Efficacy of guided autofluorescence laser therapy in MRONJ: a systematic review.

OBJECTIVE: This review aims to explore the efficacy of fluorescence-guided excision in the treatment of necrotic bone and highlights the importance of fluorescence in distinguishing viable margins from necrotic ones for a more targeted and predictable management of MRONJ. MATERIALS AND METHODS: The review was conducted according to PRISMA guidelines using PubMed, Scopus, and Web of Science databases from January 1, 2008, to May 17, 2023. The Boolean search strategy with the following keywords "osteonecrosis" AND "fluorescence" was performed. Then, the articles were subjected to screening and eligibility phases. The papers about the use of autofluorescence-guided laser therapy in patients with jaw osteonecrosis were included. RESULTS: A total of 320 articles were initially identified through an electronic search, and ultimately, 17 papers were included in the qualitative analysis. CONCLUSIONS: In conclusion, our findings demonstrate that the VELscope system allows for clear visualization of the bone, making guided autofluorescence a precise, safe, and reliable technique.

PO-19 - Platelet (PLT) adhesion under flow condition in essential thrombocythemia (ET) and polycythemia vera (PV) is variably influenced according to patient mutational status.

INTRODUCTION: The myeloproliferative neoplasms ET and PV are characterized by a high incidence of both arterial and venous thrombosis, and/or microcirculatory disturbances. Three somatic mutations, i.e. JAK2-V617F, Calreticulin (CalR) and MPL, commonly found in these diseases, correlate with different thrombotic risk levels. AIM: To analyze the influence of JAK2-V617F, CalR and MPL mutations on PLT adhesion, evaluated by a dynamic method under flow conditions in a group of patients with ET and PV. MATERIALS AND METHODS: 86 patients, i.e. 51 ET (19 M/32 F; age range 32-86 years) and 35PV (22 M/13 F; 41-83 yrs.), and 24 healthy controls (13 M/11 F; 28-61 yrs.) were enrolled upon informed consent. For the adhesion assay, peripheral venous whole blood was perfused over collagen for 4' at a 1,000 s-1 shear rate. PLTs were then stained with an anti-P-selectin-FITC antibody to evaluate PLT activation, and annexin V-AlexaFluor647 to detect procoagulant phosphatidylserine expression. Then, images of adherent PLTs in random fields were taken using phase contrast and fluorescence imaging by EVOS® fluorescence microscope. Results are mean±SEM of the % area covered by PLTs, or as the % of adherent PLTs positive for P-selectin or phosphatidylserine. Main hematological parameters and mutational status were recorded. RESULTS: PLT adhesion was significantly (p<0.01) greater in ET (44.6±1.6%) and PV patients (49.0±1.9%) compared to controls (37.9±1.7%). In ET, PLT adhesion was highest in JAK2-V617F mutation carriers (n=23), followed by CalR-positive (n=16) and triple negative subjects (n=9), and lowest in the MPL-positive patients (n=3). In PV, no difference in PLT adhesion was observed between JAK2-V617F heterozygous and homozygous subjects. P-selectin expression by adherent PLTs was not statistically different between patients and controls. Differently, phosphatidylserine expression on adherent PLTs was significantly reduced (p<0.01) in both ET and PV compared to healthy subjects. In ET patients, a significant (p<0.05) correlation was found between PLT adhesion and PLT count in JAK2-V617F and CalR-positive mutation carriers. Multivariate regression analysis adjusted for age and sex, confirmed PLT count as a significant determinant of PLT adhesion in JAK2-V617F positive patients only. CONCLUSIONS: ET and PV platelets show an increased adhesion to collagen in vitro, particularly in those carrying the JAK2-V617F mutation. A prospective study is ongoing to evaluate the predictive value of our PLT thrombus formation dynamic model for the thrombotic risk in ET and PV patients. ACKNOWLEDGEMENT: Project funded by "AIRC-IG2013" grant Nr. 14505 from the "Italian Association for Cancer Research" (A.I.R.C.).

PO-26 - Whole blood rotational thromboelastometry (ROTEM) to detect hypercoagulability in patients with myeloproliferative neoplasms (MPN).

