Isoproterenol induces primary loss of dystrophin in rat hearts: correlation with myocardial injury

The mechanism of isoproterenol-induced myocardial damage is unknown, but a mismatch of oxygen supply vs. demand following coronary hypotension and myocardial hyperactivity is the best explanation for the complex morphological alterations observed. Severe alterations in the structural integrity of the sarcolemma of cardiomyocytes have been demonstrated to be caused by isoproterenol. Taking into account that the sarcolemmal integrity is stabilized by the dystrophin-glycoprotein complex (DGC) that connects actin and laminin in contractile machinery and extracellular matrix and by integrins, this study tests the hypothesis that isoproterenol affects sarcolemmal stability through changes in the DGC and integrins. We found different sensitivity of the DGC and integrin to isoproterenol subcutaneous administration. Immunofluorescent staining revealed that dystrophin is the most sensitive among the structures connecting the actin in the cardiomyocyte cytoskeleton and the extracellular matrix. The sarcomeric actin dissolution occurred after the reduction or loss of dystrophin. Subsequently, after lysis of myofilaments, gamma-sarcoglycan, beta-dystroglycan, beta 1-integrin, and laminin alpha-2 expressions were reduced followed by their breakdown, as epiphenomena of the myocytolytic process. In conclusion, administration of isoproterenol to rats results in primary loss of dystrophin, the most sensitive among the structural proteins that form the DGC that connects the extracellular matrix and the cytoskeleton in cardiomyocyte. These changes, related to ischaemic injury, explain the severe alterations in the structural integrity of the sarcolemma of cardiomyocytes and hence severe and irreversible injury induced by isoproterenol.

Magnetic Resonance Imaging in Knee Osteoarthritis Research: Semiquantitative and Compositional Assessment

Semiquantitative assessment of the knee by expert magnetic resonance imaging readers is a powerful research tool for understanding the natural history of osteoarthritis (OA). Several reliable semiquantitative scoring systems have been applied to large observational cross-sectional and longitudinal epidemiologic studies and interventional clinical trials. Such evaluations have enabled understanding of the relevance of disease in structures within the knee joint to explain pain and progression of OA. Compositional imaging of cartilage has added to our ability to detect early degeneration before morphologic changes are present, which may help to prevent the permanent morphologic changes commonly seen in knee OA.

Hypertrophy and neuron loss: structural changes in sheep SCG induced by unilateral sympathectomy

Recently, superior cervical ganglionectomy has been performed to investigate a variety of scientific topics from regulation of intraocular pressure to suppression of lingual tumour growth. Despite these recent advances in our understanding of the functional mechanisms underlying superior cervical ganglion (SCG) growth and development after surgical ablation, there still exists a need for information concerning the quantitative nature of the relationships between the removed SCG and its remaining contralateral ganglion and between the remaining SCG and its modified innervation territory. To this end, using design-based stereological methods, we have investigated the structural changes induced by unilateral ganglionectomy in sheep at three distinct timepoints (2, 7 and 12 weeks) after surgery. The effects of time, and lateral (left-right) differences, were examined by two-way analyses of variance and paired t-tests. Following removal of the left SCG, the main findings were: (i) the remaining right SCG was bigger at shorter survival times, i.e. 74% at 2 weeks, 55% at 7 weeks and no increase by 12 weeks, (ii) by 7 weeks after surgery, the right SCG contained fewer neurons (no decrease at 2 weeks, 6% fewer by 7 weeks and 17% fewer by 12 weeks) and (iii) by 7 weeks, right SCG neurons were also larger and the magnitude of this increase grew substantially with time (no rise at 2 weeks, 77% by 7 weeks and 215% by 12 weeks). Interaction effects between time and ganglionectomy-induced changes were significant for SCG volume and mean perikaryal volume. These findings show that unilateral superior cervical ganglionectomy has profound effects on the contralateral ganglion. For future investigations, it would be interesting to examine the interaction between SCGs and their innervation targets after ganglionectomy. Is the ganglionectomy-induced imbalance between the sizes of innervation territories the milieu in which morphoquantitative changes, particularly changes in perikaryal volume and neuron number, occur? Mechanistically, how would those changes arise? Are there any grounds for believing in a ganglionectomy-triggered SCG cross-innervation and neuroplasticity? (C) 2011 ISDN. Published by Elsevier Ltd. All rights reserved.

