240 results on '"J. Chayen"'
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2. The Cytochemical Bioassay of Polypeptide Hormones
- Author
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J. Chayen and J. Chayen
- Subjects
- Endocrinology, Biochemistry, Internal medicine
- Abstract
The cytochemical bioassay system was described in a short abstract in 1971, and more fully, in the cytochemical bioassay of corticotrophin, in 1972. Since then, cytochemical bioassays have been described for several polypeptide hormones, and these assays are already widely used. It is expedient that the subject should be reviewed, as it is in this monograph, by one writer who has had the good fortune to have taken part in the growth of cytochemistry from its early origins to its present position as the basis of possibly the most sensitive bioassay system currently available. However, it should be noted that major contributions have been made by many, both to the development of the subject and to the establishment of the bioassays. The object of this preface is to try to give some perspective to the growth of this subject and to record that the cytochemical bioassay system has been fostered by many outstanding scientists in an atmosphere of remarkable goodwill. To begin with, there could have been no cytochemical bioassays until cytochem istry had been converted from its rather unsure origins into a precise and quantitative form of cellular biochemistry. This was done with skill and enthusiastic dedication by my colleagues, Dr. Lucille Bitensky, Dr. F. P. Altman, Dr. R. G. L. W. Poulter and Mr. A. A. Silcox, first at the Royal College of Butcher, Dr.
- Published
- 2012
3. Intramuscular vitamin K and childhood cancer
- Author
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J. Chayen
- Subjects
medicine.medical_specialty ,Pediatrics ,Letter ,business.industry ,Childhood cancer ,General Engineering ,General Medicine ,Vitamin k ,medicine.disease ,Infant newborn ,Surgery ,Leukemia ,medicine ,General Earth and Planetary Sciences ,business ,General Environmental Science - Published
- 1992
4. Synthesis of arachidonate cyclo-oxygenase products by rheumatoid and nonrheumatoid synovial lining in nonproliferative organ culture
- Author
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J. Chayen, B. Cashman, J. A. Salmon, B Henderson, L Bitensky, J. R. Vane, and G. A. Higgs
- Subjects
musculoskeletal diseases ,Adult ,Male ,medicine.medical_specialty ,Adolescent ,medicine.medical_treatment ,Immunology ,6-Ketoprostaglandin F1 alpha ,Organ culture ,General Biochemistry, Genetics and Molecular Biology ,Dinoprostone ,Arthritis, Rheumatoid ,chemistry.chemical_compound ,Organ Culture Techniques ,Rheumatology ,Internal medicine ,medicine ,Immunology and Allergy ,Humans ,Prostaglandin E2 ,skin and connective tissue diseases ,Aged ,business.industry ,Prostaglandins E ,Synovial Membrane ,Thromboxanes ,Articles ,Middle Aged ,Thromboxane B2 ,medicine.anatomical_structure ,Endocrinology ,chemistry ,Prostaglandin-Endoperoxide Synthases ,lipids (amino acids, peptides, and proteins) ,Female ,Synovial membrane ,Cyclo-oxygenase ,business ,Prostaglandin E ,medicine.drug - Abstract
Specimens of human rheumatoid and nonrheumatoid synovial lining were maintained in nonproliferative organ culture for 20 hours. The culture fluids were then assayed for prostaglandin E(2) (PGE(2)), thromboxane B(2) (TXB(2)), and 6-keto-prostaglandin F(1alpha) (6-keto-PGF(1alpha)) by specific radioimmunoassay. The presence of each of these substances was confirmed by gas chromatography and mass spectrometry. Rheumatoid tissue produced significantly more of each cyclo-oxygenase product than nonrheumatoid tissue.
- Published
- 1983
5. Comparison of Effects of Long-term Corticotrophin and Corticosteroid Treatment on Responses of Plasma Growth Hormone, ACTH, and Corticosteroid to Hypoglycaemia
- Author
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J. R. Daly, D. Glass, M. R. Fletcher, L Bitensky, D. J. Chambers, and J. Chayen
- Subjects
Blood Glucose ,Male ,medicine.medical_specialty ,endocrine system ,Hypothalamo-Hypophyseal System ,Time Factors ,medicine.drug_class ,medicine.medical_treatment ,Pituitary Function Tests ,Pituitary-Adrenal System ,Adrenocorticotropic hormone ,Hypoglycemia ,Arthritis, Rheumatoid ,Adrenocorticotropic Hormone ,Adrenal Cortex Hormones ,Internal medicine ,medicine ,Humans ,Insulin ,Secretion ,General Environmental Science ,business.industry ,General Engineering ,Area under the curve ,General Medicine ,Papers and Originals ,medicine.disease ,Endocrinology ,Rheumatoid arthritis ,Depression, Chemical ,Growth Hormone ,General Earth and Planetary Sciences ,Corticosteroid ,Female ,Hormone therapy ,business ,hormones, hormone substitutes, and hormone antagonists - Abstract
The development of the highly sensitive cytochemical bioassay for ACTH has permitted the measurement of plasma ACTH levels during the insulin hypoglycaemia test (I.H.T.) in patients treated with corticosteroids and corticotrophin. The ACTH, corticosteroid, and growth hormone (GH) responses in the I.H.T. were measured in three groups of 12 rheumatoid arthritis patients. One group was receiving long-term corticotrophin treatment, the second was undergoing long-term corticosteroid treatment, and the third had never received systemic hormone therapy. The increments in plasma ACTH, corticosteroids, and GH were diminished in the corticosteroid-treated group, as were increments in plasma GH and ACTH in the corticotrophin-treated group; but in this group the corticosteroid increment was normal. Examination of the area under the curve of the ACTH response showed that the total amount of ACTH secreted was normal though the rate of secretion was reduced. In the corticosteroid-treated group both rate and total secretion were diminished.
