Osteogenic potential of cells derived from nasal septum.

BACKGROUND: The research addressed to detect new molecular targets in the development of therapeutic strategies aimed to repair bone tissues. The AIM OF THIS STUDY was to determine the potential osteogenic activity of bone cells from the nasal septum and their use to perform accurate molecular analysis from a single sample. METHODOLOGY: The cells, after nasal septum surgery, were subjected to gene silencing, Reverse Transcriptase - Polymerase Chain reactions, immunocytochemistry and chromatin immunoprecipitation. RESULTS: Cells from the nasal septum can give rise to mature osteoblasts that express osteogenic markers (ALP, Runx2, Slug) and are able to mineralize. We demonstrated that Runx2, a transcription factor critical in early osteospecific differentiation, interacts in vivo with the promoter of the SLUG gene, a marker of osteoblast maturation. CONCLUSIONS: We demonstrated that nasal septum-derived osteoblasts represent an interesting alternative source for bone forming cells, and a promising material to be utilized in bone cellular therapy.

A possible solvent effect of adenosine diphosphate influences the binding of 1,N6 ethenoadenosine diphosphate to myosin from skeletal muscle.

Skeletal muscle myosin displays two independent and equivalent binding sites for 1,N6 ethenoadenosine diphosphate, with a dissociation constant of 24.7 microM. MgADP, 10 to 40 microM, behaves as a pure competitive type inhibitor (K(SI)=8-9 microM) for the binding of 1,N6 ethenoadenosine diphosphate to skeletal muscle myosin. On the contrary, the inhibition by MgADP, 0.11-1.54 mM, is neither competitive nor non-competitive nor mixed, as is revealed by the analysis with the general kinetic equation (K.J. Laidler, P.S. Bunting, The Chemical Kinetics of Enzyme Action, 2nd ed., Clarendon, Oxford, 1973, p. 94). To explain our finding we propose that MgADP operates a complex type of inhibition, acting both directly as a competitor for myosin active sites, and indirectly by perturbing the regions of the solvent near to the protein.

Protein cross talking through osmotic work: the free energy of formation of the MgADP-myosin complexes at the muscle protein osmotic pressure.

A method is presented to determine the energy of formation of the myosin-ADP complexes at the muscle protein osmotic pressure. It is found that, at 18 kP, the putative protein osmotic pressure in skeletal muscle, the increase of MgADP from 0.05 to 2 mmolal, increases the free energy of myosin-ADP and of myosin-(ADP)2 by 0. 756 and by 9.85 kJ/mol, respectively, and decreases the free energy of myosin by 8.34 kJ erg/mol. It is pointed out that the local changes of water chemical potential, induced by the binding of MgADP to myosin, can be sensed by other structures of the contractile machinery, which per se may even be insensitive to MgADP. Cross talking between macromolecules can thus be achieved by changes of the water chemical potential.

The control of cellular motility and the role of gelsolin.

Solation of actin gel by gelsolin is much less efficient in the presence of a high concentration of macromolecular solutes. The rigidity of the gel formed by 12 microM actin is lowered from 4 to 0.33 dynes/cm2 by 15 nM gelsolin, while in 6% (w/v) polyethylene glycol, rigidity is lowered only from 20 to 11 dynes/cm2 by 64 nM gelsolin. Owing to the large concentration of protein, transitions in the fluid- and gel-like properties of the cytoplasm are expected to be problematic when promoted by gelsolin alone.

The stiffness of the crossbridge is a function of the intrinsic protein osmotic pressure generated by the crossbridge itself.

A model is presented that makes it possible to determine the stiffness of the crossbridge from protein osmotic stress experiments. The model was elaborated while studying the osmotic properties of F-actin and of myosin subfragment-1 F-actin. These studies showed that the elastic modulus by bending of the monomer is directly related to the intrinsic protein osmotic pressure of the system. At a protein osmotic pressure of 1.8 x 10(5) dynes/cm2, the physiological protein osmotic pressure of frog skeletal muscle, it was found that the elastic moduli by bending of the monomer in F-actin and in the myosin subfragment-1 decorated F-actin are 6.5 X 10(7) and 3.3 X 10(8) dynes/cm2, respectively. The value of the elastic modulus by bending of the monomer in the myosin subfragment-1 decorated F-actin compares favorably with the values of the elastic modulus by stretching determined in skeletal muscle fibres.

The actin gelling activity of chicken gizzard alpha-actinin at physiological temperature is triggered by water sequestration.

At 37 degrees C, in the presence of 6% (w/v) polyethylene glycol 6000, 30 nM alpha-actinin from chicken gizzard induces the gelation of 12 microM actin. Static measurement shows that the addition of 30 nM alpha-actinin increases the rigidity of the system from 23.5 to 54 dynes/cm2. According to the theory of osmoelastic coupling, also large additives, such as the proteins of the cell sap, are able to cause an osmotic stress equivalent to that caused by polyethylene glycol. We thus conclude that, in vivo, alpha-actinin acts as an actin gelling protein.

