Usefulness of a test for slime production as a marker for clinically significant infections with coagulase-negative staphylococci

The usefulness of a test for slime production as a marker for clinically significant infections with coagulase-negative staphylococci and its implications for therapy were examined. Hospital records were reviewed for 59 patients from each of whom more than one isolate of coagulase-negative staphylococci was obtained. In patients with a prosthetic device, 81% of 59 infectious episodes were due to a slime-positive coagulase-negative staphylococci. In contrast, 22 noninfectious episodes (in which the organisms were contaminants) were equally distributed between episodes due to slime-positive or slime-negative isolates (P = .005). Only 32% of infections caused by slime-positive organisms, in contrast to 100% of infections caused by slime-negative organisms, were improved by treatment with antibiotics alone (P = .02). Prosthetic device removal in addition to antibiotic treatment significantly improved the outcome in patients with infections due to slime-positive organisms when compared with treatment with antibiotics alone (93% vs. 32% improvement; P = .00025).

Comparison of inhibition by a tumor promoter (12-O-tetradecanoylphorbol-13-acetate) of expression of the differentiated phenotype of chondrocytes in rabbit costal chondrocytes in culture with inhibition by retinoic acid

Both retinoids and the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) inhibit expression of the differentiated phenotype by rabbit costal chondrocytes in culture, as judged by morphological changes and decreased sulfation of glycosaminoglycans (GAG). However, the inhibition of the differentiated phenotype of chondrocytes in TPA-treated cells is restored by parathyroid hormone (PTH), while the inhibition by retinoids is not [Takigawa et al. (1982) Mol. Cell. Biochem. 42, 145-153; Takigawa et al. (1983) Cell Differ. 13, 283-291]. In the present study, we examined the difference between TPA-treated chondrocytes and retinoic acid-treated chondrocytes to determine the mechanism of the restoration of the differentiated phenotype in de-differentiated cells treated with TPA. PTH increased the activity of ornithine decarboxylase [ODC; EC 4.1.1.17], a rate limiting enzyme of polyamine biosynthesis, and proteoglycan synthesis in chondrocytes pretreated with TPA as well as in normal chondrocytes. The maximal stimulations of ODC activity and GAG synthesis were observed 4 h and 24-36 h, respectively, after addition of PTH. The dose-response curve for ODC induction by PTH was parallel to that of PTH-stimulated proteoglycan synthesis both in TPA-treated chondrocytes and in normal chondrocytes. PTH also increased the intracellular cyclic AMP level after 2 min in TPA-treated cells as in normal cells. Addition of dibutyryl cyclic AMP (DBcAMP) induced ODC and restored proteoglycan synthesis in TPA-treated cells. The dose-response curve for induction of ODC by DBcAMP was parallel to that of DBcAMP-stimulated proteoglycan synthesis in both TPA-treated chondrocytes and normal chondrocytes. On the other hand, the increases by PTH in the intracellular cyclic AMP level, ODC activity, and proteoglycan synthesis were inhibited in chondrocytes pretreated with a combination of TPA and retinoic acid as well as in those pretreated with retinoic acid alone. TPA stimulated the syntheses of DNA and RNA in chondrocytes but did not increase the cyclic AMP level or ODC activity. PTH and DBcAMP inhibited the syntheses of DNA and RNA both in TPA-treated cells and in normal cells. These results suggest that ODC induction mediated by elevation of cyclic AMP plays an important role in re-differentiation of de-differentiated cells pretreated with these agents.

Synthetic activities of mass cultures and clones of human gingival fibroblasts

The percentage of synthesis dedicated to collagen is elevated in low-density cultures of human gingival fibroblasts, as is per-cell total protein synthetic activity and glycosaminoglycan accumulation. These observations can be explained, in part, by a decrease in membrane transport of precursor substance in high-density cultures. Synthetic activity by human fibroblasts can be reliably assayed in vitro using as few as 500 cells sparsely seeded. Such low-cell number assay is essential for study of single-cell clones, where replicative life span is limited.

