Influence of surgical ultrasound used in the detachment of flaps, osteotomy and odontosection in lower third molar surgeries. A prospective, randomized, and "split-mouth" clinical study.

BACKGROUND: As third molar surgery is the most commonly procedure performed in Dentistry and has been accompanied by serious postoperative disorders such as pain, edema and trismus, the study aimed to evaluate if ultrasound device would be able to reduce such postoperative features. The aim of this study was to assess the effects of soft tissue flap elevation, osteotomy and odontosection using piezosurgery versus conventional technique in mandibular third molar extractions. MATERIAL AND METHODS: Twenty patients with impacted mandibular third molars underwent tooth extractions using two different methods. Ten patients were included in the Piezo Flap Group (PFG - the flap was elevated using piezosurgery) and ten patients were part of the Piezo Ostectomy Group (POG - osteotomy and odontosection were carried out with ultrasound tips). The contralateral tooth was included in the Control Group (CG - conventional technique). The patients were evaluated at postoperative periods of 1, 3, 7 and 14-days. The measured parameters were duration of surgery, pain, trismus and swelling. RESULTS: The mean duration of surgery for the PFG was 17.21 minutes (CG 10.07 minutes) and POG was 40.09 minutes (CG 15.97 minutes). There was no statistically significant difference in pain and trismus for any of the postoperative periods evaluated in PFG and POG (p>0.05). There was a statistically significant difference in swelling between the PFG and POG, presenting less swelling at the 3-day postoperative period (p=0.038; p<0,05). However, for the remaining analyzed periods there was no difference (p>0.05). CONCLUSIONS: Piezosurgery for tissue elevation of the surgical flap, osteotomy and dental sectioning in mandibular third molar extraction surgery promoted less edema in the early postoperative stages in mandibular third molar extractions despite the longer surgical duration.

Periodontal status of individuals with Down syndrome: sociodemographic, behavioural and family perception influence.

BACKGROUND: The aim of the present study was to assess the periodontal condition of individuals with Down syndrome and the association with sociodemographic and behavioural characteristics and family perception of oral health. METHODS: This cross-sectional observational study was performed at a referral centre for dental assistance to disabled persons in Araçatuba, Brazil. Parents of the individuals were interviewed, and the visible plaque index, bleeding on probing, probing pocket depth and clinical attachment level were recorded by one periodontist in six sites per tooth of all teeth. The individual was the unit of analysis. The significance level was set at 5%. RESULTS: Sixty-four subjects (23.8 ± 8.3 years old) were included. Eighteen (28.1%) were diagnosed with gingivitis and 46 (71.9%) with periodontitis. In the multiple logistic regression final model, age and self-reported oral hygiene practices were associated with the occurrence of periodontitis. The chance of having periodontitis was 4.7 times higher among individuals older than 20 years and approximately 4 times higher in patients whose oral hygiene was performed by themselves and their parents, compared with those who performed oral hygiene alone. Sex, follow-up time in the centre, education, degree of participants' dependence, flossing and family history of periodontal disease were not associated with the occurrence of periodontitis. Higher levels of plaque and bleeding were observed for participants with parents reporting bad gingival health (76.2% and 46.9%) and deficient oral hygiene (79.5% and 47.3%). The perception of parents regarding gingival bleeding was correlated with higher bleeding detected clinically (P = 0.01; 50.1%). CONCLUSIONS: The prevalence of periodontitis in individuals with Down syndrome is high and increases with age, even in the face of the parents' perception about their children's oral condition.

Predictive value of stabilometry and fear of falling on falls in postmenopausal women.

OBJECTIVES: Falls are one of the leading causes of fractures and impaired quality of life in the elderly, and they are related to balance deficit and to fear of falls. The purpose of our study is to evaluate predictors of falls in the 50-65-year-old postmenopausal population. METHODS: A prospective cohort study was conducted on 96 postmenopausal women. Fear of falling and postural stability were assessed by using the FES-I (Falls Efficacy Scale-International) and a force platform, respectively. Fall frequency was determined in the 12-month follow-up study period. Multivariate logistic regression was used to identify predictive factors of falls. RESULTS: Fear of falls, the FES-I scale and four stabilometric parameters, specifically under eyes-closed condition, were significantly higher in the group of fallers. The root mean square amplitude in the medial-lateral direction with eyes closed (RMSXec) (odds ratio 5.1, 95% confidence interval (CI) 1.6-15.5, p = 0.004) and FES-I (odds ratio 3.4, 95% CI 1.1-10.5, p = 0.026) were the best independent predictive factors of the risk of falling. CONCLUSIONS: RMSXec > 0.133 was the best predictive factor for falls in our group of 50-65-year-old postmenopausal women studied, and a FES-I score > 20 could predict falls in this population.

