Does immediate loading affect clinical and patient-centered outcomes of mandibular 2-unsplinted-implant overdenture? : a 2-year within-case analysis

Objective To provide 2-year clinical- and patient-oriented data with regard to mandibular overdenture assisted by 2 immediately loaded unsplinted implants. Material and methods In this pre-post design, Phase-I clinical trial, 18 edentate individuals (62.4 ± 7.7 years) received a new set of complete denture. Then, following standard procedures, 3 threaded implants (OsseoSpeed TX™, Dentsply Implants, Mölndal, Sweden) were placed in the mandible in each patient, and locator abutments (Zest Anchors LLC, Escondido, U.S.A.) were inserted on the right and left side implants. The midline implant served as a control for within-patient comparison. The immediate loading was conducted within 24 h of surgery. Data were collected at baseline (T0), 12 (T1) and 24 (T2) months after immediate loading. The clinical outcomes included implant survival rate, crestal bone level changes and implant stability. These criteria were assessed through clinical and radiographic examinations as well as resonance frequency analysis. Patient-centered outcomes included patient satisfaction and oral health-related quality of life measured using validated questionnaires. Brunner-Langer approach was used for statistical analysis. Results Implant survival rate for immediate loaded implants was 91.7% at 2-year follow-up. None of the unloaded implants failed. There was no statistically significant difference at baseline and follow-ups with regard to clinical outcomes between loaded and unloaded implants. Patient satisfaction and quality of life improved (p < 0.0001) from baseline to 2-year follow-up. Conclusion Immediate loading protocol did not negatively affect clinical outcomes, satisfaction and quality of life of patients wearing 2-unsplinted-implant mandibular overdenture for 2 years. This conclusion requires confirmation by randomized control trials. Clinical significance statement Mandibular overdenture assisted by two immediately-loaded unsplinted implants is successful treatment based on 2-year clinical and patient-based outcomes.

(Tables 1,2) Site characteristics and phenotypic attributes of King Penguins (Aptenodytes patagonicus) on Possession Island

In colonial species, it is often assumed that locations in the center of the colony are of highest quality and provide highest breeding success. We tested this prediction, known as the "central-periphery model," in a King Penguin colony in the subantarctic Crozet Archipelago. Breeding activity and survival of 150 penguins, fitted with transponder tags, were monitored over an entire breeding season. Among these 150 birds, 50 bred on the slope at the upper periphery of the colony, where the rates of predation and parasitism by ticks were high. Fifty birds bred in the center of the colony, where rates of predation and tick parasitism were low, and 50 bred at the lower end of the colony, where the rate of tick parasitism was low but predation and flooding were important risks. We predicted that the center of the colony should provide the safest breeding place and consequently be characterized by the highest breeding success and be used by the highest-quality individuals. Yet we found that penguins breeding in the center of the colony had the same breeding success as those at both peripheral locations. In addition, penguins breeding on the upper slope had a higher survival rate than penguins breeding at the center or bottom of the slope and were likely of higher quality. Our study does not support the central-periphery model and emphasizes the complexity behind the relationships among breeding site, breeding success, and individual quality.

The influence of viral genotypes and rejection episodes on the recurrence of hepatitis C after liver transplantation

Purpose. The aim of this study was to report the influence of hepatitis C virus (HCV) genotype and rejection episodes on the outcome of orthotopic liver transplantation (OLT), hepatitis recurrence, and progression to graft cirrhosis after OLT. Methods. Fifty-three patients who all had undergone OLT for end-stage liver cirrhosis were selected for this study. Hepatitis C genotype was determined. Recurrent hepatitis and rejection were diagnosed based on elevated liver function tests and a liver biopsy. Results. The patients were followed up for a mean of 51.9 +/- 34.3 months. The cumulative survival rate was no different in OLT for hepatitis C and OLT for all other liver diseases. After OLT, serum HCV RNA was detected in 93%. Histological recurrence occurred in 85% of all patients. The 1-, 3-, and 5-year recurrence rates were 48%, 77%, and 85%, respectively. Of the 41 patients with recurrent hepatitis C, 4 (10%) had cirrhosis, 18 (44%) had hepatitis with fibrosis, and 91 (46%) had hepatitis without fibrosis at the end of follow-up. A total of 32% of the patients were infected by HCV genotype 1b and 68% by other HCV genotypes. The recurrence rates were significantly higher in patients infected with genotype 1b than in those with other genotypes (p = 0.04). Twenty of 48 patients (42%) experienced acute rejection. There was a strong association between the number of rejection episodes and the incidence of HCV-related cirrhosis (p < 0.01). Conclusion. Our findings showed the genotype 1b to result in a higher recurrence rate after OLT. On the other hand, rejection episodes were associated with a more rapid progression to graft cirrhosis.

