Hydroxyapatite paste Ostim, without elevation of full-thickness flaps, improves alveolar healing stimulating BMP- and VEGF-mediated signal pathways: an experimental study in humans.

OBJECTIVE: Tooth extraction is considered as the starting point of jaw atrophy via osteoclast activity stimulation. The maintenance of dental alveolar bone depends on surgery procedure and use of materials to maintain prior space favoring bone regeneration. Among substitutes used in dentistry to fill bone defects, Ostim-Pastes (Ostim) is a nanocrystalline paste tested for treatment of severe clinical conditions. This research first investigated the effect of Ostim on alveolar healing, comparing in the same healthy subjects, an Ostim-filled socket with a not-filled one. Moreover, it also proposed a new surgical protocol for the post-extractive socket treatment using the graft materials without elevation of full-thickness flaps. MATERIAL AND METHODS: Fourteen patients were enrolled to bilateral maxillary or mandibular extraction that was performed without elevation of full-thickness flaps. In each patient, one socket was filled using Ostim, and the other one was allowed to undergo natural healing. No suture was carried out. Clinical and biologic parameters were screened at 1, 7, and 14 days. RESULTS: Obtained results evidenced that nanocrystalline hydroxyapatite supports bone regeneration, increasing the synthesis of pro-osteogenic factors as bone morphogenetics protein (BMP)-4, BMP-7, alkaline phosphatase, and osteocalcin. Moreover, filling post-extractive socket with nanocrystalline hydroxyapatite paste leads to a complete epithelialization already at 7 days after extraction, despite the fact that the teeth were extracted without elevation of full-thickness flaps . The improved epithelialization is mediated by increased vascular endothelial growth factor (VEGF) expression. No significant change was observed in inflammatory parameters, with exception of an early and transient IL-1ß induction, that could trigger and improve alveolar healing. CONCLUSIONS: Clinical and biomolecular observations of this explorative study evidenced that nanocrystalline hydroxyapatite improves alveolar socket healing, increasing angiogenesis, epithelialization, and osteogenesis, also in absence of elevation of full-thickness flaps.

Importance of inverse correlation between ALDH3A1 and PPARγ in tumor cells and tissue regeneration.

Aldehyde dehydrogenase (ALDH) enzymes are involved in maintaining cellular homeostasis by metabolizing both endogenous and exogenous reactive aldehydes. They modulate several cell functions including proliferation, differentiation, survival as well as cellular response to oxidative stress. We previously reported that ALDH3A1 expression is inversely correlated with the activation of PPARs (Peroxisome Proliferators-Activated Receptors), a category of orphan nuclear hormone receptors, in both rat and human cells. PPARγ is involved in cell proliferation. In this study, we have used PPARγ transfection and inhibition to examine the relationship between ALDH3A1 and PPARγ and their role as regulators of cell proliferation. Induction of PPARγ in A549 and NCTC 2544 cells by transfection caused a decrease in ALDH3A1 and inhibition of cell proliferation, a result we obtained previously using ligands that induce PPARγ. A reduction of PPARγ expression using siRNA increased ALDH3A1 expression and cell proliferation. In cells induced to proliferate in a model of tissue regeneration, ALDH3A1 expression increased during the period of proliferation, whereas PPARγ expression decreased. In conclusion, through modulation of PPARγ or ALDH3A1, it may be possible to reduce cell proliferation in tumor cells or stimulate cell proliferation in normal cells during tissue regeneration.

A split-mouth study on microbiological profile in clinical healthy teeth and implants related to key inflammatory mediators.

This split-mouth study investigated the correlation of the qualitative and quantitative bacterial composition in dental plaque around clinically healthy periodontal and peri-implant subgingival sites with the levels of selected pro- and anti-inflammatory cytokines and the inflammatory infiltrate in the soft tissue surrounding a healthy dental implant and natural tooth in the same patient. Nine patients, all in good health and non-smokers, were studied. All of the patients were highly motivated in terms of oral hygiene and had healthy natural teeth and at least one healthy implant. After three sessions of professional oral care, clinical parameters were recorded. A sample of subgingival plaque was harvested with a sterile curette from the buccal side of the selected implants and teeth. The plaque samples were cultured to quantify the total microbiota and the number of obligate and facultative bacterial strains. Simultaneously, from the lingual/palatal aspect of the same implants and teeth the keratinized periodontal and peri-implant soft tissues were biopsied for cytokine expression and histomorphometric analysis. The tissue biopsies were halved: the real-time reverse transcriptase-polymerase chain reaction (PCR) was performed to detect active TNF-alpha, IL-1beta, IL-8, and TGF-beta2 and distribution, composition, quantification of inflammation were assessed in parallel. The patients harbored no periodontopathogens and the microbiological composition of the plaque taken from implant sites did not differ from that harvested from teeth. No significant differences were seen between implants and teeth for both proand anti-inflammatory cytokines. Even the histological examination showed no significant epithelial changes, although slight perivascular lymphocytic infiltration was seen in some biopsies.

