Anatomical Diameter Research Articles

Evaluation of apically extruded debris during endodontic retreatment

A growing interest to preserve teeth into the mouth by patients resulted in the increasing number of endodontic retreatments, and when these happen, many different types of irritants are extruded through the foramen. Objective: This study analyzed in vitro the amount of debris extruded through the foramen using four instrumentation techniques during endodontic retreatment. Material and methods: Forty mesial-buccal roots of first molars were selected, instrumented with anatomical diameter up to size #30 ISO file and then obturated with gutta-percha and grossman sealer by lateral condensation. After, they were separated and randomly allocated into four groups with 10 teeth each for the endodontic retreatment procedure: G1 – conventional technique + solvent, G2 – conventional technique without solvent, G3 – ProTaper retreatment + solvent, G4 – ProTaper retreatment without solvent. In all groups, gutta-percha in the coronal portion was removed by using size 1-3 Gates Glidden drills. All teeth were irrigated with distilled water. The debris extruded through the foramen were collected and weighed by an analytical balance. Results: Group 4 had the lowest average for material extrusion through the foramen followed by groups 2, 3 and 1. When Tukey test for statistical analysis was applied, no significant difference among groups were found (p = 0.5664). Conclusion: We conclude that all instrumentation techniques used in this study produced debris which goes beyond the foramen.

Influência do pré-alargamento na escolha da lima patência e lima apical inicial

The present study evaluated the influence of cervical preflaring in the choice of patency and initial apical files. Forty mesial canals of mandibular molars were divided into two groups. In the first, no cervical preflaring was performed while in the second it was performed with Gates Glidden drills. The measurement of the anatomic diameter of the apical foramen and of the working length was performed by the retrograde method with the aid of a microscope. The choice of patency and initial apical files was determined in the root canal. When the preflaring was not performed, the difference between the diameters of the files and the anatomic diameters was greater. Preflaring was shown to be essential for the determination of patency and initial apical files.

English

Introduction Ultrasound guidance for cannulation of the internal jugular vein has been shown to improve success and complication rates in comparison with the landmark techniques. The aim of this study is to verify if ultrasound is also cost-effective. Materials and Methods A systematic review of the literature in PubMed, Medline, and Google was performed between years 1966 and 2010. A decision tree model was built with failure and complication rates from the studies selected. A costeffectiveness analysis and sensitivity analysis were performed with this model. Randomised controlled trials on adult patients, with real-time B-mode ultrasound guidance, comparison between ultrasonography and landmark methods and reported outcomes (early complications, failures, time to successful cannulation) were included. Exclusion criteria were: enrolment of paediatric patients, ultrasound before puncture, Doppler ultrasound guidance, no clear description of outcomes, and no prospective clinical trial. Results About 8 randomised controlled trials were selected. The ultrasound guidance significantly reduces the occurrence of arterial puncture (risk ratio, risk ratio 0.21, 95% CI 0.13–0.33), pneumothorax complications (risk ratio 0.15, 95% CI 0.03–0.88), and cannulation failures (R 0.12, 95% CI 0.04-0.39). It proves to have € 1,225 additional cost every 1,000 procedures. The major determinants of ultrasound costs are the purchase cost of the ultrasound unit and the machine uses per week. Conclusion Although the ultrasound approach introduces a clinically relevant improvement of success and complication rates, it does not appear to be cost-effective. Introduction Central venous catheters (CVCs) are essential for the clinical management of many patients both in the acute care setting and in the chronic, longterm care. Studies have reported an associated complication rate >15% for central venous cannulations1,2. Up to recent years, the internal jugular vein (IJV) has gained the greatest popularity among the different central cannulation routes due to its consistent anatomical position, large diameter, and low likelihood of catheter obstruction or misplacement3. This route, however, is not devoid of early mechanical complications like arterial puncture and pneumothorax. Two meta-analyses have shown that ultrasound-guided CVC placement is associated with a significant improvement of early complication rates, length of execution, and firstpass success rate when compared with the landmark (LM) technique4,5. However, in a survey by the Society of Cardiovascular Anaesthesiologists only 15% of responders stated to routinely use ultrasound (US) for CVC placement6. A presumed higher procedural cost was among the most common objections for not utilizing this approach. According to many providers, the initial financial investments for equipment and operators’ training, and fixed costs for maintenance and additional supplies (e.g. sterile sheaths), may not be outweighed by the better clinical performances of US guidance. Calvert and coworkers have performed a decision analysis showing that B-mode US guidance for CVC placement is significantly cost-effective when compared with the traditional LM technique7,8. Their decision model considered a 12% incidence of arterial puncture and a 9% failure for internal jugular vein cannulations with the LM technique. Although the analysis used conservative assumptions against the US approach (such as no pneumothorax complications, expert operators, allowance of only one failed attempt), these complication rates are higher than data published in the studies on CVC placement with the LM approach9,10. The aim of this study is to perform a systematic review of the existing literature and to update the economic evaluation of cost-effectiveness of real-time B-mode US guidance compared with the LM technique for IJV cannulation. Materials and Methods Selection of studies A search in PubMed, Medline, and Google was carried out with the following headings: central venous catheter, internal jugular vein, and ultrasound. Articles were limited to those in English. The time period was between 1966 and December 2010. Inclusion criteria were: * Corresponding author Email: riccardo.moretti77@gmail.com 1 Teaching Hospital of Val Vibrata, Department of Anesthesia and Critical Care, Sant’Omero (Teramo) Italy 2 Department of Cost Analysis and Control, HBG, Rome, Italy

