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Cui X, Jee K, Hu M, Bao J, Lu HM. Improvement of proton beam range uncertainty in breast treatment using tissue samples. Phys Med Biol 2022; 67. [PMID: 36379067 DOI: 10.1088/1361-6560/aca315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 11/15/2022] [Indexed: 11/16/2022]
Abstract
Objective.Proton therapy after breast-conserving surgery (BCS) can substantially reduce the dose to lung and cardiac structures. However, these dosimetric benefits are subject to beam range uncertainty in patient. The conversion of the CT-Hounsfield unit (HU) into relative stopping power (RSP) is the primary contribution to range uncertainty. Hence, an accurate HU-RSP conversion is essential.Approach.Real tissue samples, including muscle and adipose, were prepared. The water equivalent path length (WEPL) of these samples was measured under homogeneous conditions using a 12-diode detector array of our time-resolvedin vivorange verification system (IRVS). The HU-RSP conversion was improved using the measured WEPL and HU for adipose tissue. The measured WEPL values were compared with the treatment planning calculation results based on the stoichiometric CT-HU calibration technique. The effect was investigated for both with and without adipose tissue in HU-RSP conversion.Main results.The IRVS was calibrated based on the solid water phantom. The relative differences in WEPL (RSP) between measurements and calculations for muscle, adipose, and water was -1.19% (-0.75%), -4.25%(-4%), and -0.23%(-0.07%), respectively. Based on the improved HU-RSP conversion, the relative differences in WEPL was reduced to -0.97%(-0.62%), -1.50%(-1.46%), and -0.22% (0.00%), respectively.Significance.The WEPL deviation of adipose tissue is larger than the testing limit of 3.5% for beam range robustness in current clinical practice. However, the improved HU-RSP conversion reduced this deviation. The main component of breast tissue is adipose. Hence, the proton treatment of BCS can be undershooting if no proper measures are taken against this specific uncertainty.
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Affiliation(s)
- Xiangli Cui
- Institute of Health and Medical Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, Anhui, 230031, People's Republic of China.,Hefei Cancer Hospital, Chinese Academy of Sciences, Hefei, Anhui, 230031, People's Republic of China
| | - Kyungwook Jee
- Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02114, United States of America
| | - Man Hu
- Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong, 250117, People's Republic of China
| | - Jie Bao
- Institute of Health and Medical Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, Anhui, 230031, People's Republic of China
| | - Hsiao-Ming Lu
- Hefei Ion Medical Center, Hefei, Anhui, 230088, People's Republic of China
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Dedes G, Drosten H, Götz S, Dickmann J, Sarosiek C, Pankuch M, Krah N, Rit S, Bashkirov V, Schulte RW, Johnson RP, Parodi K, DeJongh E, Landry G. Comparative accuracy and resolution assessment of two prototype proton computed tomography scanners. Med Phys 2022; 49:4671-4681. [PMID: 35396739 DOI: 10.1002/mp.15657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 02/14/2022] [Accepted: 03/07/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Improving the accuracy of relative stopping power (RSP) in proton therapy may allow reducing range margins. Proton computed tomography (pCT) has been shown to provide state-of-the-art RSP accuracy estimation, and various scanner prototypes have recently been built. The different approaches used in scanner design are expected to impact spatial resolution and RSP accuracy. PURPOSE The goal of this study was to perform the first direct comparison, in terms of spatial resolution and RSP accuracy, of two pCT prototype scanners installed at the same facility and by using the same image reconstruction algorithm. METHODS A phantom containing cylindrical inserts of known RSP was scanned at the phase-II pCT prototype of the U.S. pCT collaboration and at the commercially oriented ProtonVDA scanner. Following distance-driven binning filtered backprojection reconstruction, the radial edge spread function of high-density inserts was used to estimate the spatial resolution. RSP accuracy was evaluated by the mean absolute percent error (MAPE) over the inserts. No direct imaging dose estimation was possible, which prevented a comparison of the two scanners in terms of RSP noise. RESULTS In terms of RSP accuracy, both scanners achieved the same MAPE of 0.72% when excluding the porous sinus insert from the evaluation. The ProtonVDA scanner reached a better overall MAPE when all inserts and the body of the phantom were accounted for (0.81%), compared to the phase-II scanner (1.14%). The spatial resolution with the phase-II scanner was found to be 0.61 lp/mm, while for the ProtonVDA scanner somewhat lower at 0.46 lp/mm. CONCLUSIONS The comparison between two prototype pCT scanners operated in the same clinical facility showed that they both fulfill the requirement of an RSP accuracy of about 1%. Their spatial resolution performance reflects the different design choices of either a scanner with full tracking capabilities (phase-II) or of a more compact tracker system which only provides the positions of protons but not their directions (ProtonVDA). This article is protected by copyright. All rights reserved.
