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1.
Eur Rev Med Pharmacol Sci ; 26(9): 3138-3150, 2022 05.
Article in English | MEDLINE | ID: mdl-35587064

ABSTRACT

OBJECTIVE: This study investigated the impact of McKenzie exercises against deep neck flexor (DNF) combined with scapulothoracic exercises on improving pain severity, cervical mobility, and functional disability. PATIENTS AND METHODS: Fifty-five subjects suffering from chronic neck pain participated in this randomized controlled study. They were randomly assigned to three groups; the DNF group, which was treated by traditional physical therapy (i.e., physical therapy agents, stretching, and isometric exercises), combined with DNF, and scapulothoracic exercises; the McKenzie group, treated by traditional physical therapy, combined with McKenzie exercises; and finally, a control group, treated by traditional physical therapy. Before and after 6 weeks of treatment, they were assessed for neck pain severity, cervical range of motion (ROM), and functional disability using a visual analog scale (VAS), a gravity-reference goniometer, and the Copenhagen neck functional disability scale (CNFDS), respectively. RESULTS: Compared to baseline, all groups showed a significant decrease in neck pain severity and disability (p <0.05), and there was a significant increase in neck flexion/extension, lateral right flexion/left flexion, and right/left rotation ROMs (p<0.05). The improvement of the McKenzie group was significantly higher than the DNF group, and control group. Moreover, the improvement of the DNF group was significantly higher than the control group (p<0.05). CONCLUSIONS: The McKenzie exercises were better than DNF combined with scapulothoracic exercises to treat neck pain, functional disability, and mobility.


Subject(s)
Chronic Pain , Neck Pain , Chronic Pain/therapy , Exercise , Exercise Therapy/methods , Humans , Neck , Neck Pain/rehabilitation , Randomized Controlled Trials as Topic , Range of Motion, Articular
2.
Int J Pharm ; 535(1-2): 1-17, 2018 Jan 15.
Article in English | MEDLINE | ID: mdl-29111097

ABSTRACT

During the past decades, lipid nanocarriers are gaining momentum with their multiple advantages for the management of skin diseases. Lipid nanocarriers enable to target the therapeutic payload to deep skin layers or even to reach the blood circulation making them a promising cutting-edge technology. Lipid nanocarriers refer to a large panel of drug delivery systems. Lipid vesicles are the most conventional, known to be able to carry lipophilic and hydrophilic active agents. A variety of lipid vesicles with high flexibility and deformability could be obtained by adjusting their composition; namely ethosomes, transfersomes and penetration enhancer lipid vesicles which achieve the best results in term of skin permeation. Others are designed with the objective to perform higher encapsulation rate and higher stability, such as solid lipid nanoparticles and nanostructured lipid nanocarriers. In this review, we attempted to give an overview of lipid based nanocarriers developed with the aim to enhance dermal and transdermal drug delivery. A special focus is put on the nanocarrier composition, behavior and interaction mechanisms with the skin. Recent applications of lipid-based nanocarriers for the management of skin diseases and other illnesses are highlighted as well.


Subject(s)
Drug Carriers/chemistry , Lipids/chemistry , Nanoparticles/chemistry , Pharmaceutical Preparations/administration & dosage , Skin/metabolism , Administration, Cutaneous , Animals , Drug Delivery Systems , Humans , Hydrophobic and Hydrophilic Interactions , Pharmaceutical Preparations/chemistry , Skin/ultrastructure , Skin Absorption/drug effects , Skin Diseases/drug therapy , Skin Diseases/metabolism
3.
J Biomed Nanotechnol ; 12(1): 217-30, 2016 Jan.
Article in English | MEDLINE | ID: mdl-27301185

