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Biomedical subjects

A Jung

Publications and source records attributed to A Jung.

At least 181 records · Page 10Linked to original sources

[Further purification of a tissue specific inhibitor in lymphopoiesis (lymphocyte chalone?) (author's transl)].

A partially purified calf spleen extract, which exhibits the properties of a lymphocyte chalone (tissue-specific, species non-specific, non-toxic and reversible acting, endogenous inhibitor of cell proliferation) as concerning biological activities, has been described earlier. This fraction has been further purified by ion exchange chromatography with DEAE-Sephacel to a 10,000-fold purification. The most active fraction inhibited 3H-thymidine incorporation into phytohemagglutinin- or pokeweed-mitogen-stimulated lymphocytes by 86% resp. 70%, when given in a concentration of 100 ng/ml. Ehrlich-ascites-cells were not inhibited by the same concentration. The inhibiting activity is compared to other published lymphocyte inhibitors.

Animals↗

Uptake by bone of pyrophosphate, diphosphonates and their technetium derivatives.

1. The uptake of inorganic pyrophosphate (PPi) from blood to bone was investigated in the rat in vivo. 2. PPi is taken up by the bone, where it appears both as PPi and as inorganic orthophosphate (Pi). The latter is due at least partly to local hydrolysis. 3. The fraction of injected PPi taken up by bone, measured as total PPi, was in the same range as that of technetium-tin-PPi, diphosphonates, technetium-tin-ethane-1-hydroxy-1,1-diphosphonate and Pi, but lower than that of calcium. 4. The plasma half-life of PPi is in the same order of magnitude as that of technetium-tin-PPi, diphosphonates, technetium-tin-ethane-1-hydroxy-1,1-diphosphonate, Pi and calcium. 5. PPi, diphosphonates and their technetium complexes are only partly ultrafiltrable in plasma. 6. It appears that the technetium complexes behave in a similar fashion to free PPi or diphosphonate.

Animals↗

[Imidazole nucleosides, III. Nucleosides of 4(5)-aminoimidazole-5(4)-carboxamide (author's transl)].

The synthesis and properties of 13 nucleosides derived from 5-aminoimidazole-4-carboxamide and from 4-aminoimidazole-5-carboxamide are described. The isomers were oriented by comparison of their spectra and colour reactions. All compounds were tested for anticancer activity. 4-Amino-1-(alpha-D-arabinopyranosyl)-imidazole-5-carboxamide significantly inhibits the growth of Ehrlich ascites carcinoma (fluid form) in mice.

Aminoimidazole Carboxamide↗

[Treatment of 10 cases of symptomatic Paget's disease with etidronate (EHDP)].

10 patients with active symptomatic Paget's disease of bone have been treated for 6 months with disodium etidronate (EHDP) at a dose of 20 mg/kg/day. A statistically significant fall in the serum levels of alkaline phosphatase and urinary hydroxyproline was observed. However, only 2 patients experienced a significant reduction of bone pain. 6 patients were partially improved and 2 patients showed no change. Iliac crest biopsies after treatment demonstrated dimunution of the abnormal structure of the pagetic bone, but also a considerable increase in unmineralized osteoid borders. The future potentialities for treatment of Paget's disease are discussed.

Aged↗

[Tissue specific inhibition of lymphocyte proliferation by spleen extract (lymphocyte chalone) (author's transl)].

Aqueous spleen extracts were purified using acetone precipitation, membrane filtration, affinity chromatography, and dialysis. These extracts were able to inhibit thymidine incorporation into lymphoid cells (MKT-CH and PHA-stimulated lymphocyte cultures). They did not influence non lymphoid tissue (melanoma cells Mel Ei 78 and Ehrlich ascites cells). The inhibition was reversible and the purified extracts were not cytotoxic. The extracts correspond to a chalone. Their importance for prevention of graft versus host reaction and for treatment of lymphoproliferative diseases is discussed.

Animals↗

Molecular and kinetic properties of 15-hydroxyprostaglandin dehydrogenase (PG-15-HDH) from human placenta.