Use of oesophagogastroscopy to assess the response of oesophageal carcinoma to neoadjuvant therapy

Background: Approximately 25 per cent of patients with oesophageal cancer who undergo neoadjuvant chemoradiotherapy have no evidence of tumour in the resected specimen (complete pathological response). Those who do not respond have a poor 5-year survival compared with complete responders, regardless of whether or not they undergo surgery. Selecting for surgery only those who have a response to neoadjuvant therapy has the potential to improve overall survival as well as to rationalize the management of non-responders. This study assessed the accuracy of oesophagogastroscopy in this setting. Methods: A prospective database of 804 patients undergoing oesophageal resection for carcinoma was reviewed. Endoscopic assessment of the response to neoadjuvant therapy in 100 consecutive patients was compared with the pathological assessment of response. The survival for each level of response was compared. Results: At endoscopy 30 patients were considered to have had a complete response. This was confirmed pathologically in 15 patients. Survival was improved in those with a pathologically confirmed complete response (3-year survival rate 62.4 (s.e. 12.9) per cent) compared with non-responders (16.3 (s.e. 6.6) per cent). Those with microscopic residual disease also had an improved 3-year survival rate (46.3 (s.e. 12.2) per cent); however, oesophagogastroscopy failed to identify this subset. Conclusion: Oesophagogastroscopy may be useful in the assessment of tumour response to neoadjuvant therapy. However, owing to its poor accuracy patients should not be excluded from further therapeutic intervention on the basis of this assessment alone.

Changes to porcine blastocyst vitrification methods and improved litter size after transfer

The objective was to improve the protocol that was used to obtain the first reported piglets from transferred vitrified and warmed zona-intact blastocysts. Blastocysts were collected from superovulated sows and gilts, centrifuged to polarize lipid, vitrified, warmed and cultured for 24 h or transferred immediately. Removing the zona pellucida after warming increased the number of cells in the surviving blastocysts (zona-free 60.8 +/- 4.3, zona-intact 39.1 +/- 2.8; P < 0.05). Thinning the zona pellucida produced similar results to zona removal. Changing the basal medium of the vitrification and warming solutions from modified PBS to phosphate buffered NCSU-23 increased the number of cells (44.7 +/- 2.2 versus 56.0 +/- 3.9, respectively; P < 0.05). Reducing the plunge temperature of the liquid nitrogen from - 196 degrees C to less than -204 degrees C improved the embryo survival rate (61.9% versus 82.9%, respectively; P < 0.05). These modifications were incorporated into the vitrification protocol that was used to vitrify and warm 105 blastocysts (that were subsequently transferred into four recipients). Three recipients became pregnant, farrowing three litters (average litter size, 5.3; 18.8% embryo survival in farrowing sows). Changing the warming protocol to using sucrose rather than ethylene glycol resulted in a trend towards improved embryo survival (73.5% versus 91.2%) but this was not statistically significant. Incorporating this modification, 203 blastocysts were vitrified, warmed and transferred into seven recipients. Five became pregnant and 36 fetuses were recovered (average litter size 7.2; 24.8% embryo survival in pregnant sows) at Day 40 of pregnancy. In conclusion, changes made to the vitrification protocol improved pregnancy rate and in vivo embryo survival compared to an earlier study using the original protocol. (c) 2005 Elsevier Inc. All rights reserved.