Alveolar repair after the use of piezosurgery in the removal of lower third molars: a prospective clinical, randomised, double-blind, split-mouth study.

The objective of this study was to evaluate the use of piezosurgery for osteotomy and odontosection in the repair of the alveoli four months after exodontia. Fifteen young patients who needed third molars extracted were included. During the extractions, one of the teeth was included in the Piezo group, in which ultrasound motor tips were used in both procedures. The other tooth was removed with a conventional rotary instrument. The values of density of the repair regions of the right and left third molars were compared using digital panoramic radiographs. There were no significant differences (p>0.05): piezo group mean (SD) 125.7 (15.4) and control group 126.7 (21.2). The bone density of the alveoli after extraction of the lower third molars with rotary instruments and surgical ultrasound was similar in both groups.

Tumour malignancy loss and cell differentiation are associated with induction of gef gene in human melanoma cells.

BACKGROUND: Gene therapy is a new method used to induce cancer cell differentiation. Our group previously showed that transfection of the gef gene from Escherichia coli, related to cell-killing functions, may be a novel candidate for cancer gene therapy. Its expression leads to cell cycle arrest unrelated to the triggering of apoptosis in MS-36 melanoma cells. OBJECTIVES: To determine the basis of the antiproliferative effect of the gef gene in this cell line. METHODS: Transmission electron microscopy, apoptosis analysis by confocal microscopy, flow cytometry and immunocytochemical analysis were used. RESULTS: Ultrastructural analysis showed a strikingly different morphology after treatment with dexamethasone and expression of the gef gene, with large accumulations of pigment throughout the cell cytoplasm and presence of melanosomes in different stages of development. High mitochondrial turnover and myeloid bodies, characteristics of neurone cells, were also observed. In addition, both immunocytochemical and indirect immunofluorescence analysis demonstrated a significant decrease in HMB-45, Ki-67 and CD44 antigen expression and an increase in S100 and p53 expression in gef gene-transfected MS-36 melanoma cells that were correlated with the duration of dexamethasone treatment. In the present work, we report that gef gene not only reduces cell proliferation in transfected melanoma MS-36TG cell line but also induces morphological changes clearly indicative of melanoma cell differentiation and a reduction in tumour malignancy. CONCLUSIONS: These findings support the hypothesis that the gef gene offers a new approach to differentiation therapy in melanoma.

Induction of drug resistance in embryonal rhabdomyosarcoma treated with conventional chemotherapy is associated with HLA class I increase.

Effectiveness of conventional cytotoxic treatment of rhabdomyosarcoma (RMS) may be limited by the development of multidrug resistance (MDR) mediated by mdr1 gene. This gene codes for P-glycoprotein (P-gp) which has been related to a immunoregulatory function. Modulation of HLA expression by P-gp has been described in different types of tumor cells including RMS. However, very little is known about biological implications of the P-gp expression in RMS patients treated with conventional chemotherapy. In order to study the problem, we used embryonal RMS tissue samples from treated patients. Our results indicated that positive RMS samples to mdr1 show higher HLA class I expression than those which were negative to mdr1 PCR, what indicates a significant correlation between the expression of both molecules. In addition, we developed two resistant RMS cell lines (A-204-1 and 2) using similar concentrations of actinomycin D as are plasma levels in clinical situation. Both resistant cell lines showed mdr1 expression and an increase of HLA class I expression which was dose-dependent. These results demonstrated that conventional chemotherapy of embryonal RMS is able to induce resistance which can modulate HLA class I expression and suggest that immunological studies of these tumors may be necessary to the design new specific therapeutic strategies.

Non-viral and viral vectors for gene therapy.

Human gene therapy can be defined as the delivery of genetic material into a patient's cells with a therapeutic aim. The success or failure of gene therapy depends on the development and efficiency of the transfection of viral and non-viral vectors. Viral vectors typically offer higher transduction efficiency and long-term gene expression, but may be associated with toxicity, immunogenicity, restricted target cell specificity and high cost. Non-viral methods have become widespread because of their relative safety, capacity to transfer large genes, site-specificity and their non-inflammatory, non-toxic and non-infectious properties. However, the clinical usefulness of non-viral methods is limited by their low transfection efficiency and relatively poor transgene expression. In this review, we describe the progress made in the development of gene delivery technology and its possible application in clinical trials.

Cancer gene therapy: strategies and clinical trials.

