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1.
Prim Care Diabetes ; 18(1): 91-96, 2024 02.
Article in English | MEDLINE | ID: mdl-38000979

ABSTRACT

INTRODUCTION: The prevalence of type 1 diabetes is increasing worldwide. The advent of new monitoring devices has enabled tighter glycemic control. AIM: To study the impact of glucose monitoring devices on the everyday life of young children with type 1 diabetes (T1D) and their parents. METHODS: A questionnaire was addressed to parents of children with T1D under the age of 6 years with an insulin pump treated in one of the hospitals of the ADIM network in France between January and July 2020. RESULTS: Among the 114 families included in the study, 53% of parents (26/49) woke up every night to monitor blood glucose levels when their child had flash glucose monitoring (FGM), compared with 23% (13/56) of those whose child had continuous glucose monitoring (CGM). Overall, 81% of parents (86/108) found that glucose monitoring improved their own sleep and parents whose child had CGM were significantly more likely to report improved sleep (86% vs 73%, pĀ =Ā 0.006). Forty-nine percent of parents (55/113) declared that they (in 87% of cases, the mother only) had reduced their working hours or stopped working following their child's T1D diagnosis. Maternal unemployment was significantly associated with the presence of siblings (pĀ =Ā 0.001) but not with glycemic control (pĀ =Ā 0,87). Ninety-eight percent of parents (105/107) think that glucose monitoring improves school integration. CONCLUSION: In these families of children with T1D, new diabetes technologies reduced the burden of care but sleep disruption remained common. Social needs evaluation, particularly of mothers, is important at initial diagnosis of T1D in children.


Subject(s)
Diabetes Mellitus, Type 1 , Child , Humans , Child, Preschool , Diabetes Mellitus, Type 1/diagnosis , Diabetes Mellitus, Type 1/drug therapy , Blood Glucose , Hypoglycemic Agents/therapeutic use , Blood Glucose Self-Monitoring , Continuous Glucose Monitoring , Parents
2.
Dev Cogn Neurosci ; 69: 101397, 2024 Oct.
Article in English | MEDLINE | ID: mdl-39029330

ABSTRACT

Measures of physical growth, such as weight and height have long been the predominant outcomes for monitoring child health and evaluating interventional outcomes in public health studies, including those that may impact neurodevelopment. While physical growth generally reflects overall health and nutritional status, it lacks sensitivity and specificity to brain growth and developing cognitive skills and abilities. Psychometric tools, e.g., the Bayley Scales of Infant and Toddler Development, may afford more direct assessment of cognitive development but they require language translation, cultural adaptation, and population norming. Further, they are not always reliable predictors of future outcomes when assessed within the first 12-18 months of a child's life. Neuroimaging may provide more objective, sensitive, and predictive measures of neurodevelopment but tools such as magnetic resonance (MR) imaging are not readily available in many low and middle-income countries (LMICs). MRI systems that operate at lower magnetic fields (< 100mT) may offer increased accessibility, but their use for global health studies remains nascent. The UNITY project is envisaged as a global partnership to advance neuroimaging in global health studies. Here we describe the UNITY project, its goals, methods, operating procedures, and expected outcomes in characterizing neurodevelopment in sub-Saharan Africa and South Asia.


Subject(s)
Brain , Child Development , Developing Countries , Magnetic Resonance Imaging , Neuroimaging , Humans , Magnetic Resonance Imaging/methods , Neuroimaging/methods , Child Development/physiology , Brain/growth & development , Brain/diagnostic imaging , Infant , Child, Preschool , Child , Male , Female , Poverty
3.
J Physiol ; 591(23): 6017-37, 2013 Dec 01.
Article in English | MEDLINE | ID: mdl-24042504