Fracture load and marginal fit of shrinkage-free ZrSiO4 all-ceramic crowns after chewing simulation

The aim of this in vitro study was to evaluate the fracture load and marginal accuracy of crowns made from a shrinkage-free ZrSiO4 ceramic cemented with glass-ionomer or composite cement after chewing simulation. Thirty-two human mandibular molars were randomly divided into two groups. All teeth were prepared for and restored with shrinkage-free ZrSiO4 ceramic crowns (Everest HPC (R), KaVo). The crowns of group A (N = 16) were luted to the teeth using KetacCem (R) and group B (N = 16) were adhesively cemented using Panavia (R) 21EX. Measurements of the marginal accuracy before and after cementation were made using replicas and an image analysis system. All specimens were exposed to 1.2 million cycles of thermo-mechanical fatigue in a chewing simulator. Surviving specimens were subsequently loaded until fracture in a static testing device. Fracture loads (N) were recorded. All specimens survived chewing simulation. The mean fracture loads (+/- s.d.) were Group A, 1622 N (+/- 433); group B, 1957 N (+/- 806). There was no significant difference between the two groups (P > 0.05). The marginal gap values before cementation were (mean +/- s.d.): Group A, 32.7 mu m (+/- 6.8); group B, 33.0 mu m (+/- 6.7).The mean marginal gap values after cementation were (+/- s.d.): Group A, 44.6 mu m (+/- 6.7); group B, 46.6 mu m (+/- 7.7). The marginal openings were significantly higher after cementation for both groups (P < 0.05). All test groups demonstrated fracture load and marginal accuracy values within the range of clinical acceptability.

Perinatal outcomes with laser surgery for twin-twin transfusion syndrome

The aim of this tertiary hospital-based cohort study was to determine and compare perinatal outcome and neonatal morbidities of pregnancies with twin-twin transfusion syndrome (TTTS) before and after the introduction of a treatment program with laser ablation of placental communicating vessels. Twenty-seven pregnancies with Stage II-IV TTTS treated with amnioreduction were identified (amnioreduction group). The data were compared with that obtained from the first 31 pregnancies with Stage II-IV TTTS managed with laser ablation of placental communicating vessels (laser group). Comparisons were made for perinatal survival and neonatal morbidities including abnormalities on brain imaging. The median gestation at therapy was similar between the two groups (20 vs. 21 weeks, p = .24), while the median gestation at delivery was significantly greater in the laser treated group (34 vs. 28 weeks, p = .002). The perinatal survival rate was higher in the laser group (77.4% vs. 59.3%, p = .03). Neonatal morbidities including acute respiratory distress, chronic lung disease, requirement for ventilatory assistance, patent ductus arteriosus, hypotension, and oliguric renal failure had a lower incidence in the laser group. On brain imaging, ischemic brain injury was seen in 12% of the amnioreduction group and none of the laser group of infants (p = .01). In conclusion, these findings indicate that perinatal outcomes are improved with less neonatal morbidity for monochorionic pregnancies with severe TTTS treated by laser ablation of communicating placental vessels when compared to treatment by amnioreduction.

Accounting for management costs in sensitivity analyses of matrix population models

Traditional sensitivity and elasticity analyses of matrix population models have been used to p inform management decisions, but they ignore the economic costs of manipulating vital rates. For exam le, the growth rate of a population is often most sensitive to changes in adult survival rate, but this does not mean that increasing that rate is the best option for managing the population because it may be much more expensive than other options. To explore how managers should optimize their manipulation of vital rates, we incorporated the cost of changing those rates into matrix population models. We derived analytic expressions for locations in parameter space where managers should shift between management of fecundity and survival, for the balance between fecundity and survival management at those boundaries, and for the allocation of management resources to sustain that optimal balance. For simple matrices, the optimal budget allocation can often be expressed as simple functions of vital rates and the relative costs of changing them. We applied our method to management of the Helmeted Honeyeater (Lichenostomus melanops cassidix; an endangered Australian bird) and the koala (Phascolarctos cinereus) as examples. Our method showed that cost-efficient management of the Helmeted Honeyeater should focus on increasing fecundity via nest protection, whereas optimal koala management should focus on manipulating both fecundity and survival simultaneously, These findings are contrary to the cost-negligent recommendations of elasticity analysis, which would suggest focusing on managing survival in both cases. A further investigation of Helmeted Honeyeater management options, based on an individual-based model incorporating density dependence, spatial structure, and environmental stochasticity, confirmed that fecundity management was the most cost-effective strategy. Our results demonstrate that decisions that ignore economic factors will reduce management efficiency.