Change in the synthesis of glycosaminoglycans by fibrotic vitreous induced by erythrocytes

Vitreous fibrosis was induced in rabbit eyes by intravitreal injection of erythrocytes. The fibrotic vitreous removed from experimental animals were then incubated with [3H]glucosamine at 37 degrees C for 24 h. The newly synthesized 3H-labeled glycosaminoglycans were isolated by 4 M guanidium hydrochloride extraction followed by pronase digestion. The 3H-labeled glycosaminoglycans were then characterized by gel filtration column chromatography and by specific enzymatic degradation, i.e., hyaluronidase, chondroitinase AC, and/or chondroitinase ABC. The disaccharides derived from chondroitinase ABC degradation were identified by thin-layer chromatography. We previously demonstrated that 91% of the total glycosaminoglycan synthesized by normal vitreous was hyaluronic acid. Our present results indicate that in the fibrotic vitreous, the synthesis of hyaluronic acid was decreased to 26%, whereas the synthesis of chondroitin sulfate increased to 59% of the total newly synthesized glycosaminoglycans. These results suggest that cells present in fibrotic vitreous resemble fibroblasts with respect to their activities in glycosaminoglycans synthesis.

[Changes in the metabolism of chondrocytes after chronic intake of phenol and lead]

White rats and guinea pigs were given phenol (0.2 and 10 mg/kg) or lead acetate (10 mg/kg of the body mass) for 3-6 months. Intensity of biosynthesis was estimated by glycosaminoglycane cells and by collagene (by means of 35S and 3H-glycine inclusion), distribution of glycoproteids, glycogene and alcaline phosphomonoesterase. The intensity of glycosaminoglycanes biosynthesis decrease in chondrocytes, as does glycogene content and alcaline phosphomonoesterase activity in the zones of the cartilage mineralization. In the intercellular cartilage substance, sertain deviations in quantity and in artio of different types of macromolecules appear, that results in decreasing rates of the cartilage substitution and of the osseous trabecules growth and in development of osteoporosis.

Control of repair in articular tissues and the development of osteoarthritis

Bones from different mammalian species, including man, contain a low molecular weight extractable activity which stimulates proteoglycan synthesis by connective tissue cells in culture ("matrigenin" activity). Partial purification of matrigenin activity has been achieved from bovine bone. The activity shows a strong tendency for reversible physical associations in low ionic strength solutions and binds tightly to collagenous and other bone matrix proteins. It is speculated that the pathophysiological role of matrigenins may be to initiate repair during injury to bone. Chronic repair reactions are more likely to occur at sites of repeated anatomical stress at the ligamentous, tendon and synovial attachments at the ends of bones, in the subchondral bone and in the articular cartilage regions abbuting to subchondral bone. At these sites, repair reactions may be broadly viewed as the development of osteophytes and fibrocartilage and the progression of subchondral bone sclerosis. Repeated anatomical stress leads to the activation of extracellular, small molecular weight factors, which in turn, stimulate the biosynthesis of matrix macromolecules that are an important feature of these repair reactions of osteoarthritis.

Persistence of scleroderma-like phenotype in normal fibroblasts after prolonged exposure to soluble mediators from mononuclear cells