INSULIN‐INDUCED AUGMENTATION OF CREMASTER MUSCLE INTRACAPILLARY BLOOD VOLUME IS IMPAIRED IN DB/DB MICE

Insulin sensitivity has been related to insulin's ability to increase capillary blood volume in skeletal muscle. Based on our previous studies indicating that agonists augment intracapillary blood volume by increasing blood access into the endothelial glycocalyx, we hypothesize that insulin increases blood volume within individual capillaries in muscle of healthy mice, but not of diabetic mice with manifested glycocalyx damage. Intravital microscopy of cremaster muscle was performed in anesthetized C57Bl/6 (CON, n=5) and db/db mice (DB, n=5). Capillary hemodynamics (red blood cell flux & velocity, anatomic diameter) were monitored at baseline and during insulin administration to the superfusate (20 – 200 μU/ml). Capillary tube hematocrit (Hcap) was calculated as measure of functionally perfused capillary blood volume. In CON, Hcap was 0.093 ± 0.008 (SEM, n=25 capillaries) at baseline; insulin increased (P<0.05) Hcap to 0.143 ± 0.011 (20 μU/ml) and 0.0139 ± 0.008 (200 μU/ml). In DB, baseline Hcap was already elevated (0.154 ± 0.01, n=36 capillaries); insulin administration resulted in stagnant RBCs in 44% of the examined capillaries while in the remaining Hcap did not change. Our results indicate that the insulin‐induced increase of capillary blood volume in muscle involves a glycocalyx‐dependent volume increase in individual capillaries rather than recruitment of additional capillaries.

Regression equation for estimation of length of humerus from its mophometry in a Nigerian population.

While intact long bones are most ideal in estimation of the stature of unidentified individual, in forensic cases as may occur when natural or man-made disasters present bone fragments, regression equations derived from measurements of these bone fragments have been used to determine the length of the intact long bone. The study reports on the morphometry of the humerus and the estimation of its length using regression equations in a Nigerian population. The maximum length of the humerus was measured using an osteometric board while theAnatomical neck circumference (ANC), Anatomical neck diameter (AND), mid shaft diameter (MSD), olecranon vertical diameter (OVD), olecranon transverse diameter (OTD), transverse diameter of the inferior articular surface (IASD), transverse trochlea diameter (TTD) proximal point of the caput humeri and collum anatomicum (CHCAD), proximal edge of the fossa olecrani (PEFO) and the most distal point of trochlea humeri (FOTHD) and the biepicondylar width (BEW) of the distal segment were measured using a digital vernier caliper. Partial correlation and Persian regression were used to derive the linear regression equations for the measured parameters that showed correlation with the humeral length. Estimation of the maximum length of the humerus from the measures of its ANC, FOTHD, and MSD was achieved with relative accuracy. In deriving regression equations for the length of the humerus of the right and left sides, irrespective of side, the ANC and MSD were both significant in estimating the maximum length of the humerus; on the right side only the ANC exhibited significant correlation, while on the left side both the ANC and FOTHD exhibited significant correlation. These previously unreported findings may help in anthropometric, forensic, and archaeological investigations for the estimation of the stature of the remains of unknown bodies by using regression equations in a Nigerian population.