ABSTRACT

S-nitrosoglutathione (GSNO) is a potential therapeutic for infectious disease treatment because of its pivotal role in macrophage-mediated inflammatory responses and host defense in addition to direct antibacterial activities. In this study, sterically stabilized cationic liposomes (SSCL) and sterically stabilized anionic liposomes (SSAL) were developed as nanocarriers for macrophage targeting. Elaborated liposomes were characterized in terms of size, zeta potential, morphology, encapsulation efficiency, in vitro drug release behavior and cytotoxicity. Their versatility in targeting monocytes/macrophages was determined by confocal laser scanning microscopy and transmission electron microscopy. Flow cytometry revealed that cellular uptake of both SSCL and SSAL was governed by several endocytic clathrin- and caveolae-dependent mechanisms. Quantitative assessments of intracellular nitric oxide demonstrated highly efficient uptake of GSNO-loaded SSCL that was twenty-fold higher than that of GSNO-free molecules. GSNO-loaded SSCL displayed strong bacteriostatic effects on Staphylococcus aureus and Pseudomonas aeruginosa, which can be involved in pulmonary infectious diseases. These results reveal the potential of liposomal GSNO as an anti-infective therapeutic due to its macrophage targeting capacity and direct antibacterial effects.


Subject(s)
Bacterial Physiological Phenomena/drug effects , Glutathione/analogs & derivatives , Liposomes/chemistry , Macrophages/chemistry , Nanocapsules/chemistry , Nitro Compounds/administration & dosage , Nitro Compounds/chemistry , Anti-Bacterial Agents/administration & dosage , Anti-Bacterial Agents/chemistry , Cell Survival/drug effects , Cells, Cultured , Delayed-Action Preparations/administration & dosage , Delayed-Action Preparations/chemistry , Diffusion , Glutathione/administration & dosage , Glutathione/chemistry , Humans , Nanocapsules/ultrastructure , Particle Size , Subcellular Fractions/chemistry
4.
J Mater Chem B ; 4(48): 7929-7935, 2016 Dec 28.
Article in English | MEDLINE | ID: mdl-32263783

ABSTRACT

Lactobacillus rhamnosus GG (LGG) was encapsulated in core-shell alginate-silica microcapsules by coating the electrosprayed ionogel with a silica shell via hydrolysis/condensation of alkoxysilane precursors. The viability of encapsulated LGG highly depends on the mineralisation conditions (in aqueous or organic phases), identified as a critical step. More importantly, due to the unswelling of silica and to its mesoporosity that allows nutriment-metabolite diffusion, it was possible to avoid cell leakage and additionally insure bacterial growth inside the microcapsules. The results of this work gave a proof-of-concept for controlled bacterial proliferation in microcompartments, which have straightforward applications in oral delivery of probiotics.

5.
J Biol Regul Homeost Agents ; 28(2): 213-24, 2014.
Article in English | MEDLINE | ID: mdl-25001654

ABSTRACT

There is now a wealth of experimental evidence indicating that the deficit in endogenous estrogen facilitates the onset of inflammation that can be antagonized by estrogen replacement therapy. This work investigated the role of estrogen in the control of intestinal inflammation in a panel of colitis models, focusing on the morphological changes, the activity of mast cells, the expression of cytokines (IL-1beta, IL-6, and TNF-alpha), fibronectin and reactive oxygen species. Two hundred adult male rats were divided into 4 groups: colitis was induced in Group I and Group II but only the latter was treated with estrogen; Group III received estrogen only, and Group IV saline. Colitis was induced in 4 models using: iodoacetamide; iodoacetamide + enteropathogenic E. coli; 2, 4, 6-Trinitrobenzene sulfonic acid; and dextran sulfate sodium salt. Macroscopic and microscopic evaluations of abdominal structures as well as molecular analysis were made on days 7, 14, 28 and 56. There was a significant improvement in the health condition of the estrogen-treated rats: the inflammation scores were reduced by at least 10-15%, the number of mast cells in the colon decreased by 30%, fibronectin expression was only 50% and reactive oxygen species decreased by 30%. In addition, there was a significant decrease in TNF-alpha, IL-6 and IL-1beta expression by about 25%. In conclusion, there was an improvement in the inflammatory status in all estrogen-treated groups through the duration of the experiment at all-time points. In addition, there was less tissue necrosis as depicted by less fibronectin and a marked antioxidant effect.


