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Biomedical subjects

J Klem

Publications and source records attributed to J Klem.

31 records · Page 2Linked to original sources
PubMed1986

Effect of dipyridamole on adenosine incorporation into hypoxanthine nucleotides of fresh human red cells.

Fresh human red cells were incubated for 2 hours in a medium containing adenosine, pyruvate and inorganic phosphate (APP medium), or in APP medium supplemented with 10(-4) M dipyridamole (APPD medium). No measureable amount of ITP was found in fresh red cells, and the average IMP content in these cells was 0.18 +/- 0.09 mumol/g Hb. After 2 hours incubation in APP medium, the IMP content increased almost 8.5-fold to 1.52 +/- 0.78 mumol/g Hb. Under these conditions the ITP level also increased to 1.40 +/- 0.84 mumol/g Hb. After 2 hours incubation of red cells in APPD medium, the average IMP content increased to 5.30 +/- 2.33 mumol/g Hb, about 3.5 times that found in APP medium. At the same time ITP content was about 53.6% lower, that is 0.65 mumol/g Hb. In red cells incubated in APPD medium, penetration of 8-14C-adenosine decreased by 50%, and incorporation of this nucleotide into the pool of all free nucleotides also decreased by 18.2% as compared to red cells incubated in APP medium. It is concluded that IMP is probably formed directly from AMP gained by the phosphorylation of adenosine during its penetration.

Adenosine↗
PubMed1986

Effect of dipyridamole on adenine incorporation into hypoxanthine nucleotides of fresh red blood cells.

An investigation was carried out on the penetration of [8-14C]adenine into fresh human red blood cells and of adenine incorporation into hypoxanthine nucleotides of red blood cells incubated in: 1) a medium containing adenosine, pyruvate, inorganic phosphate and NaCl, and 2) APP medium containing 1 X 10(-4) M dipyridamole (APPD medium). It was found that dipyridamole inhibits by about 45% the penetration of adenine into the red blood cells, and by 18% the incorporation of the isotope into the nucleotides of the cells under study. The inhibition of nucleotide synthesis and incorporation of the isotope into them did not apply to IMP, whose content--following erythrocyte incubation in APPD medium--increased 3.5 times, i.e. from 1.52 to 5.30 mumole/g Hb. At the same time there was an increase of the isotope count from 0.12% in IMP isolated from APP incubated erythrocytes to 0.34% in IMP synthesized in APPD incubated erythrocytes. Erythrocyte incubation in APPD medium reduced ITP synthesis by about 53% relative to its synthesis observed after erythrocyte incubation in APP medium equal to 1.40 mumole per g Hb.

Adenine↗
PubMed1981

Hypoxanthine nucleotides synthesis in fresh and stored human erythrocytes.

Human erythrocytes incubated in inosine-pyruvate-phosphate (IPP) medium are able to accumulate great amounts of inosine monophosphate (IMP) and inosine triphosphate (ITP). Accumulation of ITP is low in freshly drawn cells. It increases during blood storage in acid-citrate-dextrose solution. Addition of labelled inosine or hypoxanthine to the IPP medium allowed to show the synthesis of small amounts of inosine diphosphate and the appearance of radioactivity in the ATP fraction. Conditions of incubation and the pathways of hypoxanthine nucleotides synthesis are discussed.

Blood Preservation↗
PubMedDate not supplied

Superoxide dismutase and catalase activity in psoriatic patients treated topically with ointment containing 2-chloroethyl-3-chloropropyl sulfide.

The purpose of this study was to determine dismutase and catalase activities in erythrocytes of psoriatic patients with psoriasis vulgaris topically treated with an ointment (in accordance with recommendations of the Helsinki Declaration), in which 2-chloroethyl-3-chloropropyl sulfide (CLEPS) is an active compound. SOD activity in hemolysates was determined according to the method of Misra and Fridovich [12] and calculated as units per g of hemoglobin. CAT activity in hemolysates was determined by Beers and Sizer method [2] and expressed in U/g Hb. SOD activity in the control group was 1.61 +/- 0.48 U/g Hb x 10(3). However, the activity of CAT was 5.72 +/- 1.17 U/g Hb x 10(4). Before treatment SOD activity was decreased by ca. 22.5% (1.25 +/- 0.53 U/g Hb x 10(3)) while that of CAT by about 7% (5.30 +/- 1.41 U/g Hb x 10(4)), in comparison with the normal control. After treatment with the ointment, activity of both enzymes increased by about 18% to 1.55 x 10(3) U/g Hb and by about 16.5% to 6.25 x 10(4) U/g Hb, respectively. The results of our investigations showed that the ointment (containing mustard gas derivative) applied on psoriatic skin, causes increased of SOD and CAT activity in erythrocytes after regression of psoriatic lesions and treatment termination.

Administration, Topical↗
PubMedDate not supplied

Activity of adenosine deaminase in red blood cells of patients suffering from multiple sclerosis treated with adrenocorticotropic hormone.

Adenosine deaminase (ADA) activity was studied in red blood cells of patients suffering from multiple sclerosis treated with adrenocorticotropic hormone (ACTH). ADA activity in hemolysates was determined according to the method of Hopkinson and calculated as units per g of hemoglobin. Activity of adenosine deaminase in healthy subjects was 0.871 +/- 0.251 U/g Hb. In patients with multiple sclerosis, before treatment ADA activity was 0.765 +/- 0.131 U/g Hb and was about 15.2% lower than in the control group (p < 0.02). After treatment with ACTH, ADA activity increased to 1.005 +/- 0.211 U/g Hb (p < 0.001). We have suggested that increased activity of adenosine deaminase in red blood cells of patients suffering from multiple sclerosis after treatment with ACTH is caused by diminution of superoxide generation, and therefore its sparing effect on cell membrane and enzyme is connected with membranes.

Adenosine Deaminase↗
PubMedDate not supplied

Red blood cell superoxide dismutase and catalase activities in patients suffering from multiple sclerosis treated with adrenocorticotropic hormone.

The purpose of this study was to determine superoxide dismutase (SOD) and catalase (CAT) activities in erythrocytes of patients with multiple sclerosis treated with ACTH. SOD activity in hemolysates was determined according to the method of Misra and Fridovich and calculated as units per gram of hemoglobin (Hb). CAT activity in hemolysates was determined with Beers and Sizer's method and expressed in IU/g Hb. SOD activity in control group was (1.61 +/- 0.45) x 10(3) U/g Hb whereas, the activity of CAT amounted to (5.88 +/- 1.36) x 10(4) U/g Hb. Before the treatment, SOD activity was decreased by approximately 20% ((1.25 +/- 0.25) x 10(3) U/g Hb) while that of CAT-by about 7.7% ((5.43 +/- 0.68) x 10(4) U/g Hb) in comparison to the normal control. After treatment with ACTH, activity of both enzymes increased: SOD-by about 34.4% to (1.68 +/- 0.38) x 10(3) U/g Hb and CAT-by about 7% to (6.29 +/- 0.55) x 10(4) U/g Hb. Results of investigations showed that ACTH caused an increase in CAT and SOD activities in erythrocytes of patients after three-week treatment.

Adrenocorticotropic Hormone↗