect of Sulfhydryl Reagents on the Ribosomes of Bacillus subtilis
- Author
-
Rajinder Singh Ranu and Akira Kaji
- Subjects
Sucrose ,Protein subunit ,Iodoacetates ,Genetics and Molecular Biology ,Bacillus subtilis ,Buffers ,Biology ,Benzoates ,Microbiology ,Ribosome ,chemistry.chemical_compound ,Centrifugation, Density Gradient ,Magnesium ,Centrifugation ,Sulfhydryl Compounds ,Molecular Biology ,Mercaptoethanol ,50S ,Carbon Isotopes ,Sulfhydryl Reagents ,Temperature ,Ribosomal RNA ,biology.organism_classification ,Culture Media ,Molecular Weight ,Monomer ,Biochemistry ,chemistry ,Ethylmaleimide ,Chromatography, Gel ,Iodoacetamide ,Chloromercuribenzoates ,Dialysis ,Ribosomes - Abstract
The effect of various sulfhydryl reagents on the ribosomes of Bacillus subtilis was studied. The 70 S ribosomes were completely dissociated into 30 S and 50 S subunits by appropriate concentrations of p -chloromercuribenzoic acid (PCMB) and 5,5′-dithio- bis -(2-nitro-benzoic acid). The N -ethylmaleimide and iodoacetamide failed to dissociate the ribosomes even at relatively high concentrations. The rate of dissociation of ribosomes by PCMB varied with the concentration of ribosomes. A progressive decrease in the rate of dissociation was observed as the concentration of ribosomes in the reaction mixture was increased. The PCMB-induced ribosomal subunits were unable to reassociate into 70 S monomers unless they were dialyzed against buffer containing β-mercaptoethanol. On the average, four molecules of PCMB per 70 S ribosome and two molecules of PCMB per each 30 S and 50 S subunit were bound. The number of PCMB molecules bound per ribosome did not change with increasing concentrations of PCMB, even though higher concentrations of PCMB resulted in dissociation of ribosomes into subunits.
- Published
- 1971
65. A numerical model to simulate micro-fracture of field hockey players due to jumping.
- Author
-
Hasan, M.S., Singh Ranu, H., and Lander, J.E.
- Published
- 1996
- Full Text
- View/download PDF
66. An evaluation of the centre of pressure for successive steps with miniature triaxial load cells
- Author
-
Harcharan Singh Ranu
- Subjects
Adult ,Male ,musculoskeletal diseases ,Engineering ,medicine.medical_specialty ,Centre of pressure ,Biomedical Engineering ,Load cell ,Gait (human) ,Physical medicine and rehabilitation ,Amputees ,Pressure ,medicine ,Humans ,Pronation ,Gait ,Simulation ,Foot ,Stance phase ,business.industry ,Equipment Design ,General Medicine ,Biomechanical Phenomena ,Shoes ,Female ,business ,Poliomyelitis - Abstract
A methodology is described for measuring the centre of pressure for successive steps during stance phase. Three persons were assessed, one normal, one below knee amputee and one having suffered from poliomyelitis. The clinical significance of this parameter of gait as measured by the miniature shoe-borne load cells is highlighted.
- Published
- 1988
67. Discrimination between eukaryotic and prokaryotic, and formylated and non-formylated, initiator tRNAs by eukaryotic initiation factor EIF-3
- Author
-
Ira G. Wool and Rajinder Singh Ranu
- Subjects
Formic Acid Esters ,Saccharomyces cerevisiae ,macromolecular substances ,environment and public health ,Mice ,Structure-Activity Relationship ,Methionine ,Eukaryotic translation ,RNA, Transfer ,Species Specificity ,Peptide Initiation Factors ,Eukaryotic initiation factor ,Escherichia coli ,Animals ,heterocyclic compounds ,Prokaryotic initiation factor ,Genetics ,Multidisciplinary ,Chemistry ,Prokaryotic initiation factor-2 ,Eukaryotic transcription ,Prokaryotic initiation factor-1 ,hemic and immune systems ,EIF4A1 ,Eukaryotic translation initiation factor 4 gamma ,Kinetics ,RNA, Bacterial ,Biochemistry ,Guanosine Triphosphate - Abstract
Discrimination between eukaryotic and prokaryotic, and formylated and non-formylated, initiator tRNAs by eukaryotic initiation factor EIF-3
- Published
- 1975
68. Regulation of protein synthesis in rabbit reticulocyte lysates
- Author
-
Singh Ranu, Rajinder
- Abstract
The heme-regulated protein kinase, which specifically phosphorylates the 38-kDa subunit of initiation factor eiF-2, can utilize adenosine 5′- O-(3-thiotriphosphate) (ATP[γS]) as a substrate. The rate of thiophosphorylation is 5-6-times slower than that observed with ATP. It is of special interest that thiophosphorylated derivatives of eIF-2 are resistant to dephosphorylation catalyzed by eIF-2 phosphoprotein phosphatase. The thiophosphorylated eIF-2 is less effective in promoting protein synthesis in hemin-deficient lysates under physiological conditions. In addition, ATP[γS] could also be utilized by the self-phosphorylation activity intrinsically associated with HRI.