Subject(s)
Colitis/drug therapy , Colitis/metabolism , Estrogens/pharmacology , Animals , Colitis/chemically induced , Colitis/pathology , Colon/metabolism , Colon/pathology , Cytokines/biosynthesis , Disease Models, Animal , Fibronectins/biosynthesis , Inflammation/chemically induced , Inflammation/metabolism , Inflammation/pathology , Male , Mast Cells/metabolism , Mast Cells/pathology , Rats , Rats, Sprague-Dawley
6.
Exp Parasitol ; 143: 30-8, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24852215

ABSTRACT

Toxoplasmosis is a worldwide infection caused by obligate intracellular protozoan parasite which is Toxoplasma gondii. Chitosan and silver nanoparticles were synthesized to be evaluated singly or combined for their anti-toxoplasma effects as prophylaxis and as treatment in the experimental animals. Results were assessed through studying the parasite density and the ultrastructural parasite changes, and estimation of serum gamma interferon. Weight of tissue silver was assessed in different organs. Results showed that silver nanoparticles used singly or combined with chitosan have promising anti-toxoplasma potentials. The animals that received these compounds showed statistically significant decrease in the mean number of the parasite count in the liver and the spleen, when compared to the corresponding control group. Light microscopic examination of the peritoneal exudates of animals receiving these compounds showed stoppage of movement and deformity in shape of the tachyzoites, whereas, by scanning electron microscope, the organisms were mutilated. Moreover, gamma interferon was increased in the serum of animals receiving these compounds. All values of silver detected in different tissues were within the safe range. Thus, these nanoparticles proved their effectiveness against the experimental Toxoplasma infection.


Subject(s)
Chitosan/pharmacology , Coccidiostats/pharmacology , Metal Nanoparticles , Silver/pharmacology , Toxoplasma/drug effects , Toxoplasmosis/drug therapy , Animals , Chitosan/administration & dosage , Chitosan/therapeutic use , Coccidiostats/administration & dosage , Coccidiostats/therapeutic use , Drug Synergism , Drug Therapy, Combination , Interferon-gamma/blood , Liver/parasitology , Male , Metal Nanoparticles/therapeutic use , Metal Nanoparticles/ultrastructure , Mice , Microscopy, Electron, Scanning , Microscopy, Electron, Transmission , Pyrimethamine/pharmacology , Pyrimethamine/therapeutic use , Silver/administration & dosage , Silver/therapeutic use , Spleen/parasitology , Toxoplasma/growth & development , Toxoplasma/ultrastructure , Toxoplasmosis/parasitology
7.
J Biol Regul Homeost Agents ; 27(2): 351-63, 2013.
Article in English | MEDLINE | ID: mdl-23830386

ABSTRACT

Integrins can modulate the infiltration of inflammatory cells and the secretion of various inflammatory mediators, essential players in the pathogenesis of colitis. This study explores the role of beta2 and beta3 integrin signaling and their possible role in experimental colitis. A total of 160 adult male Sprague-Dawly rats were divided into 4 equal groups: methylcellulose, bacteria, iodoacetamide and iodoacetamide plus bacteria. Clinical symptoms and signs of colitis were checked daily and colonic tissues were biopsied on days 3, 14, 28, and 56 post induction. Histological studies along with histochemical analysis and polymerase chain reaction of beta2, beta3 and alphavbeta3 were performed according to standard procedures. The symptoms and signs were consistent with previously reported data on active colitis. The highest expression of beta3 integrin was in the combined treatment mostly on platelets, endothelial and inflammatory cells. In the same group, the expression of alphavbeta3 integrin complex reached the highest score after 56 days in all colonic layers. Beta2 integrin expression showed a 3-4-fold increase in the combined treatment group at all time points and kept increasing till day 56. It was mostly expressed in the mucosa and submucosa. In addition, the expression of both αvβ3 and αiiβ3 integrins was also elevated 2- to 10-fold, respectively, in the same colitis groups throughout the duration of the experiment. In conclusion, the combined treatment of IA and Enteropathogenic E. coli led to a significant upregulation of all the tested integrins throughout the experimental duration. Such upregulation of integrins could have contributed to the increase and chronicity of inflammation.