Socioeconomic causes of loss of animal genetic diversity: Analysis and assessment

The number of breeds of domesticated animals, especially livestock, have declined rapidly. The proximate causes and processes involved in loss of breeds are outlined. The path-dependent effect and Swanson's dominance-effect are discussed in relation to breed selection. While these help to explain genetic erosion, they need to be supplemented to provide a further explanation of biodiversity loss. It is shown that the extension of markets and economic globalisation have contributed significantly to genetic loss of breeds. In addition, the decoupling of animal husbandry from surrounding natural environmental conditions is further eroding the stock of genetic resources, particularly industrialised intensive animal husbandry. Recent trends in animal husbandry raise very serious sustainability issues, apart from animal welfare concerns.

Validation of body condition score as a predictor of subcutaneous fat in Nelore (Bos indicus) cows

The aim of the present study was to determine the relationship among body weight (BW), body condition score (BCS) and rump fat thickness (RFAT) measured by ultrasonography, and validate the relationship between BCS and RFAT over the time. Two hundred sixty and six Nelore cows had their BW, BCS and RFAT evaluated at five different moments during the production cycle: M1) weaning: M2) parturition, M3) 42 days post-partum; M4) 82 days postpartum and M5) 112 days post-partum. A BCS value was attributed for each cow following a I to 5 points scale. Ultrasonographic images for RFAT measurement were obtained using a 3.5 MHz linear transducer. Images were immediately analyzed as soon as they were formed and frozen. Body condition scores and ultrasound measurements were collected on the same day by a single trained technician. The relationship between BCS and RFAT values was investigated by regression models. The analysis of similarity among the five obtained models was performed using the proc MIXED from SAS and the correlations among variables were analyzed with proc CORR from SAS. The BCS was able to predict RFAT in Nelore cows in all different moments evaluated. Also, it was shown that BCS presented high correlation (r=0.82 to 0.93) and relationship (R(2) = 0.73 to 0.92) with RFAT. However, both BCS and RFAT showed low correlation (r=0.37 to 0.50) and relationship (R(2) = 0.13 to 0.25) with BW. The BCS classification by visual method using a 1 to 5 point scale, was able to predict the RFAT in Nelore cows over the time. (C) 2008 Elsevier B.V. All rights reserved.

Periodontal attachment loss in an untreated isolated population of Brazil

Background: The aim of this study was to assess the prevalence, extent, and severity of clinical attachment loss (CAL) and to investigate the association of demographic, socioeconomic, and behavioral risk indicators with CAL in an untreated isolated population in Brazil. Methods: All subjects aged >= 12 years were identified by a census. Participants were submitted to a full-mouth clinical examination of six sites per tooth and were interviewed using a structured, written questionnaire. Results: Among the 214 subjects who were interviewed and examined clinically, CAL >= 5 mm in at least one site was observed in 8% of the 12- to 19-year-olds and in all dentate subjects >= 50 years of age; the age-dependent prevalence of CAL >= 7 mm in at least one site ranged from 5% among 12- to 19-year-olds to 83% among subjects >= 50 years old. Multivariate analysis identified plaque (odds ratio [OR] = 2.8), supragingival calculus (OR = 2.9 to 10.6), age >= 30 years (OR = 11.4), and smoking (OR = 2.4) as risk indicators for CAL >= 5 mm and smoking (OR = 8.2) as a risk indicator for CAL >= 7 mm. Conclusions: CAL is highly prevalent in this isolated population. The high occurrence of CAL in young age groups and the confirmation of traditional risk indicators for CAL in this study suggest that other factors, such as host susceptibility, may be needed to explain the high levels of CAL found. Age and behavioral factors were risk indicators associated significantly with the CAL found in this population and may be useful indicators of high-risk subjects for periodontal diseases.

The severity of epithelial dysplasia is associated with loss of maspin expression in actinic cheilitis

Background Prolonged exposure of the lip to sunlight may cause actinic cheilitis (AC) and squamous cell carcinoma (SCC). Maspin is a serpin with tumor suppressor functions. This work analyzed the presence and distribution of maspin in AC and lip SCC. Methods Sections from 36 cases diagnosed as AC (18 cases with mild epithelial dysplasia, 11 with moderate and 7 with severe), 18 cases diagnosed as lip SCC and 7 specimens containing normal lip vermillion epithelium were submitted for immunohistochemical analysis to detect maspin. Results All AC cases with mild and two cases with moderate dysplasia were scored 3. The remaining nine cases with moderate dysplasia were identified as score 2, whereas all cases with severe dysplasia were scored 1. Positive staining for maspin decreased from the basal layer to the surface. Among the 18 lip SCCs studied, 15 cases showed abundant staining for maspin. Epithelium adjacent to the SCCs also showed intense positive staining in all cells. Conclusions Our results suggest that the loss of maspin expression occurs from the basal layer to the surface. Lip SCCs related to solar radiation show an intense presence of maspin protein in almost all tumor cells as well as the neighboring epithelium. Fontes A, Sousa SM, Santos E, Martins MT. The severity of epithelial dysplasia is associated with loss of maspin expression in actinic cheilitis.