ABSTRACT

The role of OPA1, a GTPase dynamin protein mainly involved in the fusion of inner mitochondrial membranes, has been studied in many cell types, but only a few studies have been conducted on adult differentiated tissues such as cardiac or skeletal muscle cells. Yet OPA1 is highly expressed in these cells, and could play different roles, especially in response to an environmental stress like exercise. Endurance exercise increases energy demand in skeletal muscle and repeated activity induces mitochondrial biogenesis and activation of fusion-fission cycles for the synthesis of new mitochondria. But currently no study has clearly shown a link between mitochondrial dynamics and biogenesis. Using a mouse model of haploinsufficiency for the Opa1 gene (Opa1(+/-)), we therefore studied the impact of OPA1 deficiency on the adaptation ability of fast skeletal muscles to endurance exercise training. Our results show that, surprisingly, Opa1(+/-) mice were able to perform the same physical activity as control mice. However, the adaptation strategies of both strains after training differed: while in control mice mitochondrial biogenesis was increased as expected, in Opa1(+/-) mice this process was blunted. Instead, training in Opa1(+/-) mice led to an increase in endurance capacity, and a specific adaptive response involving a metabolic remodelling towards enhanced fatty acid utilization. In conclusion, OPA1 appears necessary for the normal adaptive response and mitochondrial biogenesis of skeletal muscle to training. This work opens new perspectives on the role of mitochondrial dynamics in skeletal muscle cells and during adaptation to stress.


Subject(s)
GTP Phosphohydrolases/physiology , Mitochondria, Muscle/physiology , Muscle, Skeletal/physiology , Physical Conditioning, Animal/physiology , Physical Endurance/physiology , Animals , Behavior, Animal/physiology , DNA/metabolism , Male , Mice , Mice, Knockout , Microscopy, Electron , Mitochondria, Muscle/ultrastructure , Psychomotor Performance/physiology , Running
4.
Anaesth Crit Care Pain Med ; 38(5): 507-516, 2019 10.
Article in English | MEDLINE | ID: mdl-30586601

ABSTRACT

BACKGROUND: Patients on either antiplatelet or anticoagulant therapy may need procedures performed under peripheral nerve blocks in preference to general anaesthesia techniques. The risk of bleeding associated with peripheral nerve blocks under these circumstances remains unknown. This systematic review evaluates the incidence of bleeding complications following peripheral nerve blocks in patients receiving antiplatelet and/or anticoagulant medication. METHOD: All English, French and Spanish publications on peripheral nerve blocks in patients receiving antiplatelet and/or anticoagulant medication, from 1978 to 2018 from various sources including Pubmed, were reviewed. Publications on neuraxial anaesthesia (spinal or epidural) and eye blocks were excluded. RESULTS: Twenty-four articles were selected, including six observational studies and 18 case reports. Patients received antiplatelet agents only, in 4 studies, anticoagulants only in 14 studies, and both in 6 studies. In the observational studies, 80 bleeding complications (haematoma or minor bleeding at the puncture site) were identified following 9738 peripheral nerve blocks. Amongst case reports, 15 bleeding complications were noted following 50 peripheral nerve blocks. Bleeding complications were reported mostly with lumbar plexus blocks (1 requirement for blood transfusion, 1 catheter embolization, 1 surgical exploration and 1 death). The overall estimate of the incidence of bleeding complications was 0.82% (0.64%-1.0%). CONCLUSION: This systematic review found that bleeding complications following peripheral nerve blocks were rare in patients receiving antiplatelet and/or anticoagulant medication.


Subject(s)
Anesthesia, Conduction/adverse effects , Anticoagulants/adverse effects , Hemorrhage/chemically induced , Nerve Block/adverse effects , Platelet Aggregation Inhibitors/adverse effects , Anticoagulants/administration & dosage , Catheterization/adverse effects , Hematoma/chemically induced , Hematoma/epidemiology , Hemorrhage/epidemiology , Humans , Incidence , Medical Records , Observational Studies as Topic , Platelet Aggregation Inhibitors/administration & dosage , Punctures/adverse effects
5.
J Mater Chem B ; 6(7): 1095-1104, 2018 Feb 21.
Article in English | MEDLINE | ID: mdl-32254297