Preferential binding of alpha-actinin to actin bundles.

At 37 degrees C, the alpha-actin-F-actin binding isotherm is anomalous. In 6.7% polyethylene glycol 6000, concomitantly with the formation of actin bundles, the binding isotherm becomes hyperbolic (Kdiss. = 11.3 microM). alpha-Actinin increases the rigidity of the networks formed by actin bundles in polyethylene glycol and by paracrystalline actin in 16 mM MgCl2 but not by F-actin. It is proposed that in the cell alpha-actinin functions are mostly carried on by interaction with actin bundles.

Evidence for androgen receptor gene expression in human thyroid cells and tumours.

Androgen-binding activity has been identified in normal and pathological thyroids, but evidence for the expression of the canonic androgen receptor (AR) in the thyroid has not been provided so far. In this study we have used reverse transcription (RT)-PCR to examine RNA expression of the canonic AR gene in human thyroid tissues, in primary cultures of human thyrocytes and in a variety of neoplastic thyroid cell lines (NPA, TPC and WRO). An AR cDNA fragment with the expected size of 262 bp was detected in normal tissues and cultured thyrocytes as well as in neoplastic cell lines, demonstrating that the gene for AR is indeed expressed in thyroid follicular cells. Immunocytochemical analysis revealed the presence of the AR protein in cancer cell lines and androgen treatment increased nuclear positivity to AR. In a survey of 35 thyroid tissues AR cDNA was detected in all the non-neoplastic samples (6 normal and 3 goitrous) and in 19 of 26 neoplastic samples. AR cDNA was not detected in 4 of the 9 follicular adenomas and in 3 of the 12 papillary carcinomas. AR was revealed by immunohistochemistry in 1 of 2 normal thyroids, in 1 goiter and in 1 of 2 neoplastic thyroids. These findings show the presence of the canonic AR in the human thyroid.

Inhibitory effect of dihydrotestosterone on human thyroid cell growth.

Sex steroid-binding activities have been identified by several authors in normal and pathological thyroids and the expression of the canonic androgen receptor (AR) has recently been demonstrated in human thyroid follicular cells. In order to assess what influence, if any, androgen exposure has on thyroid cell growth, the effect of dihydrotestosterone (DHT) on [3H]thymidine (thy) incorporation and cell proliferation was investigated in thyroid follicular cells in vitro. In a primary culture of goitrous cells, DHT induced a significant reduction of [3H]thy incorporation at concentrations ranging from 10(-12) to 10(-8) M, with a more pronounced effect at 10(-9) M. At this concentration, the inhibitory effect was evident after both 24 and 48 h of treatment and in various types of primary thyroid cell cultures. In goitrous cells, the DHT-induced decrease of [3H]thy was associated with a reduction of expression of the proliferation-associated nuclear Ki-67 antigen, a protein commonly used to assess cell growth fraction. In TPC cells, an AR-positive thyroid papillary carcinoma cell line, DHT at concentrations between 10(-12) and 10(-8) M significantly decreased the growth rate. DHT (10(-9) M) produced an approximately 50-60% inhibition of cell proliferation and the antiandrogen cyproterone acetate was capable of reversing such effects. The DHT-induced reduction of TPC cell proliferation was associated with a significant reduction of c-myc RNA levels. Thyroperoxidase mRNA levels and thyroglobulin production were not reduced by androgen in primary cultures of goitrous cells. In conclusion, our results indicated that androgens may have a role in this gland by reducing the proliferation, but not the function, of follicular cells.

MIB-1 proliferative activity in invasive breast cancer measured by image analysis.

AIMS: To determine cell proliferation in infiltrating breast carcinomas. METHODS: Using the MIB-1 monoclonal antibody, the proliferation index was measured in paraffin wax sections of 871 breast cancers. The MIB-1 proliferation index was compared with other markers of disease progression: size, lymph node status, histotype, oestrogen and progesterone receptor status, expression of p53 and Neu, and DNA ploidy. All parameters were measured using image analysis. In 347 tumours, the MIB-1 and Ki-67 proliferation indexes were compared. Follow up data were available for 170 cases (median 66.5 months). RESULTS: Of the tumours, 314 (36%) had a high proliferation index. The MIB-1 proliferation index was correlated directly with size, nodal status, overexpression of p53 and Neu, and the DNA index; and inversely with oestrogen and progesterone receptor status. The correlation between MIB-1 and Ki-67 proliferation indexes was statistically significant. In patients with pT1 tumours, a low proliferation index correlated with a longer relapse-free interval and overall survival; node negative patients with a low proliferation index had a longer overall survival. CONCLUSIONS: The MIB-1 proliferation index is a reliable, practical and useful method of measuring proliferative activity and is an important predictor of clinical behaviour.

