Quantitative myocardial contrast echocardiography during pharmacological stress for diagnosis of coronary artery disease: a systematic review and meta-analysis of diagnostic accuracy studies

Aims We conducted a meta-analysis to evaluate the accuracy of quantitative stress myocardial contrast echocardiography (MCE) in coronary artery disease (CAD). Methods and results Database search was performed through January 2008. We included studies evaluating accuracy of quantitative stress MCE for detection of CAD compared with coronary angiography or single-photon emission computed tomography (SPECT) and measuring reserve parameters of A, beta, and A beta. Data from studies were verified and supplemented by the authors of each study. Using random effects meta-analysis, we estimated weighted mean difference (WMD), likelihood ratios (LRs), diagnostic odds ratios (DORs), and summary area under curve (AUC), all with 95% confidence interval (0). Of 1443 studies, 13 including 627 patients (age range, 38-75 years) and comparing MCE with angiography (n = 10), SPECT (n = 1), or both (n = 2) were eligible. WMD (95% CI) were significantly less in CAD group than no-CAD group: 0.12 (0.06-0.18) (P < 0.001), 1.38 (1.28-1.52) (P < 0.001), and 1.47 (1.18-1.76) (P < 0.001) for A, beta, and A beta reserves, respectively. Pooled LRs for positive test were 1.33 (1.13-1.57), 3.76 (2.43-5.80), and 3.64 (2.87-4.78) and LRs for negative test were 0.68 (0.55-0.83), 0.30 (0.24-0.38), and 0.27 (0.22-0.34) for A, beta, and A beta reserves, respectively. Pooled DORs were 2.09 (1.42-3.07), 15.11 (7.90-28.91), and 14.73 (9.61-22.57) and AUCs were 0.637 (0.594-0.677), 0.851 (0.828-0.872), and 0.859 (0.842-0.750) for A, beta, and A beta reserves, respectively. Conclusion Evidence supports the use of quantitative MCE as a non-invasive test for detection of CAD. Standardizing MCE quantification analysis and adherence to reporting standards for diagnostic tests could enhance the quality of evidence in this field.

SPINAL POSTURAL ALIGNMENT VARIANCE ACCORDING TO SEX AND AGE IN 7-AND 8-YEAR-OLD CHILDREN

Purpose: Children`s postural alignment undergoes many adjustments due to the changes in body proportions during the stages of growth. The objective of this study was to quantitatively characterize and analyze spinal postural standards in 7- and 8-year-old children to verify which of the differences found were correlated to age and sex. Methods: Two hundred thirty public school students (Amparo, Sao Paulo, Brazil) aged 7 to 8 years were divided into groups according to postural alignment, which were further subdivided by sex and age, for comparison. Digital photos of upright Subjects were analyzed to evaluate posture. Lumbar and thoracic curvature, pelvic inclination, head posture, and lateral spine deviation were measured using CorelDraw (Ottawa, Canada) software guidelines and bone landmarks. Descriptive statistics and analysis of variance data analysis were utilized to verify differences among the groups. This was a cross-sectional, descriptive study. Results: Mean values for the variables analyzed were calculated. For lumbar lordosis, 7-year-old boys showed 38.49 degrees +/- 15.32 degrees in comparison to all other groups (42.29 degrees +/- 7.13 degrees). For thoracic kyphosis, the 7-year-old children presented 28.07 degrees +/- 7.73 degrees. and the 8-year-olds 30.32 degrees +/- 7.73 degrees. Pelvic inclination presented a mean value of 15.82 degrees +/- 5.46 degrees and single lateral spine deviation mean value of 3.48 degrees +/- 2.12 degrees. Conclusion: For the sample studied, differences based on sex and age were found for some of the body segments analyzed. The values found in this study may contribute to improved physiotherapeutic treatment when associated with other aspects of the clinical assessment and symptomatology. (J Manipulative Physiol Ther 2009;32: 154-159)

High prevalence of pituitary magnetic resonance abnormalities and gene mutations in a cohort of Brazilian children with growth hormone deficiency and response to treatment