- Published
- 1986
- Full Text
- View/download PDF
69. [44] Purification of the heme-reversible form of the translational inhibitory protein kinase
- Author
-
Hans Trachsel, Rajinder Singh Ranu, and Irving M. London
- Subjects
chemistry.chemical_compound ,chemistry ,Biochemistry ,P70S6 kinase ,Protein biosynthesis ,Substrate specificity ,Protein kinase A ,Inhibitory postsynaptic potential ,Heme ,Peptide Initiation Factors - Published
- 1979
70. The Role of Carbon Fibers in Orthopedic Implants: A Review
- Author
-
John M. Lipka and Harcharan Singh Ranu
- Subjects
Materials science ,Implant material ,Carbon fibers ,medicine.disease_cause ,Patellar tendon ,Tendon ,medicine.anatomical_structure ,Creep ,visual_art ,medicine ,visual_art.visual_art_medium ,Ligament ,Acrylic fiber ,Biomedical engineering - Abstract
Man has recognized carbon as an implant material well tolerated by the body for many years. Indeed, carbon in an impure form (Indian ink) was first used in the making of tatoos. Most recently carbon has been used in a filamentous form of high strength. These carbon fibers are produced in long tows of 40,000 fibers, each with a cross sectional area of about 7μ (Figure 1), by heating acrylic fibers to high temperature. This causes the noncarbon components to be removed while maintaining the molecular structure (scaffold) of the acrylic. Fibers can be chopped into short lengths and used to reinforce polyethylenes (8, 11, 12). These reinforced plastics have-twice the strength and ten times the stiffness of their non-reinforced counterparts, but suffer only one tenth as much creep when subjected to a load (11). Long tows of carbon fibers are used in tendon and ligament replacement (1, 2, 4, 5, 6, 7, 9, 10). This application warrants further investigation because of the apparent ability of the carbon fibers to induce the formation of ligaments and tendons (3, 4, 5, 6, 7).
- Published
- 1986
71. Control of protein synthesis in reticulocyte lysates: effects of 3':5'-cyclic AMP, ATP, and GTP on inhibitions induced by hemedeficiency, double-stranded RNA, and a reticulocyte translationa inhibitor
- Author
-
Vivian Ernst, Irving M. London, Daniel H. Levin, and Rajinder Singh Ranu
- Subjects
Reticulocytes ,Time Factors ,GTP' ,Protein subunit ,Heme ,Guanosine triphosphate ,Biology ,chemistry.chemical_compound ,Adenosine Triphosphate ,Reticulocyte ,RNA, Transfer ,Peptide Initiation Factors ,medicine ,Protein biosynthesis ,Cyclic AMP ,Animals ,Peptide Chain Initiation, Translational ,Multidisciplinary ,Cell-Free System ,Kinase ,Molecular biology ,medicine.anatomical_structure ,chemistry ,Biochemistry ,Protein Biosynthesis ,Phosphorylation ,Nucleic Acid Conformation ,RNA ,Guanosine Triphosphate ,Rabbits ,Adenosine triphosphate ,Protein Kinases ,Ribosomes ,Research Article - Abstract
Protein chain initiation in reticulocyte lysates is inhibited by (a) heme-deficiency, (b) low levels of double-stranded RNA, and (c) a purified translational inhibitor isolated from heme-deficient lysates. Previous studies have shown that the inhibitions produced by heme-deficiency and double-stranded RNA are prevented by 3': 5'-cyclic AMP, and that GTP, but not ATP, prevents the inhibition of heme-deficiency. In view of the recent finding that the inhibitor purified from heme-deficient lysates is associated with a protein kinase which appears to be involved in the mechanism of inhibition, the effects of cyclic AMP, GTP, and ATP on the three modes of inhibition were examines. In all three types of inhibition, cyclic AMP or GTP (a) prevents the onset of inhibition when added at zero time, and (b) restores protein synthesis in inhibited lysates. In contrast to these effects, ATP potentiates each inhibition, and blocks reversal of inhibition by cyclic AMP or GTP. On the basis of these and earlier findings, we propose that (a) these inhibitions involve the phosphorylation by protein kinases of the Met-tRNAf binding factor and/or a related site(s) on the 40S ribosomal subunit; and (b) cyclic AMP, GTP, and ATP exert their effects by their actions on this phosphorylation mechanism.