ABSTRACT

Here, we report the formulation of hybrid nanoparticles consisting of aggregated gold nanoparticles (GNPs) impregnated into a gemcitabine-polymer conjugate matrix that exhibit synergistic photo-chemo-therapeutic activity against pancreatic cancer. Well-defined, sub-100 nm hybrid NPs were successfully formulated and their photothermal conversion efficiency was evaluated, which was found to be as high as 63% in the red-visible spectrum. By varying the GNP and GEM-polymer feed, it was possible to control the red-shifting of the surface plasmon resonance at therapeutically relevant wavelengths. The hybrid NPs exhibited significant cytotoxicity against MiaPaCa-2 cells with a half-maximal inhibitory concentration (IC50) of 0.0012 mg mL-1; however the IC50 decreased by a factor of 2 after the cells were irradiated with a continuous wave red laser for 1 min (1.4 W cm-2). Although the irradiation of the aggregated GNPs loaded in the hybrid NPs produced a higher thermal effect for the same amount of non-loaded GNPs, the IC50 of the hybrid NPs was significantly lower than that of the free GNPs, hence indicating a synergistic effect of the polymer bound GEM and the GNPs.

6.
J Ethnopharmacol ; 112(2): 312-8, 2007 Jun 13.
Article in English | MEDLINE | ID: mdl-17433588

ABSTRACT

Sutherlandia frutescens is a well-known South African herbal remedy traditionally used for stomach problems, internal cancers, diabetes, various inflammatory conditions and recently to improve the overall health in cancer and HIV/AIDS patients. The influence of crude Sutherlandia frutescens extracts (prepared with 70% ethanol) was investigated on cell numbers, morphology, and gene expression profiles in a MCF-7 human breast adenocarcinoma cell line. Time-dependent (24, 34, 48 and 72 h) and dose-dependent (0.5-2.5 mg/ml) studies were conducted utilizing spectrophotometrical analysis with crystal violet as DNA stain. A statistically significant decrease to 50% of malignant cell numbers was observed after 24 h of exposure to 1.5 mg/ml Sutherlandia frutescens extract when compared to vehicle-treated controls. Morphological characteristics of apoptosis including cytoplasmic shrinking, membrane blebbing and apoptotic bodies were observed after 24h of exposure. A preliminary global gene expression profile was obtained by means of microarray analysis and revealed valuable information about the molecular mechanisms and signal transduction associated with 70% ethanolic Sutherlandia frutescens extracts.


Subject(s)
Adenocarcinoma/drug therapy , Adenocarcinoma/pathology , Antineoplastic Agents, Phytogenic/pharmacology , Breast Neoplasms/drug therapy , Breast Neoplasms/pathology , Fabaceae/chemistry , Gene Expression Regulation, Neoplastic/drug effects , Antineoplastic Agents, Phytogenic/chemistry , Apoptosis/drug effects , Cell Count , Cell Cycle/drug effects , Cell Line, Tumor , Cell Proliferation/drug effects , Cell Shape , DNA, Complementary/biosynthesis , DNA, Complementary/genetics , DNA, Neoplasm/biosynthesis , DNA, Neoplasm/genetics , Female , Humans , Mitotic Index , Oligonucleotide Array Sequence Analysis , Plant Extracts/pharmacology , Signal Transduction/drug effects
7.
Biochim Biophys Acta ; 493(1): 216-27, 1977 Jul 22.
Article in English | MEDLINE | ID: mdl-880314

ABSTRACT

Three phospholipases A, CM-I, CM-II and CM-III, were purified from Naja mossambica mossambica venom by gel filtration on Sephadex G-50 followed by ion-exchange chromatography on CM-cellulose. They comprise each 118 amino acid residues and are close-linked by seven intrachain disulphide bridges. The complete primary structure of the three phospholipases A have been elucidated. The sequences and the invariant amino acid residues of CM-I, CM-II and CM-III resemble those of phospholipases A from other snake venoms and also from porcine pancreas. However, the letality (LD50 values) of the three phospholipases A from Naja mossambica mossambica venom, differ among themselves, and are also much higher than the LD100 value encountered for notexin from Notechis scutatus scutatus venom.