In vivo evaluation of venular glycocalyx during hemorrhagic shock in rats using intravital microscopy

Hemorrhage is responsible for a large percentage of trauma‐related deaths but the mechanisms underlying tissue ischemia are complex and not well understood. Despite the evidence linking glycocalyx degradation and hemorrhagic shock, there is no direct data obtained in vivo showing glycocalyx thickness reduction in skeletal muscle venules after hemorrhage. We hypothesize that damage to the endothelial glycocalyx is a key element in hemorrhage pathophysiology and tested the hypothesis that hemorrhage causes glycocalyx degradation in cremaster muscle microvessels. We utilized intravital microscopy to estimate glycocalyx thickness in 48 microvessels while other microvascular parameters were measured using non-invasive techniques. Systemic physiological parameters and blood chemistry were simultaneously collected. We studied 27 post-capillary venules (<16μm diameter) of 8 anesthetized rats subjected to hemorrhage (40% of total blood volume). Six control rats were equally instrumented but not bled. Dextrans of different molecular weights labeled with FITC or Texas Red were injected. Glycocalyx thickness was estimated from the widths of the fluorescence columns and from anatomical diameter. While control rats did not show remarkable responses, a statistically significant decrease of about 59% in glycocalyx thickness was measured in venules after hemorrhagic shock. Venular glycocalyx thickness and local blood flow changes were correlated: venules with the greatest flow reductions showed the largest decreases in glycocalyx. These changes may have a significant impact in shock pathophysiology. Intravital microscopy and integrated systems such as the one described here may be important tools to identify mechanisms by which resuscitation fluids may improve tissue recovery and outcome following hemorrhage.

Shedding of the Endothelial Glycocalyx and the Resistance to Flow in Capillaries

The endothelial glycocalyx serves as a barrier to transvascular exchange of fluid, macromolecules, and leukocyte‐endothelium (EC) adhesion during the inflammatory process. Shedding of glycosaminoglycans and proteoglycans of the glycocalyx occur in response to several agonists. To elucidate the hemodynamic effects of glycan shedding on capillary resistance to flow during inflammation, intestinal mesentery (rat) was superfused with 10−7 M fMLP. Shedding was quantified by reductions of fluorescently labeled lectin (BS‐1) bound to the EC and reductions in thickness of the barrier to infiltration of 70 kDa dextran (Dx70) on the EC surface. Red cell velocities (two‐slit technique), pressure drops (dual servo‐null method), and capillary hematocrit (direct cell counting) were measured in parallel experiments. Glycocalyx thickness decreased by 80 nm. Capillary resistance rose 18% due to diminished deformability of activated WBCs and fell significantly 26% over a 30 min period, as glycans were shed from the EC surface to increase effective capillary diameter while capillary hematocrit and anatomical diameter remained invariant. This decrease in capillary resistance mitigated the increase in resistance due to diminished WBC deformability and hence these concurrent rheological events may be of equal importance in affecting capillary flow during the inflammatory process.Supported by R01‐HL39286‐20.

Optimization and quality assurance of an image-guided radiation therapy system for intensity-modulated radiation therapy radiotherapy

To develop a quality assurance (QA) of XVI cone beam system (XVIcbs) for its optimal imaging-guided radiotherapy (IGRT) implementation, and to construe prostate tumor margin required for intensity-modulated radiation therapy (IMRT) if IGRT is unavailable. XVIcbs spatial accuracy was explored with a humanoid phantom; isodose conformity to lesion target with a rice phantom housing a soap as target; image resolution with a diagnostic phantom; and exposure validation with a Radcal ion chamber. To optimize XVIcbs, rotation flexmap on coincidency between gantry rotational axis and that of XVI cone beam scan was investigated. Theoretic correlation to image quality of XVIcbs rotational axis stability was elaborately studied. Comprehensive QA of IGRT using XVIcbs has initially been explored and then implemented on our general IMRT treatments, and on special IMRT radiotherapies such as head and neck (H and N), stereotactic radiation therapy (SRT), stereotactic radiosurgery (SRS), and stereotactic body radiotherapy (SBRT). Fifteen examples of prostate setup accounted for 350 IGRT cone beam system were analyzed. IGRT accuracy results were in agreement ± 1 mm. Flexmap 0.25 mm met the manufacturer's specification. Films confirmed isodose coincidence with target (soap) via XVIcbs, otherwise not. Superficial doses were measured from 7.2–2.5 cGy for anatomic diameters 15–33 cm, respectively. Image quality was susceptible to rotational stability or patient movement. IGRT using XVIcbs on general IMRT treatments such as prostate, SRT, SRS, and SBRT for setup accuracy were verified; and subsequently coordinate shifts corrections were recorded. The 350 prostate IGRT coordinate shifts modeled to Gaussian distributions show central peaks deviated off the isocenter by 0.6 ± 3.0 mm, 0.5 ± 4.5 mm in the X(RL)- and Z(SI)-coordinates, respectively; and 2.0 ± 3.0 mm in the Y(AP)-coordinate as a result of belly and bladder capacity variations. Sixty-eight percent of confidence was within ± 4.5 mm coordinates shifting. IGRT using XVIcbs is critical to IMRT for prostate and H and N, especially SRT, SRS, and SBRT. To optimize this modality of IGRT, a vigilant QA program is indispensable. Prostate IGRT reveals treatment accuracy as subject to coordinates' adjustments; otherwise a 4.5-mm margin is required to allow for full dose coverage of the clinical target volume, notwithstanding toxicity to normal tissues.