- Published
- 1976
72. The mechanical and structural response of skin to irradiation
- Author
-
Harcharan Singh Ranu
- Subjects
Low stress ,Skin Physiological Phenomena ,Materials science ,X-Rays ,Rehabilitation ,Biomedical Engineering ,Biophysics ,Elastic Tissue ,Biomechanical Phenomena ,Rats ,Stress (mechanics) ,medicine.anatomical_structure ,Dermis ,Tensile Strength ,Ultimate tensile strength ,medicine ,Animals ,Orthopedics and Sports Medicine ,Female ,Irradiation ,Collagen ,Biomedical engineering ,Skin - Abstract
Fracture of the fibrous networks of normal and irradiated rat dermis have been studied using the SEM. The implications of these observations are discussed with regard to the mechanical behaviour of the tissue in the living animal. It is shown that after radiation the normal fibrous structure of collagen is replaced by a solid mat which is ill adapted to support stress, so that rupture at low stress levels is inevitable.
- Published
- 1979
73. Relation between Metal Corrosion and Electrical Polarization
- Author
-
Harcharan Singh Ranu and Surendra Singh
- Subjects
Materials science ,Metal ions in aqueous solution ,Inorganic chemistry ,chemistry.chemical_element ,Electrochemistry ,Oxygen ,Redox ,Corrosion ,Cathodic protection ,Metal ,chemistry ,visual_art ,visual_art.visual_art_medium ,Polarization (electrochemistry) - Abstract
The increasing use of metals as implant materials in orthopaedic surgery has stimulated a considerable amount of interest among researchers and orthopaedic surgeons enabling the study of corrosion, wear, hypersensitivity, toxcity and carcinogenicity (Furst and Haro, 1960; Mears, 1979; Woodman, 1980). Partly, the corrosion Phenomena is due to the metal implant ionization in living tissue (Ferguson et al, 1960; Lautenschlager et al, 1974). Corrosion is a complex electrochemical deterioration of metals (Clark and Hickman, 1953). Futhermore, corrosion is referred to as a combination of oxidation and reduction of reactions at the implant-tissue interface. The basic reactions in corrosion are the removal of positive metal ions from their positions in the metal crystal lattice. This is called an anodic reaction. Similarly, the freed electrons, as a result of removed cations, also react to oxygen and hydrogren molecules in tissues to form hydroxyle. This is defined as cathodic reactions at the metal-tissue interface (Mears, 1979).