- Published
- 1974
6. Hartley's Microscopy
- Author
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J Chayen
- Subjects
Materials science ,Information retrieval ,Microscopy ,General Medicine ,Bioinformatics ,Pathology and Forensic Medicine ,Book Review - Published
- 1980
7. Circulating levels of biologically active parathyroid hormone in rheumatic diseases
- Author
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J. Dunham, J T Scott, B E Bourke, J Chayen, Nigel Loveridge, and L Bitensky
- Subjects
Adult ,Male ,medicine.medical_specialty ,Hypercalcaemia ,Immunology ,Parathyroid hormone ,Chondrocalcinosis ,Asymptomatic ,General Biochemistry, Genetics and Molecular Biology ,Arthritis, Rheumatoid ,Rheumatology ,Internal medicine ,Diabetes mellitus ,Rheumatic Diseases ,Osteoarthritis ,medicine ,Immunology and Allergy ,Humans ,Spondylitis, Ankylosing ,Hemochromatosis ,Subclinical infection ,Aged ,Hyperparathyroidism ,business.industry ,Middle Aged ,medicine.disease ,Endocrinology ,Parathyroid Hormone ,Biological Assay ,Female ,medicine.symptom ,business ,Hormone ,Research Article - Abstract
There has been doubt as to whether elevated levels of parathyroid hormone, reported previously by radioimmunoassay, reflect increased concentrations of the biologically active hormone. The application of a recently developed, highly sensitive bioassay has shown considerable disparity between bioactivity and immunoreactivity in 5 rheumatic conditions and in normal subjects. Six patients with chondrocalcinosis had elevated levels; 3 of these did not have hypercalcaemia or any obvious cause other than possible subclinical hyperparathyroidism. One patient, assayed during an acute episode, had an elevated concentration of the hormone which reverted to normal when she was asymptomatic. Most patients with osteoarthrosis (13 our of 15) had low normal levels; 2 showed unexplained slightly elevated concentrations. Of 6 patients with haemochromatosis 3 had elevated levels, though this may have been related to the associated presence of diabetes mellitus. A third of patients with ankylosing spondylitis (10 out of 30) showed elevated parathyroid hormone levels but without hypercalcaemia. A number of spondylitic patients also showed anomalous results in this assay, possibly due to the presence of an antagonist. This would be consistent with the absence of clinical or biochemical evidence of hyperparathyroidism.
- Published
- 1982
8. Glycolytic activity in human synovial lining cells in rheumatoid arthritis
- Author
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J Chayen, L Bitensky, and B Henderson
- Subjects
musculoskeletal diseases ,Adult ,Male ,Adolescent ,Immunology ,Arthritis ,General Biochemistry, Genetics and Molecular Biology ,Arthritis, Rheumatoid ,chemistry.chemical_compound ,Rheumatology ,Glyceraldehyde ,Lactate dehydrogenase ,medicine ,Immunology and Allergy ,Humans ,Glycolysis ,skin and connective tissue diseases ,Glyceraldehyde 3-phosphate dehydrogenase ,chemistry.chemical_classification ,biology ,L-Lactate Dehydrogenase ,Synovial Membrane ,Glyceraldehyde-3-Phosphate Dehydrogenases ,Middle Aged ,medicine.disease ,Molecular biology ,medicine.anatomical_structure ,Enzyme ,Biochemistry ,chemistry ,Rheumatoid arthritis ,biology.protein ,Female ,Synovial membrane ,Research Article - Abstract
It was conceivable that the previously reported elevated pentose-shunt activity in human rheumatoid synoviocytes could be at the expense of glycolytic activity. To test this possibility the activities of glyceraldehyde 3-phosphate and lactate dehydrogenase, the two dehydrogenase enzymes of the latter pathway, have been investigated in the synovial lining cells in fresh sections of nonrheumatoid and rheumatoid synovial tissue. To measure the activity solely in the lining cells, apart from that in underlying infiltrating cells, quantitative cytochemical reactions have been used; the activities were measured by microdensitometry. The results showed highly and significantly increased activity of both enzymes in the rheumatoid cells. Increased activity was also found in synoviocytes in nonrheumatoid synovial tissue after trauma, so that the increased activity of these enzymes is not characteristic of the rheumatoid condition. However, the results indicate that the increased pentose shunt activity in rheumatoid synovial lining cells is not at the expense of glycolytic activity but may be part of an enhanced potential for utilising glucose 6-phosphate in these cells.
- Published
- 1979
9. Metabolic alterations in human synovial lining cells in pigmented villonodular synovitis
- Author
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B Henderson, J J Johnstone, J Chayen, A Catterall, and L Bitensky
- Subjects
Adult ,Male ,medicine.medical_specialty ,Immunology ,Glucosephosphate Dehydrogenase ,Synovitis, Pigmented Villonodular ,Aminopeptidases ,Glyceraldehyde 3-Phosphate ,General Biochemistry, Genetics and Molecular Biology ,chemistry.chemical_compound ,Rheumatology ,Lactate dehydrogenase ,Synovitis ,Internal medicine ,medicine ,Immunology and Allergy ,Humans ,Sulfhydryl Compounds ,Phospholipids ,Aged ,L-Lactate Dehydrogenase ,business.industry ,Synovial Membrane ,Middle Aged ,medicine.disease ,medicine.anatomical_structure ,Endocrinology ,chemistry ,Biochemistry ,Pigmented villonodular synovitis ,Rheumatoid arthritis ,Cytochemistry ,Villonodular synovitis ,Female ,Glyceraldehyde 3-phosphate ,Synovial membrane ,business ,Lysosomes ,Research Article - Abstract
Synovial tissue from 3 patients with villonodular synovitis has been examined by quantitative cytochemistry. Considerable changes in the metabolism of the synoviocytes have been observed. These included a massive rise in the activity of glucose 6-phosphate dehydrogenase to levels even greater than those found in rheumatoid arthritis, and a significant rise in the activity of 2 glycolytic enzymes, glyceraldehyde 3-phosphate and lactate dehydrogenase. Lysosomal napthhylamidase showed raised activity with no latency. The sulphydryl content in the synoviocytes was raised, as was the amount of available phospholipid. This pattern of metabolic alterations is similar to that found in human rheumatoid synoviocytes.
- Published
- 1979
10. An aqueous mounting medium
- Author
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J Chayen and G Zaman
- Subjects
chemistry.chemical_compound ,Aqueous solution ,Chromatography ,Histocytochemistry ,Chemistry ,Polyvinyl Alcohol ,Specimen Handling ,General Medicine ,Polyvinyl alcohol ,Pathology and Forensic Medicine ,Research Article - Published
- 1981
11. Crystals in skeletal muscle
- Author
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R. W. E. Watts, J T Scott, R A Chalmers, J Chayen, and Lucille Bitensky
- Subjects
Chemistry ,Allopurinol ,Muscles ,General Engineering ,Skeletal muscle ,General Medicine ,law.invention ,Cold Temperature ,medicine.anatomical_structure ,law ,medicine ,Biophysics ,General Earth and Planetary Sciences ,Humans ,Crystallization ,General Environmental Science ,Research Article - Published
- 1972
12. Books and Monographs: Der gerechtfertigte Haeckel. Einblicke in seine Schriften aus Anlass des Erscheinens seines Hauptwerkes 'Generelle Morphologie der Organismen' vor 100 Jahren
- Author
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J. Chayen
- Subjects
Philosophy ,Genetics ,Humanities ,Genetics (clinical) ,Book Review - Published
- 1969
13. Die Evolution der Organismen. Band I. Ergebnisse und Probleme der Abstammungslehre 3rd ed
- Author
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J. Chayen
- Subjects
Philosophy ,Genetics ,Humanities ,Genetics (clinical) ,Book Review - Published
- 1968
14. Cryostat sections of undemineralized bone
- Author
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J Chayen, J J Johnstone, and L Bitensky
- Subjects
Cryostat ,Pathology ,medicine.medical_specialty ,Chemistry ,General Medicine ,Microtomy ,Bone and Bones ,Pathology and Forensic Medicine ,law.invention ,Cold Temperature ,law ,Microtome ,medicine ,Methods ,Animals ,Humans ,Research Article - Published
- 1972
15. Nucleic Acid Metabolism Cell Differentiation and Cancer Growth: Proceedings of the second international symposium for cellular chemistry
- Author
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J. Chayen
- Subjects
chemistry.chemical_compound ,Biochemistry ,Chemistry ,Cellular differentiation ,Genetics ,medicine ,Cancer ,Bioinformatics ,medicine.disease ,Genetics (clinical) ,Nucleic acid metabolism ,Book Review - Published