LONGEVIDADE EMPRESARIAL: UM ESTUDO EM MICRO E PEQUENAS EMPRESAS DE SÃO BERNARDO DO CAMPO DO SETOR DE VAREJO

A quantidade de micro e pequenas empresas que encerram suas atividades no Brasil, antes de dois, três ou cinco anos, chega a taxas de mortalidade que se aproximam dos 75%. O presente estudo buscou analisar dez empresas de micro porte do setor de varejo na cidade de São Bernardo do Campo que estão em atividade e que conseguiram superar e vencer as taxas de mortalidade empresarial e de concorrência mercadológica. A investigação iniciou-se pelo ABC paulista, efetuando um levantamento no SEBRAE (Serviço Brasileiro de Apoio às Micro e Pequenas Empresas) e na JUCESP (Junta Comercial do Estado de São Paulo) para descobrir a quantidade de micro e pequenas empresas que estavam em atividade e que inauguraram entre 2006 e 2007. Posteriormente o foco foi para a cidade de São Bernardo do Campo onde foram inauguradas 744 MPE´s (Micro e Pequenas Empresas), sendo que 49 delas estavam categorizadas no setor de varejo do vestuário e por fim definiram-se dez empresas que atenderam aos pré-requisitos metodológicos do estudo. A discussão sobre o tema da longevidade empresarial, ou seja, entender quais foram às capacidades que algumas empresas tiveram de manter-se operante por tantos anos, foi fator essencial para o estudo. O objetivo central deste trabalho foi de verificar a forma de administrar e de tratar de seus negócios destes dez empresários que fizeram com que tivessem sobrevida no mercado. Este estudo valeu-se dos métodos qualitativos, de recorte transversal com amostra não probabilística e por cota para poder efetuar todo processo metodológico e construir a análise final da pesquisa.

Matrix changes induced by transglutaminase 2 lead to inhibition of angiogenesis and tumor growth

Administration of active TG2 to two different in vitro angiogenesis assays resulted in the accumulation of a complex extracellular matrix (ECM) leading to the suppression of endothelial tube formation without causing cell death. Matrix accumulation was accompanied by a decreased rate of ECM turnover, with increased resistance to matrix metalloproteinase-1. Intratumor injection of TG2 into mice bearing CT26 colon carcinoma tumors demonstrated a reduction in tumor growth, and in some cases tumor regression. In TG2 knockout mice, tumor progression was increased and survival rate reduced compared to wild-type mice. In wild-type mice, an increased presence of TG2 was detectable in the host tissue around the tumor. Analysis of CT26 tumors injected with TG2 revealed fibrotic-like tissue containing increased collagen, TG2-mediated crosslink and reduced organized vasculature. TG2-mediated modulation of cell behavior via changes in the ECM may provide a new approach to solid tumor therapy.

Disturbance regime and limits on benefits of refuge use for fishes in a fluctuating hydroscape