- Published
- 1988
74. Regulation of protein synthesis in rabbit reticulocyte lysates: purification and characterization of heme-reversible translational inhibitor
- Author
-
Hans Trachsel, Irving M. London, and Rajinder Singh Ranu
- Subjects
Reticulocytes ,Protein subunit ,Heme ,Biology ,environment and public health ,chemistry.chemical_compound ,Adenosine Triphosphate ,Reticulocyte ,Peptide Initiation Factors ,medicine ,Protein biosynthesis ,Animals ,Phosphorylation ,Protein kinase A ,Polyacrylamide gel electrophoresis ,Multidisciplinary ,Molecular biology ,Enzyme Activation ,Repressor Proteins ,medicine.anatomical_structure ,Biochemistry ,chemistry ,Ethylmaleimide ,Protein Biosynthesis ,Hemin ,Rabbits ,Adenosine triphosphate ,Protein Kinases ,Research Article ,Transcription Factors - Abstract
To define the mechanism of regulation of the protein kinase that is activated in heme deficiency and that inhibits initiation of protein synthesis, we have isolated and purified the heme-reversible form of the protein kinase from rabbit reticulocytes. The inhibitory activity is found in a single band after polyacrylamide gel electrophoresis under nondenaturing conditions. It migrates as a 95,000-dalton polypeptide in 15% sodium dodecyl sulfate/polyacrylamide gels. This purified inhibitor becomes self-phosphorylated in the presence of ATP; the phosphorylated protein and the inhibitory activity copurify. The inhibitor produces characteristic biphasic kinetics of inhibition in reticulocyte lysates and phosphorylates the 38,000-dalton subunit of eukaryotic initiation factor 2 (eIF-2); the inhibition is reversed by added eIF-2. In contrast to the heme-irreversible inhibitor, this heme-reversible inhibitor is no longer inhibitory after incubation with 20 micron hemin. Incubation with hemin also inhibits self-phosphorylation. Preincubation of the heme-reversible inhibitor in the presence of ATP potentiates the inhibition of protein synthesis in the subsequent incubation, as does treatment with N-ethylmaleimide. Phosphorylation of the heme-reversible inhibitor and inhibition of protein synthesis in the lysate due to phosphorylation of eIF-2 appear to be related. These findings suggest that hemin acts directly on the heme-reversible inhibitor.
- Published
- 1978
75. Regulation of protein synthesis in rabbit reticulocyte lysates: additional initiation factor required for formation of ternary complex (eIF-2.GTP.Met-tRNAf) and demonstration of inhibitory effect of heme-regulated protein kinase
- Author
-
Rajinder Singh Ranu and Irving M. London
- Subjects
Conformational change ,Reticulocytes ,GTP' ,Protein subunit ,macromolecular substances ,Heme ,Biology ,environment and public health ,Methionine ,RNA, Transfer ,Peptide Initiation Factors ,Initiation factor ,Animals ,Eukaryotic Small Ribosomal Subunit ,Magnesium ,Protein kinase A ,Peptide Chain Initiation, Translational ,Ternary complex ,Multidisciplinary ,Blood Proteins ,Eukaryotic Initiation Factor-2 ,Molecular Weight ,enzymes and coenzymes (carbohydrates) ,Kinetics ,Biochemistry ,Protein Biosynthesis ,Biophysics ,Guanosine Triphosphate ,Rabbits ,Biological Sciences: Biochemistry ,Protein Kinases - Abstract
Heme deficiency in rabbit reticulocytes and their lysates leads to the activation of a heme-regulated translational inhibitor (HRI) which causes the cessation of polypeptide initiation. HRI is a protein kinase that specifically phosphorylates the 38,000-dalton subunit of eukaryotic initiation factor 2 (eIF-2). eIF-2 binds Met-tRNA f and GTP in ternary complex. As a continuation of the studies on the molecular basis of the inhibition of the formation of 40S ribosomal subunit-Met-tRNA f complexes by HRI [Ranu, R. S., London, I. M., Das, A., Dasgupta, A., Majumdar, A., Ralston, R., Roy, R. & Gupta, N. K. (1978) Proc. Natl. Acad. Sci. USA 75, 745-749], we describe here the isolation and some characteristics of a factor that is required for the HRI-catalyzed inhibition of eIF-2-promoted ternary complex formation. In the presence of 1 mM Mg 2+ , ternary complex formation by eIF-2 is dependent on the presence of this stabilization factor (SF). Under these conditions, SF increases the rate and the extent of ternary complex formation. This finding suggests that the interaction of SF with eIF-2 causes a conformational change that stabilizes eIF-2 and promotes efficient ternary complex formation by increasing the affinity of eIF-2 for GTP and Met-tRNA f . In the absence of Mg 2+ , however, eIF-2 efficiently forms the ternary complex and SF has little effect on its ternary complex formation capacity—hence, the name eIF-2 stabilization factor (SF). In the presence of SF, HRI markedly inhibits (70-80%) the ternary complex formation capacity of eIF-2. The inhibitory effect requires both HRI and ATP. Under these conditions, HRI phosphorylates only the 38,000-dalton subunit of eIF-2. Both the rate and the extent of the SF-dependent ternary complex formation are inhibited. These findings are consistent with the idea that phosphorylation causes a conformational change in eIF-2 such that its interactions with other initiation factors in the formation and the binding of ternary complex to 40S ribosomal subunits are inhibited.