In recent years, great advances have been made in developing novel therapeutic systems based on the introduction of genetic material into damaged cells and designed to correct the error underlying the disease or destroy the pathological cell. One of the main applications of this new approach, known as gene therapy, is the treatment of malignant pathological tumours, in which classic treatments with radiotherapy, chemotherapy and surgery are only palliative. Strategies developed to date include the use of suicide genes, immunity-enhancing genes, apoptosis-inducing genes or genes that inhibit the neovascularization of the tumour, and the blocking of mutated tumour suppressor genes or their restoration in the tumour cell. The effectiveness shown in cell culture and animal experiments and some promising results in clinical trials suggest that gene therapy will help to improve the prognosis of cancer patients and may become the treatment of choice.

Modulation of Ki-67 expression and morphological changes induced by gef gene in MCF-7 human breast cancer cells.

New therapeutic strategies are required to overcome the limitations of conventional breast cancer treatment. Suicide gene therapy offers a potential approach to this type of tumour, since systems based on the use of prodrugs may present some drawbacks related to toxicity, drug release and bioavailability. The gef gene has cell-killing functions in Escherichia coli and does not depend on the use of a prodrug for its action, making it an attractive target for suicide gene therapy. We created a gef-overexpressing human breast cancer cell line (MCF-7TG) by transfecting the gef gene under the control of a pMAMneo promotor. Dexamethasone-induction of gef gene expression in MCF-7TG cells produced a significant decrease in Ki-67 expression, which is a known proliferation marker. In addition, annexin-V-FITC and propidium iodide assays showed the presence of apoptotic cell death, which was confirmed by scanning electron microscopy. The most significant finding was the presence of "craters" in the cell membrane, as previously described in other apoptotic breast cancer cells. These results demonstrate the ability of the gef gene to down regulate Ki-67 expression and induce apoptosis in a breast cancer cell line, suggesting its potential application as a new gene therapy strategy for this type of tumor.

Release of alpha-actin into serum after skeletal muscle damage.

OBJECTIVE: The skeletal muscle protein alpha-actin was investigated in the serum of subjects with severe skeletal muscle damage to assess its utility as a reliable and predictive marker of muscle damage. METHODS: Serum samples were obtained from 33 healthy controls and 33 patients with severe skeletal muscle damage, defined by a total creatine kinase value of >500 IU/l (Rosalki method). Troponin I, troponin T, and myoglobin concentrations were determined by immunoassay and alpha-actin concentrations by Western blot and densitometry. RESULTS: The mean serum concentration of alpha-actin in controls and patients with skeletal muscle damage was 600.9 and 1968.51 ng/ml, respectively, a statistically significant difference. Sera of patients with muscle damage showed higher levels of alpha-actin than of troponin or myoglobin. No significant difference in troponin I levels was observed between the groups. CONCLUSIONS: According to these results, alpha-actin was the most significant skeletal muscle damage marker analysed and may be an ideal candidate for the identification of all types of myofibre injury, including sports injuries. Our findings support the use of alpha-actin as a marker alongside other currently used biological proteins.

Antitumoural properties of benzannelated seven-membered 5-fluorouracil derivatives and related open analogues. Molecular markers for apoptosis and cell cycle dysregulation.

Attention is increasingly being focussed on the cell cycle and apoptosis as potential targets for therapeutic intervention in cancer. We prepared a series of bioisosteric benzannelated seven-membered 5-FU O,N-acetals to test them against the MCF-7 human breast cancer cell line. Benzo-fused seven-membered O,O-acetals or their acyclic analogues led to the expected 5-FU O,N-acetals (or aminals), in addition to six- and 14-membered aminal structures and acyclic compounds. All the cyclic aminals provoked a G0/G1-phase cell cycle arrest, whereas Ftorafur, a known prodrug of 5-FU, and 1-[2-(2-hydroxymethyl-4-nitrophenoxy)-1-methoxyethyl]-5-fluorouracil (11) induced an S-phase cell cycle arrest. Although breast cancer is most often treated with conventional cytotoxic agents it has proved difficult to induce apoptosis in breast cancer cells, but improved clinical responses may be obtained by identifying therapies that are particularly effective in activating apoptosis. 1-(2,3-Dihydrobenzoxepin-2-yl)-5-fluorouracil (5) may be particularly useful in stimulating apoptosis in breast cancer.

HLA class I and II expression in rhabdomyosarcomas.

