35,699 research outputs found
Short-term variation in the subgingival microbiota in two groups of patients treated with clear aligners and vestibular fixed appliances: A longitudinal study
No full textObjective: To evaluate the subgingival microbiological changes during the first six months of therapy with clear aligners (CAs) and fixed appliances (FAs). The null hypothesis was that there would be no microbiological differences between the two. Setting/Sample: Two groups of patients to be treated, respectively, with CAs (14 patients; 9 females and 5 males; mean age 21 years ± 0.25) and FAs (13 patients; 8 females and 5 males; mean 14 years ± 0.75) were consecutively recruited. Materials and Methods: Subgingival microbiological samples were obtained at the right upper central incisor and right first molar at four different time points: before appliance fitting (T0), and at 1 month (T1), 3 months (T3) and 6 months (T6) thereafter. Total bacterial load (TBL) and counts of the bacteria Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Fusobacterium nucleatum, Campylobacter rectus, Treponema denticola and Tannerella forsythia were determined using real-time PCR. Results: Total bacterial load did not vary in the CA group, while a significant increase was detected after 3 and 6 months of treatment in the FA group. Unlike red complex species, C rectus and F nucleatum were often detected: levels remained stable in the CA group but increased progressively in the FA group. Conclusion: The type of orthodontic appliance influences the subgingival microbiota. TBL increased in the FA group but not in the CA group, although the levels of the individual periodontal pathogenic bacteria species did not significantly increase during the observation period
Fisiopatologia della Coagulazione.
No full textLa capacità di controllare e mantenere all’interno del vaso il flusso di sangue dopo un danno vasale è deputata a un complesso di eventi fisiologici denominati nel loro insieme processo emostatico-coagulatorio, mediante la formazione del trombo emostatico. In tale processo si possono distinguere due fasi,una precoce, l’emostasi primaria, che porta alla formazione del cosiddetto “trombo bianco“, costituito principalmente da piastrine e scarsa presenza di fibrina, e una più tardiva, emostasi secondaria o coagulazione del sangue, con formazione del trombo rosso principalmente composto da un reticolo di fibrina con piastrine e globuli rossi imbrigliati al suo interno
Experimental model for studying the effects of 2-ethylhexyl-phthalate and dialysate on connective tissue
No full textIn order to have a model for studying the possible implications of 2-ethylhexyl-phthalate and dialysate on connective tissue, we evaluated their direct effects on the air pouch lining tissue and on fibroblast cultures. Air pouches were formed on the backs of 60 ten-week-old Wistar rats by subcutaneous injections of 10 ml sterile air. On the tenth day 2 ml sterile air, or 2 ml 5μg/L or 2 ml 10 μg/L 2-ethylhexyl-phthalate in olive oil, or 2 ml olive oil alone, or 2 ml 5 mg/ml or 12 mg/ml lyophilized dialysate were injected into the air pouches. After sampling at seven or twenty-one days, the rats were killed. The biochemical data showed an increase in sulphated glycosaminoglycans with 2-ethylhexyl-phthalate and dialysate. Electron microscopy findings revealed cellular alterations such as vacuolation and cell remnants with 2-ethylhexyl-phthalate, while the cells of the air pouches treated with dialysate showed regular organelles with increased and dilated cisternae of rough endoplasmic reticulum. Moreover, an increase in collagen fibres surrounding the damaged zones was noticed in 2-ethylhexyl-phthalate and dialysate treated rats. The glycosaminoglycan modifications and collagen fibre increase seem to suggest that the morfological changes, with the features of fibrosis, could be the result of 2-ethylhexyl-phthalate and dialysate action on connective tissue. Moreover, the air pouch technique can be considered a good model for studying the direct effects of 2-ethylhexyl-phthalate and other substances, such as uremic toxins, on connective tissue
A modified functional Global test to measure protein C, protein S activities and the activated protein C-resistance phenotype.