FDG PET/CT interobserver agreement in head and neck cancer

Interobserver agreement in measuring positron emission tomography (PET)/computed tomography (CT) parameters is critical for head and neck cancer management. The purpose of this study is to assess the interobserver agreement when measuring the standardized uptake value (SUV) parameters and the diameter of primary head and neck tumors between readers with varied experience in PET/CT. PET/CT images of 47 patients (59.8 ± 10.6 years, range 26-86 years) with head and neck cancer who had a baseline PET/CT at our institution (January 2007-May 2009) were retrieved and independently reviewed by four readers with varying experience reading PET/CT. Novice reader 1 was a preinternship medical student; novice reader 2 was a fourth-year radiology resident; expert reader 1 was a board-certified radiologist with a nuclear radiology fellowship and a junior faculty; and expert reader 2 was a dual radiology and nuclear medicine board-certified radiologist and a senior faculty. Intraclass correlation coefficients (ICCs) were estimated separately across novice and expert readers, between novice 1 and expert 1, and between novice 2 and expert 1 readers. The ICCs (95% confidence interval) for primary tumor diameter, primary tumor SUVmax, and primary tumor SUVmax normalized to liver SUVmean within novices were 0.36 (0.09-0.59) (slight agreement), 0.60 (0.38-0.80) (fair agreement), and 0.91 (0.84-0.94) (almost perfect agreement), respectively. ICCs within experts were 0.84 (0.73-0.90) (almost perfect agreement), 0.91 (0.84-0.94) (almost perfect agreement), and 0.91 (0.84-0.95) (almost perfect agreement), respectively. The ICCs between novice 1 and experts are lower than those between novice 2 and experts for all parameters, and this disparity is greater for anatomic diameter than for fluorodeoxyglucose metabolic parameters. Fluorodeoxyglucose metabolic parameters have higher interobserver agreement than anatomic diameter measurement and are more robust in the setting of varied reading experiences.

To determine whether the first file to bind at the working length corresponds to the apical diameter in roots with apical curvatures both before and after preflaring

Aim:To evaluate the discrepancies between the diameter of the canal and the first file to bind at the working length, before and after preflaring in teeth with apical curvatures.Materials and Methods:Twenty teeth with apical curvatures were selected for the study. Following access, the patency file was fixed at the working length, and the apices were ground perpendicular to the canal at this level. Diameters of canal and the first file to bind at the working length were observed for each tooth, both before and after preflaring, under stereomicroscope at 30X magnification.Results:ANOVA and post hoc Bonferroni tests showed significant differences in both groups regarding anatomical diameter at working length and the first file to bind. The area of contact of the file at apical region remained the same in both groups.Conclusion:Using the first file to bind for gauging the diameter of the apical canal was found to be an unreliable method in teeth with apical curvatures, even after preflaring.

Shedding of the endothelial glycocalyx in arterioles, capillaries, and venules and its effect on capillary hemodynamics during inflammation

The endothelial glycocalyx has been identified as a barrier to transvascular exchange of fluid, macromolecules, and leukocyte-endothelium [endothelial cell (EC)] adhesion during the inflammatory process. Shedding of glycans and structural changes of the glycocalyx have been shown to occur in response to several agonists. To elucidate the effects of glycan shedding on microvascular hemodynamics and capillary resistance to flow, glycan shedding in microvessels in mesentery (rat) was induced by superfusion with 10(-7) M fMLP. Shedding was quantified by reductions of fluorescently labeled lectin (BS-1) bound to the EC and reductions in thickness of the barrier to infiltration of 70-kDa dextran on the EC surface. Red cell velocities (two-slit technique), pressure drops (dual servo-null method), and capillary hematocrit (direct cell counting) were measured in parallel experiments. The results indicate that fMLP caused shedding of glycans in all microvessels with reductions in thickness of the barrier to 70-kDa dextran of 110, 80, and 123 nm, in arterioles, capillaries, and venules, respectively. Intravascular volumetric flows fell proportionately in all three divisions in response to rapid obstruction of venules by white blood cell (WBC)-EC adhesion, and capillary resistance to flow rose 18% due to diminished deformability of activated WBCs. Capillary resistance fell significantly 26% over a 30-min period, as glycans were shed from the EC surface to increase effective capillary diameter, whereas capillary hematocrit and anatomic diameter remained invariant. This decrease in capillary resistance mitigates the increase in resistance due to diminished WBC deformability, and hence these concurrent rheological events may be of equal importance in affecting capillary flow during the inflammatory process.