Tooth loss prevalence and risk indicators in an isolated population of Brazil

Objective. The aim of this study was to assess the prevalence, extent, and risk indicators of tooth loss in an isolated population of Brazil. Material and methods. Two-hundred-and-forty-two subjects, ranging in age from 14 to 82 years (mean 36.2 years), were identified by census in an isolated population of Brazil. All consenting subjects received a full-mouth clinical (DFT index and information about missing teeth) and periodontal examination of 6 sites per tooth. Furthermore, they were interviewed using a structured written questionnaire in order to gather information about demographic, environmental, and biological variables. Results. Of the 200 subjects (80% response rate), 19 (9.5%) were edentulous, 90% had lost at least one tooth, and 39% had lost more than 8 teeth. The mean number of teeth lost was 9.5 (95% CI = 8.2-10.8). First mandibular molars were the most commonly missing teeth. In a multiple logistic regression analysis based on a theoretical hierarchical model of tooth loss, having more than 8 teeth lost was strongly associated with adult age (OR = 18.3-17.3, 95% CIs = 4.8-69.7 and 4.0-75.1) and female gender (OR = 5.9, 95% CI = 1.9-18.2) in the final model. Conclusions. Tooth loss was highly prevalent and extensive in this isolated population. Demographic and behavioral factors played an important role in tooth loss prevalence in this population.

The Potential Role of Suppressors of Cytokine Signaling in the Attenuation of Inflammatory Reaction and Alveolar Bone Loss Associated with Apical Periodontitis

Inflammatory cytokines contribute to periapical tissue destruction. Their activity is potentially regulated by suppressors of cytokine signaling (SOCS), which down-regulate signal transduction as part of an inhibitory feedback loop. We investigated the expression of the cytokines tumor necrosis factor alpha (TNF-alpha); interleukin (IL)-10 and RANKL; and SOCS-1, -2, and -3 by real-time polymerase chain reaction in 57 periapical granulomas and 38 healthy periapical tissues. Periapical granulomas exhibited significantly higher SOCS-1, -2, and -3, TNF-alpha, IL-10, and RANKL messenger RNA levels when compared with healthy controls. Significant positive correlations were found between SOCS1 and IL-10 and between SOCS3 and IL-10. Significant inverse correlations were observed between SOCS1 and TNF-alpha, SOCS1 and RANKL, and SOCS3 and TNF-alpha. Increased SOCS-1, -2, and -3 messenger RNA levels in periapical granulomas may be related to the downregulation of inflammatory cytokines in these lesions; therefore, SOCS molecules may play a role in the dynamics of periapical granulomas development. (J Endod 2008;34:1480-1484)

Unilateral hearing loss: benefits and satisfaction from the use of hearing aids

A unilateral hearing loss is characterized by reduced hearing in one ear. The problems caused by sensory deprivation can be minimized with the use of hearing aids (HA). Aim: To analyze the correlation between the prescribed grain and the insertion gain difference and with the results obtained regarding the benefit and satisfaction with the use of hearing aids in unilateral hearing impaired patients. Materials and Methods: Prospective study with 15 subjects, mean age of 41.6 years, of both genders, users of hearing aids effectively. We used the International Questionnaire Results for hearing aids (International Outcome Inventory for Hearing Aids - IOI-HA), measured with a probe microphone. Results: The mean values in the analyses of the IOI-HA per item were positive and higher than four points. In relation to the objective measures, the frequencies in which we obtained the gain values which were closer to the target were: 1K Hz, 2K Hz and 500 Hz, respectively. Conclusion: The satisfaction of individuals using hearing aid unilaterally is not completely correlated to the prescribed gain, because even if the target is not being reached in some frequencies, the individuals were pleased as to the use of their hearing aids.

