Maija Aalto

The effect of silica-treated macrophages on the synthesis of collagen and other proteins in vitro☆

Abstract Treatment with SiO 2 releases from peritoneal macrophages a soluble factor which stimulates the synthesis of collagen and other proteins in incubated slices of experimental granulation tissue. This factor can also be obtained by SiO 2 -treatment from certain subcellular particles of intact macrophages. A similar agent is released from the macrophages by incubation with rheumatoid synovialtissue extract. Macrophages induced by paraffin or thioglycollate medium cannot be stimulated further by SiO 2 . The SiO 2 -treated macrophages have no effect on detached matrix-free cells from embryonic-chick tendon or granulation tissue. Another factor from macrophages, present in the 100000 g-supernatant of the homogenate, inhibits the synthesis of collagen in granuloma slices. The synthesis of DNA and RNA in slices is suppressed by the extract from intact macrophages but not affected by preparations obtained with SiO 2 . The possible relevance of these findings to lysosomal actions, to the regulation of granuloma formation and to inflammation are discussed.

Effects of serotonin, indomethacin and other antirheumatic drugs on the synthesis of collagen and other proteins in granulation tissue slices

Abstract Slices of sponge-induced granulation tissue, both at proliferating and mature (collagen-synthetizing) phases, were incubated in the presence of labelled proline. The addition of serotonin in the medium stimulated the synthesis of collagen, especially at the concentration of 10 5 –10 6 M. Indomethacin inhibited the synthesis of all proteins at high concentrations ( 10 −4 M) but stimulated at lower concentrations (≦ 10 5 M). Phenylbutazon (but not myocrisin and certain other antirheumatic drugs) had similar effect as indomethacin. Bradykinin, histamine and vasopressin also stimulated the synthesis of proteins, including collagen.

Effect of neuraminidase on the synthesis of collagen and other proteins

Abstract When slices from experimental granulation tissue or matrix-free embryonal fibroblasts had been pretreated with bacterial neuraminidase (EC 3.2.1.18), their capacity to incorporate [3H]proline into collagen at a subsequent incubation was decreased significantly. Less or no decrease was observed in the synthesis of non-collagenous proteins or of nucleic acids.

Elevated Serum Total Renin Is Insensitive in Detecting Incipient Diabetic Nephropathy

OBJECTIVE To assess the influence of incipient diabetic nephropathy on the levels of total renin in serum. RESEARCH DESIGN AND METHODS Fifty-five adult patients with insulin-dependent diabetes mellitus (IDDM) were examined in a cross-sectional study. The main outcome measures were serum total renin concentration and urinary albumin excretion rate. RESULTS The total renin concentrations in serum were significantly (P < 0.05) higher in 12 patients with microalbuminuria than in 43 patients without albuminuria, but this difference was significant only in men. There was a significant but weak positive correlation between urinary albumin excretion rate and serum total renin concentration in all patients (r = 0.412, P < 0.05, n = 55), but the sensitivity of high serum concentrations of total renin in detecting incipient nephropathy was low (17%). In the study group, two of the three patients suffering from proliferative retinopathy had the highest total renin concentrations in serum. CONCLUSIONS Microalbuminuric patients have higher mean serum total renin concentrations than normoalbuminuric patients, but because of low sensitivity, high total renin concentration cannot be used for screening incipient diabetic nephropathy.

Inhibition of protein synthesis in tendon cells by extracts from experimental granulation tissue.

When working with the synthesis of collagen in detached, matrix-free tendon cells of chick embryos we became interested in the effect of the recombination of the cells with the extracellular matrix of the connective tissue, in this case extracted from the experimental granulation tissue of rat. Recently, Balazs and Darzynkiewics [l] as also Wiebkin and Muir [2,3] have elaborated the effects of hyaluronate and other glycosaminoglycans on the synthetic and other functions of connective tissue cells. Here we report the effect of the extracellular matrix on the synthesis of collagen and especially, on its transfer from the cells to the medium.