Involvement of PPARs in Cell Proliferation and Apoptosis in Human Colon Cancer Specimens and in Normal and Cancer Cell Lines.

PPAR involvement in cell growth was investigated "in vivo" and "in vitro" and was correlated with cell proliferation and apoptotic death. "In vivo" PPARgamma and alpha were evaluated in colon cancer specimens and adjacent nonneoplastic colonic mucosa. PPARgamma increased in most cancer specimens versus mucosa, with a decrease in c-Myc and in PCNA proteins, suggesting that colon cancer growth is due to increased cell survival rather than increased proliferation. The prevalence of survival over proliferation was confirmed by Bcl-2 or Bcl-X(L) increase in cancer versus mucosa, and by decreased PPARalpha. "In vitro" PPARgamma and PPARalpha were evaluated in human tumor and normal cell lines, treated with natural or synthetic ligands. PPARgamma was involved in inhibiting cell proliferation with a decrease in c-Myc protein, whereas PPARalpha was involved in inducing apoptosis with modulation of Bcl-2 and Bad proteins. This involvement was confirmed using specific antagonists of two PPARs. Moreover, the results obtained on treating cell lines with PPAR ligands confirm observations in colon cancer: there is an inverse correlation between PPARalpha and Bcl-2 and between PPARgamma and c-Myc.

Effect of superpulsed laser irradiation on bone formation in a human osteoblast-like cell line.

AIM: The effect superpulsed of low-level laser therapy (SLLLT) on bone regeneration has been the focus of recent research. This preliminary study investigated the effect of superpulsed laser irradiation on proliferation and bone formation in human osteoblast-like cells MG-63. METHODS: Human osteoblast-like cells MG-63 were exposed every 24 h to superpulsed low-level laser produced by the device Lumix 2 HFPL Dental (Fisioline s.n.c., Verduno, Cuneo, Italy); the experimental protocol comprised 4 days of treatment. At each experimental time, cell proliferation and some markers of osteoblast activity were evaluated. RESULTS: Numbers of laser-treated cells increased starting from day 2 of treatment. The ability of SLLLT irradiation to stimulate bone production was evaluated by determining the expression of osteocalcin and alkaline phosphatase, proteins involved in calcium nodule formation. These proteins increased markedly after 3 days of laser treatment. CONCLUSIONS: These preliminary results show that repeated SLLLT irradiation stimulates cell proliferation in human osteoblast-like cells and, importantly, increases the expression of proteins essential for bone formation.

Development of glass-ceramic scaffolds for bone tissue engineering: characterisation, proliferation of human osteoblasts and nodule formation.

Glass-ceramic macroporous scaffolds for tissue engineering have been developed using a polyurethane sponge template and bioactive glass powders. The starting glass (CEL2) belongs to the system SiO(2)-P(2)O(5)-CaO-MgO-Na(2)O-K(2)O and has been synthesised by a conventional melting-quenching route. A slurry of CEL2 powder, polyvinyl alcohol and water has been prepared in order to coat, by impregnation, the polymeric template. An optimised thermal treatment was then use to remove the sponge and to sinter the glass powders, leading to a glass-ceramic replica of the template. Morphological observations, image analyses, mechanical tests and in vitro tests showed that the obtained devices are good candidates as scaffolds for bone-tissue engineering, in terms of pore-size distribution, pore interconnection, surface roughness, and both bioactivity and biocompatibility. In particular, a human osteoblast cell line (MG-63) seeded onto the scaffold after a standardised preconditioning route in simulated body fluid showed a high degree of cell proliferation and a good ability to produce calcium nodules. The obtained results were enhanced by the addition of bone morphogenetic proteins after cell seeding.

HMG-CoA reductase and PPARalpha are involved in clofibrate-induced apoptosis in human keratinocytes.