Supernatants of mononuclear cells (MNC-SN) were shown to increase synthesis of glycosaminoglycan (GAG) by cultured normal dermal fibroblasts. Fibroblasts from the skin of patients with progressive systemic sclerosis (PSS, scleroderma) were hyporesponsive. We exposed fibroblasts outgrowing from explants of normal adult skin to MNC-SN for up to 30 generations in culture. MNC-SN were obtained by incubating normal MNC with concanavalin A. Four experimental, 4 normal control, and 3 PSS control lines were passaged by trypsinizing and splitting the cultures 1:2 every 7 days. At the third and fifth passages, portions of the experimental fibroblasts were removed from MNC-SN, then passaged in medium alone. Cell counts, assays for GAG, and electron microscopy were performed and increases in GAG after brief reexposure to MNC-SN were determined at the third, fifth, and eighth passages. In normal dermal fibroblasts, baseline GAG production, measured by 3H-glucosamine uptake, was low and increased as much as 15 times after reexposure to MNC-SN. In contrast, production was high in both experimental and PSS lines, and increases after reexposure to MNC-SN were consistently small. This PSS-like behavior persisted in experimental fibroblasts removed from MNC-SN at the third and fifth passages. Growth of experimental and scleroderma fibroblasts was slower than that of control fibroblasts. Ultrastructurally, both scleroderma and experimental dermal fibroblasts differed from normal fibroblasts by their oval cellular shape, indentations in nuclear membrane, numerous organelles and bundles of microfilaments, prominent Golgi, and intranuclear inclusions. These experiments indicate that normal adult dermal fibroblasts subjected to MNC-SN in vitro acquire a scleroderma-like phenotype that persists for many generations.

Increased degradation of carbohydrate deficient arterial basement membrane-like material from 2-deoxyglucose modified myomedial cell cultures

The effect of 1.6 mM 2-deoxyglucose on the incorporation of [3H]leucine, [3H]glucosamine and [35S]sulphate into arterial basement membrane-like (BM) material was evaluated. BM-like material was isolated from the cell-matrix layer of cultured arterial smooth muscle cells by a sonication-differential centrifugation technique. 1.6 mM 2-deoxyglucose inhibited the 24 hr incorporation of [3H]glucosamine into BM-like material by 46% with a reduction in both [3H]glucosamine labelled glycopeptides and glycosaminoglycans. A marked decrease in [35S]sulphate incorporation (reduced by 80%) was demonstrated suggesting that 2-deoxyglucose may affect sulphatation of glycosaminoglycans. At 1.6 mM 2-deoxyglucose no effect on [3H]leucine incorporation was found. By gel filtration on Bio-Gel P6 a heterogeneous mixture of shortened glycopeptides was found after 2-deoxyglucose. The electrophoretic mobility of fibronectin and other glycoprotein components of BM-like material was increased. The stability of carbohydrate deficient BM-like material against removal/degradation was evaluated. A significantly increased removal of [3H]leucine from insufficiently glycosylated BM-like material was observed after a 24 hr chase period. The increased removal/degradation of BM-like material formed in the presence of 2-deoxyglucose was found to be a cellular dependent event.

Stimulation of collagen and glycosaminoglycan production by phenytoin 5,5-diphenylhydantoin in monolayer cultures of mesenchymal cells derived from embryonic chick sternae

Cultures grown with or without phenytoin (PHT) at a concentration of 5 micrograms/ml from the fifth to the eighth day after plating were labelled with [14C]-proline (0.2 microCi/ml) from the sixth to eighth day. Collagenase digestion indicated that collagen content increased approx. 2-fold after PHT exposure. Increases in sulphated glycosaminoglycan product in response to PHT were approx. 1.5-fold; PHT also stimulated protein production. Both actinomycin D and cycloheximide blocked incorporation of [3H]-leucine, [3H]-proline, and H2(35)SO4 approx. 90 per cent with or without PHT. Continuous sucrose density-gradient fractionation indicated that PHT produced quantitative but not qualitative changes in cellular RNA.

Growth hormone effect on accumulation of arterial basement membrane-like material studied on rabbit aortic myomedial cell cultures

The effect of human growth hormone on arterial basement membrane-like (BM) material was studied. BM-like material was obtained from the cell layer of cultured aortic myomedial cells using a sonication-differential centrifugation technique. After the addition of small amounts of growth hormone (1 ng/ml) to the cultures, we observed a 26% increased incorporation of amino acids into BM-like material (2p less than 0.005). However, further increase in the incorporation was not observed using either 3 ng or 10 ng growth hormone per ml. Growth hormone inhibited removal/degradation of BM-like material by 16% (2p less than 0.01). However, pinocytosis rate and activity of major lysosomal enzymes: cathepsin D, acid phosphatase and beta-N-acetyl-glucosaminidase were unchanged. Incorporation of glycosaminoglycans as evaluated by [35SO4]-labelling was reduced by 8% when cells were exposed to growth hormone (2p less than 0.01). The present study demonstrates an effect of growth hormone on the turnover and composition of BM-like material in cultured arterial myomedial cells.