- 1970
16. Histochemical Comparison of the Effects of a Carcinogenic and a Non-Carcinogenic Derivative of Tricycloquinazoline.
- Author
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Diengdoh, J. V. and Baldwin J. Chayen, R. W.
- Published
- 1971
17. Cytochemical Bioassays : Techniques and Clinical Applications
- Author
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J Chayen, Lucille Bitensky, J Chayen, and Lucille Bitensky
- Subjects
- Cytochemical bioassay, Hormones--Analysis
- Abstract
Cytochemical Bioassays: Techniques and Clinical Applications describes the techniques and clinical applications of cytochemical bioassays, particularly with respect to polypeptide hormones. This book discusses the clinical and research implications of studies that use these techniques. This text is comprised of 14 chapters; the first of which introduces the reader to the origins and general principles of cytochemical bioassays, along with their advantages. This discussion is followed by a chapter that explains what is meant by''an assay''; for what purpose assays are done; the basic components of an assay method; and the nature of the difference between in vivo and in vitro hormone bioassays, in vitro ligand assays, and enzyme assays. Attention then turns to the techniques of cytochemical bioassays and the cytochemical bioassay procedures for adrenocorticotropic hormones; thyroid-stimulating hormones; the thyroid-stimulating antibody of Graves'disease; thyroid growth stimulating and blocking immunoglobulins; and luteinizing hormones. The next chapters focus on the technique and clinical relevance of a cytochemical bioassay for gastrin-like activity and for measurement of antidiuretic hormones, parathyroid hormones, angiotensin II, natriuretic hormones, and hypothalamic regulating hormones. This book will be of interest to clinicians and practitioners of biology, biochemistry, and endocrinology.
- Published
- 1983
18. The natural substrate for nitric oxide synthase activity.
- Author
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Alaghband-Zadeh J, Mehdizadeh S, Khan NS, O'Farrell A, Bitensky L, and Chayen J
- Subjects
- Animals, Female, Hydrogen-Ion Concentration, Liver chemistry, NADP metabolism, Rats, Rats, Wistar, Substrate Specificity, Time Factors, Arginine metabolism, Carnosine metabolism, Liver enzymology, Nitric Oxide Synthase metabolism
- Abstract
There has been little evidence to indicate that arginine is the natural substrate for generating nitric oxide synthase (NOS) activity. It is now shown that carnosine, which is widely distributed in tissues, is likely to be the true substrate. In tissue sections it gives a stronger NOS reaction than does arginine., (Copyright 2001 John Wiley & Sons, Ltd.)
- Published
- 2001
- Full Text
- View/download PDF
19. An improved histochemical method for measuring nitric oxide synthase activity.
- Author
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Alaghband-Zadeh J, Mehdizadeh S, O'Farrell A, Weisz J, Bitensky L, and Chayen J
- Subjects
- Acetates, Animals, Citric Acid, Female, Lead, Oxides, Rats, Rats, Wistar, Sensitivity and Specificity, Tissue Preservation, Histological Techniques, Nitric Oxide Synthase analysis
- Abstract
The previous quantitative histochemical method for measuring nitric oxide synthase (NOS) activity in tissue sections involved the loss of about 15 per cent of the NOS, presumably from the section into the reaction medium. Two changes are now described. The first is concerned with the preparation in the laboratory of the active reagent, lead ammonium citrate/acetate (LACA). The second change involves an improvement of the procedure for measuring NOS activity. The new method appears to retain all the measurable NOS activity inside the section., (Copyright 1999 John Wiley & Sons, Ltd.)
- Published
- 1999
- Full Text
- View/download PDF
20. Modulation of murine osteoarthritis.
- Author
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Chayen J, Bitensky L, and Chambers MG
- Subjects
- Animals, Anti-Inflammatory Agents, Non-Steroidal pharmacology, Cartilage enzymology, Cartilage pathology, Densitometry, Diclofenac pharmacology, Disease Models, Animal, Drug Combinations, Glycosides pharmacology, Male, Mice, Mice, Inbred Strains, Monoamine Oxidase drug effects, Monoamine Oxidase metabolism, Osteoarthritis enzymology, Osteoarthritis drug therapy
- Abstract
Up to nine out of 10 male STR/ORT mice develop osteoarthritis (OA) of the medial tibial cartilage at an early age. This has now been shown to be related to changes in the activity and distribution of monoamine oxidase which is related to the metabolism of catecholamines. Treatment with diclofenac sodium tended to normalize this activity but there was no significant histological improvement. It was therefore postulated that two influences were involved in the development of OA: a cellular and an extracellular factor. The first was improved by diclofenac sodium; the second, namely oedema of the matrix, was improved by tribenoside. In very preliminary studies, feeding the two drugs simultaneously resulted in 7/9 mice having no sign of OA.
- Published
- 1996
- Full Text
- View/download PDF
21. Measurement of nitric oxide synthase activity in sections of rat liver.
- Author
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Mehdizadeh S, O'Farrell A, Bitensky L, Weisz J, Alaghband-Zadeh J, and Chayen J
- Subjects
- Animals, Azides pharmacology, Female, Guanylate Cyclase metabolism, Liver drug effects, Rats, Rats, Wistar, Sodium Azide, Substrate Specificity, Time Factors, Liver enzymology, Nitric Oxide Synthase analysis
- Abstract
In the previous communication we described a histochemical method for measuring soluble guanylate cyclase (sGC) activity in sections of rat liver. In theory, this method could be used to assess nitric oxide synthase (NOS) activity by the increased sGC activity induced by the additional presence of the substrates for NOS activity. We found that this was correct provided that the concentration of the colloid stabilizer in the reaction medium was decreased to just below the concentration required to fully stabilize the guanylate cyclase activity in the sections. This was related to the fact that the site of NOS activity was different from that of the sGC activity in the hepatocytes, so that the NO generated had to diffuse from the Kupffer cells to the hepatocytes as could occur only in partially unstabilized sections. Optimal concentrations of arginine and of NADPH have been determined for demonstrating NOS activity; the increased reaction was shown to be largely inhibited by methyl-arginine.