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Affiliation(s)
- G Dedes
- Department of Medical Physics, Faculty of Physics, Ludwig-Maximilians-Universität München, Am Coulombwall 1, Garching b. München, 85748, Germany
| | - H Drosten
- Department of Medical Physics, Faculty of Physics, Ludwig-Maximilians-Universität München, Am Coulombwall 1, Garching b. München, 85748, Germany
| | - S Götz
- Department of Medical Physics, Faculty of Physics, Ludwig-Maximilians-Universität München, Am Coulombwall 1, Garching b. München, 85748, Germany
| | - J Dickmann
- Department of Medical Physics, Faculty of Physics, Ludwig-Maximilians-Universität München, Am Coulombwall 1, Garching b. München, 85748, Germany
| | - C Sarosiek
- Department of Physics, Northern Illinois University, 1425 W. Lincoln Highway DeKalb, Illinois, IL, 60115, United States of America
| | - M Pankuch
- Northwestern Medicine Chicago Proton Center, 4455 Weaver Parkway, Warrenville, Illinois, IL, 60555, United States of America
| | - N Krah
- University of Lyon, INSA-Lyon, Université Claude Bernard Lyon 1, UJM-Saint Etienne, CNRS, Inserm, CREATIS UMR 5220, U1294, LYON, F-69373, France
| | - S Rit
- University of Lyon, INSA-Lyon, Université Claude Bernard Lyon 1, UJM-Saint Etienne, CNRS, Inserm, CREATIS UMR 5220, U1294, LYON, F-69373, France
| | - V Bashkirov
- Division of Biomedical Engineering Sciences, Loma Linda University, Loma Linda, California, CA 92354, United States of America
| | - R W Schulte
- Division of Biomedical Engineering Sciences, Loma Linda University, Loma Linda, California, CA 92354, United States of America
| | - R P Johnson
- Department of Physics, U.C. Santa Cruz, 1156 High Street Santa Cruz, California, CA, 95064, United States of America
| | - K Parodi
- Department of Medical Physics, Faculty of Physics, Ludwig-Maximilians-Universität München, Am Coulombwall 1, Garching b. München, 85748, Germany
| | - E DeJongh
- ProtonVDA LLC, 1700 Park Street STE 208, Naperville, Illinois, IL, 60563, United States of America
| | - G Landry
- Department of Medical Physics, Faculty of Physics, Ludwig-Maximilians-Universität München, Am Coulombwall 1, Garching b. München, 85748, Germany.,Department of Radiation Oncology, University Hospital, LMU Munich, Munich, 81377, Germany.,German Cancer Consortium (DKTK), Munich, 81377, Germany
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Torén K, Schiöler L, Brisman J, Malinovschi A, Olin AC, Bergström G, Bake B. Restrictive spirometric pattern and true pulmonary restriction in a general population sample aged 50 - 64 years. BMC Pulm Med 2020; 20:55. [PMID: 32106839 DOI: 10.1186/s12890-020-1096-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Accepted: 02/19/2020] [Indexed: 11/10/2022] Open
Abstract
Background There is low diagnostic accuracy of the proxy restrictive spirometric pattern (RSP) to identify true pulmonary restriction. This knowledge is based on patients referred for spirometry and total lung volume determination by plethysmograpy, single breath nitrogen washout technique or gas dilution and selected controls. There is, however, a lack of data from general populations analyzing whether RSP is a valid proxy for true pulmonary restriction. We have validated RSP in relation to true pulmonary restriction in a general population where we have access to measurements of total lung capacity (TLC) and spirometry. Methods The data was from the Swedish CArdioPulmonary bioImage Study (SCAPIS Pilot), a general population-based study, comprising 983 adults aged 50–64. All subjects answered a respiratory questionnaire. Forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) were obtained before and after bronchodilation. TLC and residual volume (RV) was recorded using a body plethysmograph. All lung function values are generally expressed as percent predicted (% predicted) or in relation to lower limits of normal (LLN). True pulmonary restriction was defined as TLC < LLN5 defined as a Z score < − 1.645, i e the fifth percentile. RSP was defined as FEV1/FVC ≥ LLN and FVC < LLN after bronchodilation. Specificity, sensitivity, positive and negative likelihood ratios were calculated, and 95% confidence intervals (CIs) were calculated. Results The prevalence of true pulmonary restriction was 5.4%, and the prevalence of RSP was 3.4%. The sensitivity of RSP to identify true pulmonary restriction was 0.34 (0.20–0.46), the corresponding specificity was 0.98 (0.97–0.99), and the positive likelihood ratio was 21.1 (11.3–39.4) and the negative likelihood ratio was 0.67 (0.55–0.81). Conclusions RSP has low accuracy for identifying true pulmonary restriction. The results support previous observations that RSP is useful for ruling out true pulmonary restriction.