Glycosaminoglycan production in cultures of early and late passage human endothelial cells: the influence of an anionic endothelial cell growth factor and the extracellular matrix

An endothelial cell (EC) growth factor isolated from bovine brain stimulates in vitro growth of human umbilical vein endothelial cells, and permits long term serial propagation. In the presence of increasing concentrations of EC growth factor, confluent cultures of early (CPDL less than or equal to 20) and late (CPDL greater than 20) passage human endothelial cells exhibit an increased incorporation of 3H-glucosamine and Na235SO4 into the glycosaminoglycans (GAG), hyaluronic acid, chondroitin, chondroitin-4-sulfate, dermatan-4-sulfate, and chondroitin-6-sulfate. An increase in both labelled sulfated and nonsulfated GAG was observed in the cytosol, membrane, secreted and extracellular matrix fractions. In contrast, endothelial cells grown in the presence of EC growth factor contained decreased amounts of labelled heparan sulfate than cells grown without EC growth factor. Confluent cultures of early passage cells had significantly more labelled GAG but significantly less heparan sulfate than cultures of late passage cells on a per cell basis. Extracellular matrix from early passage cells contained about two- to seven-fold more labelled GAG than extracellular matrix from late passage cells, but only about half as much labelled heparan sulfate. Cell adhesion was enhanced when cells were grown in the presence of EC growth factor as compared to adhesion of cells grown without EC growth factor. Conversely, trypsin-mediated detachment of cells grown in the presence of growth factor was inhibited as compared to detachment of cells grown in medium without EC growth factor. The composition of the extracellular matrix influenced incorporation of labelled GAG into extracellular matrix. Early passage cells grown to confluence on a matrix from late passage cells incorporated significantly less labelled GAG into extracellular matrix than when grown to confluence on matrix from early passage cells. Incorporation of labelled GAG into extracellular matrix was significantly higher when late passage cells were grown on a matrix from early passage endothelial cells than when grown on matrix from late passage cells. We conclude that EC growth factor selectively stimulates incorporation of isotopic precursors into GAG in cultures of early and late passage endothelial cells but inhibits incorporation of radiolabel into heparan sulfate; early passage cells contain more GAG but less heparan sulfate than late passage cells, extracellular matrix controls the amount of GAG and heparan sulfate incorporated into matrix.(ABSTRACT TRUNCATED AT 400 WORDS)

The lung parenchyma--a dynamic matrix. J. Burns Amberson lecture

The matrix of the lung parenchyma is composed predominantly of collagen, elastin, glycosaminoglycans, and fibronectin. This presentation focuses on the newer insights into injury and repair of lung elastin and glycosaminoglycans. Elastin and glycosaminoglycans respond in characteristic patterns to destructive and proliferative forms of lung injury. Elastin degradation induced by elastases induces a prompt and marked response by elastin resynthesis in situ. The signal for the stimulus remains unknown and deserves to be understood. The measurement of elastin peptides in plasma, urine, or bronchoalveolar lavage fluid can provide an objective index of elastin degradation in disease. Elastin depletion may be augmented by factors that interfere with elastin resynthesis such as exposure to tobacco smoke. Glycosaminoglycans participate in similar fashion in many different forms of lung injury as an early response to injury, which may then determine the subsequent cellular processes of repair. Studies of injury and repair in organ systems, other than the lung, suggest a general role for glycosaminoglycans in interstitial tissue and repair. The mediators that alter matrix chemical structure and function could provide powerful instruments for controlling the process of tissue injury and repair in the lung.