Data were retrospectively collected from 69 Brazilian patients (45 boys) with growth hormone deficiency (GHD) who received exogenous growth hormone (GH) for a median duration of 4 years (range 1-13 years). Forty-two patients had multiple pituitary hormone deficiencies and 27 had isolated GHD. Peak GH was <7 ng/ml (IRMA) or <3.2 ng/ml (IFMA) after two stimulation tests.. Therapy was started at median age of 10.0 years (range 2.2-21.6 years), bone age of 5.8 years (0.5-13.5 years) and height standard deviation score -4.4 (range -9.3 to -1.6). MRI revealed pituitary abnormalities in 87% of patients. Homozygous mutations in PROP-1, GHRH-R, GH-1 or HESX-1 genes were found in 12 patients. Mean height velocities were 3.3 pretreatment and 10.3, 7.8, 7.4 and 6.4 cm/yr, respectively, during 1-4 years of treatment with GH. In conclusion, the high prevalence (96%) of genetic and/or pituitary abnormalities probably reflects the stringent diagnostic criteria used, and GH replacement resulted in significant catch-up growth.

Migration in Afro-Brazilian Rural Communities: Crossing Demographic and Genetic Data

Many studies have used genetic markers to understand global migration patterns of our species. However, there are only few studies of human migration on a local scale. We, therefore, researched migration dynamics in three Afro-Brazilian rural communities, using demographic data and ten Ancestry Informative Markers. In addition to the description of migration and marriage structures, we carried out genetic comparisons between the three populations, as well as between locals and migrants from each community. Genetic admixture analyses were conducted according to the gene-identity method, with Sub-Saharan Africans, Amerindians, and Europeans as parental populations. The three analyzed Afro-Brazilian rural communities consisted of 16% to 30% of migrants, most of them women. The age pyramid revealed a gap in the segment of men aged between 20 to 30 yrs. While endogamous marriages predominated, exogamous marriages were mainly patrilocal. Migration dynamics are apparently associated with matrimonial customs and other social practices of such communities. The impact of migration upon the populations` genetic composition was low but showed an increase in European alleles with a concomitant decrease in the Amerindian contribution. Admixture analysis evidenced a higher African contribution to the gene pool of the studied populations, followed by the contribution of Europeans and Amerindians, respectively.

A general hazard model for lifetime data in the presence of cure rate

Historically, the cure rate model has been used for modeling time-to-event data within which a significant proportion of patients are assumed to be cured of illnesses, including breast cancer, non-Hodgkin lymphoma, leukemia, prostate cancer, melanoma, and head and neck cancer. Perhaps the most popular type of cure rate model is the mixture model introduced by Berkson and Gage [1]. In this model, it is assumed that a certain proportion of the patients are cured, in the sense that they do not present the event of interest during a long period of time and can found to be immune to the cause of failure under study. In this paper, we propose a general hazard model which accommodates comprehensive families of cure rate models as particular cases, including the model proposed by Berkson and Gage. The maximum-likelihood-estimation procedure is discussed. A simulation study analyzes the coverage probabilities of the asymptotic confidence intervals for the parameters. A real data set on children exposed to HIV by vertical transmission illustrates the methodology.

Electromyographic standardized indices in healthy Brazilian young adults and data reproducibility