- Published
- 1979
76. REGULATION OF EUKARYOTIC PROTEIN CHAIN INITIATION BY PROTEIN KINASES AND HEME
- Author
-
Rajinder Singh Ranu, Vivian Ernst, Daniel H. Levin, Irving M. London, and Hans Trachsel
- Subjects
chemistry.chemical_compound ,chemistry ,Biochemistry ,Kinase ,Polysome ,Translational regulation ,Protein biosynthesis ,Initiation factor ,Globin ,Biology ,Heme ,Hemin - Abstract
Publisher Summary This chapter describes the regulation of eukaryotic protein chain initiation by protein kinases and heme. Reticulocyte lysates provide a model system for studies on the regulation of protein synthesis owing to several unique properties. They include an efficient rate of initiation, the extensive synthesis of one major protein species, and the complete dependence of protein synthesis on exogenous hemin. In the presence of optimal concentrations of added hemin, protein synthesis proceeds at linear rates for prolonged periods. During the period of linear synthesis, the polyribosomes are maintained, and initiation factors are utilized catalytically. In efficient lysates, the rate of globin synthesis is comparable to the in vivo rate. In the absence of added hemin, protein synthesis proceeds at the control rate for several minutes, and then declines abruptly yielding characteristic biphasic kinetics of inhibition. The studies have established that the inhibition is mediated through a translational inhibitor which is rapidly activated in the absence of heme.
- Published
- 1978
77. The thermal properties of human cortical bone: an in vitro study
- Author
-
Harcharan Singh Ranu
- Subjects
Adult ,Contraction (grammar) ,Materials science ,In Vitro Techniques ,Biomedical Engineering ,General Medicine ,Anatomy ,Thermal expansion ,Bone and Bones ,medicine.anatomical_structure ,Thermal ,medicine ,In vitro study ,Humans ,Thermodynamics ,Cortical bone ,Biomedical engineering - Abstract
In vitro thermal properties of human cortical bone have been measured using a specially developed technique. The technique enables accurate measurement of the coefficient of thermal expansion and contraction and the average values have been measured to be 27.5 ± 3.9 × 10−6 mm/°C for expansion and 27.2 ± 5.2 × 10−6 mm/°C for contraction.
- Published
- 1987
78. Regulation of protein synthesis in reticulocyte lysates: phosphorylation of methionyl-tRNAf binding factor by protein kinase activity of translational inhibitor isolated from hemedeficient lysates
- Author
-
Daniel H. Levin, Irving M. London, Vivian Ernst, and Rajinder Singh Ranu
- Subjects
Ribosomal Proteins ,endocrine system ,Multidisciplinary ,Reticulocytes ,Protein subunit ,Biology ,Globins ,Biochemistry ,Ribosomal protein ,TAF4 ,Peptide Initiation Factors ,Cyclic AMP ,Phosphorylation ,Initiation factor ,Eukaryotic Small Ribosomal Subunit ,Kinase activity ,Protein kinase A ,Peptide Chain Initiation, Translational ,Protein Kinases ,Research Article - Abstract
A previous study demonstrated that the translational inhibitor from lysates of heme-deficient rabbit reticulocytes is associated with a protein kinase activity. Chromatography of this inhibitor preparation on phosphocellulose yields two distinct protein kinase activities, PC1 and PC2. PC1, which consitutes about 90% of the activity in the unresolved preparation, does not inhibit protein synthesis in lysates, but actively phosporylates calf thymus histone II in a 3':5'-cyclic AMP-denpendent reaction. PC2 contains the translational inhibitor, phosphorylates histone poorly, and is not cyclic AMP-dependent. While [gamma-32P]ATP as the phosphate donor, the two kinase fractions were analyzed with the putative substrates, salt-washed 40S ribosomal subunits, and the initiation factor that mediates the binding of Met-tRNAf to the 40S subunit. PC1 is inactive with the initiation factor, but phosphorylates 40S subunits at a single major site that migrates as a 31,000-dalton band in sodium dodecyl sulfate-acrylamide gels; phosphorylation requires cyclic AMP. Similar phosphorylation of the reticulocyte 40S site (31,000 daltons) can be demonstrated with other cyclic AMP-dependent kinases from reticulocytes, rat liver, and bovine heart muscle. PC2 phosphorylates the small subunit (38,000 daltons) but not the large subunit(s) of the initiation factor; the reaction does not require cyclic AMP. PC2 does not phosphorylate 40S subunits. In the presence of 40S subunits, the initiation factor appears to be rapidly bound in a manner that effectively blocks phosphorylation of the initiation factor by PC2; under the same conditions phosphorylation of the 40S subunit by PC1 is not affected. The initiation factor has been shown to reverse the inhibitions of protein chain initiation induced in lysates by heme deficiency, double-stranded RNA, oxidized glutathione, or the purified translational inhibitor. The observation that the Met-tRNAf binding factor is phosphorylated by PC2 supports the hypothesis that this initiation factor is a target for the action of the translational inhibitor activated in heme deficiency.