INTRODUCTION: Essential Thrombocythemia (ET) and Polycythemia Vera (PV) are two MPNs characterized by a "clonal" overproduction of one or more blood cell lines, hypercoagulability, and an increased incidence of thrombosis. ROTEM is a point of care global coagulation assay performed in whole blood, able to evaluate platelets and fibrinogen contributions to the clotting process. Until now few studies evaluated the thromboelastometry profile of MPN patients. AIM: This study assess the feasibility of using ROTEM to characterize the prothrombotic state of MPN patients and to evaluate whether the thromboelastometry profile varies according to mutational status and/or treatment, and is influenced by hemocromocytometric parameters. MATERIALS AND METHODS: Venous blood samples were collected from 39 ET and 23PV patients upon informed consent. Analysis was performed using INTEM and EXTEM reagents, to evaluate the intrinsic and extrinsic pathway, respectively. Maximum clot firmness (MCF, [mm]), which reflects the maximum tensile strength of the thrombus, clotting formation time (CFT [sec]), namely the time that clot takes to increase from 2 to 20mm above baseline, and clotting time (CT [sec]), the time to clot initiation, were recorded. Nineteen healthy subjects acted as a control group. RESULTS: ROTEM analysis showed a hypercoagulable profile in MPN patients, who had shorter CFT and higher MCF compared to controls, both with EXTEM and INTEM reagents; no differences were observed in CT parameters. Platelet count was significantly higher in patients compared to controls (p<0.01). In patients, a strong statistically significant (p<0.01) correlation was found between platelet count, and MCF [r=0.650 (ET), r=0.601 (PV)] or CFT [r=-0.641 (ET), r=-0.558 (PV)]. Multivariate analysis, according to blood cell counts, showed that only platelet count was independently associated to ROTEM results. To correct for platelet differences, a ratio between MCF and the respective platelet value (rMCF) was created. Interestingly, rMCF was significantly lower in patients compared to controls (p<0.01), suggesting a weaker clot formation potential of patients' samples. Furthermore, rMCF was lower in ET compared to PV (p<0.05), and in calreticulin-positive subjects (p<0.05), while was higher in patients under cytoreductive therapy (Hydroxyurea) (p=ns). CONCLUSIONS: This study confirms, by the ROTEM evaluation, the occurrence of a hypercoagulable state in ET and PV patients. In addition, the ROTEM parameters are significantly influenced by the platelet count. Finally, MCF values corrected for platelet count reveal a lower platelet reactivity in MPN patients, confirming the hypothesis that platelet function is exhausted upon clotting activation. ACKNOWLEDGEMENT: Project funded by "AIRC-IG2013" grant Nr. 14505 from the "Italian Association for Cancer Research" (A.I.R.C.).

Nestin expression associates with poor prognosis and triple negative phenotype in locally advanced (T4) breast cancer.

Nestin, an intermediate filament protein, has traditionally been noted for its importance as a neural stem cell marker. However, in recent years, expression of nestin has shown to be associated with general proliferation of progenitor cell populations within neoplasms. There is no reported study addressing nestin expression in T4 breast cancer patients. Thus, the aim of the present study was to investigate, through immunohistochemistry, the expression and distribution of nestin in T4 breast cancer, in order to determine its association with clinical and pathological parameters as well as with patients' outcome. Nestin was detectable in tumoral cells and in endothelial cells of blood microvessels, and it is significantly expressed in triple-negative and in inflammatory breast cancer (IBC) subgroups of T4 breast tumours. The Kaplan-Meier analysis showed that the presence of nestin in tumoral cells significantly predicted poor prognosis at 5-years survival (P=0.02) and with borderline significance at 10-years of survival (P=0.05) in T4 breast cancer patients. On the basis of these observations, we speculate that nestin expression may characterize tumours with an aggressive clinical behavior, suggesting that the presence of nestin in tumoral cells and vessels may be considered an important factor that leads to a poor prognosis. Further studies are awaited to define the biological role of nestin in the etiology of these subgroups of breast cancers.

Experimental analysis and modelling of in vitro proliferation of mesenchymal stem cells.

OBJECTIVES: Stem cell therapies based on differentiation of adult or embryonic stem cells into specialized ones appear to be effective for treating several human diseases. This work addresses the mathematical simulation of proliferation kinetics of stem cells. MATERIALS AND METHODS: Sheep bone marrow mesenchymal stem cells (phenotype characterized by flow cytometry analysis) seeded at different initial concentrations in Petri dishes were expanded to confluence. Sigmoid temporal profiles of total counts obtained through classic haemocytometry were quantitatively interpreted by both a phenomenological logistic equation and a novel model based on a one-dimensional, single-staged population balance approach capable of taking into account contact inhibition at confluence. The models' parameters were determined by comparison with experimental data on population expansion starting from single seeding concentration. Reliability of the models was tested by predicting cell proliferation carried out starting from different seeding concentrations. RESULTS AND DISCUSSION: It was found that the proposed population balance modelling approach was successful in predicting the experimental data over the whole range of initial cell numbers investigated, while prediction capability of phenomenological logistic equation was more limited.