Dissecting the free energy of formation of the 1:1 actomyosin complex.

The behaviour of solutions of pure myosin, of pure F-actin and of the equimolar mixture of myosin and of F-actin is studied. It is found that the chemical potential of the two proteins, in separate solutions, increases monotonically with the increase of protein osmotic pressure. A method is presented to determine the chemical potential of the 1:1 actin-myosin complex formed from equimolar solutions of myosin and of F-actin (as monomer). This is the first evaluation of the chemical potential of actomyosin under conditions similar to those of skeletal muscle. It is found that the filament suspensions of myosin and of the 1:1 actin-myosin complex display a high non-ideal behavior as well as distinctly different energy profiles as a function of protein osmotic pressure. This supports the hypothesis that, in muscle: (a) detached cross-bridge change significantly their free energy when sarcomere is shifting from the relaxed to the active or to the rigor state; and (b) the cross-bridge attachment-detachment process is accompanied by changes of muscle protein osmotic pressure.

Biophenotypes of breast carcinoma in situ defined by image analysis of biological parameters.

In 50 in situ breast cancers an immunohistochemical study, evaluating estrogen (ER) and progesterone (PR) receptors, Proliferation Index (PI), c-erbB-2/Neu and p53 expression was performed. According to histopathological diagnosis, cases were classified as follows: 14 comedo, 8 solid, 5 micropapillary, 6 lobular, 3 papillary, 1 apocrine and 12 mixed in situ carcinomas. The quantitation of immunohistochemical results was obtained with an image analysis computerized system (CAS 200) with a lesion-field method; tumors were subdivided in fields (1177) histologically homogeneous, with 40 x microscopic objective. For ER, PR, Neu and p53, 10% of the positive area was used as cut-off value; 13% was used for PI. Cribriform and lobular types showed a higher positivity for ER (92.1% and 95.5% of the fields); cribriform and papillary a higher for PR (92.6% and 93.9%). Comedo variant demonstrated the higher PI (52.7%), Neu and p53 expression (67.7% and 43%). A cluster analysis performed on 608 fields, defined two groups according to biological homogeneous criteria. The results obtained identify the different biophenotypes of in situ carcinomas, suggesting the possibility of multiple cancerogenetic ways with a different weight of biological events.

[Clinico-experimental study of a new antibactorial agent for local use in stomatology]. / Contributo clinico-sperimentale allo studio di un nuovo antibatterico per uso locale in stomatologia

Tibezonium iodide is a new drug having antibacterial activity for the therapy and the prevention of mouth infections. Before testing its therapeutic efficacy, its effect on the bacterial flora of the human saliva was verified as follows. Salivary samples, collected before and after the administration (double-blind, cross-over) to volunteers, were counted for bacteria. The drug reduced the bacterial count in the saliva with statistical significance in both the pharmaceutical forms. Subsequently the drug was tested in different dental or oral conditions. To 90 patients suffering from marginal paradentitis or other diseases with this type of complications tablets were administered. The results obtained in this group were satisfactory or almost satisfactory in 73.5% of the cases examined. The patients treated with bubble-gums were 70. All of them were suffering from the same kind of disease of the first group; a few of them had alveolitis following tooth extraction. The results in these subjects were satisfactory or almost satisfactory in 77% of the cases examined. Tibezonium proved to be particularly effective in marginal paradentitis and in piorrhoic paradontosis. Bubble-gums should not be used in subjects with dental mobile prosthesis.

Extended operations for extracolic invasion by colon cancer.

Out of 618 cases of colon cancer treated between 1976 and 1986, 25 had an unusual local invasion. They underwent radical surgery with total resection of one or more adjacent organs. This group is made of 17 female and 8 male patients, with an average age of 58 years. All the patients underwent resection of the colon with radical excision of the locally invaded organs. Only one case of postoperative death is recorded. Postoperative surgical complications were rare. This experience confirms that colic resection extended to adjacent organs invaded by the tumor gives a low risk of relapse and satisfying long term results in relatively young patients with good general conditions and without remote metastases.

Carcinoma of the gastric stump following partial gastrectomy (Billroth II operation) for benign gastroduodenal lesions. Preliminary results.

A series of 110 patients out of 2,200, who had undergone Billroth II partial gastrectomy for benign lesions, between 1945 and 1980, was reviewed in order to perform clinical, biochemical and endoscopical examinations. In this group 9 patients (8.18%) showed gastric stump cancer and in 4 (3.63%) esophageal cancer was detected. The average time interval between previous operation and carcinoma diagnosis was of 28 years and 6 months. Eight patients out of 9 were males aging from 47 to 82, while the only woman was 65 (overall average: 63). The stump cancer presents at the same age and gives the same symptoms as primitive gastric carcinoma, but with worse results and prognosis. After having underlined some pathogenetic problems, the Authors show personal results and confirm the utility of an accurate endoscopical and clinical follow up especially for patients operated on since more than twenty years.