- Published
- 1976
79. Engineering aspects of rehabilitation for the handicapped
- Author
-
Harcharan Singh Ranu
- Subjects
Engineering ,Automobile Driving ,Injury control ,medicine.medical_treatment ,Population ,Biomedical Engineering ,Poison control ,Transport engineering ,Disability Evaluation ,Microcomputers ,Human–computer interaction ,medicine ,Humans ,Disabled Persons ,education ,Recreation ,education.field_of_study ,Rehabilitation ,business.industry ,Human factors and ergonomics ,Rehabilitation, Vocational ,General Medicine ,Work (electrical) ,Wheelchairs ,business ,Independent living ,Software - Abstract
An engineering approach to functional assessment has been utilized to assist the moderate-to-severely physically handicapped. These computer-aided assessments are directed at work, keyboard operation and driving. In order to improve the quality of life for this population, independent living systems, recreational and mobility aids, and automated retrieval systems for information on assistive devices have been developed. This paper discusses their implementation and applications.
- Published
- 1986
80. VISCOELASTIC BEHAVIOUR OF THE HUMAN SPINAL DISC AND THE VERTEBRA
- Author
-
Harcharan Singh Ranu
- Subjects
musculoskeletal diseases ,Materials science ,Annulus (oil well) ,Strain (injury) ,Anatomy ,musculoskeletal system ,medicine.disease ,Pressure sensor ,Viscoelasticity ,Vertebra ,medicine.anatomical_structure ,Disc degeneration ,medicine ,Stress relaxation ,Nucleus ,Biomedical engineering - Abstract
Pressures in the nucleus pulposus and under the annulus fibrosus have been measured, using the specially developed miniature pressure transducers, when the vertebral segment was subjected to physiological loading. Strain data and stress-relaxation were also measured. Results show that pressures are linear with loading. Pressure variations within the nucleus are due to disc degeneration.
- Published
- 1982
81. Characterization of a rat liver factor that inhibits initiation of protein synthesis in rabbit reticulocyte lysates
- Author
-
Rajinder Singh Ranu, Vivian Ernst, Jean Delaunay, Irving M. London, and Daniel H. Levin
- Subjects
Male ,Reticulocytes ,GTP' ,Protein subunit ,Biology ,Guanosine triphosphate ,chemistry.chemical_compound ,Adenosine Triphosphate ,Reticulocyte ,Peptide Initiation Factors ,medicine ,Protein biosynthesis ,Cyclic AMP ,Animals ,Peptide Chain Initiation, Translational ,Multidisciplinary ,Kinase ,Proteins ,Molecular biology ,Rats ,Enzyme Activation ,Perfusion ,Kinetics ,medicine.anatomical_structure ,Biochemistry ,chemistry ,Liver ,Protein Biosynthesis ,Phosphorylation ,Guanosine Triphosphate ,Rabbits ,Biological Sciences: Biochemistry ,Adenosine triphosphate ,Protein Kinases - Abstract
Protein synthesis in rabbit reticulocytes and their lysates is regulated by heme. In heme-deficient reticulocyte lysates, protein synthesis proceeds at the initial rate for several minutes and then declines abruptly. Inhibition of protein synthesis is due to the activation of a heme-regulated translational inhibitor (HRI) which blocks the initiation of protein synthesis. Addition of the isolated HRI to hemin-supplemented lysates causes inhibition of initiation similar to that observed in heme-deficiency. HRI has been shown to be a protein kinase that specifically phosphorylates the Met-tRNA f binding factor (eIF-2). We have isolated an inhibitor (LI) of protein chain initiation from rat liver which displays properties similar to those of HRI: ( i ) the chromatographic behavior of LI on DEAE-Sephadex, DEAE-cellulose, and phosphocellulose is similar to that of HRI; ( ii ) both LI and HRI inhibit protein chain initiation in rabbit reticulocyte lysates with the same kinetics of inhibition—i.e., an initial period of synthesis for several minutes at the control rate followed by an abrupt decline in the rate of initiation; ( iii ) both inhibitions are prevented or reversed by eIF-2; ( iv ) GTP (2 mM) prevents, and ATP (2 mM) potentiates, the inhibition of protein synthesis induced by either inhibitor; ( v ) LI is associated with a protein kinase that also phosphorylates the 38,000-dalton subunit of elF-2. These findings indicate that a mechanism for the regulation of protein synthesis similar to that found in rabbit reticulocytes may be present in rat liver.
