The Subtalar Angle: A Proposed Measure of Rearfoot Structure

1996 ◽  
Vol 17 (8) ◽  
pp. 499-502 ◽  
Author(s):  
Irene McClay ◽  
James Bray

The purpose of this study was to propose a new measure of rearfoot structure to further enhance the understanding of the function of the foot. Landmarks visible on sagittal plane radiographs were used to represent the approximate direction of the subtalar joint axis in the sagittal plane based upon descriptions from the literature of its orientation. Four landmarks were chosen, resulting in four calculated angles. One hundred lateral view radiographs were analyzed. The mean values ranged from 28.7° to 47.7°. These values are within the ranges reported from both cadaver and in vivo studies. Tests of repeatability of the measures resulted in intraclass coefficient values between 0.94 and 0.98, suggesting good reliability. All four angles correlated highly among each other ( r = 0.88–0.97). Examination of the validity of any one of these measures is left to those who are able to accurately calculate the orientation of the subtalar joint axis.

2017 ◽  
Vol 16 (1) ◽  
pp. 38-41
Author(s):  
MAURICIO COELHO LIMA ◽  
MARCELO ITALO RISSO NETO ◽  
GUILHERME REBECHI ZUIANI ◽  
IVAN GUIDOLIN VEIGA ◽  
MARCOS ANTONIO TEBET ◽  
...  

ABSTRACT Objective: There are no values defined as standard in the literature for the parameters of assessment of cervical sagittal balance in patients with idiopathic scoliosis. This study describes the sagittal cervical parameters in patients with idiopathic scoliosis. Methods: Study carried out in a tertiary public hospital in patients with adolescent idiopathic scoliosis, through the evaluation of panoramic radiographs in lateral view. The Cobb method was used to evaluate cervical lordosis from C2 to C7, distance from the center of gravity (COG) of the skull to C7, measurement of T1 slope, thoracic inlet angle (TIA), neck tilt, and plumb line from C7 to S1 (SVA C7-S1). A statistical analysis was performed, to demonstrate the relationship between the alignment of the thoracic spine in the sagittal plane and the cervical sagittal balance of patients with scoliosis. Results: Thirty-four patients were female (69.4%) and 15 male (30.6%). The mean values for COG-C7 were 0.71 mm (median 0.8 mm/standard deviation [SD]= 0.51 mm). For Cobb C2-C7, the mean was -11.7° (median -10°/SD= 20.4°). The mean slope of T1 was 23.5° (median 25°/SD= 9.5°). The mean cervical version was 58.8° (median 60°/DP= 15.4°). The mean TIA was 81.8° (median 85°/SD= 16.7°). The mean plumb line C7-S1 was -0.28 (-0.3/SD= 1.0). Conclusion: The analysis of the results showed that the mean values for the cervical lordosis are lower than the values described as normal in the literature, suggesting a loss of sagittal cervical balance in these patients.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Lena Dalal ◽  
Abdul Wahab Allaf ◽  
Hind El-Zein

AbstractSelf-nanoemulsifying drug delivery systems (SNEDDS) were used to enhance the dissolution rate of furosemide as a model for class IV drugs and the system was solidified into liquisolid tablets. SNEDDS of furosemide contained 10% Castor oil, 60% Cremophor EL, and 30% PEG 400. The mean droplets size was 17.9 ± 4.5 nm. The theoretical model was used to calculate the amounts of the carrier (Avicel PH101) and coating materials (Aerosil 200) to prepare liquisolid powder. Carrier/coating materials ratio of 5/1 was used and Ludipress was added to the solid system, thus tablets with hardness of 45 ± 2 N were obtained. Liquisolid tablets showed 2-folds increase in drug release as compared to the generic tablets after 60 min in HCl 0.1 N using USP apparatus-II. Furosemide loaded SNEDDS tablets have great prospects for further in vivo studies, and the theoretical model is useful for calculating the adequate amounts of adsorbents required to solidify these systems.


