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Biomedical subjects

H Greiling

Publications and source records attributed to H Greiling.

At least 73 records · Page 4Linked to original sources
PubMed1981

Synthesis in vitro of glycosaminoglycans in regenerating rat liver.

Chronic liver damage is accompanied by both liver cell multiplication and stimulated synthesis of proteoglycans, but the relationship between the two biochemical processes has not been investigated so far. We found that the incorporation of [14C]glucosamine into total glycosaminoglycans of rat liver slices from regenerating tissue is depressed by about 50% 1 and 3 days after operation if referred to that measured in sham-operated control liver slices. 6 h after partial hepatectomy [14C]glucosamine incorporation into glycosaminoglycans is stimulated by more than 30% in relation to sham operated livers. The proportional rates of synthesis of heparan sulfate and chondroitin sulfate (about 8:1) did not change in regenerating liver tissue. Furthermore, there was no difference in the intracellular uptake of [14C]glucosamine by rat liver slices from sham operated and partially hepatectomized rats; the pool size of UDP-N-acetylhexosamine was only slightly larger (about 14%) under the latter experimental condition. We conclude that liver regeneration by itself is not responsible for the elevated production and the changing pattern of proteoglycans in long-lasting hepatic injury.

Animals↗
PubMed1980

Metabolic and structural studies on serum- and liver-glycosaminoglycans in normal and liver-injured rats.

The incorporation of [35S]sulfate into total and specific types of serum glycosaminoglycans was studied in rats with acute, subacute or chronic liver injury (liver cirrhosis), and compared with that of normal rats. The macromolecular (protein-bound) nature of serum glycosaminoglycans in normal and diseased animals was also analysed. The results show a strong increase in rate and extent of [35S]sulfate incorporation into total serum glycosaminoglycans for acutely but a decrease for subacutely and chronically liver damaged rats. The time-course of distribution of label between serum chondroitin sulfate and dermatan sulfate exhibits significant changes in liver-injured animals, in particular a relatively high proportion of dermatan [35S]sulfate in rats with cirrhotic livers. In comparison with serum glycosaminoglycans the labeling profile of glycosaminoglycans in the cirrhotic liver was quite different (heparan sulfate:dermatan sulfate:chondroitin sulfate = 1:0.34:0.09) and changed only insignificantly during a 1 h labeling period. The protein-bound moiety of serum glycosaminoglycans was not affected by liver disease; but the elution profile of chondroitin [35S]sulfate from Dowex 1 X 2 for treated rats was altered, thus indicating a structural modification of its carbohydrate chain.

Animals↗
PubMed1979

Changes in the glycosaminoglycans distribution pattern in the human uterine cervix during pregnancy and labor.

The glycosaminoglycans distribution pattern of uterine cervix samples obtained from 42 women of reproductive age was determined by means of proteolytic digestion and subsequent chromatographic separation. The following glycosaminoglycans were detected: chondroitin 4- and 6-sulfates, dermatan sulfate, hyaluronate, chondroitin, and keratan sulfate. The connective tissue of the uterine cervix shows a characteristic distribution pattern with regard to glycosaminoglycans which does not correspond to that found in any other tissue studied so far. Based on dry weight, the content of keratan sulfate increases during pregnancy while the concentration of chondroitin remains unchanged. The chondroitin sulfates and dermatan sulfate drop simultaneously. During labor chondroitin increases threefold. The hyaluronate content of the postpartum cervix is higher than that of the cervix in nonpregnant women. Both changes in the solubility of collagen as well as in the distribution pattern of the glycosaminoglycans seem to be related to cervical dilatation.

Adult↗
PubMed1979

The synthesis of glycosaminoglycans in aging rat liver. A brief note.

The synthesis of glycosaminoglycans (GAG) was studied in liver slices from postnatal (9 days), young (140 days), adult (490 days) and senescent (940 days) rats. It was found that the rate of synthesis was highest in postnatal rat liver and decreased to about half in young rats with no further reduction in adult and senescent age groups. The specific radioactivity of the precursors of GAG synthesis did not change with age. The synthesis pattern of specific types of GAG in postnatal liver was characterized by a significant higher percentage of chondroitin sulfate and hyaluronic acid. In the following age classes the profile of specific GAG synthesis did not change significantly (heparin sulfate: chondroitin sulfate" hyaluronic acid: "keratin sulfate" = 84%:8.3%:1.5%:1.6%).