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Secco S, Galfano A, Barbieri M, Piccinelli M, Di Trapani D, Napoli G, Strada E, Petralia G, Bocciardi AM. Technical features and the demonstrated advantages of the Retzius sparing robotic prostatectomy. ARCH ESP UROL 2019; 72:247-256. [PMID: 30945651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
OBJECTIVE Robot-assisted laparoscopic radical prostatectomy (RARP) is nowadays considered the main surgical option for localized prostate cancer (PCa). We recently developed a new approach for RARP avoiding all the Retzius structures involved in continence and potency preservation, the so called Retzius-sparing technique (RSP). The objective of the paper is to report technical aspects and functional results of RSP. METHODS: We evaluated our data and available literature regarding RSP, functional results and advantages. RESULTS: RSP is oncologically safe and guarantee high early continence rates. CONCLUSION Long-term, prospective, comparative, and possibly randomized studies are needed but RSP is now spreading all over the world thanks to the different advantages that offers to patients. The most recognized benefit is surely the achievement of early continence, as well documented in multiple studies and papers, without compromising the oncological outcomes.
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Affiliation(s)
- Silvia Secco
- Department of Urology. ASST Grande Ospedale Metropolitano Niguarda. Milan. Italy
| | - Antonio Galfano
- Department of Urology. ASST Grande Ospedale Metropolitano Niguarda. Milan. Italy
| | - Michele Barbieri
- Department of Urology. ASST Grande Ospedale Metropolitano Niguarda. Milan. Italy
| | - Mattia Piccinelli
- Department of Urology. ASST Grande Ospedale Metropolitano Niguarda. Milan. Italy
| | - Dario Di Trapani
- Department of Urology. ASST Grande Ospedale Metropolitano Niguarda. Milan. Italy
| | - Giancarlo Napoli
- Department of Urology. ASST Grande Ospedale Metropolitano Niguarda. Milan. Italy
| | - Elena Strada
- Department of Urology. ASST Grande Ospedale Metropolitano Niguarda. Milan. Italy
| | - Giovanni Petralia
- Department of Urology. ASST Grande Ospedale Metropolitano Niguarda. Milan. Italy
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Lin CQ, Hu GR, Yu RL, Han L. [Speciation and Ecological Risk of Heavy Metals in Surface Sediments from Jiulong River]. Huan Jing Ke Xue 2017; 38:1002-1009. [PMID: 29965570 DOI: 10.13227/j.hjkx.201607087] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Speciation characteristics of fifteen heavy metals in seventeen surface sediments from Jiulong River was analyzed using the modified BCR protocol and dilute HNO3 method, respectively. The results of the modified BCR protocol showed that most of the elements (Fe, Ni, V, Tl, Ba, Sb, Ga, Cr and Sr) existed mainly in residual fractions, and extractable fraction was dominant for Mn (83.8%), followed by Cd, Pb, Zn, Co and Cu (80.0%, 75.5%, 74.3%, 70.8% and 57.7%). The results of dilute HNO3 method showed that the proportions of the dilute HNO3-extractable fractions of Pb, Mn, Cd, Co, Zn and Cu were higher (70.4%, 65.4%, 58.7%, 48.4%, 44.5% and 45.5%). The assessment results of RSP (ratio of secondary phase to primary phase) indicated that Pb, Mn, Cd, Co, Zn and Cu in surface sediments of Jiulong River had higher ecological risks. Both extraction methods had merits and demerits respectively. In general, the dilute HNO3 method is enough to analyze the bioavailability and ecological risk of heavy metals in sediments.