2021 ◽  
pp. 155633162199633
Author(s):  
Mehran Ashouri-Sanjani ◽  
Shima Mohammadi-Moghadam ◽  
Parisa Azimi ◽  
Navid Arjmand

Background: Pedicle screw (PS) placement has been widely used in fusion surgeries on the thoracic spine. Achieving cost-effective yet accurate placements through nonradiation techniques remains challenging. Questions/Purposes: Novel noncovering lock-mechanism bilateral vertebra-specific drill guides for PS placement were designed/fabricated, and their accuracy for both nondeformed and deformed thoracic spines was tested. Methods: One nondeformed and 1 severe scoliosis human thoracic spine underwent computed tomographic (CT) scanning, and 2 identical proportions of each were 3-dimensional (3D) printed. Pedicle-specific optimal (no perforation) drilling trajectories were determined on the CT images based on the entry point/orientation/diameter/length of each PS. Vertebra-specific templates were designed and 3D printed, assuring minimal yet firm contacts with the vertebrae through a noncovering lock mechanism. One model of each patient was drilled using the freehand and one using the template guides (96 pedicle drillings). Postoperative CT scans from the models with the inserted PSs were obtained and superimposed on the preoperative planned models to evaluate deviations of the PSs. Results: All templates fitted their corresponding vertebra during the simulated operations. As compared with the freehand approach, PS placement deviations from their preplanned positions were significantly reduced: for the nonscoliosis model, from 2.4 to 0.9 mm for the entry point, 5.0° to 3.3° for the transverse plane angle, 7.1° to 2.2° for the sagittal plane angle, and 8.5° to 4.1° for the 3D angle, improving the success rate from 71.7% to 93.5%. Conclusions: These guides are valuable, as the accurate PS trajectory could be customized preoperatively to match the patients’ unique anatomy. In vivo studies will be required to validate this approach.


2009 ◽  
Vol 53 (7) ◽  
pp. 2857-2864 ◽  
Author(s):  
Zheng Ma ◽  
Jiping Wang ◽  
Roger L. Nation ◽  
Jian Li ◽  
John D. Turnidge ◽  
...  

ABSTRACT Nephrotoxicity is an important limitation to the clinical use of colistin against Pseudomonas aeruginosa and other gram-negative pathogens. Previous work reported net tubular reabsorption of colistin by the kidney in vivo, but there is no knowledge of its disposition within the kidney. This study investigated the renal disposition and potential transport mechanisms of colistin in the isolated perfused rat kidney (IPK) model by perfusing with colistin sulfate alone (2 μg/ml) or in the presence of potential inhibitors (tetraethylammonium [TEA], glycine-glycine [Gly-Gly], or hydrochloric acid [HCl]) at three different concentrations. When perfused alone, the renal clearances (CLR) for colistin A and B (the major components of colistin) in control kidneys were constant and low (mean values < 0.05 ml/min throughout the perfusion). The mean clearance ratios [CR, defined as CLR/(f u × GFR), where f u is the fraction of drug unbound in perfusate and GFR is the glomerular filtration rate] were significantly less than 1. It was concluded that there is net tubular reabsorption of colistin, and this exceeded the reabsorption of water. Less than 10% eliminated from perfusate was recovered in urine, suggesting considerable renal accumulation of colistin. The CR values for colistin were significantly increased when perfused with TEA (500 μM), Gly-Gly (833 μM), and HCl (2,500, 5,000, and 10,000 μM). It is proposed that renal reabsorption of colistin may involve organic cation transporters (inhibited by TEA) and peptide transporters (inhibited by Gly-Gly) and that the process is sensitive to the pH of urine.


1963 ◽  
Vol 18 (4) ◽  
pp. 815-817 ◽  
Author(s):  
Earl S. Barker ◽  
Archer P. Crosley ◽  
John K. Clark

Renal respiratory quotient (RQ) has been calculated from data collected in unanesthetized human subjects. In contrast to RQ recently reported on anesthetized dogs, these data do not indicate a mean value greater than 1. Under control conditions in 24 subjects, renal RQ calculated without special corrections averaged 0.88. Correcting for differences in blood flow between renal artery and vein due to urine formation the mean was 0.73, with 95% confidence limits 0.49–0.97. With alkaline urines an additional correction for urinary excretion of CO2 is advised. Excluding procedures known to alkalinize the urine, RQ values were similar in 46 observations after a variety of experimental procedures. Since both numerator and denominator of the ratio involve small differences between large values, small analytical errors can produce large changes indistinguishable from physiologic variation. Therefore mean values rather than individual observations are stressed. While such values in our data appear similar to RQ for other organs and the whole body, they do not preclude considerable anaerobic metabolism. Submitted on August 9, 1962