Total renin after gonadotropin stimulation in polycystic ovarian disease

OBJECTIVEnTo examine the influence of polycystic ovarian disease (PCOD) on the levels of total renin in plasma and follicular fluid (FF) after stimulation with hMG.nnnDESIGNnComparative study of the plasma and FF concentrations of total renin in women with and without PCOD after stimulation with hMG.nnnSETTINGnIn vitro fertilization-embryo transfer program at the Department of Obstetrics and Gynecology, the University Central Hospital of Turku, Finland.nnnPATIENTSnThirty-six women undergoing IVF-ET for infertility with (n = 10) or without (n = 26) ultrasonographically diagnosed PCOD. Of the latter group, 15 women had tubal infertility, and the rest suffered from an anovulatory infertility and reacted with PCO-like ovarian response to stimulation.nnnMAIN OUTCOME MEASURESnThe concentrations of total renin in plasma and FF, serum E2, and protein in FF.nnnRESULTSnThe concentrations of plasma total renin after the gonadotropin stimulation were significantly higher in the PCOD and PCO-like groups when compared with the tubal group. The concentration of total renin in FF and the ratio of total renin per protein in FF were higher in the PCOD and PCO-like groups than in the tubal group, but the differences did not reach statistical significance. Positive correlations were found between the plasma total renin and serum E2 concentrations in the PCO-like and in the tubal group and between plasma total renin concentrations and the number of mature follicles in all groups. Follicular fluid total renin did not correlate with FF protein in any group. All findings were independent of the total hMG dosage used and the body mass index of the patients.nnnCONCLUSIONSnIn the present study the concentrations of total renin in plasma were enhanced markedly after gonadotropin stimulation in women with PCOD compared with women having tubal infertility. The pattern of the hormonal secretions revealed a group of infertile patients reacting biochemically like women with PCOD.

Glycoproteins from experimental granulation tissue and their effects on collagen synthesis in embryonic chick tendon cells

Buffer-soluble and pronase-liberated glycoproteins from experimental granulation tissue were fractionated by gel filtration and DEAE-cellulose chromatography. The age of the granuloma was reflected in the gel filtration pattern. Two glycoproteins were isolated, purified to homogeneity and analyzed for their carbohydrate and amino acid compositions. The collagen synthesis in embryonic chick tendon cells was measured in the presence of these fractions, which were found to be inhibiting even at 10(-6) M. These glycoproteins may be significant in the feedback regulation of the development of granulation tissue and fibrosis.

Urinary glycosaminoglycans in aspartylglycosaminuria: evidence for disturbed proteoglycan metabolism

An abnormal excretion pattern of urinary glycosaminoglycans was found in patients with aspartylglycosaminuria, a lysosomal storage disorder of glycoprotein metabolism. The mean daily GAG excretion, measured as uronic acids, was within the reference range, though higher than that of matched controls. However, in AGU patients fractionation of isolated urinary glycosaminoglycans revealed markedly increased proportions of heparan sulfate which were nearly 50% of the total glycosaminoglycans. The changes observed in glycosaminoglycan excretion reflect abnormalities of proteoglycan metabolism. They offer further evidence for the presence of a generalized connective tissue disorder in aspartylglycosaminuria. Increase of heparan sulfate may also refer to abnormalities of glycosaminoglycan metabolism in the central nervous system with a possible role in the neurological manifestations of the disorder.

Total Renin in Preeclamptic Placenta

Objective: Total renin, i.e., prorenin and active renin, synthesized in the uteroplacental unit plays an important role in maintaining the low-resistance state in the fetoplacental vasculature during normal pregnancy. In preeclampsia, characterized by generalized vasoconstriction, local dysfunction of the renin-angiotensin system may be involved. Because the source of total renin during pregnancy is mainly the fetoplacental unit and the ovaries, the aim of this study was to examine if there are differences in the placental concentration of total renin in normal and preeclamptic pregnancy.Methods: Total renin concentrations in the homogenates of 10 normal and 12 preeclamptic human placentas were measured with a time-resolved immu-nofluorometric assay.Results: The mean total renin concentration was 22.6 ng (range 10.2-58.3) per milligram of protein of normal placental tissue and 24.8 ng (range 12.8-52.8) per milligram of protein in preeclamptic placentas.Conclusions: Although the renin-angiotensin system pa...