P>The determination of normal parameters is an important procedure in the evaluation of the stomatognathic system. We used the surface electromyography standardization protocol described by Ferrario et al. (J Oral Rehabil. 2000;27:33-40, 2006;33:341) to determine reference values of the electromyographic standardized indices for the assessment of muscular symmetry (left and right side, percentage overlapping coefficient, POC), potential lateral displacing components (unbalanced contractile activities of contralateral masseter and temporalis muscles, TC), relative activity (most prevalent pair of masticatory muscles, ATTIV) and total activity (integrated areas of the electromyographic potentials over time, IMPACT) in healthy Brazilian young adults, and the relevant data reproducibility. Electromyography of the right and left masseter and temporalis muscles was performed during maximum teeth clenching in 20 healthy subjects (10 women and 10 men, mean age 23 years, s.d. 3), free from periodontal problems, temporomandibular disorders, oro-facial myofunctional disorder, and with full permanent dentition (28 teeth at least). Data reproducibility was computed for 75% of the sample. The values obtained were POC Temporal (88 center dot 11 +/- 1 center dot 45%), POC masseter (87 center dot 11 +/- 1 center dot 60%), TC (8 center dot 79 +/- 1 center dot 20%), ATTIV (-0 center dot 33 +/- 9 center dot 65%) and IMPACT (110 center dot 40 +/- 23 center dot 69 mu V/mu V center dot s %). There were no statistical differences between test and retest values (P > 0 center dot 05). The Technical Errors of Measurement (TEM) for 50% of subjects assessed during the same session were 1 center dot 5, 1 center dot 39, 1 center dot 06, 3 center dot 83 and 10 center dot 04. For 25% of the subjects assessed after a 6-month interval, the TEM were 0 center dot 80, 1 center dot 03, 0 center dot 73, 12 center dot 70 and 19 center dot 10. For all indices, there was good reproducibility. These electromyographic indices could be used in the assessment of patients with stomatognathic dysfunction.

Use of lignin extracted from different plant sources as standards in the spectrophotometric acetyl bromide lignin method

A nongravimetric acetyl bromide lignin (ABL) method was evaluated to quantify lignin concentration in a variety of plant materials. The traditional approach to lignin quantification required extraction of lignin with acidic dioxane and its isolation from each plant sample to construct a standard curve via spectrophotometric analysis. Lignin concentration was then measured in pre-extracted plant cell walls. However, this presented a methodological complexity because extraction and isolation procedures are lengthy and tedious, particularly if there are many samples involved. This work was targeted to simplify lignin quantification. Our hypothesis was that any lignin, regardless of its botanical origin, could be used to construct a standard curve for the purpose of determining lignin concentration in a variety of plants. To test our hypothesis, lignins were isolated from a range of diverse plants and, along with three commercial lignins, standard curves were built and compared among them. Slopes and intercepts derived from these standard curves were close enough to allow utilization of a mean extinction coefficient in the regression equation to estimate : lignin concentration in any plant, independent of its botanical origin. Lignin quantification by use of a common regression equation obviates the steps of lignin extraction, isolation, and standard curve construction, which substantially expedites the ABL method. Acetyl bromide lignin method is a fast, convenient analytical procedure that may routinely be used to quantify lignin.

Precise Insertion of Orthodontic Miniscrews with a Stereolithographic Surgical Guide Based on Cone Beam Computed Tomography Data: A Pilot Study

Purpose: Orthodontic miniscrews are commonly used to achieve absolute anchorage during tooth movement. One of the most frequent complications is screw loss as a result of root contact. Increased precision during the process of miniscrew insertion would help prevent screw loss and potential root damage, improving treatment outcomes. Stereo lithographic surgical guides have been commonly used for prosthetic implants to increase the precision of insertion. The objective of this paper was to describe the use of a stereolithographic surgical guide suitable for one-component orthodontic miniscrews based on cone beam computed tomography (CBCT) data and to evaluate implant placement accuracy. Materials and Methods: Acrylic splints were adapted to the dental arches of four patients, and six radiopaque reference points were filled with gutta-percha. The patients were submitted to CBCT while they wore the occlusal splint. Another series of images was captured with the splint alone. After superimposition and segmentation, miniscrew insertion was simulated using planning software that allowed the user to check the implant position in all planes and in three dimensions. In a rapid-prototyping machine, a stereolithographic guide was fabricated with metallic sleeves located at the insertion points to allow for three-dimensional control of the pilot bur. The surgical guide was worn during surgery. After implant insertion, each patient was submitted to CBCT a second time to verify the implant position and the accuracy of the placement of the miniscrews. Results: The average differences between the planned and inserted positions for the ten miniscrews were 0.86 mm at the coronal end, 0.71 mm at the center, and 0.87 mm at the apical tip. The average angular discrepancy was 1.76 degrees. Conclusions: The use of stereolithographic surgical guides based on CBCT data allows for accurate orthodontic mini screw insertion without damaging neighboring anatomic structures. INT J ORAL MAXILLOFAC IMPLANTS 2011;26:860-865