Some molecular properties of PG-15-HDH from human term placenta were investigated. Using a computer-based weighted linear regression analysis, intersecting initial rate patterns were received for the forward reaction with the prostaglandins (PG) E1, E2, and F2alpha, respectively, and NAD as substrates. NADH exerted a linear competitive inhibition with respect to NAD. The 15-ketoprostaglandins (15-keto-PG) E1 and F2alpha showed a linear noncompetitive inhibition with respect to their corresponding PG. The kinetic patterns suggest an ordered Bi Bi mechanism of PG-15-HDH reaction. The results are discussed with respect to their possible biological significance.

Alcohol Oxidoreductases↗

[Treatment of Paget's disease with phosphonates].

A group of 22 patients with Paget's disease of bone was treated with a diphosphonate (sodium etidronate; EHDP), a stable synthetic analogue of inorganic pyrophosphate. This substance was given during 3 months at the dose of 20 mg/kg body weight per day, and proved effective by reducing the raised urinary excretion of total hydroxyproline and by lowering the concentration of serum alcaline phosphatase. It also improved the disease-related osteo-articular pain in 60% of the patients. A rise in serum phosphate under EHDP therapy is due to the increase in renal tubular reabsorption of phosphate. Bone histology showed regression of disease activity and the appearance of lamellar structure in newly formed bone. Because of a transient increase of the amount of uncalcified osteoid, it is advisable to give the diphosphonate in courses not over 3 months or at a reduced daily dose.

Adult↗

[Alkaline phosphatase isoenzymes. Selection of the seperation methods and their diagnostic value].

Polyacrylamide gel electrophoresis (PAGE) of alkaline phosphatase (AP) was performed in 116 patients with elevated AP and in 36 controls. Results were compared with clinical data and with the heat inactivation techniques for AP isoenzyme separation. This latter method is simple but approximate; it is without value in the case of coexistent bone and liver pathology. PAGE gave a clear separation of liver, bile, bone, and intestinal AP isoenzymes. Disagreement with clinical data was rare (6 out of 86) and occurred in cases of associated bone and liver pathology (with 1 exception only), where one of these two abnormalities was not detected. Heat inactivation is useful as a screening test. If the cause of the elevated AP remains unknown after a few simple examinations, PAGE should then be utilized. Although more time-consuming, it is certainly more effective in the separation of AP isoenzymes.

Adult↗

Effects of a diphophonate on calcium metabolism in calcium-deprived rats.

Calcium metabolism was studied in growing rats, submitted to calcium deprivation ofvarious intensity. A decreased intake resulted in decreased net absorption of calcium(V'na), no change in bone formation (V'o+), and an increase in bone resorption (V'o -). In animals given dichloromethylene disphosphate (Cl'2MDP), a compoundknown to inhibit bone resorption, V'o+ was less than in the controls but again the same at all calcium intakes; V'na was below V'o+, V'o- still increased as the calcium intake was reduced. The various kinetic parameters in rats receiving Cl'2MDPwere indistinguishable from published data in parathyroidectomized (PTX) animals, yetblood calcium was low in PTX rats but normal in Cl'2MDP-atreated rats. It appears that the rat has an efficient mechanism for increasing bone resorption which is not inhibited by Cl'2MDP and does not require parathyroid hormone.

Animals↗

Inorganic pyrophosphate pool size and turnover rate in arthritic joints.