Saethre-Chotzen Syndrome, Pro136His TWIST Mutation, Hearing Loss, and External and Middle Ear Structural Anomalies: Report on a Brazilian Family

Objective: To describe the clinical, speech, hearing, and imaging findings in three members of a Brazilian family with Saethre-Chotzen syndrome (SCS) who presented some unusual characteristics within the spectrum of the syndrome. Design: Clinical evaluation was performed by a multidisciplinary team. Direct sequencing of the polymerase chain reaction amplified coding region of the TWIST1 gene, routine and electrophysiological hearing evaluation, speech evaluation, and imaging studies through computed tomography (CT) scan and magnetic resonance imaging (MRI) were performed. Results: TWIST1 gene analysis revealed a Pro136His mutation in all patients. Hearing evaluation showed peripherial and mixed hearing loss in two of the patients, one of them with severe unilateral microtia. Computed tomography scan showed structural middle ear anomalies, and MRI showed distortion of the skull contour as well as some of the brain structures. Conclusions: We report a previously undescribed TWIST1 gene mutation in patients with SCS. There is evidence that indicates hearing loss (conductive and mixed) can be related both with middle ear (microtia, high jugular bulb, and enlarged vestibules) as well as with brain stem anomalies. Here we discuss the relationship between the gene mutation and the clinical, imaging, speech, and hearing findings.

Electron beam current loss at the high-vacuum-high-pressure boundary in the environmental scanning electron microscope

A significant loss in electron probe current can occur before the electron beam enters the specimen chamber of an environmental scanning electron microscope (ESEM). This loss results from electron scattering in a gaseous jet formed inside and downstream (above) the pressure-limiting aperture (PLA), which separates the high-pressure and high-vacuum regions of the microscope. The electron beam loss above the PLA has been calculated for three different ESEMs, each with a different PLA geometry: an ElectroScan E3, a Philips XL30 ESEM, and a prototype instrument. The mass thickness of gas above the PLA in each case has been determined by Monte Carlo simulation of the gas density variation in the gas jet. It has been found that the PLA configurations used in the commercial instruments produce considerable loss in the electron probe current that dramatically degrades their performance at high chamber pressure and low accelerating voltage. These detrimental effects are minimized in the prototype instrument, which has an optimized thin-foil PLA design.

COX-2 inhibition decreases VEGF expression and alveolar bone loss during the progression of experimental periodontitis in rats

Background: Vascular endothelial growth factor (VEGF) is a macromolecule of importance in inflammation that has been implicated in periodontitis. The aims of this study were to investigate VEGF expression during the progression of periodontal disease and to evaluate the effect of a preferential cyclooxygenase (COX)-2 inhibitor meloxicam on VEGF expression and alveolar bone loss in experimentally induced periodontitis. Methods: A total of 120 Wistar rats were randomly separated into groups 1 (control) and 2 (meloxicam, 3 mg/kg/day, intraperitoneally, for 3, 7, 14, or 30 days). Silk ligatures were placed at the gingival margin level of the lower right first molar of all rats. VEGF expression was assessed by reverse transcription-polymerase chain reaction (RT-PCR), Western blot (WB), and immunohistochemical (IHC) analyses. The hemiarcades were processed for histopathologic analysis. RT-PCR and WB results were submitted to analysis of variance, the Tukey test, and Pearson correlation analysis (P<0.05). Results: A reduction in alveolar bone resorption was observed in the meloxicam-treated group compared to the control group at all periods studied. There was a positive correlation between COX-2 mRNA and VEGF mRNA in the gingival tissues and periodontal disease (R = 0.80; P = 0.026). Meloxicam significantly reduced the increased mRNA VEGF expression in diseased tissues after 14 days of treatment (P = 0.023). Some alterations in VEGF receptor I mRNA expression were observed, but these were not statistically significant. VEGF protein expression in WB experiments was significantly higher in diseased sites compared to healthy sites (P<0.05). After 14 days of treatment with meloxicam, an important decrease in VEGF protein expression was detected in diseased tissues (P = 0.08). Qualitative IHC analysis revealed that VEGF protein expression was higher in diseased tissues and decreased in tissues from rats treated with meloxicam. Conclusions: The present data suggest an important role for VEGF in the progression of periodontal disease. Systemic therapy with meloxicam can modify the progression of experimentally induced periodontitis in rats by reducing VEGF expression and alveolar bone loss.

Hydraulic Performances of Minimum Energy Loss Culverts in Australia

Culverts are among the most common hydraulic structures. Modern designs do not differ from ancient structures and are often characterised by significant afflux at design flows. A significant advance was the development of the Minimum Energy Loss (MEL) culverts in the late 1950s. The design technique allows a drastic reduction in upstream flooding associated with lower costs. The development and operational performances of this type of structure is presented. The successful operation of MEL culverts for more than 40 years is documented with first-hand records during and after floods. The experiences demonstrate the design soundness while highlighting the importance of the hydraulic expertise of the design engineers.