- Published
- 1995
- Full Text
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22. Histochemistry of guanylate cyclase activity.
- Author
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Mehdizadeh S, O'Farrell A, Bitensky L, Weisz J, Alaghband-Zadeh J, and Chayen J
- Subjects
- Animals, Azides pharmacology, Female, Liver drug effects, Liver metabolism, Nitric Oxide Synthase metabolism, Rats, Rats, Wistar, Sodium Azide, Substrate Specificity, Guanylate Cyclase analysis
- Abstract
Guanylate cyclase liberates pyrophosphate from guanosine triphosphate (GTP). In studies published previously, this phosphate is trapped by lead ions even though it is known that free lead ions inactivate a considerable proportion of this enzymatic activity. To overcome the damaging effects of fixation, this study used fresh cryostat sections stabilized with a sufficient concentration of a collagen-derived polypeptide to ensure no measurable loss of guanylate cyclase activity. To avoid the damaging influence of free lead ions, we used a hidden metal capture reagent, i.e., a complex of lead ammonium citrate/acetate that does not react with GTP but which rapidly forms a precipitate with the pyrophosphate liberated by the enzyme. The lead precipitate is then converted into the colored sulfide which is measured in individual cells by microdensitometry. This system was used to measure guanylate cyclase activity in individual cells in unfixed sections of rat liver.
- Published
- 1995
- Full Text
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23. Histo- and cytochemistry of guanylate cyclase and nitric oxide synthase: a critical appraisal.
- Author
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Chayen J, Bitensky L, and Mehdizadeh S
- Subjects
- Animals, Histocytochemistry, Humans, NADPH Dehydrogenase analysis, Nitric Oxide Synthase, Staining and Labeling, Amino Acid Oxidoreductases analysis, Guanylate Cyclase analysis
- Published
- 1994
- Full Text
- View/download PDF
24. Testing drugs on human osteoarthritic articular cartilage.
- Author
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Chayen J, Bitensky L, Mehdizadeh S, Dunham J, and Older J
- Subjects
- Aged, Aged, 80 and over, Alcian Blue, Birefringence, Cartilage, Articular metabolism, Female, Hip Joint metabolism, Humans, Male, Middle Aged, Organ Culture Techniques, Osteoarthritis, Hip metabolism, Proteoglycans biosynthesis, Proteoglycans metabolism, Reproducibility of Results, Uridine Diphosphate Glucose Dehydrogenase metabolism, Cartilage, Articular drug effects, Diclofenac therapeutic use, Hip Joint drug effects, Indomethacin therapeutic use, Osteoarthritis, Hip drug therapy
- Abstract
New drugs are generally developed against animal models of the human disease. Before they are subjected to clinical trials it might be helpful to be able to test whether they are as effective against the disease in human tissue as they were in animals. It is proposed that this can be achieved by the use of organ maintenance culture of the human diseased tissue, the relevant biochemical parameters being measured by quantitative cytochemistry. In the present studies differences between the effect of indomethacin and of the 'chondroprotective' drug diclofenac sodium, on human osteoarthritic cartilage, have been measured.
- Published
- 1994
- Full Text
- View/download PDF
25. Abnormalities of DNA in human osteoarthritic articular cartilage.
- Author
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Macha N, Older J, Bitensky L, and Chayen J
- Subjects
- Aged, Aged, 80 and over, Cartilage, Articular pathology, Cell Nucleus chemistry, Female, Femoral Neck Fractures etiology, Fractures, Spontaneous etiology, Humans, Male, Osteoarthritis pathology, Osteoporosis complications, Osteoporosis metabolism, Osteoporosis pathology, Cartilage, Articular chemistry, DNA analysis, Osteoarthritis metabolism
- Abstract
The normal amount of DNA in human diploid nuclei was determined by the use of the Feulgen reaction measured by microdensitometry. The DNA-content of nuclei in normal human articular cartilage was determined in nuclei of zones 3 and 4 of cartilage of the femoral head removed from osteoporotic fractured necks of femur. Analysis of the results indicated that a degree of synthesis of DNA occurred even in these zones of very elderly persons. Results on these zones in the articular cartilage of osteoarthritic joints indicated that different populations occurred. In some there was DNA-synthesis related to tetraploidy; in others, the DNA was very stable to acid hydrolysis with no sign of biosynthetic activity; in the last group, which contained erosions of the superficial zones, the DNA was unstable to hydrolysis.
- Published
- 1993
- Full Text
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26. Intramuscular vitamin K and childhood cancer.
- Author
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Chayen J
- Subjects
- Humans, Infant, Newborn, Injections, Intramuscular, Leukemia chemically induced, Phenols administration & dosage, Vitamin K adverse effects
- Published
- 1992
- Full Text
- View/download PDF
27. Chondrocytic monoamine oxidase activity in the development of natural murine osteoarthritis.
- Author
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Chambers MG, Jasani MK, Bitensky L, and Chayen J
- Subjects
- Animals, Cartilage, Articular drug effects, Diclofenac pharmacology, Epinephrine pharmacology, Knee Joint enzymology, Male, Mice, Mice, Inbred Strains, Monoamine Oxidase Inhibitors pharmacology, Cartilage, Articular enzymology, Monoamine Oxidase metabolism, Osteoarthritis enzymology
- Abstract
Most of the male STR/ORT mice develop osteoarthritis (OA) involving the medial tibial plateau. A peculiarity of two chondroprotective drugs is the presence of a nitrogen atom so that cleavage of the molecule could generate a molecule that might act as an inhibitor of monoamine oxidase (MAO). Direct examination showed abnormal localization of MAO in the potentially osteoarthritic cartilage indicating possible abnormal response to catecholamines. In normal cartilage, the direct effect of excessive concentration of adrenaline caused considerable oedema, as measured by microscopic interferometry. It is therefore suggested that the excess of water found in the matrix of osteoarthritic cartilage may be related to disturbance of the MAO activity.