Refuge habitats increase survival rate and recovery time of populations experiencing environmental disturbance, but limits on the ability of refuges to buffer communities are poorly understood. We hypothesized that importance of refuges in preventing population declines and alteration in community structure has a non-linear relationship with severity of disturbance. In the Florida Everglades, alligator ponds are used as refuge habitat by fishes during seasonal drying of marsh habitats. Using an 11-year record of hydrological conditions and fish abundance in 10 marshes and 34 alligator ponds from two regions of the Everglades, we sought to characterize patterns of refuge use and temporal dynamics of fish abundance and community structure across changing intensity, duration, and frequency of drought disturbance. Abundance in alligator ponds was positively related to refuge size, distance from alternative refugia (e.g. canals), and abundance in surrounding marsh prior to hydrologic disturbance. Variables negatively related to abundance in alligator ponds included water level in surrounding marsh and abundance of disturbance-tolerant species. Refuge community structure did not differ between regions because the same subset of species in both regions used alligator ponds during droughts. When time between disturbances was short, fish abundance declined in marshes, and in the region with the most spatially extensive pattern of disturbance, community structure was altered in both marshes and alligator ponds because of an increased proportion of species more resistant to disturbance. These changes in community structure were associated with increases in both duration and frequency of hydrologic disturbance. Use of refuge habitat had a modal relationship with severity of disturbance regime. Spatial patterns of response suggest that decline in refuge use was because of decreased effectiveness of refuge habitat in reducing mortality and providing sufficient time for recovery for fish communities experiencing reduced time between disturbance events.

Three essays on a longitudinal analysis of business start-ups using the Kauffman Firm Survey

This dissertation focused on the longitudinal analysis of business start-ups using three waves of data from the Kauffman Firm Survey. ^ The first essay used the data from years 2004-2008, and examined the simultaneous relationship between a firm's capital structure, human resource policies, and its impact on the level of innovation. The firm leverage was calculated as, debt divided by total financial resources. Index of employee well-being was determined by a set of nine dichotomous questions asked in the survey. A negative binomial fixed effects model was used to analyze the effect of employee well-being and leverage on the count data of patents and copyrights, which were used as a proxy for innovation. The paper demonstrated that employee well-being positively affects the firm's innovation, while a higher leverage ratio had a negative impact on the innovation. No significant relation was found between leverage and employee well-being.^ The second essay used the data from years 2004-2009, and inquired whether a higher entrepreneurial speed of learning is desirable, and whether there is a linkage between the speed of learning and growth rate of the firm. The change in the speed of learning was measured using a pooled OLS estimator in repeated cross-sections. There was evidence of a declining speed of learning over time, and it was concluded that a higher speed of learning is not necessarily a good thing, because speed of learning is contingent on the entrepreneur's initial knowledge, and the precision of the signals he receives from the market. Also, there was no reason to expect speed of learning to be related to the growth of the firm in one direction over another.^ The third essay used the data from years 2004-2010, and determined the timing of diversification activities by the business start-ups. It captured when a start-up diversified for the first time, and explored the association between an early diversification strategy adopted by a firm, and its survival rate. A semi-parametric Cox proportional hazard model was used to examine the survival pattern. The results demonstrated that firms diversifying at an early stage in their lives show a higher survival rate; however, this effect fades over time.^

Correlação da imunoexpressão do fator de choque térmico 1 (hsf1) com aspectos clinicopatológicos em carcinomas de células escamosas de língua oral

Squamous cell carcinoma of oral tongue shows high rates of morbidity and mortality in the population, therefore, great efforts are being made to classify morphological changes and identify biomarkers that have prognostic value and that are able to group patients in individualized therapeutic options. From this perspective, there is the heat shock factor 1 (HSF1), which is a heat shock factor transcription protein (HSPs) that allows the cancer to deal with stressors associated with malignancy, acting differently in tumor progression. This research aimed to perform a clinico-pathological analysis of 70 cases of oral tongue squamous cell carcinoma (OTSCC) and immunohistochemical study of the expression of HSF1 protein in OTSCC, comparing it with 30 specimens of normal oral mucosa (NOM), and correlating this immunostaining with clinico-pathological aspects of OTSCC. To analyze the association between immunoexpression of HSF1 and clinicophatoloical aspects, the cases were categorized in minor and major overexpression, based in the median immunostaining score. Regarding the cases of OTSCC, 57.1% showed clinical stage III or IV, 82.9% were graded as high grade according to Bryne (1998) and 47.1% as high risk of malignancy according to Brandwein-Gensler et al., (2005). A disease free survival rate of 47.84% and overall survival rate of 68.20% was observed in the analyzed cases, and the high degree of malignancy according to Bryne’s system (1998) (p=0.05), tumor size T3 or T4 (p=0.04), local recurrence (p=0.02), and perineural invasion (p=0.02) determined negative impacts in survival time. We observed also a statistically significant result (p<0.01) when comparing the immunoreactivity of HSF1 between NOM and OTSCC. This significantly increased expression of HSF1 in cases of OTSCC suggests that this protein acts, indeed, in the pathogenesis of this disease. However, there were no statistically significant associations between this overexpression and the clinico-pathological parameters analyzed. This finding may reflect the influence of epigenetic events on HSF1 gene or a possible stability of this protein expression throughout disease progression.