No full textIdentifying a defect affecting the protein C/protein S (PC/PS) anticoagulant system, using a single global test, has recently become possible thanks to a new methodological approach based on the activation of endogenous plasma PC by Protac, derived from Agkistrodon Contortix snake venom (ACV). The introduction of a commercial test (ProC Global), ACV-based, provides a useful tool for the screening of thrombotic patients since the most frequent causes of inherited thrombophilia are found in the PC/PS system. The test provides information only on the global activity of the anticoagulant pathway but not on PC and PS activity or on the factor V related conditions (e.g., FV Leiden). The present study shows that by carrying out the test alternating the presence of PC-, PS-, or FV-deficient plasma and using appropriate amounts of ACV, it is possible to increase the specificity of the test to correctly evaluate respectively the PC or PS activities or the activated protein C resistance condition (APC-R). These simple modifications applied to the original commercial test allow to detect exactly, using a single, basic methodology, the principal defects affecting the PC/PS anticoagulant pathway. Furthermore, carrying out the tests on an automated coagulometer, in combination or not with the classic ProC Global assay, it is possible to use a unique reagent profile to simultaneously investigate in the same or different samples, the PC, PS, and APC-R defect
Association Between TGFB3 and Nonsyndromic Cleft Lip With or Without Cleft Palate in a Chilean Population.
No full textObjective: To assess the possible association between TGFB3 allele variants and nonsyndromic cleft lip with or without cleft palate in a Chilean population. Design: In our study we used a case-parents trios design. The sample consisted of 150 unrelated trios ascertained through probands affected with nonsyndromic cleft lip with or without cleft palate. Three TGFB3 polymorphisms were analyzed (rs2268626, rs2268625, and rs3917201). An allele/haplotype transmission disequilibrium test was used to evaluate the possible genotype-phenotype association. Results: An overtransmission from parents to affected progeny was observed for the A allele of rs3917201 (p = .03) and for the rs2268625-rs3917201 A-A haplotype (p = .022). A defect of transmission of rs2268625-rs3917201 G-G haplotype (p = .022) was observed also. Conclusions: Allelic and haplotypic associations implicate a possible role of TGFB3 in nonsyndromic cleft lip with or without cleft palate in the Chilean population. Additional studies are needed in order to elucidate the possible mechanisms that can explain the role of TGFB3 genetic variants in the condition
Fisiopatologia dell'Emostasi e della Coagulazione
No full textLa capacità di controllare e mantenere all’interno dei vasi il flusso del sangue dopo un danno vasale è deputata a un complesso di eventi fisiologici denominati nel loro insieme processo emostatico-emocoagulatorio, mediante la formazione del trombo emostatico o coagulo. Il coagulo è una massa fibro-spugnosa di consistenza gelatinosa costituito da fibrina entro cui vengono trattenuti gli elementi figurati del sangue. Esso si forma attraverso una serie di complesse reazioni enzimatiche a cascata quando il sangue fuoriesce dal vaso, all’interno o all’esterno del corpo, in seguito a lesioni dell’endotelio. In tale processo si possono distinguere due fasi, una cronologicamente precoce, l’emostasi primaria, che porta alla formazione del cosiddetto “trombo bianco”, costituito principalmente da piastrine e scarsa presenza di fibrina, e una più tardiva, emostasi secondaria o coagulazione del sangue, con formazione del “trombo rosso” principalmente composto da un reticolo di fibrina con piastrine e globuli rossi imbrigliati al suo interno
Influence of hyaluronic acid on extracellular matrix produced by mesenchymal stem cells
