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Aim: The aim of the present study was to evaluate in vitro the biological behavior of human gingival fibroblasts cultured on two different titanium surfaces., Methods: Titanium test disks were prepared with a machined, relatively smooth (S) surface or a rough surface (O) obtained by a double acid etching procedure. Primary cultures of human gingival fibroblasts were plated on the experimental titanium disks and cultured up to 14 days. Titanium disk surfaces were analysed by scanning electron microscopy (SEM). Cell proliferation and a quantitative analysis by ELISA in situ of ECM components as CoI, FN and TN were performed., Results: Results have shown different effects of titanium surface microtopography on cell expression and differentiation. At 96 hours of culture on experimental surfaces human gingival fibroblasts displayed a favourable cell attachment and proliferation on both surfaces although showing some differences., Conclusion: Both the relatively smooth and the etched surfaces interacted actively with in vitro cultures of human gingival fibroblasts, promoting cell proliferation and differentiation. Results suggested that the microtopography of a double acid-etched rough surface may induce a greater Co I and FN production, thus conditioning in vivo the biological behaviour of human gingival fibroblasts during the process of peri-implant soft tissue healing.

During and after menopause the skin shows up clearly how the lack of estrogen affects tissues, and menopause can in fact be considered a "multisystemic" disorder of connective tissue. The low menopausal estrogen levels combined with age-related skin changes, accelerating skin aging. This affects both the epidermis and the dermis: fibroblasts not only become fewer, but they produce 30% less collagen, reflecting its metabolic decline. Estrogens act on collagen synthesis by directly stimulating fibroblasts. However, hormone replacement can prevent the postmenopausal loss of collagen--or eliminate it once it has started. The results of the Women's Health Initiative study drastically changed Italian gynecologists' prescribing habits. Natural products with estrogen-like activity are increasingly accepted, since they have good effects on collagen synthesis and/or inhibit collagenase activity, with a reassuring safety profile. This was confirmed by an in vitro study that assessed the tonic-trophic properties of two treatments on cultured skin fibroblasts. Cells were treated with resveratrol either alone or combined with NAC 10-100-1000 μM. There was a dose-related increase in the rate of cell proliferation and in inhibition of collagenase activity.

The use of short term in vitro tests is an important step in the evaluation of the mechanism of action of cigarette smoke condensate (CSC). This study evaluated the effects of both CSC and solvents on Swiss 3T3 murine fibroblast cells. Results show that after 24 hours of treatment, CSC exerts a dose-dependent cytotoxic activity, both in methanol and dimethyl sulfoxide (DMSO), through mechanisms involving cell death and alterations in cell proliferation and metabolism. On the contrary, after 1 hour of treatment, a cytotoxic effect is seen only with CSC in DMSO. In cell cultures devoid of CSC, similar results have been obtained after 24 hours with both types of treatment.

Background: Recent data demonstrated that somatostatin (SRIH) analogues octreotide is effective in Graves' ophthalmopathy (GO), but their mechanism of action in GO is still unclear. In this study we investigated the expression of SRIH receptor (sst1-5) genes and the effect of octreotide treatment on primary cultures of fibroblasts established from retroorbital tissue of GO patients and of control subjects., Methods: Retro-orbital connective tissue was obtained from 10 patients with GO and from 6 control subjects undergoing eye surgery. Fibroblasts were established in MEM with 5-10% FCS. The expression of sst1-5 genes was studied by RT-PCR using specific primers and GAPDH as internal control. Cells were treated with octreotide (10-8M, 10-9M) for 48-72-96 h to evaluate cell growth by MTT, cAMP accumulation by RIA and apoptosis by TUNEL techniques., Results: All primary cultures expressed one or more ssts genes that have a high affinity for the two analogues (class 1 sst). The sst2 transcript was found in 9, sst3 in 5 and sst5 in 8 out of 10 GO cell cultures. sst2 was detected in all 6, and sst3 in 4 of the 6 control cell cultures. Octreotide (10-6 and 10-7M) significantly inhibited cell growth (p<0,01-0,05), significantly decreased forskolin-induced-cAMP accumulation, and determined apoptosis (10-18%)., Conclusions: Our study demonstrated that sst transcripts are expressed and functional in cultured retroorbital fibroblasts. The presence of class 1 sst in GO tissue and the inhibition exerted by octreotide on retroorbital cell growth and activity in vitro may account for the effects of SRIH analogue administration in vivo in GO.