Understanding Contradictory Data in Contraction Stress Tests

The literature shows contradictory results regarding the role of composite shrinkage and elastic modulus as determinants of polymerization stress. The present study aimed at a better understanding of the test mechanics that could explain such divergences among studies. The hypothesis was that the effects of composite shrinkage and elastic modulus on stress depend upon the compliance of the testing system. A commonly used test apparatus was simulated by finite element analysis, with different compliance levels defined by the bonding substrate (steel, glass, composite, or acrylic). Composites with moduli between 1 and 12 GPa and shrinkage values between 0.5% and 6% were modeled. Shrinkage was simulated by thermal analogy. The hypothesis was confirmed. When shrinkage and modulus increased simultaneously, stress increased regardless of the substrate. However, if shrinkage and modulus were inversely related, their magnitudes and interaction with rod material determined the stress response.

Influence of Calcium Hydroxide Association on the Physical Properties of AH Plus

Introduction: This study evaluated in vitro the radiopacity, setting time, flow, film thickness, solubility, and dimensional changes of AH Plus sealer pure (Dentsply De Trey Gmbh, Konstanz, Germany) and containing 5% and 10% of calcium hydroxide. Methods: The study was performed according to the requirements of the ISO 6876:2001 standard and the American National Standards Institute/American Dental Association (ANSI/ADA)`s Specification No. 57. The following tests were performed: setting time, flow, film thickness, dimensional stability, radiopacity, and solubility. Data were analyzed statistically by analysis of variance and the Tukey tests with a significance level of 5%. Results: The addition of 5% or 10% calcium hydroxide to AH Plus sealer did not alter significantly the radiopacity or setting time values (p > 0.05). Adding 10% calcium hydroxide reduced the flow compared with pure AH Plus and AH Plus/5% calcium hydroxide. The addition of 5% and 10% calcium hydroxide increased the solubility and expansion of AH Plus. All materials presented expansion valued above those recommended by the ADA. The addition of calcium hydroxide to the sealer resulted in greater film thickness. Conclusions: The addition of 5% calcium hydroxide did not affect most physical properties of AH Plus sealer. (J Endod 2010;36:1048-1051)

Evaluation of the radiopacity of some commercial and experimental root-end filling materials

Objective. The aim of the present study was to evaluate the radiopacity of 5 root end filling materials (white MTA Angelus, MTA Bio, light-cured MTA, Sealepox RP, and Portland cement clinker with bismuth oxide and calcium sulfate). Method. Five specimens, 10 mm in diameter and 1 mm in thickness according to specification ISO 6876: 2001 were fabricated from each material and radiographed using Insigth occlusal films close to a graduated aluminum step-wedge (2 to 16 mm in thickness). Radiographs were digitized and compared to the aluminum step-wedge. The radiographic density data were converted into millimeters of aluminum (mm Al), using the Digora 1.51 software. Results were evaluated statistically using the analysis of variance (ANOVA) followed by Tukey test. The level of significance was set at 5% (P<.05%). Results. Radiopacity values ranged from 1.21 mm Al (light-cured MTA) to 6.45 mm Al (MTA Angelus). Comparison between materials showed significant difference (P<.05) between MTA Angelus and all other materials, between Sealepox RP and MTA Bio, and between light-cured MTA and Portland cement clinker. Light-cured MTA was significantly less radiopaque than all other materials. No significant difference (P>.05) was found between MTA Bio and Portland cement clinker. Conclusions. All retrograde filling materials evaluated showed greater radiopacity than dentin. All the materials, except light-cured MTA met the minimum radiopacity standards of 3 mm Al recognized by the ISO 6876: 2001 and ADA n.57. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2009; 108: e35-e38)