Letter by Lauten et al Regarding Article, “Interventional Cardiology Perspective of Functional Tricuspid Regurgitation”

HomeCirculation: Cardiovascular InterventionsVol. 3, No. 3Letter by Lauten et al Regarding Article, “Interventional Cardiology Perspective of Functional Tricuspid Regurgitation” Free AccessLetterPDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissions ShareShare onFacebookTwitterLinked InMendeleyReddit Jump toFree AccessLetterPDF/EPUBLetter by Lauten et al Regarding Article, “Interventional Cardiology Perspective of Functional Tricuspid Regurgitation” Alexander Lauten, MD, Markus Ferrari, MD and Hans R. Figulla, MD Alexander LautenAlexander Lauten Department of Internal Medicine I (Cardiology, Angiology, Pneumology and Intensive Care) University Heart Center Jena, Germany (Lauten, Ferrari, Figulla) Search for more papers by this author , Markus FerrariMarkus Ferrari Department of Internal Medicine I (Cardiology, Angiology, Pneumology and Intensive Care) University Heart Center Jena, Germany (Lauten, Ferrari, Figulla) Search for more papers by this author and Hans R. FigullaHans R. Figulla Department of Internal Medicine I (Cardiology, Angiology, Pneumology and Intensive Care) University Heart Center Jena, Germany (Lauten, Ferrari, Figulla) Search for more papers by this author Originally published1 Jun 2010https://doi.org/10.1161/CIRCINTERVENTIONS.110.944926Circulation: Cardiovascular Interventions. 2010;3:e10To the Editor:In their recent article, Agarwal et al1 discuss the current perspective for interventional treatment of tricuspid regurgitation (TR). As stated by the authors, this disease is frequently encountered in patients with left heart valvular disease and substantially contributes to mortality. Because surgical repair or replacement of the tricuspid valve is associated with an excessive operative mortality, there is a vast unmet need for percutaneous techniques.The tricuspid annulus is a complex and highly dynamic structure that offers little resistance for orthotopic long-term fixation of valves with the current technique. As demonstrated by Boudjemline et al,2 orthotopic valve replacement is possible but carries a risk of injury and paravalvular leakage. The vicinity to the endocardium is likely to contribute to ventricular arrhythmia. Similar to percutaneous mitral valve replacement, unique challenges have to be overcome to facilitate orthotopic percutaneous tricuspid valve replacement.In their article, Agarwal et al also relate to the concept of valve implantation into the caval veins as a potential interventional approach to TR. We experimentally investigated this approach, demonstrating feasibility and hemodynamic function of heterotopic valves.3,4 Unpublished data even demonstrate caval valve function up to 3 months after implantation. As stated previously, this concept has several obvious advantages, including the straightforward implantation technique owing to the distance to vulnerable cardiac structures and making this an attractive approach to the interventional cardiologist. The concept could even be simplified further by single valve implantation into the inferior vena cava, because the deleterious effects of TR in humans primarily result from venous congestion to the lower body.However, there are also limitations that have to be considered when transferring this to human patients. Caval valve implantation addresses the regurgitation of blood in the caval veins, which is not found in every patient with TR. Especially in chronic TR with right atrial and ventricular enlargement, the right atrium functions as a reservoir, reducing the prominence of the ventricular wave and limiting the backflow of blood to the caval veins in any degree of TR. Because pulsatile blood flow, however, is a prerequisite for the caval valve to function, hemodynamic proof of regurgitation is required before implantation. Therefore, caval valve implantation will function and have an effect only in patients with severe TR and preserved right ventricular function. The significance of preserved right ventricular function is already known to affect the outcome after tricuspid valve surgery and should—to a different degree—also be taken into account in interventional tricuspid valve replacement.Furthermore, we have to be aware of anatomic differences when transferring caval valve implantation from preclinical studies to human application. Apart from the inflow of the hepatic veins being close to the right atrium in the human inferior vena cava, there is also a considerable variation of the anatomic diameter in patients with severe TR, reaching up to 45 mm in isolated cases. These require a specific, potentially individual solution for percutaneous device implantation.In summary, although percutaneous valve implantation into the caval veins may seem straightforward and simple, this approach still poses the earlier mentioned challenges and probably several more yet unknown. We believe these challenges to be surmountable, but this approach will likely be limited to the most severely ill group of patients with TR.Alexander Lauten, MDMarkus Ferrari, MDHans R. Figulla, MD Department of Internal Medicine I (Cardiology, Angiology, Pneumology and Intensive Care) University Heart Center Jena, GermanyDisclosuresNone.