Expression of survivin protein in pterygium and relationship with oxidative DNA damage.

Ultraviolet radiation is known to cause oxidative DNA damage and is thought to be a major factor implicated in the pathogenesis of pterygium. Among all the photo-oxidative DNA products, the 8-hydroxydeoxyguanosine (8-OHdG) is regarded a sensitive and stable biomarker for evaluating the degree of DNA damage. The protein p53 is a major cell stress regulator that acts to integrate signals from a wide range of cellular stresses. UV radiation has a carcinogenic effect resulting in DNA damaged cells with loss of normal growth control. This assumption is supported by the association between UV-B exposure and activation of survivin, a member of the inhibitor of apoptosis protein family (IAP), highly up-regulated in almost all types of human malignancy. In this study we demonstrate, for the first time in pterygium, the immunohistochemical presence of survivin, and investigate the correlation between survivin, p53 and 8-OHdG. Our results demonstrate that oxidative stress could lead to a significant activation of survivin expression, suggesting that this might be an important event in the development of pterygium, inducing and supporting a hyperproliferative condition. Survivin expression in pterygium would counteract UV-B-induced apoptosis and would cooperate with loss of p53. The co-operation between survivin and functional loss of p53 might provide a general mechanism for aberrant inhibition of apoptosis that could be responsible for the development of pterygium and its possible progression to neoplasia.

Nuclear survivin is associated with disease recurrence and poor survival in patients with cutaneous malignant melanoma.

AIMS: Survivin is expressed in neoplastic cells and appears to be associated with resistance to therapy and shorter survival in various types of tumours. The aim of the present study was to determine whether nuclear or cytoplasmic expression of survivin is related to disease recurrence and overall survival of patients with Stage I and II melanoma according to the American Joint Committee on Cancer (AJCC) staging system. METHODS AND RESULTS: Immunohistochemistry was performed on formalin-fixed paraffin-embedded sections of primary cutaneous melanoma from 50 patients. Survival rates were estimated using the Kaplan-Meier method and compared using the log rank test. Association of clinical variables (gender, age, tumour location, thickness, Clark level and AJCC stage) with survivin expression was analysed by Fisher's exact test. Patients with nuclear immunoreactivity for survivin had an increased risk of disease recurrence during the first three postoperative years (P < 0.05) and of death (P < 0.05). Cytoplasmic immunoreactivity was not correlated with either survival or clinical variables. CONCLUSIONS: Nuclear presence of survivin may be an independent biomarker for disease recurrence and overall survival in patients with Stage I and II melanoma.

Prognostic prediction of the immunohistochemical expression of p16 and p53 in cutaneous melanoma: a comparison of two populations from different geographical regions.

p16INK4a and p53 are tumor-suppressor genes frequently altered in various malignancies, including cutaneous melanoma. The purpose of the study was to establish the prognostic value of immunohistochemical expression of p16INK4a a and p53 in sporadic cutaneous melanoma (CM) in two regions with a high-risk for melanoma in Italy and Ecuador. Immunohistochemical staining of p16 and p53 was performed in samples of primary CM from 82 patients with Stage I and II melanoma according to the American Joint Committee on Cancer (AJCC) staging system. Survival differences between categories of p16 or p53 expression were analyzed using the product-limit procedure (Kaplan-Meier method, log-rank test). Clinical variables (gender, age, tumor location, Clark's level, thickness) were correlated with survival and p16 or p53 expression. p16 nuclear immunoreactivity was observed in 85% of Italian patients compared to 48.7% of Ecuadorians; a small number of cases showed p53 immunoreactivity in both populations. Only nuclear p16 expression exhibited a significant correlation with survival (Italians p=0.001, Ecuadorians p=0.017) but did not appear to correlate with any clinicopathological parameter. No significant difference was observed in survival with regard to p53 expression or cytoplasmic p16. Our results demonstrate that nuclear expression of p16 can be considered a molecular prognostic factor in patients with sporadic CM and indicate its importance as a clinical marker.