Contrasting data have been reported on the effects of clofibrate, a PPARalpha agonist and hypolipidemic drug. The carcinogenic and anti-apoptotic effects have been demonstrated especially in rodents in both "in vivo" and "in vitro" experiments. In contrast, in rat and human hepatoma cell lines, several reports have shown its concentration-dependent pro-apoptotic effect. No epidemiological data exist about its carcinogenetic effect in man. This study shows that clofibrate also induced apoptosis in a human non-tumour cell line, NCTC 2544, which shares the characteristic of proliferation with tumour cells. Both HMG-CoA reductase and PPARalpha were found to be involved in the signal transduction pathway inducing apoptosis, the former being the principal target: HMG-CoA reductase decreased and PPARalpha increased. Changes in HMG-CoA reductase expression caused activation of parameters leading to apoptosis via the mitochondria pathway. Clofibrate must be considered a pro-apoptotic molecule at concentrations of 0.25 mM and above: the effect is exercised not only on tumour cells but also on normal human proliferating cells. Clofibrate should thus be regarded as a potential drug to reduce the number of proliferating cells in pathological conditions.

Increase in class 2 aldehyde dehydrogenase expression by arachidonic acid in rat hepatoma cells.

Aldehyde dehydrogenase (ALDH) is a family of several isoenzymes important in cell defence against both exogenous and endogenous aldehydes. Compared with normal hepatocytes, in rat hepatoma cells the following changes in the expression of ALDH occur: cytosolic class 3 ALDH expression appears and mitochondrial class 2 ALDH decreases. In parallel with these changes, a decrease in the polyunsaturated fatty acid content in membrane phospholipids occurs. In the present study we demonstrated that restoring the levels of arachidonic acid in 7777 and JM2 rat hepatoma cell lines to those seen in hepatocytes decreases hepatoma cell growth, and increases class 2 ALDH activity. This latter effect appears to be due to an increased gene transcription of class 2 ALDH. To account for this increase, we examined whether peroxisome-proliferator-activated receptors (PPARs) or lipid peroxidation were involved. We demonstrated a stimulation of PPAR expression, which is different in the two hepatoma cell lines: in the 7777 cell line, there was an increase in PPAR alpha expression, whereas PPAR gamma expression increased in JM2 cells. We also found increased lipid peroxidation, but this increase became evident at a later stage when class 2 ALDH expression had already increased. In conclusion, arachidonic acid added to the culture medium of hepatoma cell lines is able to partially restore the normal phenotype of class 2 ALDH, in addition to a decrease in cell growth.

Bladder tumor antigen assay as compared to voided urine cytology in the diagnosis of bladder cancer.

BACKGROUND: The study was aimed at comparing the diagnostic accuracy of the quantitative bladder tumor antigen (BTA) TRAK immunoassay with exfoliative urine cytology in the detection of primary and recurrent bladder cancer. METHODS: The analysis was carried out on 194 high risk patients undergoing a diagnostic cystoscopy, 279 patients with previous history of transitional cell carcinoma awaiting a follow-up cystoscopy, and 45 healthy controls. Urine cytology was performed by a skilled cytopathologist on three consecutive samples. RESULTS: BTA TRAK values resulted significantly higher in tumor positive cases than in absence of bladder tumor for both groups of patients. Non neoplastic urothelial diseases as well as the absence of mucosal abnormalities were associated with a marked increase in BTA TRAK levels with respect to the control group. Overall sensitivity and specificity was 63 and 63% for BTA TRAK (cut-off 34 U/ml), and 68.3 and 73.4% for urine cytology, respectively. The diagnostic advantage of urine cytology was maintained when patients were stratified by tumor grade. CONCLUSIONS: The clinical performance of the BTA TRAK in the detection of primary or recurrent bladder cancer is acceptable and reproducible as shown by similar results with previous reports, although urine cytology performed on three samples showed the highest sensitivity and specificity.

BTA quantitative assay and NMP22 testing compared with urine cytology in the detection of transitional cell carcinoma of the bladder.