Subject(s)
Phospholipases , Snake Venoms , Amino Acid Sequence , Amino Acids/analysis , Isoenzymes/isolation & purification , Isoenzymes/metabolism , Peptide Fragments/analysis , Phospholipases/isolation & purification , Phospholipases/metabolism , Species Specificity
8.
Biochim Biophys Acta ; 379(2): 329-44, 1975 Feb 27.
Article in English | MEDLINE | ID: mdl-1122291

ABSTRACT

Reduced and S-carboxymethylated phospholipase A (Fraction DE-III) from Naja melanoleuca venom was digested with trypsin, chymotrypsin and thermolysin. The resulting peptides were purified by ion-exchange chromatography on DEAE-cellulose, gel filtration on Sephadex G-25 or G-50 and chromatography and electrophoresis on paper. The amino acid sequences of the intact enzyme and the pur peptides were determined by the Edman procedure, either through the use of the automatic sequencer or by manual manipulation. The chymotryptic digest provided the necessary overlapping peptides which allowed the alignment of the tryptic peptides into a single chain of 119 amino acids. The amino acid sequence of N. melanoleuca phospholipase A shows a high degree of homology with phospholipases A from Bitis gabonica and also from porcine pancreas.


Subject(s)
Phospholipases , Snake Venoms/analysis , Venoms/analysis , Amino Acid Sequence , Amino Acids/analysis , Animals , Chromatography, Gel , Chromatography, Paper , Chymotrypsin , Cyanogen Bromide , Electrophoresis, Paper , Peptide Fragments/analysis , Phospholipases/isolation & purification , Species Specificity , Thermolysin , Trypsin
9.
Biochim Biophys Acta ; 379(2): 345-59, 1975 Feb 27.
Article in English | MEDLINE | ID: mdl-1122292

ABSTRACT

The complete amino acid sequences of phospholipase A (Fractions DE-I and DE-II) from Naja melanoleuca (Forest cobra) have been elucidated. The reduced and S-carboxymethylated isoenzyme were digested with trypsin and thermolysin and the peptides were purified by ion-exchange chromatography, gel filtration and chromatography or electrophoresis on paper. The Edman procedure, either through the use of the automatic sequencer or by manual manipulation, was employed to obtain the sequences of the intact isoenzymes and the pure peptidesmthe thermolysin digest provided the necessary overlapping peptides which allowed the alignment of the tryptic peptides of Fraction DE-I. The tryptic peptides of Fraction DE-II were either identical or homologous to the tryptic peptides of Fraction I and Fraction III [12] and were aligned in the same order as that of Fractions DE-I or DE-III. The amino acid sequence of N. melanoleuca phospholipase A, Fraction I, shows a high degree of homology with Fraction DE-II and also with Fraction DE-III, previously reported on [12].


Subject(s)
Phospholipases , Snake Venoms/analysis , Venoms/analysis , Amino Acid Sequence , Amino Acids/analysis , Animals , Chromatography, Gel , Chromatography, Paper , Electrophoresis, Paper , Iodoacetates , Isoenzymes/isolation & purification , Peptide Fragments/analysis , Phospholipases/isolation & purification , Protein Binding , Thermolysin , Trypsin
10.
Biochim Biophys Acta ; 537(1): 1-8, 1978 Nov 20.
Article in English | MEDLINE | ID: mdl-718974

ABSTRACT

Three reduced and S-carboxymethylated toxins (CM-5, CM-6 and CM-10a) were purified from Naja haje haje (Egyptian cobra) venom. Whereas toxin CM-5 comprises 71 amino acid residues and five intrachain disulphide bridges, toxins CM-6 and CM-10a contain each 61 residues and four disulphide bridges. The complete primary structures of the three toxins have been established. The toxicity, the immunochemical properties, the sequence and the invariant amino acid residues of toxin CM-5 resemble the properties of the long neurotoxin group, while those of toxin CM-6 and CM-10a are related to the short neurotoxin group. Further, the sequences of the three toxins from Naja haje haje venom reveal a high degree of homology with those of the corresponding neurotoxins isolated from Naja haje annulifera or Naja nivea venoms.