Aging↗
PubMed1979

Bioluminescence assay of creatine kinase and its isoenzymes in serum and cerebrospinal fluid.

We examined the sensitivity of bioluminescence for the determination of very low concentrations of creatine kinase brain-type subunit (CK-BB) in serum and in cerebrospinal fluid. To optimize the sensitivity of CK-isoenzyme assays and eliminate possible sources of error, we separated the isoenzyme fractions by using inhibiting anti-MM and precipitating anti-MM and anti-BB antibodies. The results with the bioluminescence assay correlated with spectrophotometric values such that r = 0.97 for the total CK activity and r = 0.98 for the CK-B activity. The reproducibility of the present method was comparable with the spectrophotometric method and was even better at low enzyme activities. The within-series precision for assay of total CK activity at 2 U/L corresponded to a CV of 9%; at 13 U/L the CV was 5.8%. All the assays were carried out at 25 degrees C. Even at this low temperature, CK activities as low as 0.2 U/L could be determined. In eight patients without any evidence of cerebral cell damage, total CK activity in cerebrospinal fluid was x = 1.05 +/- 0.6 U/L, and CK-BB activity was x = 0.7 +/- 0.4 U/L. In sera of these patients CK-BB activity was x = 0.6 +/- 0.5 U/L. Differences in CK and CK-BB activities in four patients with transient or progressive brain-cell damage are discussed.

Autoanalysis↗
PubMed1978

Increased urinary excretion of keratan sulfate in fucosidosis.

In two children exhibiting the clinical symptoms of fucosidosis, the diagnosis was biochemically ascertained by the demonstration of a profound altpha-L-fucosidase deficiency in cultured skin fibroblasts. The non-dialysed urines of these fucosidosis patients were separated into two fractions by chromatography on Biogel P-2. The first fraction containing the glycosaminoglycans was further fractionated on Dowex 1 X 2 by stepwise elution with increasing NaCl concentrations. Keratan sulfate-chondroitin sulfates attached to the same peptide core were assayed and characterised mainly in the fractions eluted with 1.25, 1.5, 2.0 and 3.0 mol/1 NaCl. Whereas the excretion of normal children of the same age was found to be 0.77 mumol glucosamine equivalents per day in the 2 mol/1 and 3 mol/1 NaCl fraction, the two patients excreted 6.7 (M. C.) and 3.5 (M. S.) mumol glucosamine equivalents per day, respectively. Since keratan sulfate contains alpha-fucose at the non-reducing terminal, this increase in excretion of long chain keratan sulfate in fucosidosis could result from impaired degradation of keratan sulfate, due to the alpha-fucosidase deficiency.

Acid Phosphatase↗
PubMed1977

The synthesis of total and specific glycosaminoglycans during development of experimental liver cirrhosis.

During hepatic fibrogenesis induced by long-term administration of thioacetamide, the synthesis of chondroitin 4,6-sulfate and hyaluronic acid was strongly enhanced; the formation of heparan sulfate comprising at least 70% of total liver GAG synthesis and of a keratan-sulfate-like fraction was stimulated 1.7 fold. Formation of dermatan-sulfate in liver could not be detected.

Animals↗
PubMed1977

The influence of glycosaminoglycans on the synthesis of polyphenylalanine by rat liver ribosomes.

Of the natural glycosaminoglycans tested, only heparin was a potent inhibitor of poly (U)-directed polyphenylalanine synthesis by rat liver ribosomes (50% inhibition at 10 mug/ml). A chemically oversulfated chondroitin sulfate was twice as effective, and another synthetic polyanion, sodium pentosan polysulfate was ten times more effective than heparin. Chondroitin-4,6-sulfate was inhibitory at very high concentrations (15 mg/ml) and heparan sulfate at concentrations above 100 mug/ml. The compounds interfere with the formation of ternary complex consisting of the ribosome, poly(U) and phenylalanyl-tRNA. The inhibitors prevented the attachment of the mRNA to the ribosome, probably by competition with poly(U) for the ribosomal binding site of mRNA. However, they were ineffective in doing so once phenylalanyl-tRNA has bound to the ribosomepoly(U) complex. Sucrose gradient analysis in presence of the inhibitors revealed a selective effect on the sedimentation of the small ribosomal subunit; the large subunit was unaltered. This effect, however, was dependent on the concentration of magnesium. In contrast to Escherichia coli ribosomes, no binding of the inhibitors to the particles could be demonstrated.

Animals↗