In this work we investigated the growth of skin fibroblasts, in vitro cultured, drawn from women suffering Atypical Ductal Hyperplasia (I.D.A.) and from healthy women (controls). Whether in basic conditions or after administration of 17, beta-estradiol, in single of repeated dose, cellular growth was valued. The results obtained show that skin fibroblasts drawn from women suffering I.D.A. treated with 100 microliters/ml of estradiol (effective dose), have an increase of the growth. Moreover the increase of the growth seems to be bequest to "effective dose" but not to the number of administrations.

In this study the authors examined the influence of 71, beta-estradiol on cutaneous fibroblasts taken off either from healthy patients with no family history for cancer, or from patients with breast cancer. Fibroblasts were taken from the subcutaneous tissue of the mammary gland by a biopsy carried out in each patients on the same quadrant of the granular surface. Soon after biopsy, the tissue fragments have been washed, dished ed incubated in RPMI at 37 degrees C in a humidified atmosphere of 5% CO2 and 95% air. The action of the hormone was evaluated by the means of cells count for field, in 20 fields in each dish with an inverted microscope (20 x magnification). The results demonstrated that cutaneous fibroblasts from patients with breast cancer show higher values of cell density than those from healthy one. This phenomenon is present both in basal conditions and after hormonal treatment. Two different dosages were used, but only the highest (100 microliters/ml of 17, beta-estradiol) was responsible for an increase of the cell density in all of the treated patients as compared the control groups. These data suggests the presence of a threshold dosage for the estrogens. Below such a dosage there are no effects on cellular growth.

Cimetidine is an active H2-receptor antagonist which, combined with other drugs, has antitumor effect. It has been recently shown that some drugs complexed with copper increase their inhibitory effect on tumor growth and promote cell differentiation. In the present investigation we analysed the modifications of some cell proliferation parameters (mitotic, labelling and apoptotic indices and DNA synthesis) by microfluorometry and autoradiography in 2-day low and high cell density fibroblast cultures in presence of 20 microM cimetidine or copper-cimetidine complex. In low density cultures, a more intense proliferation activity was found while in the high density ones there was accumulation of 4c and 8c polyploid cells. The highest antiproliferative effect was found in low density cultures in presence of copper cimetidine complex, which caused mitotic anomalies and increased chromocenters. Simultaneous evaluation of nuclear DNA content and 3H-T labelling indicated the extension of G1 and G2 phases, followed by a lower cell proliferation and degeneration.

This paper assesses the effect of estradiol on the in vitro growth of fibroblast taken from human breast skin. It was observed that estrogens stimulate the proliferation of phenotypically adult fibroblasts; that there is a threshold increase of hormonal concentration which can trigger off this process; and that the size of the single dose is more important than the number of doses of hormone received.

Recent advances in the study on the importance of steroid receptors in the treatment of hormone-responsive tumors established the relationship between plasma membrane and the first steps of the cellular response to the endocrine stimulus. We have therefore found interesting to study the influence of estrogen and progesterone on cell adhesion of neoplastic (SGS/3A) and normal syngeneic (FG) cells. We demonstrated the presence of a nuclear estrogenic and a cytosolic progestin receptor in the SGS/3A cells. In syngeneic fibroblasts both receptors are absent. Cell adhesion kinetics obtained determining the percent of single labeled cells with 3H-leucine adhering to confluent monolayer (cell-cell adhesion) showed that the physiological concentrations of estradiol and progesterone induce an inhibition of cell-substratum adhesion (25-30%) in neoplastic cells, but do not influence cell-cell adhesion. In FG cells the two hormones cause an increase of cell-substratum adhesion (35-40%), but do not influence cell-cell adhesion. Results suggest that FG cells, although lacking cytoplasmic or nuclear receptors for estradiol and progesterone, probably have other steroid-receptive molecules involved in adhesive processes on their cell-surface.