Subject(s)
Elapid Venoms , Amino Acid Sequence , Amino Acids/analysis , Animals , Elapid Venoms/isolation & purification , Elapid Venoms/toxicity , Methylation , Mice , Molecular Weight , Oxidation-Reduction , Peptide Fragments , Species Specificity
11.
Biochim Biophys Acta ; 534(2): 331-40, 1978 Jun 21.
Article in English | MEDLINE | ID: mdl-667107

ABSTRACT

Four toxins (CM-7, CM-8, CM-9 and CM-10b) were purified from Naja haje haje (Egyptian cobra) venom by gel filtration on Sephadex G-50 followed by ion-exchange chromatography on CM-cellulose. They each contain 60 amino acid residues and are cross-linked by four intrachain disulphide bridges. The complete primary structure of the four toxins have been elucidated. The toxicities, the immunochemical properties, the sequences and invariant amino acid residues opf toxins CM-7, CM-8, CM-9 and CM-10b resemble the corresponding properties of the cytotoxin group.


Subject(s)
Elapid Venoms , Amino Acid Sequence , Amino Acids/analysis , Animals , Disulfides/analysis , Elapid Venoms/isolation & purification , Molecular Weight
12.
Biochim Biophys Acta ; 623(2): 449-56, 1980 Jun 26.
Article in English | MEDLINE | ID: mdl-7397227

ABSTRACT

Toxins C10S2C2 and C13S1C1 from Dendroaspis angusticeps venom were purified by gel filtration and ion-exchange chromatography. Whereas toxin C10S2C2 comprises 60 amino acids, toxin C13S1C1 contains only 58 but they each include eight half-cystine residues. The complete primary structures of the toxins have been elucidated. The sequences and the invariant amino acids of toxins C10S2C2 and C13S1C1 from D. angusticeps venom resemble those of the angusticeps-type toxins. In the two toxins the ten structurally invariant amino acids of the neurotoxins and cytotoxins are conserved, but the toxins contain none of the three functionally-invariant amino acids of the neurotoxins. Further, the eight cystine residues of the angusticeps-type toxins are in similar locations to those in short neurotoxins of known structure so they are presumed to link similarly. The only structural characteristic of the angusticeps-type toxins which binds them together as a group, is the serine residue in position 5. The toxicities of the angusticeps-type toxins differ among themselves but appear to be of considerably lower toxicity relative to that of the neurotoxin group.


Subject(s)
Elapid Venoms , Amino Acid Sequence , Animals , Chromatography, Gel , Chromatography, Ion Exchange , Elapid Venoms/isolation & purification , Species Specificity
13.
Biochim Biophys Acta ; 579(1): 228-33, 1979 Jul 25.
Article in English | MEDLINE | ID: mdl-465532

ABSTRACT

Two polypeptides (protein S5C1 and toxin S5C10) were purified from Dendroaspis jamesoni kaimosae venom. Whereas protein S5C1 comprises 61 amino acid residues, toxin S5C10 contains 58 and they each comprise four disulphide bridges. The complete primary structures of the two polypeptides have been elucidated. The sequences of protein S5C1 and toxin S5C10 are structurally homologous to the short neurotoxins Type I, but they are much less toxic. In toxin S5C10 one of the functionally invariant amino acid residues, lysine 26, of the Type I neurotoxin has been replaced by a serine. In contrast protein S5C1 has the feature that it contains ten or eleven structurally invariant amino acids and apparently only one of the five functionally invariant residues.