Subject(s)
CD18 Antigens/physiology , Colitis/metabolism , Enteropathogenic Escherichia coli , Integrin beta3/physiology , Animals , CD18 Antigens/analysis , CD18 Antigens/genetics , Colitis/etiology , Escherichia coli Infections/complications , Immunohistochemistry , Integrin beta3/analysis , Integrin beta3/genetics , Iodoacetamide/toxicity , Male , Rats , Rats, Sprague-Dawley , Up-Regulation
8.
Public Health ; 127(5): 461-6, 2013 May.
Article in English | MEDLINE | ID: mdl-23608025

ABSTRACT

OBJECTIVES: In response to accumulating evidence on the detrimental health effects of second-hand smoke, governments throughout the world have adopted laws prohibiting indoor smoking in public places. Lebanon has recently enacted a law prohibiting indoor smoking in all of its forms, rendered effective as of 3 September 2012. This study examined the knowledge and attitudes of owners/managers of restaurants, cafes, pubs and nightclubs in Beirut towards the ban, three months before it came into effect. STUDY DESIGN: Self-administered cross-sectional survey. METHODS: Data were derived from a self-administered cross-sectional survey conducted in June 2012. In total, 262 hospitality venues (restaurants, cafes, pubs and nightclubs) were sampled at random to participate. RESULTS: The response rate was 74% (194/262). Overall, 84% of owners/managers reported that they were aware of the ban, yet the average knowledge score was only 3.43/10. A general positive attitude was noted towards customer satisfaction (44.8%), law enforcement (61.1%) and employee protection from second-hand smoke (74%), while 55% of owners/managers were concerned that their revenues would decrease. However, 83.3% expressed their willingness to implement the law. CONCLUSIONS: This quantitative study is the first to examine the knowledge and attitudes of owners/managers of hospitality venues regarding the indoor smoking ban in Lebanon. Civil society and government bodies should use the findings to develop a campaign to address the knowledge and attitudes of owners/managers of hospitality venues to ensure successful enforcement.


Subject(s)
Air Pollution, Indoor/legislation & jurisprudence , Health Knowledge, Attitudes, Practice , Public Policy/legislation & jurisprudence , Restaurants/legislation & jurisprudence , Smoking/legislation & jurisprudence , Tobacco Smoke Pollution/legislation & jurisprudence , Adult , Air Pollution, Indoor/prevention & control , Cross-Sectional Studies , Female , Humans , Lebanon , Male , Smoking Prevention , Tobacco Smoke Pollution/prevention & control
9.
Int J Pharm ; 436(1-2): 833-9, 2012 Oct 15.
Article in English | MEDLINE | ID: mdl-22846409

ABSTRACT

In this work a new formulation of inhalable rifampicin-loaded PLGA microspheres (RIF-MS) is proposed for the management of tuberculosis treatment. For their formulation, the non-biodegradable polyvinyl alcohol surfactant was replaced with a biodegradable and biocompatible sucrose ester, sucrose palmitate. The effects of critical process and formulation parameters have been investigated and the obtained microspheres were characterized in terms of size, morphology, encapsulation efficiencies and RIF release profile. The optimized RIF-MS showed high drug loading (34.2%, w/w), an aerodynamic diameter compliant with deep lung delivery and an in vitro gradual and almost complete drug release over a week. The drug release data fitted well to the Higuchi models suggesting a drug release governed by Fickian diffusion. The RIF-MS uptake qualitative and quantitative studies on ex vivo rat alveolar macrophages (AM) revealed an efficient internalization of RIF-MS and their location in the perinuclear area. RIF intracellular levels were 7-fold higher in AM incubated with RIF-MS than with an equivalent amount of free RIF.


Subject(s)
Antibiotics, Antitubercular/chemistry , Drug Carriers/chemistry , Lactic Acid/chemistry , Polyglycolic Acid/chemistry , Rifampin/chemistry , Sucrose/analogs & derivatives , Animals , Antibiotics, Antitubercular/administration & dosage , Cell Survival/drug effects , Cells, Cultured , Chemistry, Pharmaceutical , Delayed-Action Preparations/administration & dosage , Delayed-Action Preparations/chemistry , Drug Carriers/administration & dosage , Lactic Acid/administration & dosage , Macrophages, Alveolar/drug effects , Male , Microspheres , Polyglycolic Acid/administration & dosage , Polylactic Acid-Polyglycolic Acid Copolymer , Polyvinyl Alcohol , Rats , Rats, Sprague-Dawley , Rifampin/administration & dosage , Sucrose/administration & dosage , Sucrose/chemistry
10.
Int J Pharm ; 426(1-2): 256-262, 2012 Apr 15.
Article in English | MEDLINE | ID: mdl-22310458