- Published
- 1977
82. Effects of Ionizing Radiation on the Structure and Physical Properties of the Skin
- Author
-
Harcharan Singh Ranu
- Subjects
Single exposure ,Materials science ,integumentary system ,Skin thickness ,Viscoelasticity ,Biomedical engineering ,Ionizing radiation - Abstract
Skin is a viscoelastic material, whose properties modify with age, some diseases and certain therapeutic treatments.
- Published
- 1984
83. Points: Awareness of radiation
- Author
-
Harcharan Singh Ranu
- Subjects
business.industry ,Correspondence ,General Engineering ,General Earth and Planetary Sciences ,Medicine ,General Medicine ,business ,Data science ,General Environmental Science - Published
- 1986
84. Dissociation of eukaryotic ribosomes by purified initiation factor EIF-3
- Author
-
Rajinder Singh Ranu, Ira G. Wool, and Kazuyasu Nakaya
- Subjects
Time Factors ,Liver cytology ,Biophysics ,Peptide ,macromolecular substances ,environment and public health ,Biochemistry ,Ribosome ,Dissociation (chemistry) ,Chromatography, DEAE-Cellulose ,Mice ,Peptide Initiation Factors ,Eukaryotic initiation factor ,Centrifugation, Density Gradient ,Escherichia coli ,Initiation factor ,Animals ,Ascitic Fluid ,heterocyclic compounds ,Magnesium ,Molecular Biology ,chemistry.chemical_classification ,Messenger RNA ,Chromatography ,Cell Biology ,musculoskeletal system ,Rats ,Molecular Weight ,Organoids ,Kinetics ,chemistry ,Liver ,Glutaral ,health occupations ,Potassium ,Puromycin ,Spectrophotometry, Ultraviolet ,Hydroxyapatites ,Eukaryotic Ribosome ,Ribosomes - Abstract
Purified eukaryotic initiation factor, EIF-3, prepared from ascites cells dissociated rat liver 80S ribosomes into subunits. Ribosomes bearing endogenous mRNA and nascent peptide were not dissociated by EIF-3. When 80S ribosomes reconstituted from subunits were used as substrate the reaction had the following characteristics: Dissociation was rapid--the reaction being completed within 2 min at 30°. The extent of dissociation was directly proportional to the amount of EIF-3; with 21 μg of EIF-3 about 70% (or 10.5 μg) of the 80S monomers were dissociated. The dissociation of 80S monomers by EIF-3 decreased with increasing concentrations of magnesium. The reaction was not catalytic: 28 moles of EIF-3 were required to dissociate 1 mole of 80S ribosomes. The characteristic of the dissociation reaction promoted by EIF-3 and by E. coli initiation factor IF-3 are remarkably similar. The dissociation reaction provides a practical assay for EIF-3 independent of complimentation of other initiating factors.