Subject(s)
Bungarotoxins , Neurotoxins , Peptides , Amino Acid Sequence , Amino Acids/analysis , Animals , Disulfides/analysis , Oxidation-Reduction , Peptides/isolation & purification , Species Specificity
14.
Biochim Biophys Acta ; 379(2): 317-28, 1975 Feb 27.
Article in English | MEDLINE | ID: mdl-1122290

ABSTRACT

Three phospholipases A (Fractions DE-I, DE-II and DE-III) were purified from Naja melanoleuca (Forest cobra) venom by a combination of gel filtration on Sephadex G-50 and chromatography on DEAE-cellulosemthe purified phospholipases A were homogeneous by various physicochemical criteria. Whereas Fraction DE-I contains 118 amino acid residues, Fractions DE-II and DE-III comprise 119 residues. The three enzymes are cross-linked by seven disulphide bridges, have asparagine as N-terminal amino acid and the C-terminal is glutamic acid or glutamine. The molecular weights of the three phospholipases A from sedimentation analysis at pH 2.1, also by the sodium dodecylsulphate-gel method and calculated from the amino acid composition, were close to 13 000. Studies of circular dichroism in the spectral region between 195 to 305 nm showed that the three phospholipases A contain similar helical contents but revealed conformational differences between their side-chain chromophores.


Subject(s)
Phospholipases , Snake Venoms/analysis , Venoms/analysis , Amino Acid Sequence , Amino Acids/analysis , Animals , Binding Sites , Chromatography, DEAE-Cellulose , Chromatography, Gel , Circular Dichroism , Disulfides/analysis , Molecular Weight , Phospholipases/isolation & purification , Protein Binding , Protein Conformation , Spectrophotometry, Ultraviolet
15.
J Mol Biol ; 163(4): 623-46, 1983 Feb 05.
Article in English | MEDLINE | ID: mdl-6842589

ABSTRACT

The assignment of the 1H nuclear magnetic resonance (n.m.r.) spectrum of the trypsin inhibitor homologue K from the venom of Dendroaspis polylepis polylepis is described and documented. The assignments are based entirely on the amino acid sequence and on 2-dimensional n.m.r. experiments at 360 and 500 M Hz. Individual assignments were obtained for the backbone and C beta protons of all 57 residues of the inhibitor homologue K, with the exceptions of the N-terminal amino group, the amide protons of Arg16, Gly37 and Gly40 and the C beta protons of Arg16 and Pro19. The assignments for the non-labile protons of the amino acid side-chains are complete, with the exception of Gln29, Glu49 and all the proline, lysine and arginine residues. For Asn and Trp the labile side-chain protons have also been assigned. The chemical shifts for the assigned resonances are listed for an aqueous solution at 50 degrees C and pH 3.4.


Subject(s)
Elapid Venoms/analysis , Trypsin Inhibitors/analysis , Amino Acid Sequence , Amino Acids/analysis , Animals , Hot Temperature , Hydrogen-Ion Concentration , Magnetic Resonance Spectroscopy , Protein Denaturation
16.
Proteins ; 50(3): 464-73, 2003 Feb 15.
Article in English | MEDLINE | ID: mdl-12557188

ABSTRACT

The ornithine decarboxylase (ODC) component of the bifunctional S-adenosylmethionine decarboxylase/ornithine decarboxylase enzyme (PfAdoMetDC-ODC) of Plasmodium falciparum was modeled on the crystal structure of the Trypanosoma brucei enzyme. The homology model predicts a doughnut-shaped active homodimer that associates in a head-to-tail manner. The monomers contain two distinct domains, an N-terminal alpha/beta-barrel and a C-terminal modified Greek-key domain. These domains are structurally conserved between eukaryotic ODC enzymes and are preserved in distant analogs such as alanine racemase and triosephosphate isomerase-like proteins. Superimposition of the PfODC model on the crystal structure of the human enzyme indicates a significant degree of deviation in the carbon alpha-backbone of the solvent accessible loops. The surface locality of the ab initio modeled 38 amino acid parasite-specific insert suggests a role in the stabilization of the large bifunctional protein complex. The active site pockets of PfODC at the interface between the monomers appear to be conserved regarding the binding sites of the cofactor and substrate, but each contains five additional malaria-specific residues. The predicted PfODC homology model is consistent with mutagenesis results and biochemical studies concerning the active site residues and areas involved in stabilizing the dimeric form of the protein. Two competitive inhibitors of PfODC could be shown to interact with several parasite-specific residues in comparison with their interaction with the human ODC. The PfODC homology model contributes toward a structure-based approach for the design of novel malaria-specific inhibitors.