ABSTRACT

A commercial suspension of nanoparticles (Eudragit RS 30D) was used to manufacture a gel for topical application. Gels were prepared by mixing a polycationic polymer (Eudragit(®) RS 30D) and a low molecular weight heparin (LMWH), an antithrombotic agent. Gels formed spontaneously at a ratio of 1:1 as a result of electrostatic interactions between the polyanionic drug and the polycationic polymer. Different types of heparin were used: Bemiparin, Enoxaparin (Lovenox), Nadroparin (Fraxiparin) and Tinzaparin (Innohep). Several LMWH concentrations were tested. Rheological measurements were performed to investigate the gel behavior. Gel formation was confirmed by dynamic rheological measurements as the elastic modulus (G') was higher than the viscous one (G″). The amount of heparin incorporated into the gel matrix was determined. A maximum of incorporation (100%) was reached using a heparin solution of 600 IU/mL. The release kinetics of LMWH from the gel were also studied. Regardless of the LMWH used in the formulation, a biphasic release profile was observed. Accordingly, a burst effect was observed. Afterwards, the release rate became steady. The penetration of the LMWH through the dermal barrier was also investigated.


Subject(s)
Acrylic Resins/chemistry , Drug Carriers , Fibrinolytic Agents/administration & dosage , Heparin, Low-Molecular-Weight/administration & dosage , Nanoparticles , Administration, Cutaneous , Animals , Chemistry, Pharmaceutical , Drug Compounding , Elastic Modulus , Enoxaparin/administration & dosage , Fibrinolytic Agents/blood , Fibrinolytic Agents/chemistry , Fibrinolytic Agents/pharmacokinetics , Gels , Heparin, Low-Molecular-Weight/blood , Heparin, Low-Molecular-Weight/chemistry , Heparin, Low-Molecular-Weight/pharmacokinetics , Male , Nadroparin/administration & dosage , Nanotechnology , Permeability , Rabbits , Rats , Rats, Wistar , Rheology , Skin/metabolism , Skin Absorption , Solubility , Technology, Pharmaceutical/methods , Tinzaparin , Viscosity
11.
Transplant Proc ; 42(6): 2109-11, 2010.
Article in English | MEDLINE | ID: mdl-20692420

ABSTRACT

BACKGROUND: Islet allograft rejection in sensitized recipients is difficult to control by costimulation blockade using anti-CD154 and cytotoxic T-lymphocyte antigen-4 immunoglobulin (CTLA4Ig). Because leukocyte function antigen (LFA) 1 is highly expressed on memory T cells, adding an LFA-1 blockade may inhibit memory T-cell activities. We examined the effects on islet allograft survival of triple costimulation blockade in presensitized recipient mice. METHODS: C57BL/6 mice were sensitized by transplantation under the kidney capsule or intraperitoneal injection of Balb/c islets. Four weeks after transplantation, sensitization was confirmed by flow-cytometric detection of alloreactive antibodies. Diabetes was induced by a single intravenous injection of streptozotocin. Recipients were transplanted with 200 Balb/c islets under the right kidney capsule. Graft function was assessed by daily blood glucose and body weight records. Transplanted animals were divided into 3 treatment groups: group 1, control antibody; group 2, anti-CD154 and CTLA-4 Ig double therapy; group 3, anti-CD154, CTLA4Ig, and anti-LFA-1 triple therapy. Injections were administered every second day from day -2 to day 8. RESULTS: Naïve mice rejected islet allografts between days 7 and 29 (mean 16 +/- 6 d; n = 5), sensitized mice in group 1 between days 0 and 14 (mean 7 +/- 5 d; n = 8), in group 2 between days 4 and 16 (mean 8 +/- 4 d; n = 7), and in group 3 between days 4 and 26 (mean 11 +/- 7 d; n = 10). CONCLUSION: Triple costimulation blockade with anti-CD154, CTLA4Ig, and anti-LFA-1 was not sufficient to improve islet allograft survival in sensitized recipients.