2006 ◽  
Vol 24 (18_suppl) ◽  
pp. 9025-9025
Author(s):  
V. I. Avramis ◽  
E. H. Panosyan ◽  
I. A. Avramis ◽  
F. Dorey ◽  
P. Gaynon

9025 Background: ASNase is an important agent in the treatment of childhood acute lymphoblastic leukemia. Most other chemotherapeutic agents require entry into cells and some variety of activation. ASNase acts unmodulated and totally outside of cells, targeting extracellular ASN and glutamine. Several investigators have described a relationship between ASNase activity and ASN. In vivo, the equilibrium asparagine level depends on the input rate of ASN derived from the nutrients plus the de novo biosynthesis minus its deamination from the serum ASNase activity. Imax is a pharmacodynamic (PD) parameter developed in 1980’s representing the cumulative input of ASN from nutrients and de novo biosynthesis. Of note, glutamine is the amino group source for the synthesis of ASN from aspartate. In Enzyme-substrate relationships a sigmoid relationship exists that reaches a maximum product formation (Imax). We reported a link between Day 14 ASN depletion - not ASNase activity - and response for children with ALL in first marrow relapse (Jarrar et al, 2006). Methods: On CCG-1962, 117 children with standard risk ALL were randomly allocated to native or pegylated ASNase. Relevant PK-PD parameters have been reported (Avramis et al, Blood 2002). ASNase activity was not predictive of EFS. Induction (IND) Day 3 - 24 serum ASN levels were fitted into a PD model and the Imax values were evaluated for 112 patients. Results: The median Imax values were 1E-6 nmoles/ml/min in all 112 (range 2.0E-2 to 1.0E-7) and in the native or PEG-ASNase randomized patients. The mean values were 1.1E-3.1±3E-3 in 112 patients and 1.5E-3±4.0E-3 & 1.1E-3±3.0E-3 nmoles/ml/min in the native or PEG-ASNase randomized patients. We examined EFS by Imax values in lifetable analyses. High Imax values predicted statistically poorer outcome (p<0.00001) with various cut-off values (e.g., Imax ≥1x 10−3 or Imax ≥5 × 10−4 nmoles/ml/min. The effect was similar in the native and pegylated ASNase subsets. ASNase activity was not prognostic. Conclusions: Hence, ASN Imax in serum is a treatment-independent PD prognostic factor in a subset of children with standard risk ALL. Strategies to provide uniform therapeutic effect among patients with differing Imax are under consideration. No significant financial relationships to disclose.


2011 ◽  
Vol 62 (3) ◽  
pp. 183-189 ◽  
Author(s):  
Kristina A. Szabo ◽  
Colin E. Webber ◽  
Christopher Gordon ◽  
Jonathan D. Adachi ◽  
Richard Tozer ◽  
...  

Purpose The objectives of this study were to utilise the XCT-2000 pQCT scanner to determine the mean values and the reproducibility of in vivo total, trabecular, and cortical volumetric bone measurements at distal and diaphyseal sites of the radius and the tibia, as well as calf muscle and subcutaneous fat areas, in healthy pre- and postmenopausal women. Methods Twenty-nine women (14 premenopausal and 15 postmenopausal) were recruited to participate in this study. Distal and diaphyseal sites of the radius (at 4% and 20% of the length of the radius) and tibia (at 4%, 38%, and 66% of the length of the tibia) were examined. Results The root mean square coefficient of variation for measurements at the distal tibia gave the most favorable reproducibility values for total (1.5%) and trabecular (1.6%) density, whereas the diaphyseal tibia showed the most favorable reproducibility value for cortical density (0.3%). The root mean square coefficients of variation for measurements of muscle and fat cross-sectional areas at the calf were 0.6% and 0.7%, respectively. At the distal tibia, the mean values for total ( P < .05) and trabecular ( P < .01) density were significantly lower in postmenopausal women than in premenopausal women. Conclusions The data presented here indicate that XCT-2000 pQCT scans at the tibia provide highly reproducible measurements of total, cortical, and trabecular bone as well as muscle and fat cross-sectional areas. Furthermore, significant differences in volumetric bone measurements between healthy pre- and postmenopausal women were evident only at the distal tibia, suggesting that this site warrants further study.