A morphometric study in ordinary lungs of bronchial dimensions throughout the airway tree as a basis for the analysis of COPD

A morphometrical method was established to estimate the initial dimensions of bronchi in the state in which they are strongly deformed due to narrowing or ectasis, and to enable the determination of the grade of deformity. In ordinary lungs from 16 autopsy cases, the dimension of airways were correlated with that of the accompanying pulmonary arteries to establish a standard for the estimation of the former from the latter. In each case, cross-sectioned pairs of an airway and an artery were sampled so as to cover the entire range from segmental bronchi to respiratory bronchioles. The varyingly constricted state of airways and arteries was standardized by measuring the perimeter length L of the epithelial basement membrane (BM) for airways and the internal elastic membrane (IEM) for arteries with a digital image analyzer, and reducing these into a circular state with completely stretched BM and IEM, where D(br), the anatomical diameter of airway, and D(pa), that of artery, were calculated from L. In addition, the sectional area of the epithelium was measured to calculate Rs, the ratio of luminal stenosis by epithelial thickening. In every case, a close correlation was shown to exist between D(br) and D(pa) on bilogarithmic coordinates: When all the measurements from 671 pairs of D(br) and D(pa) were pooled, the correlation coefficient proved to be as high as 0.91 (p less than 0.001). This allows estimation of the dimension of an airway from that of the accompanying artery, even when the airway is severely deformed like in COPD. The range of D(br) for the bronchi (B), that for the membranous bronchioles (MB) and the respiratory bronchioles (RB), were shown to overlap between the neighboring ranges.(ABSTRACT TRUNCATED AT 250 WORDS)

The nature, severity and distribution of obstructive airway lesions in COPD studied by morphometry and computer-assisted 3-D reconstruction

The severity of obstructive bronchial lesions and their distribution in the airway tree were studied in autopsy lungs from ten patients with various types of chronic obstructive pulmonary disease (COPD), where the changes of bronchial dimension were studied by morphometry and the 3-D distribution of obstructive lesions by computer-assisted 3-D reconstruction. A case of paraquat intoxication was added in order to study the airway changes in lungs with early fibrotic changes. In each case, morphometry was performed on microscopic lung sections where the initial diameter of bronchi was estimated from that of the accompanying pulmonary arteries. The varyingly constricted airways and arteries were standardized into a circular state by measuring the perimeter length L of the epithelial basement membrane (BM) and the internal elastic membrane (IEM) with a digital image analyzer; D(br), the anatomical diameter of an airway, and D(pa), that of an artery, were calculated at this state of completely stretched BM or IEM. Rs, the ratio of luminal stenosis by thickened epithelia, was also determined from the area of epithelium simultaneously measured. Three-D reconstruction of airway was performed in cases typically representing different types of obstruction; from microscopic, sometimes macroscopic serial sections, where the 2-D images were inputted into a computer which integrated in its display a 3-D picture. It was shown that in lungs with chronic bronchitis, the bronchial dimension did not significantly differ from that of ordinary lungs. Overt shrinkage of bronchial dimension was demonstrated in chronic obstructive bronchiolitis; in both diffuse panbronchiolitis (DPB) and broncho-bronchiolitis obliterans (BBO), narrowing of the peripheral airways combined with ectasis of the proximal bronchi proved to be a common feature. However, reconstruction disclosed an essential difference between these in the distribution of occlusive lesions, which mainly involved the respiratory bronchioles in DPB, while in BBO, the site of obstruction was from the terminal to slightly upper bronchioles. Also in pulmonary emphysema, the pattern of bronchial dimension was a narrowing in the periphery, both in the centrilobular and panlobular types. Especially worth of attention was that the study disclosed the presence of a type of COPD hitherto poorly defined. In a patient who had a 25-year history of COPD and died of respiratory failure, the lungs, only mildly emphysematous, were shown to have uniformly narrowed bronchioles; also mucus hypersecretion and elevated Rs appeared to have contributed to the obstruction.(ABSTRACT TRUNCATED AT 400 WORDS)