The expression of class I and II histocompatibility antigens was studied in 43 specimens of skeletal and in 36 specimens of cardiac muscle. Expression was also analyzed in the tumoral counterpart of striated muscle tissue, in 21 rhabdomyosarcomas (13 embryonic, 2 alveolar and 6 pleomorphic). Normal striated muscle showed very weak HLA class I antigen expression and no class II expression. The rhabdomyosarcomas showed increased class I expression, possibly related to malignant transformation of this type of tissue and with the degree of cellular differentiation. In our series of rhabdomyosarcomas, we observed class II neoexpression only in some HLA class I positive specimens, which was unrelated to the degree of cellular differentiation in these tumors.

Production and characterization of a new monoclonal antibody, GR-ICOR-2, recognizing sarcomeric actin: analysis of the expression in the developing chick heart.

We produced and characterized a specific monoclonal antibody (mAB) designated GR-ICOR-2. This mAb recognizes sarcomeric actin molecules (43 kDa) and was used in an immunohistochemical analysis of staining patterns in Hamburger and Hamilton's stages 18, 22 and 25 (HH 18, 22 and 25) embryonic chick hearts. Staining showed a mainly cytoplasmic distrubition in three regions: the atrioventricular (AV) canal cushion tissue, the primitive ventricle, and conal crests. In addition, this mAb-cross-reacted with rabbit and human cardiac and skeletal muscle tissue; but not with smooth muscle tissue.

Modulation of contractile proteins in embryonic and fetal chick cardiac cells by phorbol ester, gamma-interferon, 5-azacytidine and diacylglycerols.

We studied changes in the concentration of tropomyosin, actin, desmin and vimentin in cultured myocardiocytes from Hamburger and Hamilton's stages 29 and 39 chick embryos (HH29 and HH39) (1), treated with 12-o-tetradecanoyl-phorbol-13-acetate (TPA), 5-azacytidine (AZA), gamma interferon (INF) and diacylglycerols (DAG). In embryonic myocardiocytes at HH29, the first three agents modified the intracellular distribution of the thin filament proteins tropomyosin and actin, increasing their cytoplasmic concentration and decreasing their cytoskeletal concentration. The concentration of the intermediate filament proteins desmin and vimentin increased in both subcellular fractions after treatment with these drugs. In fetal myocardiocytes at HH39, total protein content decreased after treatment with these drugs. Cytoplasmic and cytoskeletal concentrations of actin and tropomyosin decreased to different degrees after treatment with TPA, AZA or DAG in HH39 myocardiocytes. TPA, AZA and DAG decreased desmin in the cytoplasmic and cytoskeletal fractions. These findings suggest that the drugs tested alter the normal protein composition in cultured myocardiocytes, and have different effects depending on the developmental stage in which the embryo is treated.

Influence of fibric acid derivatives on intermediate filament proteins in myocardiocyte cultures.

We analyzed desmin and vimentin accumulation in chick myocardiocyte cultures treated with the fibric acid derivatives bezafibrate, fenofibrate and gemfibrozil. The most noteworthy finding was the 50% decrease in the cytoplasmic desmin fraction in cells treated with gemfibrozil in comparison to control cultures, and the 19% increase in the cytoskeletal fraction in cultures treated with gemfibrozil and with bezafibrate. Vimentin accumulation by cells treated with bezafibrate was similar to that in control cultures, however the cytoskeletal vimentin fraction rose by 26% after treatment with gemfibrozil, and fell 13% after treatment with fenofibrate. No vimentin was found in the cytoplasmic fraction of cell treated with bezafibrate. Given the role of intermediate filaments in heart muscle contraction, fibric acid derivative- induced changes in the cytoplasmic and cytoskeletal concentrations of intermediate filament proteins may be related with the secondary effects of these drugs on heart rate.

Circulating alpha-actin protein in acute myocardial infarction.

We used Western-blot analysis to investigate the possible presence in the bloodstream of the contractile protein alpha-actin in 70 patients diagnosed with acute myocardial infarction on the basis of clinical, electrocardiographic and laboratory (creatine kinase and lactate dehydrogenase) criteria. Circulating protein was identified with a monoclonal antibody specific for cardiac alpha-actin. Of the 70 control samples of blood, the immunoblot results were negative for alpha-actin in 98% of the cases. Of the 30 patients with skeletal muscle damage caused by surgery, 26 were negative for circulating alpha-actin. Of the 70 patients with acute myocardial infarction, circulating alpha-actin was found in 67 (95%) as a 43 kDa band in immunoblots; the highest circulating concentrations (0.0580 micrograms/microliters) were found in those with anterior acute myocardial infarction. Circulating alpha-actin was detected in samples taken between 1 and 180 h after the onset of pain, and showed a biphasic pattern of appearance. Our findings for serum alpha-actin, together with the relationship between serum concentrations of this protein and sex (p = 0.001), tobacco use (p = 0.007) and postepisode complications (p = 0.002), should make it possible to gain a deeper understanding of acute myocardial infarction as a clinical entity.