- Published
- 1992
28. The effect of menadione epoxide on the experimental immune arthritis in the rabbit.
- Author
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Pitsillides AA, Blake SM, Glynn LE, Frost GT, Bitensky L, and Chayen J
- Subjects
- Animals, Arthritis, Experimental enzymology, Arthritis, Experimental pathology, Body Temperature drug effects, Carboxylic Ester Hydrolases drug effects, Carboxylic Ester Hydrolases metabolism, Female, Glucosephosphate Dehydrogenase drug effects, Glucosephosphate Dehydrogenase metabolism, Phosphogluconate Dehydrogenase drug effects, Phosphogluconate Dehydrogenase metabolism, Rabbits, Vitamin K therapeutic use, Arthritis, Experimental drug therapy, Vitamin K analogs & derivatives, Vitamin K 3 analogs & derivatives
- Abstract
It was shown previously that the experimentally induced arthritis in the rabbit can be largely nullified by subsequent treatment with menadione (by gavage). It is now shown that menadione epoxide, as is produced in the vitamin K cycle, also exerts a beneficial effect histologically and biochemically. Such treatment decreased both the glucose 6-phosphate dehydrogenase and the 6-phosphogluconolactonase activities in the synovial lining cells of the challenged joints towards values found in the unchallenged joints; it had only equivocal effects on the 6-phosphogluconate dehydrogenase activity. The results indicated that the epoxide might be interfering primarily with the lactonase activity.
- Published
- 1991
29. The assay of uridine diphosphoglucose dehydrogenase activity: discrimination from xanthine dehydrogenase activity.
- Author
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Mehdizadeh S, Bitensky L, and Chayen J
- Subjects
- Animals, Cartilage, Articular enzymology, Enzyme Stability drug effects, Female, Kinetics, Methylphenazonium Methosulfate pharmacology, Mice, Mice, Inbred CBA, NAD pharmacology, Potassium Cyanide pharmacology, Uridine Diphosphate Glucose Dehydrogenase metabolism, Xanthine Dehydrogenase metabolism
- Abstract
The biochemical and quantitative cytochemical assays of the activity of uridine diphosphoglucose dehydrogenase (UDPG-D) have produced perplexing results. It is now shown that the perplexity may be due to the possibility that the coenzyme (NAD) required for UDPG-D activity, may be acting as a substrate for a second dehydrogenase, namely xanthine dehydrogenase, which may utilize NAD as its substrate. The activity of UDPG-D can be distinguished selectively by the pH of its optimal activity and by decreasing the concentration of the coenzyme used in the assay.
- Published
- 1991
- Full Text
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30. Depressed levels of circulating menaquinones in patients with osteoporotic fractures of the spine and femoral neck.
- Author
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Hodges SJ, Pilkington MJ, Stamp TC, Catterall A, Shearer MJ, Bitensky L, and Chayen J
- Subjects
- Aged, Aged, 80 and over, Female, Femoral Neck Fractures etiology, Humans, Male, Middle Aged, Spinal Fractures etiology, Vitamin K blood, Femoral Neck Fractures blood, Osteoporosis complications, Spinal Fractures blood, Vitamin K analogs & derivatives, Vitamin K 2 analogs & derivatives
- Abstract
Vitamin K1 functions in the conversion of glutamate residues, present in certain bone peptides, into the putatively active gamma-carboxyglutamate form. We have shown previously that the circulating levels of vitamin K1 are depressed in osteoporotic patients. However, it is known that menaquinones (vitamin K2:MK) may be more effective than vitamin K1 in this conversion of the inactive to active form of glutamate residues. A procedure for measuring such menaquinones has now demonstrated a marked deficiency of MK-7 and MK-8 in patients with osteoporotic fractures. It is suggested that estimates of circulating levels of K1, MK-7, and MK-8 might provide a biochemical risk marker of osteoporotic fractures.
- Published
- 1991
- Full Text
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31. Amelioration by menadione of the experimental chronic immune arthritis in the rabbit.
- Author
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Pitsillides AA, Blake SM, Glynn LE, Bitensky L, and Chayen J
- Subjects
- Animals, Arthritis, Experimental pathology, Disease Models, Animal, Female, Glucosephosphate Dehydrogenase metabolism, Rabbits, Synovial Membrane enzymology, Arthritis, Experimental drug therapy, Vitamin K therapeutic use
- Abstract
The immunological induction of arthritis in the knee of the rabbit is well established as a model for human rheumatoid arthritis. It has the special advantage of allowing the development of the condition, and the effect of disease-modifying agents, to be followed. Attention has been focussed on the activity of glucose 6-phosphate dehydrogenase in the synovial lining cells since the fourfold elevation of this activity was shown to be fundamental in the human condition. An equal elevation of this activity has now been demonstrated in the rabbit model. Furthermore, it has been shown that the oral administration of menadione decreases this activity towards normality with a concomitant decrease in the degree of inflammation.
- Published
- 1990
- Full Text
- View/download PDF
32. T-cell mediated cytolysis: evidence for target-cell suicide.
- Author
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Chayen J, Pitsillides AA, Bitensky L, Muir IH, Taylor PM, and Askonas BA
- Subjects
- Animals, Cell Communication, Cells, Cultured, Eflornithine pharmacology, Glucosephosphate Dehydrogenase metabolism, Mast Cells drug effects, Mast Cells enzymology, Mast Cells immunology, Mice, Polyamines pharmacology, Cytotoxicity, Immunologic drug effects, Ornithine Decarboxylase physiology, T-Lymphocytes, Cytotoxic physiology
- Abstract
The mechanism by which cytotoxic T-lymphocytes (Tc) induce the death of specific target cells is still controversial. We have used quantitative cytochemical methods to distinguish the metabolic activities of the target cells from those of the Tc, even when they are attached to each other. Early events following Tc-P8(15) target cell interaction were first, increased glucose 6-phosphate dehydrogenase activity and second, labilization of the lysosomes within the target cell: these changes could be mimicked, in part, by polyamines and could be inhibited by inhibiting ornithine decarboxylase (ODC) activity. The crucial role of ODC in the chain of events that led to cytolysis in this particular experimental system was shown first, by measuring ODC activity directly and secondly, by the inhibition of cytolysis by the presence of a selective inhibitor of ODC activity.
- Published
- 1990
33. Peculiar ultraviolet absorbing moieties of human osteoarthritic cartilage.
- Author
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Chayen J, Bitensky L, and Nahir AM
- Subjects
- Aged, Aged, 80 and over, Cartilage, Articular ultrastructure, Female, Humans, Male, Middle Aged, Osteoarthritis metabolism, Spectrophotometry, Ultraviolet, Cartilage, Articular analysis, Osteoarthritis pathology
- Abstract
The ultraviolet absorbing components of human cartilage have been measured by microspectrophotometry. The characteristics of the chondrocytes appeared to be identical, irrespective of the pathology. However the matrix of osteoarthritis cartilage contained components that absorbed maximally in the region of 270 to 250 nm; such components were not found in the matrix of cartilage of non-arthritic joints. Substances that absorb maximally in this region of the ultraviolet could generate free radicals.