Subject(s)
Models, Molecular , Ornithine Decarboxylase/chemistry , Plasmodium falciparum/enzymology , Amino Acid Sequence , Animals , Binding Sites , Dimerization , Humans , Imaging, Three-Dimensional , Ligands , Molecular Sequence Data , Molecular Structure , Ornithine Decarboxylase/metabolism , Sequence Alignment
17.
Thromb Haemost ; 57(3): 356-60, 1987 Jun 03.
Article in English | MEDLINE | ID: mdl-3116706

ABSTRACT

Trypsin and tissue plasminogen activator inhibitor DE-3 from Erythrina caffra contains 172 amino acids, including 4 half-cystine residues, and resembles the Kunitz-type inhibitors. Limited hydrolysis of DE-3 with trypsin at pH 3.2 produced two fragments, F1 and F2, containing 63 and 109 amino acids, respectively. Amino-terminal sequence studies showed that F1 was the N-terminal and that F2 was the C-terminal fragment. The complete amino acid sequence of the fragments were then determined on peptides produced by enzymatic digestion with trypsin. The sequence of trypsin and tissue plasminogen activator inhibitor DE-3 from E. caffra seeds shows a high degree of homology to that of trypsin and tissue plasminogen activator inhibitor DE-3 from E. latissima seeds and revealed only four amino acids which were replaced.


Subject(s)
Fabaceae , Plant Proteins , Plants, Medicinal , Protease Inhibitors/isolation & purification , Seeds/enzymology , Tissue Plasminogen Activator/antagonists & inhibitors , Trypsin Inhibitors/isolation & purification , Amino Acid Sequence , Chromatography, Gel , Protease Inhibitors/analysis , Trypsin Inhibitors/analysis
18.
Br J Pharmacol ; 82(3): 709-16, 1984 Jul.
Article in English | MEDLINE | ID: mdl-6743920

ABSTRACT

Three neurotoxin homologues (CM10 and CM12 from Naja haje annulifera and S5C10 from Dendroaspis jamesoni kaimosae) and two short neurotoxins (CM14 from Naja haje annulifera and erabutoxin b from Laticauda semifasciata) were examined by circular dichroism (c.d.) and tested for neuromuscular activity on chick biventer cervicis nerve-muscle preparations. All three homologues had acetylcholine receptor blocking activity, as they abolished responses to indirect stimulation, acetylcholine and carbachol but had no effect on responses to direct muscle stimulation. CM10 was only about 5 times less potent than the short neurotoxin CM14; S5C10 and CM12 were respectively 30 and 300 times less active. The block induced by the three homologues, but not by the neurotoxins, was readily reversed by washing. CM10 and CM12 had virtually identical c.d. spectra which were closely similar to those of the neurotoxins. The spectrum of S5C10 indicated changes in the environment of tyrosine-25 and in the position of tryptophan-29. These alterations could distort the 3-dimensional arrangement of the residues postulated to form the receptor binding site. The results with CM10 and CM12 highlight a role for the first loop (residues 6-16) in the binding of neurotoxins to acetylcholine receptors, in addition to the previously postulated reactive site.