Circulating alpha-actin in non-insulin-dependent diabetics with autonomic dysfunction.

Silent myocardial ischemia in non-insulin-dependent diabetic patients occurs frequently in association with autonomic dysfunction, suggesting that diabetic neuropathy may be involved in the development of this disorder. Repeated episodes of silent myocardial ischemia can induce myocardial necrosis. Recently, actin was detected with Western blotting in the serum of patients with acute myocardial infarction and angina pectoris. We found that a large proportion of non-insulin-dependent diabetic patients with neuropathy also have detectable circulating concentrations of alpha-actin, and therefore suggest that the determination by immunoblotting of serum alpha-actin in such patients is an effective method to detect myocardial cell suffering and to identify patients that may need special consideration.

Morphometric data on the arterial duct in the human fetal heart.

In a total of 496 fetuses and newborns ranging in body weight from 60 to 5000 g, we performed a morphometric study of the ascending aorta, the descending aorta, the aortic isthmus, the right pulmonary artery, the left pulmonary artery and the arterial duct. In all, nine different parameters were measured in each specimen. The variations in the correlations between two measurable characteristics, namely body weight and each of the morphometric parameters, were analyzed. The minimum, normal and maximum patterns of normality for each parameter were obtained with regression equations. We compared statistically the diameter of the arterial duct with the diameter of the ascending and descending aorta, the aortic isthmus, the right pulmonary artery and the left pulmonary artery with one way analysis of variance, using Bonferroni's test in the pairwise comparisons. The diameter of the arterial duct was smaller than the diameter of the ascending and descending aortas, the aortic isthmus, the right pulmonary artery and the left pulmonary artery, and the diameter of the ascending aorta was larger than that of the descending aorta. These morphological data have immediate clinical and surgical applications in the treatment of fetal and perinatal cardiovascular disorders.

Morphometric data concerning the great arterial trunks and their branches.

In a total of 496 fetuses and newborns ranging in body weight from 60 to 5000 g, we performed a morphometric study of the vascular complex, that is the orifices of the great arterial trunks, ascending aorta, aortic arch, vessels branching from the aortic arch, the aortic isthmus, descending aorta, pulmonary trunk, orifices of the pulmonary arteries and arterial duct. In all, 17 different parameters were measured in each specimen, using several new parameters in addition to the measurements classically used in the aortic isthmus, arterial duct and pulmonary trunk. Anatomo-geometric models of these structures were developed, and stereometric formulas used to calculate the real volumes of the aortic isthmus, arterial duct and pulmonary trunk. The variations in the correlations between two measurable characteristics, that is, body weight and each of the morphometric parameters were analyzed, and the minimum, normal and maximum patterns of normality for each parameter were obtained with regression equations. The results show that the volume of the aortic isthmus increases by 0.03 ml for each millilitre increase in left ventricular volume. The isthmic volume increases by 0.32 ml for each millilitre increase in volume of the arterial duct and the volume of the pulmonary trunk increases by 6.4 ml for each increase of 1 millilitre in the volume of the aortic isthmus. The inner circumference of the aortic isthmus is greater than that of the arterial duct, whereas the former vessel is always shorter than the latter. We believe that these morphological data, when appropriately interpreted, have immediate clinical and surgical applications in the treatment of fetal and perinatal cardiovascular disorders.

The quantitative anatomy of the normal human heart in fetal and perinatal life.

A total of 367 human fetuses and newborn subjects weighing from 60 to 5000 g provided the material for a morphometric study of the heart. A total of 17 interventricular parameters were measured in each specimen, one of the parameters representing an innovation with regard to the classically used set of measurements. A new anatomo-geometric configuration is described for each ventricle along with a new component for the left ventricular outflow tract, designated as the aortic outflow tract. The appropriate stereometric formulas were used to calculate real ventricular volumes rather than the previously studied volumetric indices. Additionally, correlation indices were calculated for ventricular wall thickness as well as the circumferences and diameters of the atrioventricular and arterial valves. The results show that, in fetuses of up to 2700 g in body weight, ventricular wall thickness is greater in the right than in the left ventricle, although the opposite is true in fetuses weighing above 2700 g. Throughout the range of weights studied, ventricular volume was greater in the left than in the right chamber. Tricuspid and pulmonary valve circumference and diameter were consistently greater than in the mitral and aortic valves, respectively. We believe the new morphometric data and their innovative interpretation to have immediate applications in both the morphological and functional areas of cardiology.