Finding of conjunctival melanocytic pigmented lesions within pterygium.

AIMS: Conjunctival pigmented lesions have characteristic clinical and histopathological appearances. Melanocytic pigmented lesions commonly occur in the conjunctiva, although they have not been previously reported in pterygium, a common lesion which originates from conjunctiva. Our aim was to evaluate the possibility of an association between pterygium and conjunctival melanocytic pigmented lesions. METHODS AND RESULTS: A total of 80 samples of pterygium excised from Ecuadorian patients in 2002 were collected. Clinical data were available regarding age, sex, race and place of residence. Histological sections were evaluated for the presence of melanocytic pigmented lesions. Nine cases of conjunctival melanocytic, pigmented lesions within pterygium were found and were classified according to the histopathological criteria previously published for pigmented lesions of the conjunctiva, as naevi and primary acquired melanosis (PAM) with varying degrees of atypia. Five of the nine cases showed primary acquired melanosis without atypia, while two cases had atypia; one case showed features of compound naevus and one lesion was designated as subepithelial naevus. CONCLUSIONS: Our findings suggest that conjunctival melanocytic, pigmented lesions occasionally occur in pterygium. All surgically removed pterygia should undergo careful histopathological examination.

Toward a detailed characterization of feline immunodeficiency virus-specific T cell immune responses and mediated immune disorders.

Infection of domestic cats with feline immunodeficiency virus (FIV) is associated with the development of an acquired immunodeficiency syndrome (AIDS). The pathogenesis of FIV is not fully understood but it has been reported that the immune system is progressively impaired during disease progression. As a result, anti-FIV specific immune response will usually not clear the virus and the acute stage is followed by a chronic asymptomatic phase. The overall objective of this study was to characterized FIV-induced immune cellular responses and -mediated immune disorder following the first weeks post-infection. Using both cytokine ELISpot and intracellular staining assays, FIV-specific T cells were monitored at 6, 9 and 12 weeks post-infection. We demonstrated that both IFNgamma(+) and, CD4 and CD8 TNFalpha(+) T cells specifically respond to FIV antigens. These responses were found to reach a peak at 9 weeks post-infection. It was further shown that the TNFalpha(+)CD8(+) responding T cells were contained within a CD8beta(low)CD62L(-) T cell subpopulation, expanded in FIV-infected cats. This T cell subpopulation which present features of activated CD8 T cells was further shown to be susceptible to spontaneous apoptosis following a short-term in vitro culture. Moreover, it was observed that cell death by apoptosis of this T cell subset was increased following FIV antigen-recognition. Therefore, FIV might alter immune homeostasis in inducing chronic activation of TNFalpha(+)CD8(+) T cells which eventually will die following antigen contact while deleting CD4(+) T cells. Interestingly, this study confirmed the strong similarity between FIV and HIV pathogenesis.

Detection of human papillomavirus DNA in pterygia from different geographical regions.

BACKGROUND/AIMS: The aetiology and pathogenesis of pterygia remain unclear and the involvement of human papillomavirus (HPV) is controversial. 41 pterygia from two geographic locations were evaluated for the presence of HPV DNA. METHODS: 41 pterygium biopsies (17 from Italy and 24 from Ecuador) were analysed using the L1C1 and PU-1ML primer sets by polymerase chain reaction (PCR) and DNA sequence analysis. RESULTS: 22 of the 41 pterygia (54%) were positive for HPV, including all 17 Italian cases and 5/24 (21%) Ecuadorean cases. DNA sequencing of the 22 positive cases showed that 11 were HPV type 52, four were type 54, five were candHPV90, and two of unknown genotype. CONCLUSIONS: The major differences in the frequency of HPV in geographically distant populations might suggest a possible explanation for the vast differences in the reported detection rates. Three subtypes of HPV were found in this sample of pterygia. None the less, these results suggest that HPV may have a pathogenic role in pterygium.

Immunohistochemical study of human pterygium.