- Published
- 1990
- Full Text
- View/download PDF
34. Changes in the orientation of proteoglycans during the early development of natural murine osteoarthritis.
- Author
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Dunham J, Chambers MG, Jasani MK, Bitensky L, and Chayen J
- Subjects
- Aging metabolism, Alcian Blue, Animals, Birefringence, Cartilage metabolism, Cartilage pathology, Collagen metabolism, Male, Mice genetics, Mice, Inbred Strains, Osteoarthritis genetics, Osteoarthritis metabolism, Osteoarthritis veterinary, Proteoglycans metabolism, Rodent Diseases metabolism
- Abstract
At least 80% of male STR/ORT mice naturally develop osteoarthritis that predominantly affects the medial tibial cartilage. Overt osteoarthritic changes, as judged by radiological and histological abnormalities, become apparent after 30 weeks of age. Consequently, mice less than 30 weeks of age were used to investigate early changes in the cartilage matrix related to the natural development of osteoarthritis, without the need for experimental intervention to induce this condition. Quantitative Alcian blue staining showed little change in the total amount of proteoglycans in mice of this age. Polarized light microscopy of the birefringence induced by such staining demonstrated a progressive decline in the orientation of the proteoglycans in the medial cartilage of these mice. This decline was not found in CBA mice, which only very rarely develop osteoarthritis of this joint. Such progressive disorganization of the proteoglycans would be likely to permit the increase free water-content characteristic of osteoarthritic cartilage.
- Published
- 1990
- Full Text
- View/download PDF
35. Selective depression of metabolic activities in cortical osteoblasts at the site of femoral neck fractures.
- Author
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Dodds RA, Emery RJ, Klenerman L, Chayen J, and Bitensky L
- Subjects
- Aged, Aged, 80 and over, Female, Histocytochemistry, Humans, Male, Middle Aged, Osteoblasts enzymology, Femoral Neck Fractures metabolism, Osteoblasts metabolism
- Abstract
The aim of this investigation was to determine whether some metabolic defect might be related to the propensity of osteoporotic femoral necks to fracture acutely. To this end, the activities of two dehydrogenases of the glycolytic Embden-Meyerhof pathway, two of the pentose phosphate pathway, two mitochondrial enzymes, and alkaline phosphatase were measured in the cortical and in the trabecular osteoblasts. Comparison was made with such activities in iliac crest biopsies from patients with these fractures and from the equivalent femoral and iliac crest samples from patients with osteoarthritis of the hip, in biopsies from the iliac crests from seven patients with no bony abnormality, and in specimens from the fracture site of six traumatic fractures. The results showed a highly significant decrease in the activities of the two enzymes of the pentose phosphate pathway (p less than 0.001) in the cortical, but not in the trabecular, osteoblasts in the osteoporotic fractures. This could not be attributed to the trauma of acute fracture since it was not found in traumatic fractures. Other experimental evidence has indicated that a relationship may occur between depressed activity of these enzymes and a retardation of bone formation.
- Published
- 1990
- Full Text
- View/download PDF
36. Age-related changes in the circulating levels of congeners of vitamin K2, menaquinone-7 and menaquinone-8.
- Author
-
Hodges SJ, Pilkington MJ, Shearer MJ, Bitensky L, and Chayen J
- Subjects
- Adult, Aged, Aged, 80 and over, Chromatography, High Pressure Liquid, Female, Humans, Male, Middle Aged, Vitamin K blood, Vitamin K 1 blood, Aging blood, Vitamin K analogs & derivatives, Vitamin K 2 analogs & derivatives
- Abstract
1. Through the vitamin K1 cycle, phylloquinone is now known to play an active role, not only in relation to prothrombin, but also in the synthesis of bone peptides. 2. The recent development of a sensitive method allowed the demonstration of a deficit of vitamin K1 in the circulation of osteoporotic subjects. 3. Vitamin K2, namely the menaquinones of various chain-lengths, has been shown by others to be more effective than vitamin K1 in the curative rat bioassay. 4. Earlier reports had shown that the concentration of menaquinones in human liver may exceed that of vitamin K1. But previous methods were too insensitive for testing the normal circulating levels of menaquinones in the human. 5. The new sensitive method has now been applied to measuring the circulating levels of vitamin K1 and of two of the menaquinones, namely menaquinone-7 and menaquinone-8. 6. In normal individuals, the circulating levels of vitamin K1 were the same, irrespective of age. 7. In young normal subjects, the combined levels of menaquinone-7 and menaquinone-8 were at least the same as the level of vitamin K1. In elderly normal subjects, there was a marked deficit of menaquinone-8.
- Published
- 1990
- Full Text
- View/download PDF
37. Synthesis of arachidonate cyclo-oxygenase products by rheumatoid and nonrheumatoid synovial lining in nonproliferative organ culture.
- Author
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Salmon JA, Higgs GA, Vane JR, Bitensky L, Chayen J, Henderson B, and Cashman B
- Subjects
- Adolescent, Adult, Aged, Arthritis, Rheumatoid enzymology, Dinoprostone, Female, Humans, Male, Middle Aged, Organ Culture Techniques, Prostaglandin-Endoperoxide Synthases metabolism, Synovial Membrane enzymology, 6-Ketoprostaglandin F1 alpha biosynthesis, Arthritis, Rheumatoid metabolism, Prostaglandins E biosynthesis, Synovial Membrane metabolism, Thromboxane B2 biosynthesis, Thromboxanes biosynthesis
- Abstract
Specimens of human rheumatoid and nonrheumatoid synovial lining were maintained in nonproliferative organ culture for 20 hours. The culture fluids were then assayed for prostaglandin E(2) (PGE(2)), thromboxane B(2) (TXB(2)), and 6-keto-prostaglandin F(1alpha) (6-keto-PGF(1alpha)) by specific radioimmunoassay. The presence of each of these substances was confirmed by gas chromatography and mass spectrometry. Rheumatoid tissue produced significantly more of each cyclo-oxygenase product than nonrheumatoid tissue.
- Published
- 1983
- Full Text
- View/download PDF
38. Use of microscopic interferometry for measuring changes in water content of small samples of tissue.
- Author
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Darracott-Canković S, Braimbridge MV, Kyösola K, Bitensky L, and Chayen J
- Subjects
- Animals, Coronary Disease metabolism, Densitometry, Edema, Cardiac metabolism, Male, Microscopy, Interference, Rats, Rats, Inbred Strains, Body Water analysis, Edema, Cardiac diagnosis, Heart Failure diagnosis
- Abstract
Oedema following periods of ischaemic arrest and subsequent reperfusion has been shown experimentally and clinically to affect the functional state of the heart. Tissue water content has been measured in myocardial sections by microscopic interferometry and densitometry, and the results correlated with those obtained by wet and dry weight analysis (r = 0.87; p less than 0.001). Microscopic interferometry also revealed the distribution of the water in the tissue. Experimentally induced ischaemic arrest in isolated rat hearts resulted in predominantly intra-fibrillar oedema, whilst subsequent reperfusion resulted in interfibrillar oedema. Microscopic interferometry facilitates accurate measurement of water content in tissue samples as small as 2 mg wet weight and shows (as conventional wet/dry weight analysis cannot) the distribution of the water in the tissue.