Influence of cervical preflaring on apical file size determination - An in vitro study

Aim: To investigate the influence of cervical preflaring on apical file size determination using 4 different rotary instruments. Methodology: Forty extracted human maxillary central incisors were used for the study. Access opening was done and the working length was established. Teeth were randomly divided into 4 groups namely, no preflaring (Control), Gates Glidden drills, Protaper instruments and LA Axxess burs. After apical file size determination for each tooth IAF were fixed at the WL. Teeth were sectioned transversally 1mm from the apex, with the binding file in position, analyzed & root canal & file maximum diameters were recorded for each sample. Results: LA Axxess burs produced the smallest differences between anatomical diameter & first file to bind . The major discrepancy was found in group 1, where no cervical preflaring was performed. Protaper instruments were ranked second & Gates Glidden Drills third with statistically significant results (p< 0.01). Conclusion: Cervical preflaring helps to gauge the apical diameter better and LA Axxess burs are more effective for preflaring compared to other rotary instruments.

Reduction in endothelial glycocalyx thickness after hemorrhage

Although some evidence suggests that ischemia induces changes in the endothelial glycocalyx (EG), little information is available about the EG following hemorrhagic hypotension (HH). We have employed video analysis to obtain preliminary data on EG changes following hemorrhage. Using intravital videomicroscopy, we studied the spinotrapezius muscle of anesthetized rats subjected to HH (40% blood vol.) for over 1 h. The analog video camera signal was digitized using standard software to DV‐AVI format. About 100 frames of several video clips (3‐5 s each) were processed using specially designed software to derive dimensions of the endothelial glycocalyx from the gap between erythrocytes and the luminal endothelial surface. Frequency distributions of the EG thickness during baseline and during HH showed a shift to lower values following hemorrhage, corresponding to a reduction in EG thickness of nearly 50 % (1.1 µm [range: 0.4 ‐ 4.3 µm] vs 0.6 µm [range: 0.3 ‐ 1.3 µm]). These changes occurred despite similar distributions of anatomic diameters (baseline range: 9 ‐ 24 µm; HH: 10 ‐ 21 µm). The findings suggest that the analysis of EG changes using in vivo video recordings can be used to investigate changes following HH and provide preliminary support for our hypothesis that these low flow states cause reductions in the endothelial surface layer thickness.SupportNIH, NWO, NHS, (HV: NHF grant 2005T037).

Differential effects of temperature on stem length and xylem vessel length distribution in Zinnia elegans

SummaryWater transport in vascular plants depends on the hydraulic conductance of the xylem system, which is dependent on the anatomical properties, number, diameter, and length of the xylem vessels. The ability to transport water through their stems influences not only the growth of many horticultural crops, but also the post-harvest quality of cut flowers. In this study, we investigated the effects of different average daily temperatures (ADT) and the difference between day-time (DT) and night-time (NT) temperature (DIF) on stem size, the length of xylem vessels within the stem, and the length of individual vessel elements within a vessel, in Zinnia elegans. Two Z. elegans cultivars, ‘Envy’ and ‘Purple Prince’, were grown in climate chambers under all nine combinations of three DT and three NT temperatures (viz. 17ºC, 21ºC, or 25ºC). An increase in ADT was positively correlated with the lengths of the stems, internodes, and xylem vessels in both cultivars. However, the lengths of the xylem vessels were influenced more strongly than the lengths of the stems. Increasing the ADT from 17ºC to 25ºC increased stem lengths by approx. 15%, but more than doubled the lengths of the xylem vessels. The increase in xylem vessel lengths was only partly (< 10%) due to an increase in the lengths of individual vessel members, which implies that temperature (ADT) had a greater influence on the number of fused vessel elements per xylem vessel. A negative DIF (i.e., lower DT than NT temperatures) decreased stem lengths and a positive DIF increased stem lengths. DIF had no effect on xylem vessel length, probably because, other than in stem length, xylem vessel length was positively correlated with NT temperature.