No full textHyaluronic acid is a natural component of the extracellular matrix found in various body fluids, organs and tissues. It is widely used in tissue engineering, as a drug delivery system and in various medical and pharmaceutical applications. It plays an important role in supporting cells during wound healing, recognizing specific surface receptors during the healing process, and favoring collagen deposition and angiogenesis. Hyaluronic acid is known to activate stem cells and is involved during the differentiation process. Nevertheless, it was demonstrated as hyaluronic acid’s biological functions and properties are strictly dependent on its molecular weight, also showing opposite effects between high-molecular- weight and low-molecular-weight. Here we tested the effects of hyaluronic acid with different molecular weights on mesenchymal stem cells, assessing the role of this natural linear polysaccharide in extracellular matrix deposition and remodeling. Gene expression of genes belonging to the “Extracellular Matrix and Adhesion Molecules” pathway was investigated in mesenchymal stem cells treated with high, medium, and low molecular weight hyaluronic acid solution 10 mg/ml for 24 h. Hyaluronic acid promotes the synthesis and stabilization of the extracellular matrix. Furthermore, treated cells respond to the treatment by opposing the inflammatory action of the molecule by down-regulating numerous metalloproteinases, thus trying to stop the degeneration processes of the extracellular matrix
Absence of Simian virus 40, BK, and JC polyomavirus DNA in squamous cell carcinoma limited to the oral cavity
No full textBACKGROUND: Head and neck squamous cell carcinomas (SCCs) are among the most aggressive types of cancer. The Simian virus 40 (SV40), which is a polyomavirus known for its oncogenic potential, was found as a contaminant of oral vaccines and has been related to human pleomorphic adenoma in the parotid gland. The aim of this study was to evaluate the presence of SV40 and 2 human polyomaviruses-BK virus (BKV) and JC virus (JCV)-in a large sample of SCCs of the oral cavity. METHODS: Quantitative real-time polymerase chain reaction (PCR) was used to evaluate virus load. RESULTS: Overall, the prevalence of SV40, BKV, and JCV in oral SCC was negligible. Matched-pair case-control analysis indicated that prevalence among the controls did not significantly differ with respect to analyzed cases. CONCLUSION: The results did not indicate a major role for SV40, BKV, and JCV in the etiology of oral SCC
Evidence of the involvement of the DHFR gene in nonsyndromic cleft lip with or without cleft palate.
No full textStudies aimed at evidencing genetic causes for neural tube defect (NTD) occurrence have often provided the inspiration for orofacial cleft aetiology investigations. The correlation between the two congenital malformations is provided by the similar incidence timing and the involvement of structures localized in the midline of the embryo. This connection is corroborated by the existence of a number of genes involved in both malformations. In this article, we considered the dihydrofolate reductase (DHFR) gene, previously seen implicated in NTDs, as a candidate for cleft lip with or without cleft palate (CL/P) risk. Four SNPs mapping on the DHFR gene were genotyped for 400 Italian CL/P triads, using TaqMan(®) approach. The rs1677693 provided evidence of association, even if at borderline level (P value 0.049). In particular, the variant allele seems to have a protective effect OR = 0.80 (95% C.I. 0.64-0.99). Moreover, the combination of rs1677693(A)-rs1650723(G) alleles showed a significant association OR 0.64 (95% C.I. 0.47-0.86) (P value = 0.006). This represents the first attempt to demonstrate a role for DHFR in CL/P aetiology, howbeit the study of such gene deserves a deepening
Molecular tools for preventing and improving diagnosis of peri-implant diseases
No full textPeri-implantitis is an inflammatory disease of tissues surrounding osseointegrated dental implants. Inflammation affecting soft and hard peri-implant tissues can cause alveolar bone resorption and subsequent implant loss. Clinical surveillance and early diagnosis are of paramount importance to reduce clinical failures and improve implant survival. Current diagnosis of implants is based on clinical and radiological signs. Molecular tests are an emerging diagnostic methodology, which potentially can help to detect and prevent early peri-implantitis and monitor the efficacy of therapy as well. A plethora of potential biomarkers are potentially available to support the clinical diagnosis of peri-implantitis. However, conflicting diagnostic conclusions have been reached, probably related to weak statistical results due to limited sample size or disease heterogeneity. The present paper reviews candidate diagnostic biomarkers for peri-implantitis, including infective agents, genetic susceptibility factors, and key proteins related to inflammation and tissue remodeling
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