- Published
- 1984
- Full Text
- View/download PDF
39. The cytochemical section-bioassay of gastrin-like activity.
- Author
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Loveridge N, Hoile RW, Johnson AG, Gardner JD, and Chayen J
- Subjects
- Animals, Carbonic Anhydrases metabolism, Cholecystokinin pharmacology, Female, Guinea Pigs, Histocytochemistry, Humans, Secretin pharmacology, Gastrins
- Abstract
A cytochemical section-bioassay of gastrin-like activity is described in which such activity in plasma is assayed by its stimulation of carbonic anhydrase activity in serial, 18 micrometers-thick, sections of suitably prepared gastric fundus of the guinea-pig. The index of precision was 0.1 +/- 0.05 (mean +/- SEM; n=8). Fiducial limits were 75-134%. Intra-assay variation was +/- 6.4% (n=4); inter-assay variation was +/- 16.3% (n=3). The mean gastrin-like activity in the plasma of 15 fasting normal subjects was 5.1 +/- 0.49 x 10(-12)M (range 1.4-18.2 x 10(-12)M).
- Published
- 1980
- Full Text
- View/download PDF
40. Changes in oxidative activities of chondrocytes during the early development of natural murine osteoarthritis.
- Author
-
Dunham J, Chambers MG, Jasani MK, Bitensky L, and Chayen J
- Subjects
- Animals, Cartilage, Articular pathology, Glucosephosphate Dehydrogenase metabolism, Glyceraldehyde-3-Phosphate Dehydrogenases metabolism, Knee Joint pathology, L-Lactate Dehydrogenase metabolism, Mice, Mice, Inbred Strains, Osteoarthritis pathology, Cartilage, Articular enzymology, Knee Joint enzymology, Osteoarthritis enzymology
- Abstract
A high incidence of natural osteoarthritis of the knee joint is found in male mice of the STR/ORT strain. The condition affects mainly the medial tibial cartilage and by the age of 27 weeks most male mice of this strain show some osteoarthritic change. Analysis of the oxidative metabolism of the chondrocytes during the development of the lesion has been facilitated by the techniques of quantitative cytochemistry. The activity of glucose-6-phosphate dehydrogenase (G6PD) has been investigated as indicative of the NADPH-generating pentose-phosphate pathway; the activities of glyceraldehyde-3-phosphate (G3PD) and lactate dehydrogenase (LDH) have been studied as indicators of glycolytic activity. In young STR/ORT mice the G6PD activity of the lateral tibial cartilage was greater and more variable than in the control mice of the CBA/HT6 strain. The activity in the medial cartilage, relative to that in the lateral cartilage, decreased with age; this change was not reflected in the activities of the other enzymes. In the lateral cartilage, the expected relationship was found between the G6PD and the G3PD activities and between the LDH and the G3PD activities. In the medial cartilage, the G6PD activities were not related to the G3PD activities. The decreased proportionality of the G6PD activities in the medial cartilage as against that in the lateral cartilage was detected in mice as young as 9 weeks; by 27 weeks of age nine of the 13 mice showed marked depression of medial as against lateral G6PD activities. In contrast, only four of the 13 mice showed any overt histological charge until up to the age of 28 weeks.(ABSTRACT TRUNCATED AT 250 WORDS)
- Published
- 1988
41. The origin of the apparent synovial lining cell hyperplasia in rheumatoid arthritis: evidence for a deep stem cell.
- Author
-
Howat DW, Glynn LE, Bitensky L, and Chayen J
- Subjects
- Animals, Autoradiography, Cell Count, Cell Differentiation, Hyperplasia, Rabbits, Synovial Membrane metabolism, Thymidine metabolism, Tritium, Arthritis, Rheumatoid pathology, Synovial Membrane pathology
- Abstract
The experimental model of inflammatory arthritis in the rabbit has been used to study the possible origin of the apparent synovial lining cell hyperplasia. A small amount of 3H-thymidine was injected into the joints and the fate of the labelled cells investigated by autoradiography. At times up to 24 h after the injection, most of the labelled cells occurred in the sub-lining region; this proportionality was reversed when the joints were sampled at later times. These results indicate that at least much of the increase of synovial lining cells may be derived from cells from deeper in the synovial tissue which move to the synovial surface.
- Published
- 1987
42. Experimental allergic arthritis in the rabbit: alterations in the cellularity and the rate of cellular proliferation in the synovial linings of the challenged joints of rabbits immunized with antigen in Freund's incomplete adjuvant.
- Author
-
Henderson B, Glynn LE, and Chayen J
- Subjects
- Animals, Arthritis, Experimental immunology, Autoradiography, Cell Division, DNA biosynthesis, Female, Male, Neutrophils, Ovalbumin immunology, Rabbits, Time Factors, Arthritis pathology, Arthritis, Experimental pathology, Synovial Membrane pathology
- Abstract
Rabbits have been immunized with ovalbumin in Freund's incomplete adjuvant (FIA) followed by the intra-articular injection of ovalbumin, in order to follow the development of inflammation in the synovial lining. The kinetics of cell proliferation have been investigated using tritiated thymidine (3HTdR) autoradiography and Feulgen cytophotometry. Unexpectedly, marked histological changes were found in the synovium, with hyperplasia of synoviocytes, and of the connective-tissue cells of the subintima, being seen as early as 3 days after challenge. Large numbers of inflammatory cells, including many plasma cells, were found in the synovium at between 5 and 11 days. Labelling of synoviocytes and connective-tissue cells reached a maximum at 3 days and declined thereafter, reaching normal levels at 14 days. Three weeks after challenge the synovium was normal in appearance.
- Published
- 1982
43. 5' nucleotidase activity in the human synovial lining in rheumatoid arthritis.
- Author
-
Henderson B, Johnstone JJ, and Chayen J
- Subjects
- Densitometry, Humans, Kinetics, Synovial Membrane blood supply, Arthritis, Rheumatoid enzymology, Nucleotidases metabolism, Synovial Membrane enzymology
- Abstract
5'-Nucleotidase (EC 3.1.3.5), a plasma membrane-bound enzyme, has been assayed in unfixed tissue sections of human synovium, activity being measured by scanning and integrating microdensitometry. Activity was markedly increased in the lining cells of the rheumatoid synovial membranes.