Correlação da imunoexpressão do fator de choque térmico 1 (hsf1) com aspectos clinicopatológicos em carcinomas de células escamosas de língua oral

Squamous cell carcinoma of oral tongue shows high rates of morbidity and mortality in the population, therefore, great efforts are being made to classify morphological changes and identify biomarkers that have prognostic value and that are able to group patients in individualized therapeutic options. From this perspective, there is the heat shock factor 1 (HSF1), which is a heat shock factor transcription protein (HSPs) that allows the cancer to deal with stressors associated with malignancy, acting differently in tumor progression. This research aimed to perform a clinico-pathological analysis of 70 cases of oral tongue squamous cell carcinoma (OTSCC) and immunohistochemical study of the expression of HSF1 protein in OTSCC, comparing it with 30 specimens of normal oral mucosa (NOM), and correlating this immunostaining with clinico-pathological aspects of OTSCC. To analyze the association between immunoexpression of HSF1 and clinicophatoloical aspects, the cases were categorized in minor and major overexpression, based in the median immunostaining score. Regarding the cases of OTSCC, 57.1% showed clinical stage III or IV, 82.9% were graded as high grade according to Bryne (1998) and 47.1% as high risk of malignancy according to Brandwein-Gensler et al., (2005). A disease free survival rate of 47.84% and overall survival rate of 68.20% was observed in the analyzed cases, and the high degree of malignancy according to Bryne’s system (1998) (p=0.05), tumor size T3 or T4 (p=0.04), local recurrence (p=0.02), and perineural invasion (p=0.02) determined negative impacts in survival time. We observed also a statistically significant result (p<0.01) when comparing the immunoreactivity of HSF1 between NOM and OTSCC. This significantly increased expression of HSF1 in cases of OTSCC suggests that this protein acts, indeed, in the pathogenesis of this disease. However, there were no statistically significant associations between this overexpression and the clinico-pathological parameters analyzed. This finding may reflect the influence of epigenetic events on HSF1 gene or a possible stability of this protein expression throughout disease progression.

Associação da imunoexpressão das proteínas XRCC1, TFIIH E XPF com características clinicopatológicas e sobrevida em carcinoma epidermoide de língua oral

DNA repair systems, genes and proteins are essential for genome integrity maintenance, avoiding serious diseases such as cancer. Deregulation in the expression of those proteins has been associated with both the risk of development and evolution of various human cancers, including oral squamous cell carcinoma. The purpose of this study was to analyze the immunoreactivity of the DNA repair proteins XRCC1, THIIF and XPF in oral tongue squamous cell carcinoma (OTSCC) and to investigate its association with clinical and histopathological parameters, outcome and 5-year survival rate. Seventy-four cases of OTSCC were analyzed semi-quantitatively through immunohistochemistry. We observed that DNA repair proteins were highly expressed in parenchymal cells; however, we only observed a significant association between XRCC1 high expression and better clinical staging (p=0,02). Cox regression showed that tumor size (p<0,01), lymph node involvement (p=0,04), tumor stage (p=0,02) and depth of invasion> 4mm (p=0,05) were prognostic factors. The results of this experiment suggest that XRCC1, TFIIH and XPF participate in the tumorigenic process, however, their immunoexpression may not be used as an independent prognostic indicator for OTSCC.