Subject(s)
Diabetes Mellitus, Experimental/surgery , Graft Survival/physiology , Islets of Langerhans Transplantation/physiology , Transplantation, Homologous/physiology , Animals , Antigens, CD/immunology , Blood Glucose/metabolism , CTLA-4 Antigen , Diabetes Mellitus, Experimental/blood , Graft Rejection/blood , Immunoglobulin G/immunology , Islets of Langerhans Transplantation/immunology , Islets of Langerhans Transplantation/pathology , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Reoperation , Transplantation, Homologous/immunology , Transplantation, Homologous/pathology
12.
J Air Waste Manag Assoc ; 50(10): 1831-42, 2000 Oct.
Article in English | MEDLINE | ID: mdl-11288311

ABSTRACT

This paper describes the development and application of an air pollution potential (APP) forecast model based on a synoptic climatological approach in a heavily industrialized area in Durban, South Africa. The aim of the forecasting procedure, based on a system of orange, red, and all-clear alerts, was to give industry advance warning of periods of poor atmospheric dispersion so that it could take action to reduce emissions. The key meteorological parameter in accurately identifying the commencement of an APP episode was found to be negative surface pressure tendency. Wind direction was the most useful parameter in estimating the end point of an APP episode. The model was very successful in identifying periods of elevated SO2, but there is a need for further refinement in forecasting the end point of an episode.


Subject(s)
Air Pollution/analysis , Climate , Models, Theoretical , Air Movements , Forecasting , Industry , Sulfur Dioxide/analysis , Urban Population
13.
Eur J Biochem ; 251(1-2): 487-95, 1998 Jan 15.
Article in English | MEDLINE | ID: mdl-9492322

ABSTRACT

Human immunodeficiency virus type-1 (HIV-1) reverse transcriptase (RT) initiates reverse transcription from tRNA(Lys3). HIV-1 RT is a heterodimer consisting of two polypeptides, p66 and p51. In this work, the possible role of each subunit of RT in the interaction with its natural primer tRNA(Lys3) was studied. Two recombinant forms of HIV-1 RT, heterodimer p66/p51 and homodimer p51/p51, were used. Previously we have expressed and purified recombinant RT p51/p51 which possesses DNA polymerase activity [El Dirani-Diab, R., Andreola, M. L., Nevinsky, G., Tharaud, D., Barr, P. J., Litvak, S. & Tarrago-Litvak, L. (1992) FEBS Lett. 301, 23-28]. Here we show that HIV-1 RT p51/p51 displays certain properties very similar to the p66/p51 recombinant enzyme. The homodimer was able to anneal tRNA(Lys3) to the primer-binding site of the HIV-1 RNA template leading to a functional complex capable of synthesizing cDNA. Further, the p51/p51 enzyme behaved like RT p66/p51 concerning the strong inhibition produced by a non-nucleoside RT inhibitor. These data show that for RT p51/p51, one of the subunits of the homodimer adopts a conformation similar to the catalytic subunit (p66) present in the heterodimeric form. Part of this work was devoted to the study of the complex between the recombinant forms of HIV-1 RT and its primer tRNA. Each enzymatic form was cross-linked to tRNA(Lys3) in the presence of a platinum derivative, giving different ribonucleoprotein complexes of molecular masses higher than 100 kDa, suggesting that primer tRNA may interact with both subunits in the heterodimeric enzyme. After RNase A treatment of the complex RT p66/p51 x tRNA, the label was mainly found to migrate with the p66 subunit, although some cross-linking was also found associated to the p51 subunit. These results show that the p66 and p51 subunits of RT interact with tRNA(Lys3). Moreover, cross-linking of tRNA(Lys3) with HIV-1 RT p66/p51 in the presence of a DNA template containing the primer-binding-site sequence yielded an enzymatically active complex.


Subject(s)
DNA, Complementary/biosynthesis , HIV Reverse Transcriptase/antagonists & inhibitors , HIV Reverse Transcriptase/genetics , RNA, Transfer, Lys/metabolism , Reverse Transcriptase Inhibitors/pharmacology , Base Sequence , Binding Sites , Cross-Linking Reagents , DNA Primers/chemistry , DNA Primers/genetics , DNA Primers/metabolism , Dimerization , HIV Reverse Transcriptase/metabolism , Molecular Sequence Data , Pyridones/chemistry , Pyridones/pharmacology , RNA, Transfer, Lys/chemistry , RNA, Viral/genetics , RNA, Viral/metabolism , Recombinant Proteins/genetics , Recombinant Proteins/metabolism , Reverse Transcriptase Inhibitors/chemistry , Saccharomyces cerevisiae/genetics , Templates, Genetic
14.
Antimicrob Agents Chemother ; 41(10): 2141-8, 1997 Oct.
Article in English | MEDLINE | ID: mdl-9333039