- Published
- 1973
85. Evidence for Specific Inhibition of Translocation of Aminoacyl-Transfer Ribonucleic Acid by the Pretreatment of Ribosomes of Bacillus subtilis with p-Chloromercuribenzoate
- Author
-
Rajinder Singh Ranu and Akira Kaji
- Subjects
Genetics, Microbial ,Peptide Biosynthesis ,Poly U ,Phenylalanine ,Peptide Chain Elongation, Translational ,Chromosomal translocation ,Genetics and Molecular Biology ,Bacillus subtilis ,Microbiology ,P chloromercuribenzoate ,Ribosome ,RNA, Transfer ,Centrifugation, Density Gradient ,Escherichia coli ,Magnesium ,Molecular Biology ,Inhibitory effect ,Mercaptoethanol ,Chromosome Aberrations ,Carbon Isotopes ,Binding Sites ,biology ,Cell-Free System ,RNA ,Chromosomes, Bacterial ,biology.organism_classification ,Molecular biology ,Biochemistry ,Transfer RNA ,Chromatography, Gel ,Puromycin ,Chloromercuribenzoates ,Ribosomes - Abstract
The biological activities of Bacillus subtilis ribosomes pretreated with 0.5, 1, or 2 m m p -chloromercuribenzoate (PCMB) were examined. The ribosomes treated with 1 or 2 m m PCMB lost their capacity to synthesize polyphenylalanine as well as the capacity to bind phenylalanyl-transfer ribonucleic acid. On the other hand, approximately 70% of the polyphenylalanine synthesis capacity was lost with ribosomes pretreated with 0.5 m m PCMB. This inhibition was found to be due to a specific inhibition of the translocation step. The effect of 0.5 m m PCMB was reversed by 20 m m Mg 2+ without the loss of PCMB bound to ribosomes, while β-mercaptoethanol partially reversed the inhibitory effect with concomitant loss of bound PCMB.
- Published
- 1972
86. Serological Activity of Protein A of Staphylococcus aureus: the Precipitinogen as an Antigen for Determining Antibodies by the Passive Hemagglutination Test
- Author
-
Rajinder Singh Ranu and I. Live
- Subjects
Immunodiffusion ,Erythrocytes ,Swine ,Staphylococcus ,Infection and Immunity ,Biology ,medicine.disease_cause ,Microbiology ,Antibodies ,Serology ,Dogs ,Antigen ,Bacterial Proteins ,medicine ,Animals ,Humans ,Horses ,Antigens ,Molecular Biology ,Sheep ,Goats ,Immune Sera ,Hemagglutination Tests ,Hemagglutinin ,Virology ,Staphylococcus aureus ,biology.protein ,Cattle ,Rabbits ,Antibody ,Protein A - Abstract
Tanned sheep erythrocytes have been considered incapable of sensitization with the precipitinogen of protein A of Staphylococcus aureus , so that the activity of this antigen in serological reactions has so far been studied by means of the agar diffusion test (ADT) only. The precipitinogen of the protein A in this study was found to become attached to the tanned erythrocytes and to sensitize them for the passive hemagglutination test (PHT). It was determined that, in contrast to nonspecific reactivity between normal human serum and the precipitinogen in the ADT, the reaction in the PHT was of specific nature. Of seven species studied, all normal human, dog, and hog sera tested were positive in the PHT. However, the hemagglutinin titers of the sera of the two animal species by far exceeded those of the human sera. The data emphasized the usefulness of the highly sensitive PHT for assaying antibodies to protein A.
- Published
- 1968
87. Basic Biomechanics of the Musculoskeletal System
- Author
-
Harcharan Singh Ranu
- Subjects
medicine.medical_specialty ,Physical medicine and rehabilitation ,business.industry ,Rehabilitation ,Biomechanics ,Medicine ,Musculoskeletal physiology ,Physical Therapy, Sports Therapy and Rehabilitation ,business - Published
- 1989
88. India's bait
- Author
-
Sushil K. Jain, Harcharan Singh Ranu, and Pankajam K. Nair
- Subjects
Multidisciplinary - Published
- 1984
89. Reply from prof. Ranu
- Author
-
Harcharan Singh Ranu
- Subjects
Biophysics - Published
- 1986
90. In vitro mechanical characteristics of human skin with particular reference to radiotherapy effects
- Author
-
Harcharan Singh Ranu
- Subjects
Radiation therapy ,Pathology ,medicine.medical_specialty ,business.industry ,medicine.medical_treatment ,Rehabilitation ,Biomedical Engineering ,Biophysics ,medicine ,Orthopedics and Sports Medicine ,Human skin ,business ,In vitro - Published
- 1980
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.