In a study performed to identify the molecular mechanisms which regulate cell to cell adhesion and contact inhibition in neoplastic and syngeneic normal cells of the rat we have observed that the adhesive capacity depends on the reagents used, either EDTA or trypsin, to release the cells from monolayer. Taking profit of this last property and of the possibility of blocking free -NH2 groups on membrane proteins with specific cross-linking reagents "in vitro", we have studied in this work the behaviour of the proteins of the cell coat involved in cell to cell adhesion of rat fibroblasts FG/2. The cross-linking reagents used were dimethyladipimidate (DMA) and dimethylsuberimidate (DMS). The cells were exposed to the reagents at 0 degrees C for 30'. Cell to cell adhesion was measured by determining the percentage of single cells labeled with 3H-leucine, adhering to a confluent monolayer at different incubation times. The inhibitory effect on cell to cell adhesion brought about by cross-linking reagents indicates that a) EDTA-released cells are more sensitive to both imides than those released with trypsin, b) DMA is more effective on trypsin-released cells and c) DMS is more effective on EDTA-released cells. Therefore, we conclude that the inhibition of adhesion by reaction with the two cross-linking reagents is more likely due to a stiffening of the molecules of the cell coat involved in the adhesion, rather than to the modification of -NH2 residues which should specifically participate to adhesive process.

Tissue reaction to an epoxy resin-carbon fibre composite was tested "in vivo" and "in vitro" in order to evaluate this material as an alternative to metal alloys for clinical use in orthopaedic surgery. While the "in vitro" tests suggest a mild toxic effect of the composite on cells, good biocompatibility "in vivo" was observed when debris are not generated. The mechanical tests compared the composite and stainless steel plates, confirming the expected values for static strength and elastic modulus, revealing, however, the formation of long needles of carbon fibre following breakage of the plate.

Stable spontaneous mutants resistant to the protein synthesis inhibitor diphtheria toxin have been selected in human cell line EUE at a very low frequency (less than 8 x 10-6). We have assayed in this system the mutagenic activity of dimethylnitrosamine (DMNA): mutation increases by this compound have been used as an estimate of his mutagenic activity. Treatment of cells with this compound increased the frequency of diphtheria toxin resistant mutants only at the highest dose used (10-1 M).

The administration of high doses of adriamycin in rabbits causes morphologically evident alterations of cardiac myocites, such as cellular structure disorganization, myofilaments disappearance and vacuolar degeneration through the cytoplasm. The less damaged myocites show protein synthesis activation with newly produced myofilaments. Macrophages and fibroblasts are seen in the interstitium among markedly injured cells. As a response to the toxic damage induced by adriamycin, it would be seen an hypertrophic compensatory response in the well preserved cells and interstitial fibrosis. The conducting system shows similar but less extensive lesions as the ventricular myocardium.

Short-chain fatty acids produced by anaerobic bacteria inhibit attachment and proliferation of gingival fibroblasts. Butyric acid, at concentration normally present in periodontal pockets, produced the highest degree of activity.

A method is described for determination of the volume of fibroblasts, grown in suspension, in normal medium, in medium supplemented with sucrose (Su) 0,04 and 0.08 M. A 4 days permanence in these last two mediums causes an obvious cytoplasmic vacuolation and an increase in cell volume (Tab.1) that reaches its maximum for cells grown in Su 0.08M (87,2%) increase in comparison with control cells). The cell volume determination was performed utilizing a Coulter ZBI Counter coupled with a P64 pulse height analyzer and X-Y recorder. The volume and number of cells for every counting channel of P64 were manually determined from recorder plot (Fig. 1). These data were then elaborated using a desk computer to obtain the mean cell volume, the coefficients of skewness and kurtosis (algorithm for grouped data).

In the present study we analyze IFN-gamma capability to modulate bacterial adherence of group A Streptococci to murine cells such as fibroblast (L-929) or phagocytic cells (P 388 and PP-induced macrophages). IFN-gamma increases adherence of Streptococci to macrophages but not to L-929 cells. This finding could have important implication for the "in vivo" adhesion of bacteria to phagocytic cells.