ABSTRACT

Retroviral reverse transcriptase (RT) is involved in the selection of a specific tRNA primer which initiates proviral DNA minus-strand synthesis. Studies of the interactions between human immunodeficiency virus type 1 (HIV-1) RT and primer tRNALys3 have shown that the dihydrouridine (diHU), anticodon, and pseudouridine regions of tRNA are highly protected in the RT-tRNA complex. The CCA 3' end of tRNA is also in close contact with the enzyme during the cDNA initiation step. Using synthetic oligoribonucleotides corresponding to the anticodon and diHU regions, we have previously shown a low but significant inhibition of HIV-1 RT activity. We extend this observation and show that primer tRNA-derived oligodeoxynucleotides (ODNs) carrying a phosphorothioate (PS) modification are strong inhibitors of HIV-1 RT. The affinity of PS-ODNs for the enzyme was monitored by gel mobility shift electrophoresis. Experiments with HIV-1-infected human cells (MT-2 cells) were performed with the latter ODNs. A PS-ODN corresponding to the 3' end of tRNALys3 (acceptor stem [AS]) was able to inhibit HIV-1 replication. No effect of the other modified ODNs was observed in infected cells. The analysis of HIV-1 RNase H activity in a cell-free system strongly suggests that the inhibitory effect of the PS-AS may be mediated via both a sense and an antisense mechanism.


Subject(s)
Anti-HIV Agents/pharmacology , HIV Reverse Transcriptase/antagonists & inhibitors , HIV-1/chemistry , HIV-1/drug effects , RNA, Transfer, Amino Acyl/pharmacology , RNA, Transfer/metabolism , Reverse Transcriptase Inhibitors/pharmacology , Thionucleotides/chemistry , Thionucleotides/pharmacology , Adsorption , Cell-Free System , Cells, Cultured , Chromatography, Gel , Cytopathogenic Effect, Viral/drug effects , Electrophoresis, Polyacrylamide Gel , Humans , Polymerase Chain Reaction , RNA/pharmacology , Virus Replication/drug effects
15.
Nephrologie ; 16(1): 111-21, 1995.
Article in French | MEDLINE | ID: mdl-7700411

ABSTRACT

The number of diabetics with end stage renal failure is growing. The best treatment at the lowest cost possible should be offered to all diabetics if therapeutics facilities are available. Such a policy requires that all dialysis methods and transplantation should be available and that transfer from one method to another should always be allowable. Results observed among diabetics are improving steadily, even in the older age group. However they are inferior to those observed in non diabetic people of the same age. In diabetic patients under fifty years of age, renal transplantation using a kidney from a cadaver or a related donor should be the first choice. In some cases kidney and pancreas transplantation is possible. However, for most patients dialysis methods are required as the only treatment or while waiting for a transplant. If home dialysis is considered, continuous ambulatory peritoneal dialysis offers the opportunity to treat many insulin or non insulin-dependent diabetics at home even those in the high risk population because of age and/or cardio-vascular instability with excellent control of blood glucose levels, hypertension, vision, residual renal function, despite the peritoneal infections. These results are obtained from data in the literature and the survey of patients treated at the Hospital de la Pitié.


Subject(s)
Diabetes Complications , Kidney Failure, Chronic/therapy , Peritoneal Dialysis, Continuous Ambulatory , Blood Glucose/metabolism , Diabetic Nephropathies/therapy , Humans , Kidney Failure, Chronic/etiology , Kidney Transplantation , Middle Aged , Peritoneal Dialysis, Continuous Ambulatory/adverse effects
16.
Biochemistry ; 32(14): 3629-37, 1993 Apr 13.
Article in English | MEDLINE | ID: mdl-7682110