Recent studies have shown elevated inorganic pyrophosphate (PPi) levels in most knee joint fluid supernates from patients with pseudogout (PG) or osteoarthritis (OA) and more modestly elevated levels in some supernates from patients with gout or rheumatoid arthritis (RA) relative to PPi levels found in the venous blood plasma of normal or arthritic subjects. We measured the intraarticular PPi pool and its rate of turnover to better understand the significance of the joint fluid-plasma PPi gradient. Preliminary studies in rabbits showed that (32-P)PPi passed from joint space to blood and vice versa without detectable hydrolysis. Incubation of natural or synthetic calcium pyrophosphate dihydrate (CPPD) microcrystals with synovial fluid in vitro in the presence of (32P)PPi tracer showed no change in PPi specific activity in the supernate over a 19-h period so that exchange of PPi in solution with that in CPPD microcrystals could be ignored. Clearance rates of (32P)PPi and of (33P)Pi, as determined by serially sampling the catheterized knee joints of volunteers with various types of arthritis over a 3-h period, were nearly identical. The (32P)PPi/(32P)Pi was determined in each sample. A mixture of a large excess of cold PPi did not influence the clearance rate of either nuclide. The quantity of PPi turned over per hous was calculated from the pool size as determined by isotope dilution and the turnover rate. The residual joint fluid nuclide was shown to be (32P)PPi. The PPi pool was generally smaller and the rate of turnover was greater in clinically inflamed joints. The mean plus or minus SEM pool size (mu-moles) and turnover rate (percent/hour) in PG knees was 0.23 plus or minus 0.07 and 117 plus or minus 11.9, hydrolysis rate (%/h) to Pi was 27.7 plus or minus 13.2; in OA knees: 0.45 plus or minus 0.26 and 72 plus or minus 9.2, hydrolysis 6.9 plus or minus 0.9; in gouty knees: 0.8 plus or minus 0.41 and 50 plus or minus 11.6, hydrolysis 9.8 plus or minus 2.8; and in RA knees: 0.14 plus or minus 0.14 and 114 plus or minus 35.8, hydrolysis 236 plus or minus 116. PPi turnover (mumoles/hour) correlated with the degree of OA change present in the joint as graded by radiologic criteria irrespective of the clinical diagnosis. Mean PPi turnover in joints with advanced OA was greater than in those with mild or moderate changes (P smaller than 0.001), but the mild and moderate groups showed no significant difference. We conclude that synovial PPi turnover and elevated PPi fluid concentrations are not specific for PG patients, and that these factors alone cannot be the only determinants of CPPD crystal deposition.

Adult↗

[The post-traumatic cervical syndrome. The whiplash injury. Symptoms, diagnosis, treatment (author's transl)].

The post-traumatic cervical syndrome (PTCS) is analysed in 61 cases. the symptomatology can be local (neck pain), cervicocephalic (traumatic vertebrobasilar insufficiency), cervicobrachialgic and also in some cases cervicomedullar. The PTCS is classified into the injuries of the cervical spine with vascular lesions: these injuries may induce severe or benign osteoarticular lesions on the one hand, sevre or reversible vascular lesions on the other hand. All these combinations are studied. The diagnosis of the PTCS is established by vertebral angiography. The surgical treatment according to the authors consists in freeing the vertebral artery or cervical nerve roots by uncusectomy or uncoforaminectomy. The results of these operations are analysed; they are very successful.

Adult↗

[Glutathionestatus of Plasmodium vinckei parasitized erythrocytes in correlation to the intraerythrocytic development of the parasite (author's transl)].

The glutathione status of Plasmodium vinckei parasitized erythrocytes of mice was determined in correlation to the intraerythrocytic stage of maturation of the parasite. The different stages of blood schizogony were separated by discontinuous Dextran-density-centrifugation. The changes of protein content, glutathione concentration (reduced/oxidized and bound/free glutathione) and in the specific activities of the following enzymes: gamma-glutamyl-cysteine-synthetase (GC-synthetase), glutathione-reductase (GR), glucose-6-phosphate dehydrogenase (Gl-DH), glutathione-peroxydase (G-POD) and catalase were investigated in dependence of the intraerythrocytic stage of development. The following changes of the investigated metabolic parameters were observed during the schizogony: - the protein content decreased to about one half, - the glutathione concentration increased about 10-fold, while the relations reduced/oxidized and free/bound glutathione remained constant, - Gl-DH activity appeared and increased steeply, - the specific activities of GC-synthetase and of GR increased more than 2-fold, while G-POD remained almost constant, - and the activities of G-6-PDH and catalase showed a significant, strong decrease to about 25% of the original values. It is tried to relate the observed changes to the growing parasite or to the host cell. The significance of the results for the metabolism of malaria parasites and for a possible adaptation to the mosquito by a GSH mediated protection of the malaria parasite against an enzymatic defence-reaction of the mosquito, is discussed.

Animals↗