Characterization of extracellular matrix-associated glycosaminoglycans produced by untransformed and transformed bovine corneal endothelial cells in culture

A cloned bovine corneal endothelial cell line was transformed in vitro by simian virus 40, and the subendothelial extracellular matrix-associated sulfated glycosaminoglycans synthesized by the cells were isolated and compared with their untransformed counterpart. The transformed endothelial cells grew at faster rates to higher stationary cell densities in the absence of fibroblast growth factor than did the untransformed cells. On a per-cell basis, the transformed cells produced slightly lower amounts of sulfated glycosaminoglycans. The rate of production of sulfated glycosaminoglycans in extracellular matrix increased during seven days of culture. At confluency the extracellular matrix-associated sulfated glycosaminoglycans synthesized by the untransformed endothelial cells consisted of about 80% heparan sulfate and about 20% chondroitin sulfate. Extracellular matrix-associated sulfated glycosaminoglycans of transformed endothelial cells were composed of about 70% heparan sulfate and about 30% chondroitin sulfate plus dermatan sulfate. High-speed gel permeation chromatography profiles on Fractogel TSK HW-55(S) of matrix-associated heparan sulfate from untransformed and transformed endothelial cells were very similar, and gave single peaks (Kav = 0.19). Apparent Mr estimated from the eluting position of the peaks were approximately 47000. Heparan sulfate from both untransformed and transformed endothelial cells was degraded by incubation with a metastatic B16 melanoma cell lysate containing heparanase (heparan-sulfate-specific endo-beta-glucuronidase). The eluting position of the heparan sulfate degradation products on gel permeation column were similar (Kav = 0.43). Size analysis and anion-exchange chromatography of the degradation products after nitrous acid deamination at low pH indicated that the degree of N-sulfation of heparan sulfate was similar in untransformed and transformed endothelial cells. The results indicated that transformation of endothelial cells only slightly changes the molecular nature of subendothelial matrix-associated sulfated glycosaminoglycans.

Proteochondroitin sulfate is the main proteoglycan synthesized in fetal hepatocytes

The synthesis of total and specific types of glycosaminoglycans (GAG) with emphasis on proteochondroitin sulfate (PCS) was studied in late embryonic and early postnatal liver parenchymal cells. In contrast to adult hepatocytes, which synthesize almost exclusively proteoheparan sulfate (PHS), PCS proved to be the major type of GAG synthesized in fetal hepatocytes (more than 60% of total GAG) whereas PHS contributes less than 40% of total GAG synthesis. Starting immediately after birth PCS synthesis in hepatocytes declines progressively, at the 6th postnatal day PCS formation is one-fifteenth of that measured in embryonic liver cells. Adult levels are reached around the 10th postnatal day. A significant portion of plasma membrane-associated proteoglycans in fetal hepatocytes is represented by PCS, its fraction declines in early postnatal life. Between the synthesis rate of PCS and [3H]thymidine incorporation into DNA exists a strong positive statistic correlation (r = 0.949). In conclusion, fetal hepatocytes have a completely different profile of GAG synthesis characterized by preponderant production of PCS. This ability is lost early after birth but might be regained in hepatocellular carcinoma cells and parenchymal cells in chronically injured liver tissue developing fibrosis.