ABSTRACT

Six affinity reagents containing chemically reactive groups, either on the phosphate residue at the 5'-end or on the 5'- or 3'-end internucleoside phosphate linkages of the oligothymidylate primers, were used to covalently modify the human immunodeficiency virus type 1 reverse transcriptase (HIV-1 RT). After covalent binding of these modified primer analogs to the enzyme, the addition of [alpha-32P]dTTP, in the presence of a complementary template, led to elongation of the primer. This reaction was catalyzed by the active site of the enzyme carrying the covalently bound primer. The relative efficiency of labeling of the p66/p51 heterodimer compared to the p66/p66 and p51/p51 homodimers of HIV-1 RT was in agreement with the previously determined affinity of the various enzyme forms toward different primers. The analogues preferentially modified the p66 subunit of the HIV-1 RT heterodimer. The labeling of all RT forms by synthetic primer analogues showed significant and specific competition by the natural primer of HIV-1 RT, tRNA(Lys). In addition, the kinetics of inactivation of RT by primer analogues was studied. The affinity of the enzyme to those derivatives in the presence of poly(A) template was about 5-10 times higher than in the absence of template. Moreover, the maximal rates of HIV-1 RT inactivation by analogues in the absence of template were 3-4 times higher. Our results suggest that the mechanism of oligonucleotide primer binding to HIV-1 RT is different in the presence or absence of template.(ABSTRACT TRUNCATED AT 250 WORDS)


Subject(s)
Affinity Labels , HIV-1/enzymology , RNA-Directed DNA Polymerase/chemistry , Aldehydes/chemistry , Alkylation , Binding Sites , Binding, Competitive , HIV Reverse Transcriptase , Kinetics , Oligonucleotides/pharmacology , Phosphates/metabolism , RNA, Transfer, Lys/metabolism , RNA-Directed DNA Polymerase/metabolism , Reverse Transcriptase Inhibitors , Sulfhydryl Compounds/metabolism , Templates, Genetic , Thymidine Monophosphate/analogs & derivatives , Thymine Nucleotides/metabolism
17.
FEBS Lett ; 301(1): 23-8, 1992 Apr 13.
Article in English | MEDLINE | ID: mdl-1280600

ABSTRACT

The biochemical properties of the p51 subunit of HIV-1 reverse transcriptase (RT) were studied in order to understand its role in the heterodimeric form p66/p51 found in virions. A recombinant form of RT, p51/p51, expressed in yeast, was purified and characterized. The enzyme was affinity labeled using a 5' modified oligonucleotide primer, covalently linked, that was further elongated in the presence of a radioactive dNTP precursor. We found that the p51 subunit was labeled in the p51/p51 form, thus reflecting its activity, while this subunit was catalytically silent in the heterodimer, since only the p66 subunit was labeled in the latter recombinant form. Processivity studies showed long-sized products synthesized by p51/p51, as in the case of the other RT forms. The effect of primer tRNA(Lys) on the p51/p51 activity showed a strong inhibitory effect in the absence of KCl, similar to that observed with the p66/p51 form, while the same p51/p51 enzyme was strongly stimulated by tRNA(Lys), like RT p66/p66, when KCl was present in the incubation mixture.


Subject(s)
HIV-1/enzymology , RNA-Directed DNA Polymerase/chemistry , Affinity Labels , DNA Replication , DNA, Viral/biosynthesis , Dose-Response Relationship, Drug , HIV Reverse Transcriptase , Oligodeoxyribonucleotides/metabolism , Potassium Chloride/pharmacology , Protein Conformation , RNA, Transfer, Lys/pharmacology , RNA-Directed DNA Polymerase/drug effects , RNA-Directed DNA Polymerase/genetics , RNA-Directed DNA Polymerase/isolation & purification , Recombinant Proteins/metabolism , Yeasts/genetics
19.
J Clin Gastroenterol ; 11(4): 411-5, 1989 Aug.
Article in English | MEDLINE | ID: mdl-2760430

ABSTRACT

We compared eleven patients in whom symptoms of Crohn's disease appeared at age greater than or equal to 65 with a younger group in whom symptoms had appeared earlier. Only 64% of the older patients were initially recognized as having Crohn's disease, as compared with 96% of the younger patients even though clinical characteristics and initial response to medical treatment were similar in both groups. A higher rate of complications occurred in the older group and follow-up data showed that they had higher mortality and a greater need for continuous treatment. We suggest that awareness of Crohn's disease in the elderly is less than in the young; the diagnosis is more often missed despite the similarity of the clinical features to those of younger patients.


Subject(s)
Crohn Disease/diagnosis , Adult , Age Factors , Aged , Aged, 80 and over , Female , Humans , Male
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