Subject(s)
Elapid Venoms/toxicity , Neuromuscular Blocking Agents/toxicity , Neuromuscular Junction , Neurotoxins/toxicity , Animals , Chickens , Circular Dichroism , Elapid Venoms/analysis , Neurotoxins/analysis , Structure-Activity Relationship
19.
Article in English | MEDLINE | ID: mdl-10582657

ABSTRACT

The effects of exogenous gamma-linolenic acid (GLA), arachidonic acid (AA), prostaglandin E2 (PGE2) and prostaglandin A2 (PGA2) were evaluated on cell growth in two squamous oesophageal carcinoma cell lines, WHCO1 and WHCO3 and normal monkey kidney (NMK) cells. In both cancer cell lines all four compounds inhibited cell growth significantly. Indomethacin (I) alone, or in combination with either GLA or AA, caused marked inhibition of cell growth in WHCO3. Total tyrosine kinase (TK) activity was determined after exposure of all three cell types to the lipid compounds. Negligible differences were observed in TK activity between treated and untreated NMK cells. Small increases were noticed in WHCO1. Marked TK stimulation was observed in WHCO3. Addition of indomethacin to WHCO3 also increased TK activity above control value. Tyrosine phosphorylation status of exposed cells indicated that a band of approximately 55 kDa (approximately 55 kDa) was primarily influenced in both WHCO3 and WHCO1. PGA2 caused a decrease in tyrosine phosphorylation of the approximately 55 kDa protein in all three cell types. Negligible differences were observed in the tyrosine phosphorylation status of the approximately 55 kDa in NMK cells exposed to GLA, AA and PGE2 respectively. However, tyrosine phosphorylation of a number of other proteins (21.5-97.4 kDa) was observed in NMK cells. Flow cytometry studies showed an increase in S phase and decrease in G1 phase in WHCO3 exposed to PGE2 and PGA2. Indomethacin alone, or in combination with GLA and AA, respectively, lead to an increase in G1 and a decrease in S phase. Induction of p53 levels was observed in WHCO3 cells exposed to GLA, AA, PGA2, indomethacin and the combination of indomethacin and GLA or AA.


Subject(s)
Cell Division/drug effects , Esophageal Neoplasms/enzymology , Esophageal Neoplasms/pathology , Fatty Acids, Unsaturated/pharmacology , Protein-Tyrosine Kinases/metabolism , Animals , Arachidonic Acid/pharmacology , Carcinoma, Squamous Cell/enzymology , Carcinoma, Squamous Cell/pathology , Cell Line , Chlorocebus aethiops , Dinoprostone/pharmacology , Flow Cytometry , Humans , Kidney , Phosphorylation , Prostaglandins A/pharmacology , Tumor Cells, Cultured , Tumor Suppressor Protein p53/analysis , Tyrosine/metabolism , gamma-Linolenic Acid/pharmacology
20.
Article in English | MEDLINE | ID: mdl-11728168

ABSTRACT

The effects of 20 microg/ml exogenous arachidonic acid (AA) and prostaglandin A(2) (PGA(2)) were evaluated on total tyrosine kinase (TK) activity and tyrosine phosphorylation status in HeLa and MCF-7 cells. AA and PGA(2) increased TK activity in both HeLa and MCF-7 cells. Western blotting employing an anti-phosphotyrosine antibody showed only one protein of approximately 55 kDa (approximately 55 kDa) to be phosphorylated in the MCF-7 cells, while a variety of proteins were phosphorylated in the HeLa cells, including the approximately 55 kDa protein. Amino acid analyses as well as Matrix Assisted Laser Desorption Ionization were conducted on this protein from different cell lines and it was shown to be similar. Comparison to p53 did not show similarities. The identity of this protein needs to be further characterized to help elucidate the signal transduction pathways of AA and PGA(2).


Subject(s)
Arachidonic Acid/pharmacology , Phosphoproteins/analysis , Prostaglandins A/pharmacology , Protein-Tyrosine Kinases/metabolism , Amino Acids/analysis , Animals , Blotting, Western , Cell Line , HeLa Cells , Humans , Kinetics , Phosphorylation , Signal Transduction , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization , Tumor Cells, Cultured
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