Bone matrix-directed chondrogenesis of muscle in vitro

Bone matrix is the largely collagenous residue of demineralized bone. Experimental data demonstrate that a substance, which is acid-stable during demineralization, occurs as a part of bone matrix, and that it is capable of stimulating the redifferentiation of skeletal muscle into cartilage. Reproducibility of redifferentiation is high and all cells derived from embryonic mesoderm appear competent to yield cartilage. This effect is highly significant to the developmental biology of musculoskeletal tissues, as muscle and cartilage arise from a similar embryonic origin. With regard to the embryonic limb as a model system, it appears that both muscle and cartilage progenitor cells do not have rigidly-defined developmental programs, and that this is a result of their origin from a common pool of embryonic mesoderm. This pool originates as embryonic mesenchyme long before any evidence of limb development can be detected. It is proposed that the active component of bone matrix, termed "bone morphogenetic protein (BMP)," acts upon a tissue whose developmental program is not stabilized, or has been experimentally destabilized (by injury), to augment and sustain syntheses of cartilage extracellular matrix. The use of bone matrix, and active substances derived from it, suggests that differentiation is not irreversible. Hard tissue growth and repair may occur via recruitment of competent responding cells from a variety of nonchondrogenic sources, provided that the extracellular milieu (i.e., presence of BMP) is supportive.

N-sulfation of heparan sulfate with microsomal fraction of endometrium of rabbit uterus

Heparan sulfate was prepared from the pronase digest of the porcine kidney and modified chemically to yield N-desulfated, N-, O-desulfated, and N- O-desulfated N-acetylated heparan sulfates. Heparan sulfate and its modifications thus obtained were used as substrates to measure the sulfotransferase activity in the microsomal fraction of the endometrium of the rabbit uterus. N-, O-Desulfated heparan sulfate was the best acceptor of sulfate from 3'-phosphoadenylyl [35S] sulfate and intact heparan sulfate was the poorest one. The products of enzymatic reaction were treated with nitrous acid and examined by gel-filtration and electrophoresis. The results indicated that sulfate was almost exclusively incorporated as N-sulfate into all the present substrates.

Decrease in cytosolic free Ca2+ and enhanced proteoglycan synthesis induced by cartilage derived growth factors in cultured chondrocytes

Cartilage-derived growth factors, enhance proteoglycan synthesis in cultured chick-embryo chondrocytes, and have almost no effect on cell proliferation. Addition of cartilage derived growth factors to cartilage cells loaded with the fluorescent Ca2+ indicator quin 2, caused a rapid, concentration dependent decrease in cytoplasmic free Ca2+. This decrease persisted also in Ca2+-free medium, indicating that it is not mediated by a decrease in the passive permeability of cell membrane to Ca2+. Addition of the Ca2+ ionophore A23187, with or without cartilage derived factors, caused an increase in cytoplasmic free Ca2+ together with inhibition of proteoglycan synthesis and enhanced cell proliferation. The results may indicate that whereas cell proliferation in chondrocytes is signaled by an increase in cytoplasmic Ca2+ ([Ca2+]in), proteoglycan synthesis is signaled by a decrease in [Ca2+]in. The data lead to suggesting a mechanism for antagonistic regulation of cell proliferation and the expression of the differentiated state.

Altered glycosaminoglycan production by HL-60 cells treated with 4-methylumbelliferyl-beta-D-xyloside

Glycosaminoglycans, mainly chondroitin 4-sulfate, are located in the primary granules of human myeloid cells. These polyanionic carbohydrates are believed to play an important role in leukocyte maturation and function. To study the effect of altered chondroitin sulfate metabolism on human promyelocytic leukemia cells, we have treated HL-60 cells with 4-methylumbelliferyl-beta-D-xyloside. beta-D-Xylosides initiate the synthesis of free chondroitin sulfate chains. Cytochemical studies of treated cells demonstrated a marked increase in cytoplasmic granules stained with cationic dyes. This was confirmed by radiolabeled precursor incorporation studies that demonstrated a 344% increase in 35S-sulfate uptake into glycosaminoglycans associated with the cells and a 39% increase in incorporation into glycosaminoglycans released into the media. Chromatographic analyses of these glycosaminoglycans from treated cells demonstrated that the newly formed chondroitin sulfate chains were not attached to protein core and were of shorter length, but of greater charge density than chondroitin sulfate produced by control cells. Thus, beta-D-xyloside appears to alter the protein linkage, chain length, and sulfation of chondroitin sulfate produced by HL-60 cells, and these changes are morphologically evident. These biochemically altered cells may provide important information concerning the role of these macromolecules in myeloid development.