The purpose of this study has been to evaluate the immunohistochemical characteristics of human pterygial tissues in order to ascertain the possible contribution of an immunological mechanism in the pathogenesis of pterygium and to investigate the presence in the pterygial tissues of some melanoma-associated antigens, in order to evaluate if there may be a small possibility of correlation of the two diseases. Human biopsy specimens of pterygium were obtained by surgery for pterygium excision. Tissue segments were fixed and processed for paraffin embedding. Microtome sections were treated for the immunohistochemical demonstration of IgA, IgM, IgG, CD3, CD20, CD68, HLA-DR, Protein S100, HMB45, and Melan A using the avidin-biotin peroxidase method or the streptavidin biotin-alkaline phosphatase method. The findings suggest that all the effector components of the mucosal immune system are present in the human pterygium and, among the most sensitive markers for melanoma, only S100 shows immunoreactivity. An immunopathogenetic mechanism seems to be responsible for the pathogenesis of pterygium, perhaps being caused by pre-existing conjunctivitis or microtrauma in combination with the patient's predisposition. No correlation between pterygium and melanoma was found.

Risk factors for intraoperative femoral fractures during total hip replacement.

BACKGROUND AND AIMS: Intraoperative femoral fractures are a serious complication of total hip replacement. The purpose of this study was to evaluate the risk factors of intraoperative femoral fractures in a retrospective analysis of a series of 3,566 total hip replacements. MATERIALS AND METHODS: The patients were divided into two groups, A and B. Group A patients had no intraoperative femoral fractures and Group B patients had intraoperative femoral fractures. In Group A there were 3,483 patients (97.7%) and in Group B, 83 (2.3%). The following potential risk factors were evaluated: sex, age, diagnosis, previous surgery at the homolateral hip, surgical approach, fixation type of the femoral component, prosthesis type, surgical stage during which the fracture occurred, and the lead operating surgeon. RESULTS: The fracture incidence was higher in females (p < 0.005) in uncemented femoral components (p = 0.005), in patients who had previous surgery at the homolateral hip (p < 0.005), and in revision surgery (p < 0.005). CONCLUSION: The analysis of intraoperative femoral fracture risk factors should allow the surgeon to improve the surgical performance and therefore reduce the incidence of this severe intraoperative complication.

The presence of a local immune system in the upper blind and lower part of the human nasolacrimal duct.

The nasolacrimal duct is exposed to exogenous agents, including potentially harmful microorganisms, coming from the eye surface by the lacrimal sac, and from the nasal cavity by the inferior meatus of the nose. The upper blind and lower part of the human nasolacrimal duct were examined immunohistochemically to ascertain the presence and localization of immunoglobulin-producing cells and the epithelial expression of IgA, IgM, and IgG in order to verify the possible antimicrobial properties of this duct. IgA-, IgM-, and IgG-positive immunocompetent cells were recognizable in the lamina propria of the upper blind and lower part of the human nasolacrimal duct, while an evident immunoreactivity for sIgA, IgM, and IgG was demonstrated in the cytoplasm of the apical epithelial cells. The results suggest that all the effector components of the mucosal immune system are present in that area of the human nasal mucosa next to the opening of the nasolacrimal duct as well as in the human lacrimal sac.

Specific binding of cardiac glycoside drugs and endogenous digitalis-like substances to particulate membrane fractions from human placenta.

We studied the characteristics of binding of cardiac glycosides to particulate membrane fractions from human placenta, to demonstrate that placental tissue is a suitable source of receptors for digitalis drugs. Moreover, we performed preliminary experiments with 125I-labeled digoxin and placental particulates to develop a radioreceptor assay for measurement of endogenous substances with activity similar to cardiac glycoside drugs (EDLS). Placental membrane fractions were incubated with [3H]ouabain (10 nmol/L) or 125I-labeled digoxin (50 pmol/L). With both ligands, binding followed a pseudo-first-order reaction kinetics and was saturable. Scatchard analysis revealed a single class of sites [for ouabain, KD = 20.2 +/- 5.8 nmol/L (mean +/- SEM), Bmax = 3.1 +/- 0.9 nmol per gram of protein; for digoxin, KD = 29.7 +/- 1.9 nmol/L, Bmax = 24.3 +/- 1.1 nmol per gram of protein]. As expected, digoxin was less potent than ouabain in displacing both tracers from digitalis drugs receptors; progesterone, cortisone, digitoxose, furosemide, bumetanide, and propranolol had no or little effect. Specific 125I-labeled digoxin binding was competitively inhibited by plasma and (or) urine extracts from newborns, adults, pregnant women, and patients with renal insufficiency. Inhibition of binding and volume of plasma and urine assayed were linearly related. These findings support the hypothesis that cardiac glycosides and EDLS can interact with the human placenta and suggest placental tissue to be a suitable source of receptors for cardiac glycosides.