ANATOMICAL AND FUNCTIONAL HETEROGENEITY AMONG DIFFERENT ROOT ORDERS OF PHELLODENDRON AMURENSE

Aims Fine roots are the primary organs for nutrient and water uptake in trees. The growth and turnover of fine roots significantly influence productivity and matter cycles in forest ecosystems. Our objective was to elucidate the basic structure, function and allocation of fine roots in Phellodendron amurense. Methods We made paraffin slices stained by safranin and fast green to observe anatomical structures (such as diameter, cortex, number of passage cells, development of vascular bundle, mycorrhizae of roots, etc.) of the first five orders of roots of P. amurense. Bright-light and fluorescence microscopes were used to observe and take photos. Important findings Root diameter (R), vascular bundle diameter (V) and V/R increased as root order increased. The thickness and layers of cortex were similar in the first three orders. Few cortical cells were in fourth-order roots and almost none in fifth-order roots. There were higher mycorrhizae infections in the first three order roots than the last two orders, and the later had almost no fungi. Primary growth occurred in all first-and second-order roots, an secondary growth occurred in all fourth and fifth order roots. Some third-order roots had only primary growth, but some had secondary growth with inconsecutive phellogen. All results suggested that the ability of roots to absorb nutrients and water decreased but transport ability and longevity increased as root orders increased. According to the relation- ships among anatomical characteristics, diameters and root orders, the fine roots of P. amurense should be involved in the first three orders at most; these have passage cells but lack successive phellogen and have diameters less than 0.8 mm.

Anatomic Diameter Femoral Heads in Total Hip Arthroplasty: A Preliminary Report

The stability of total hip replacements has been directly related to the diameter of the femoral head in several studies; however, durability has necessitated the use of femoral heads with a relatively small diameter. Recent developments in metal-on-metal technology have allowed for the use of femoral head bearings that are anatomic in diameter. In this case series, we report on the early results of patients who were at greater risk for dislocation because of anatomic deficiencies or increased range-of-motion activities and underwent hip arthroplasty with implants that had articulating surfaces approaching anatomic dimensions. Thirty-four patients underwent forty total hip arthroplasties with use of a modular metal-on-metal articulation with an anatomic diameter femoral head and a press-fit stem. Thirty patients were active, and four patients were profoundly disabled and had bone or soft-tissue deficiencies that would increase the risk for dislocation. Dislocation precautions were maintained for six weeks, and patients were allowed extreme ranges of motion at three months. There were no dislocations. Active patients continued in extreme range-of-motion activities. Disabled patients improved but were limited by their comorbidities. Anatomic diameter femoral heads offer distinct theoretical advantages in total hip arthroplasty. These short-term results are encouraging, and further study of this new technology in a larger series with a longer follow-up period is warranted.

Influence of cervical preflaring on apical file size determination in maxillary lateral incisors

The purpose of this study was to investigate the influence of cervical preflaring on determination of the initial apical file in maxillary lateral incisors. Forty human lateral incisors with complete root formation were used. After standard access cavities, a size 06 K-file was inserted into each canal until the apical foramen was reached. The WL (WL) was set 1 mm short of the apical foramen. Four groups (n=10) were formed at random, according to the type of cervical preflaring performed. Group 1 received the initial apical instrument without previous preflaring of the cervical and middle root canal thirds. Group 2 had the cervical and middle root canal thirds enlarged with nickel-titanium Orifice Opener instruments. Group 3 had the cervical and middle root canal thirds enlarged with Gates-Glidden drills. Titanium-nitrite treated, stainless steel LA Axxess burs were used for preflaring the cervical and middle root canal thirds of group 4. Each canal was sized using manual K-files, starting with size 08 files with passive movements until the WL was reached. File sizes were increased until a binding sensation was felt at the WL, and the instrument size was recorded for each tooth. The apical region was then observed under a stereoscopic magnifier, images were recorded digitally and the differences between root canal and maximum file diameters were recorded (in mm) for each sample. Significant differences were found between the groups regarding the anatomical diameter at the WL and the first file to bind the canal (p = 0.01). The major discrepancy was found when no preflaring was performed (0.1882 mm average). Canals preflared with Orifice Opener instruments (0.0485 mm average) and Gates-Glidden drills (0.1074 mm average) also showed great discrepancy. The LA Axxess burs produced the smallest differences between anatomical diameter and first file to bind (0.0119 mm average). Instrument binding technique for determining anatomical diameter at WL was not accurate. Preflaring of the cervical and middle thirds of the root canal improved anatomical diameter determination; the instrument used for preflaring played a major role on determination of the anatomical diameter at the WL. Canals preflared with LA Axxess burs created a more accurate relationship between file size and anatomical diameter.