The effects of interferon (IFN gamma) and of IFN alpha/beta on normal T and B lymphocytes and various T and non-T human and murine cell lines have been investigated. IFN gamma, unlike IFN alpha/beta, did not promote the antiviral state in T cells. The lack of antiviral activity was confirmed at the biochemical level by the finding that 2',5' oligoadenylate synthetase activity is not induced in T cells by IFN gamma only.

LS cells cultivated for 4 days in sucrose-containing medium (Su) are more fragile than cells cultivated in medium devoid of this sugar (TN) when they are incubated with Naja-Naja venom; in fact the 51Cr radioactivity released into the medium by previously labelled cells is increased for the sucrose ones. Phospholipase does not seem to contribute to the lytic activity of the venom, which is dependent on the direct lytic factor: neither varying the temperature of incubation nor adding EDTA to the incubation medium modifies the results. Adding Ca++ decreases the 51Cr radioactivity released particularly by the cells grown in TN, suggesting a stabilizing action of this cation.

In a study performed on transformed (SGS/3A) and normal syngeneic rat cells (FG/2) to identify the molecular mechanisms which regulate cell adhesion and contact inhibition in cell transformation, we investigated the effects of tumor promoters on cell to cell adhesion of rat fibroblasts. As tumor promoters we used 12-tetradecanoyl-phorbole-13-acetate (TPA) and the melittin, a polypeptide from bee venom, both substances capable of stimulating the neoplastic transformation. The intercellular adhesion assay consists in determining the percent of single cells labeled with 3H-L-leucine adhering to a confluent monolayer of unlabeled cells at different incubation times. The increase of cell-cell adhesion caused by TPA and melittin confirms what we have constantly observed in other experiments, i.e. that neoplastic cells SGS/3A always have a higher intercellular adhesion capacity than corresponding normal syngenic cells FG/2. Since one of the effects of the tumor promoters is also induction of a reversible alteration of the cytoskeleton, it is likely that their action on intercellular adhesion is regulated by a mechanism analogous to that proposed for explaining the increased intercellular adhesion observed after treatment with antimicrotubular compounds.

Mouse fibroblasts grown in the presence of dextrans of various molecular weight at various concentrations, show a small but significant decrease of the osmotic resistance (Tab. 1,2,3; ANOVA: source of variation A and C); this decrease is related to the length of time the cells stay in the dextran containing medium (Tab. 2,3; ANOVA: source of variation B). The presence of dextran in the culture medium has no effect on the cell growth (Tab. 4).

Cell culture of mouse fibroblasts and lymphocytes show an increase of mRNA and DNA synthesis after treatment with "Fitostimoline". In this activity may consist the mechanism of action of these substances, which stimulate regenerating tissues.

The -SH groups of rat fibroblasts of cell-coat were blocked with Iodacetamide. This substance interferes negatively on the homologous intercellular adhesion of the tested cells, with a proportional effect related to the concentration used. The meaning of -SH groups on the cell-cell interactions is discussed.

The Authors expose their observations about the fibroblasts adhesion to materials used as implants in orthopaedic surgery; the first part of the experiment uses normal culture conditions. In the second part the materials have been pre-coated with Fibronectin (FN), a glycoprotein involved in cell-to-substratum adhesion Fibroblasts adhesion increases about 30-40% with pre-coated materials. This observation is important for comprehension of adhesion mechanisms in a multidisciplinary approach to biocompatibility of implant materials.

We have studied antiproliferative effect of Aspergillus terreus extract on various cell lines: I-407 normal human cells, L-929 normal murine cells, K-562 erythroleukemic human cells, IAD lymphoblastoid human cells and B 95-8 monkey lymphoblastoid cells. K-562 and lymphoblastoid cells showed higher sensitivity to the extract. Moreover, "a cytostatic dose" of the extract on K-562 cells (12.5 micrograms/ml showed a reduction of 3H-thymidine (but not of 14C-uracil) incorporation, leading us to hypothesize a prevalent action on DNA synthesis.

The effect of cobalt II (CoCl2.6 H2O) on growth and plating efficiency of an established line of BALB/c mouse embryo cells was examined. The degree of inhibition of cell proliferation was dependent on both cobaltous ion dose and duration of treatment. Plating efficiency was enhanced by low doses and/or short time of exposure, but was reduced by treatment with higher doses or of longer duration.