1984 ◽  
Vol 105 (2) ◽  
pp. 194-199 ◽  
Author(s):  
Jean-Noel Hugues ◽  
Albert G. Burger ◽  
A. Eugene Pekary ◽  
Jerome M. Hershman

Abstract. Nutrition influences thyroid function at the level of TSH secretion, at the level of monodeiodination, and possibly elsewhere. In order to study the effect of starvation on TSH secretion, 8 healthy male volunteers fasted for 30 h and were then refed with 800 kcal. Refeeding was performed at 19.00 h and blood was sampled at 20 min intervals until midnight. Control experiments were performed in the same subjects both when they were normally fed and when the starvation period was prolonged a further 5 h until midnight. Starvation decreased serum TSH levels to below 1 mU/l, and without refeeding the nocturnal peak of the TSH nycthemeral rhythm was abolished. With refeeding serum TSH tended to increase towards midnight and was significantly higher than during starvation. However, the serum TSH levels remained significantly below those at the same time of the day in the absence of a preceding starvation period. Serum T3 levels were significantly lower than in the fed state. The mean values were 1.84 ± 0.03 vs 2.30 ± 0.06 nmol/l (120 ±2 vs 150 ± 4 ng/100 ml, mean ± sem P < 0.01). Refeeding did not result in a measurable change in serum T3 concentration (1.80 ± 0.05 nmol/l; 120 ± 3 ng/100 ml, mean ± sem, n.s.). The contrary was true for rT3 levels which increased in starvation and tended to fall with refeeding, but this decrease was not significant. As glucocorticoids have been implicated in the control of monodeiodination and TSH secretion, serum cortisol levels were also measured. They did not differ during the 3 experimental periods. The results show that short-term starvation and refeeding may be a valuable tool for studying in vivo control of TSH secretion. The results show that short-term starvation and refeeding may be a valuable tool for studying in vivo control of TSH secretion.


2015 ◽  
Vol 4 (1) ◽  
Author(s):  
Timothy C. Zhu ◽  
Michele M. Kim ◽  
Xing Liang ◽  
Jarod C. Finlay ◽  
Theresa M. Busch

AbstractObjective:Dosimetry of singlet oxygen (Material and methods:AnResults:The mean values (standard deviation) of theConclusions:The experimental results of [


1983 ◽  
Vol 100 (1) ◽  
pp. 127-131 ◽  
Author(s):  
P. D. Penning ◽  
R. H. Johnson

SUMMARYConcentrations of potentially indigestible cellulose (PIC) and acid insoluble ash (AIA) were determined in samples of feed and faeces in a study to determine their value as internal markers. PIC and AIA were then used to predict the organic-matter digestibilities (OMD) of samples of perennial ryegrass (Lolium perenne) and lucerne (Medicago sativa)of known OMD which had been determined using wether sheep. The mean values for OMD (%) measured in vivo were 67·2 and 62·8 for ryegrass and 58·0 and 55·8 for lucerne at intakes of 15 and 25 g D.M./kg live weight, respectively.The in vitro digestibility technique, using rumen liquor, gave OMD values of 69·5 and 57·4 for ryegrass and lucerne which are in close agreement with the in vivo values at the lower level of intake.The mean differences between OMD measured in vivo and that estimated using PIC were: -1·1 (± 0·65) and -1·6 (± 0·46) percentage units for ryegrass and lucerne respectively, and using AIA were: -1·4 (± 0·57) and -3·5 (± 1·61).For the two feeds tested, OMD was predicted more precisely by PIC than by AIA or the in vitro digestibility technique. However, the PIC technique required the use of rumen-fistulated animals and 10 days to digest samples of faeces; this may make the technique impractical if large numbers of determinations of PIC are required.


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