- Published
- 1980
- Full Text
- View/download PDF
44. Changes in crystal size and orientation of acidic glycosaminoglycans at the fracture site in fractured necks of femur.
- Author
-
Kent GN, Dodds RA, Klenerman L, Watts RW, Bitensky L, and Chayen J
- Subjects
- Aged, Birefringence, Collagen analysis, Crystallization, Female, Humans, Male, Microscopy, Polarization, Middle Aged, Osteoarthritis metabolism, Femoral Neck Fractures metabolism, Femur Neck analysis, Glycosaminoglycans analysis
- Abstract
The aim of this study was to try to elucidate the increased susceptibility of the neck of femur to fracture. Quantitative polarised light microscopy has been applied to fresh, undecalcified sections of samples of bone taken from the site of fracture, in specimens taken at operation from patients with fractures of the femoral neck or osteoarthritic femoral heads or from the equivalent site from otherwise normal subjects at necropsy. In all 21 specimens of fractured necks of femur, but in none of the other specimens, relatively large crystals (up to 2.5 X 0.5 micrometres) were found close to the site of fracture; the properties of these crystals were compatible with their being apatite. Measurement of the natural birefringence of the collagen showed no difference in the orientation of the collagen in all three types of specimen. However, the orientation of acidic glycosaminoglycans, measured by the birefringence of alcian blue bound to these moieties, was 45 per cent lower in the specimens from fractured necks of femur than in the other specimens, even though the total content of acidic glycosaminoglycans was unchanged. Although the decreased orientation was most marked close to the site of fracture, it was still apparent 15 millimetres from that site. These changes were unlikely to be simply the sequelae of fracture since they were not found in traumatic fractures of other bones. Thus it is conceivable that changes in the orientation of the ground substance allow formation of relatively large crystals of apatite and that such crystals, in the microcrystalline mass of apatite, are the cause of the increased fragility of such bones.
- Published
- 1983
- Full Text
- View/download PDF
45. The application of microdensitometry and microfluorimetry to the measurement of the biochemical activity of the individual cell.
- Author
-
Chayen J
- Subjects
- Animals, Densitometry methods, Humans, Kinetics, Microscopy, Fluorescence methods, NADP metabolism, Cells metabolism
- Published
- 1981
- Full Text
- View/download PDF
46. The effect of spermidine on lysosomes in thyroid follicle cells [proceedings].
- Author
-
Gilbert DM, Besser GM, Bitensky L, and Chayen J
- Subjects
- Aminopeptidases metabolism, Animals, Female, Guinea Pigs, Lysosomes drug effects, Thyroid Gland drug effects, Lysosomes enzymology, Spermidine pharmacology, Thyroid Gland enzymology
- Published
- 1977
- Full Text
- View/download PDF
47. Cell division in the synovial lining in experimental allergic arthritis: proliferation of cells during the development of chronic arthritis.
- Author
-
Henderson B, Glynn LE, and Chayen J
- Subjects
- Animals, Cell Division, Chronic Disease, Disease Models, Animal, Female, Knee Joint pathology, Male, Rabbits, Arthritis pathology, Synovial Membrane pathology
- Abstract
The synovial tissue in experimentally induced immune arthritis induced in the rabbit has been used as a model of rheumatoid arthritis to determine which cells may contribute to the growth of this tissue. Tissue from the challenged and from the unchallenged knee joints was taken, after the intra-articular injection of a small amount of tritiated thymidine, from rabbits up to 3 months after the arthritis was induced. DNA synthesis, as a measure of cell proliferative activity, was assessed firstly by measuring the labelling index in autoradiographs of sections of such tissue, and secondly by the DNA synthetic index obtained by Feulgen cytophotometry. These measurements were made separately on synoviocytes, on the structural cells of the stroma, on the cells lining the small blood vessels, and on the infiltrating inflammatory cells. The DNA synthetic activity of the synoviocytes, and of the stromal noninflammatory cells, was maximal between 3 and 7 days after challenge. The activity in the synoviocytes, in particular, remained raised for up to 84 days after the challenge. Thus these cells appear to be capable of contributing to the hyperplasia, but the contribution of other cells, deeper in the stroma, cannot be excluded.
- Published
- 1982
- Full Text
- View/download PDF
48. An effect of parathyroid hormone on the epiphyseal plate and osteoblasts: studies towards a cytochemical bioassay.
- Author
-
Dunham J and Chayen J
- Subjects
- Animals, Female, Humans, Parathyroid Hormone pharmacology, Rats, Rats, Inbred Strains, Biological Assay methods, Growth Plate drug effects, Osteoblasts drug effects, Parathyroid Hormone analysis
- Abstract
There are reports of an apparent dissociation between the responses of kidney and bone to parathyroid hormone (PTH): certain fragments or analogues have been shown to have differential activity in these two tissues. Consequently, cytochemical bioassay techniques have been applied to the development of an assay for PTH using the epiphyseal plate of the rat metatarsal as the target organ. Glucose 6-phosphate dehydrogenase activity in the zone of hypertrophic cartilage is stimulated in a log-linear fashion with increasing concentrations of parathyroid hormone over the range 0.001 - 1.0 pg/ml. A parallel response was found in the osteoblasts of the metaphysis. Measurements of a normal and a hyperparathyroid plasma sample showed good parallelism to the standard graph and good discrimination. Addition of a PTH - specific antibody inhibited both the effect of the standard preparation of the hormone, and the response induced by dilutions of a normal plasma.
- Published
- 1983
- Full Text
- View/download PDF
49. General introduction to cytochemical hormone bioassay.
- Author
-
Chayen J
- Subjects
- Animals, Cells metabolism, Cells, Cultured, DNA metabolism, Densitometry, Humans, Spectrophotometry, Biological Assay, Histocytochemistry, Hormones analysis
- Published
- 1974
- Full Text
- View/download PDF
50. The cytochemical bioassay of polypeptide hormones.
- Author
-
Chayen J
- Subjects
- Adrenocorticotropic Hormone analysis, Adrenocorticotropic Hormone physiology, Animals, Corticotropin-Releasing Hormone analysis, Densitometry, Forecasting, Gastrins analysis, Gastrins physiology, Histological Techniques, Humans, Infant, Newborn, Luteinizing Hormone analysis, Luteinizing Hormone physiology, Microchemistry, Organ Culture Techniques, Parathyroid Hormone analysis, Parathyroid Hormone physiology, Radioimmunoassay, Spectrophotometry, Thyrotropin analysis, Thyrotropin physiology, Thyrotropin-Releasing Hormone analysis, Biological Assay methods, Histocytochemistry methods, Hormones analysis
- Published
- 1980
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