PURPOSE: Both BTA TRAK and NMP22 urine concentrations have shown a sensitivity superior to urine cytology in the detection of bladder cancer. We compared these tumor markers with urine cytology performed on 3 consecutive samples and evaluated by an expert cytopathologist. PATIENTS AND METHODS: The investigations were conducted on 94 patients undergoing a diagnostic cystoscopy for a high suspicion of bladder cancer (group 1) and on 102 patients with previous history of transitional cell carcinoma awaiting a follow-up cystoscopy (group 2). Biopsy specimens were obtained also from tumor negative patients. Immunoassays for BTA TRAK and NMP22 were carried out according to standard methods. The choice of the cut-off was based on the ground of sensitivity and specificity curves intersection. Urine cytology results were expressed as positive, negative and 'dubious'. RESULTS: Overall sensitivity was 56% for NMP22 (cut-off 11 U/ml) and 57% for BTA TRAK (cut-off 60 U/ml). When dubious results were considered as positive cases, urine cytology achieved a sensitivity of 73.3%. Assuming dubious cases as negative results, urine cytology sensitivity resulted 59.3%. When the 2 groups of patients were evaluated separately with different cut-off, there was no significant gain in sensitivity for BTA TRAK and NMP22 over urine cytology. CONCLUSIONS: Urine cytology performed on 3 samples showed the highest sensitivity and specificity. The diagnostic advantage of urine cytology over BTA TRAK and NMP22 was maintained when patients were stratified by tumor grade.

Exhaled nitric oxide and oxygenation abnormalities in hepatic cirrhosis.

Impaired arterial oxygenation, ranging from increased alveolar-arterial oxygen gradient (AaDo2) to hypoxemia, is commonly present in patients with cirrhosis. Nitric oxide (NO), through pulmonary vasodilatation, may play a major role in the oxygen abnormalities of cirrhosis. Our aim was to study the relationship between NO production and O2 abnormalities in 45 nonsmoking patients with cirrhosis and without major cardiovascular and respiratory diseases. Intrapulmonary shunting was detected by contrast-enhanced (CE) echocardiography. Lung volumes and diffusion, arterial blood gas analysis, serum NO2-/NO3-, NO output in the exhaled air, and cardiac index by the echocardiographic method were determined in all patients. Twenty-seven (60%) patients had an abnormally increased (> 15 mm Hg) AaDo2. The mean values of exhaled NO output and serum NO2-/NO3- were significantly higher in cirrhotic patients than in controls (252 +/- 117 vs. 75.2 +/- 19 nL/min/m2, P < .0001; and 47.5 +/- 29.4 vs. 32.9 +/- 10.1 micromol/L, P < .02, respectively). In all patients, there was a significant correlation between exhaled NO and AaDo2 (r = .78, P < .0001). Twelve patients (26.6%) were found to have CE-echocardiographic evidence of intrapulmonary shunting (positive CE-echo). Nine patients were considered to have hepatopulmonary syndrome (HPS) on the basis of an AaDo2 > 15 mm Hg and positive CE-echo. These 9 patients had a mean value of exhaled NO significantly higher than patients without HPS (331 +/- 73.2 vs. 223 +/- 118.4 nL/min/m2, P < .05). In all patients, cardiac index was positively correlated with exhaled NO (r = .47, P < .001) and with serum NO2-/NO3- (r = .43, P < .01). The results suggest an important role of NO in the oxygenation and circulatory abnormalities of patients with cirrhosis.

Monoethyl glycine xylidide (MEGX) test evaluation in primary biliary cirrhosis: comparison with Mayo score.

OBJECTIVE: To evaluate the clinical and prognostic value of the monoethyl glycine xylidide (MEGX) test in patients with primary biliary cirrhosis (PBC) in comparison with the Mayo score (Mayo). DESIGN: A prospective study. METHODS: MEGX determinations at enrolment were compared to the Mayo score as well as to conventional clinical and laboratory parameters in 92 patients with PBC. RESULTS: The MEGX test yielded higher basal values in long-term survivors compared to patients that were transplanted or died during the follow up; patients belonging to the last two groups displayed significantly higher Mayo scores at baseline. Although values for prothrombin time, serum albumin, alkaline phosphatase, cholesterol, cholinesterase, and gamma-glutamyltranspeptidase were significantly different in survivors compared to either transplanted or dead patients at univariate analysis, the multivariate analysis demonstrated an independent prognostic value for the MEGX and the Mayo score solely. The best discrimination between probability of death or survival was achieved with a cutoff value of 25 ng/ml for the MEGX test and of 6 for the Mayo score. When plotting both MEGX test and Mayo score, the point distribution displayed a bimodal trend, and the wide range of values given by the MEGX test was observed to supply a more precise assessment of liver reservoir and a better discrimination of progressive changes in liver function; the limited range of the Mayo score for values below 6 could only identify gross deteriorations. CONCLUSION: Our data show that the asymptomatic progressive functional deterioration occurring during the natural history of PBC can be monitored by the MEGX test because it appears to be able to identify abnormalities prior to the onset of alterations in conventional laboratory and/or clinical parameters which are likely to affect the Mayo score.