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Affiliation(s)
- Cheng-Qi Lin
- College of Chemical Engineering, Huaqiao University, Xiamen 361021, China
| | - Gong-Ren Hu
- College of Chemical Engineering, Huaqiao University, Xiamen 361021, China.,State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China
| | - Rui-Lian Yu
- College of Chemical Engineering, Huaqiao University, Xiamen 361021, China
| | - Lu Han
- College of Chemical Engineering, Huaqiao University, Xiamen 361021, China
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Mendoza A, López de Alda M, González-Alonso S, Mastroianni N, Barceló D, Valcárcel Y. Occurrence of drugs of abuse and benzodiazepines in river waters from the Madrid Region (Central Spain). Chemosphere 2014; 95:247-255. [PMID: 24083902 DOI: 10.1016/j.chemosphere.2013.08.085] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Revised: 08/22/2013] [Accepted: 08/31/2013] [Indexed: 06/02/2023]
Abstract
This work investigates, for the first time, the occurrence of 10 drugs of abuse, six metabolites, and three benzodiazepines in surface waters from the Jarama and Manzanares Rivers in the Madrid Region, the most densely populated area in Spain and one of the most densely populated in Europe. The results of this study have shown the presence of 14 out of the 19 compounds analyzed at concentrations ranging from 1.45 to 1020 ng L(-1). The most ubiquitous compounds, found in 100% of the samples, were the cocaine metabolite benzoylecgonine (BE), the amphetamine-like compound ephedrine (EPH), the opioids morphine (MOR), methadone (METH), and the METH metabolite 2-ethylene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP), and the three investigated benzodiazepines alprazolam (ALP), diazepam (DIA) and lorazepam (LOR). Meanwhile, the largest concentrations observed corresponded to EPH (up to 1020 ng L(-1)), BE (823 ng L(-1)), EDDP (151 ng L(-1)), and LOR (167 ng L(-1)). The only not detected compounds were heroin (HER) and its metabolite 6-acetylmorphine (6ACM), lysergic acid diethylamide (LSD) and its metabolite 2-oxo-3-hydroxy-LSD (OH-LSD), and Δ(9)-tetrahydrocannabinol (THC). Overall, the levels measured are comparatively higher than those previously reported in Europe. Comparison of the results obtained for samples collected on different days (Thursday and Sunday) did not show meaningful differences between weekdays and weekends. The lack of (eco)toxicological data does not permit to predict or disregard potential adverse effects on wildlife. Risk assessment in humans would require further knowledge, not currently available, on exposure to these compounds through other routes like drinking water and/or food.
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Affiliation(s)
- A Mendoza
- Research Group in Public Health and Toxicology (ToxAmb), Department of Preventive Medicine, Public Health, Immunology and Medical Microbiology, Faculty of Health Sciences, Rey Juan Carlos University, Avda. Atenas, s/n, E-28922 Alcorcón, Madrid, Spain.
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Esteban S, Gorga M, Petrovic M, González-Alonso S, Barceló D, Valcárcel Y. Analysis and occurrence of endocrine-disrupting compounds and estrogenic activity in the surface waters of Central Spain. Sci Total Environ 2014; 466-467:939-51. [PMID: 23978587 DOI: 10.1016/j.scitotenv.2013.07.101] [Citation(s) in RCA: 120] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Revised: 07/01/2013] [Accepted: 07/22/2013] [Indexed: 05/05/2023]
Abstract
Endocrine-disrupting compounds (EDCs) are chemical compounds with the ability to alter the hormonal systems of organisms. Such compounds are used in several industrial and domestic activities and reach the aquatic environment via wastewater discharge. The aim of this study is to assess the occurrence of 30 EDCs and related compounds in the surface waters of central Spain and to determine the overall estrogenic activity of environmental samples. This study analyzed a large number of EDCs and other emergent or suspected compounds with endocrine-disrupting activity. The results have shown the presence of 19 EDCs at concentrations ranging from 2 to 5928 ng L(-1). Organophosphorus-based flame retardants, alkylphenolic compounds and anticorrosives were found at the highest concentrations. Furthermore, although insufficient data are available to calculate an average over time, these preliminary results show the need to monitor the waters in both rivers studied. Alkylphenolic compounds, particularly nonylphenol, were the main contributors to overall estrogenicity. A higher concentration of the compounds studied was detected in the river Jarama, although the estrogenicity expressed as estradiol equivalents (EEQs) was higher in the river Manzanares due to a higher concentration of nonylphenol. However, the total estrogenicity did not exceed 1 ng L(-1) (EEQ), which is the level that may cause estrogenic effects in aquatic organisms, in any of the samples. In conclusion, the potential estrogenic risk in both rivers is low, although organophosphorus-based flame retardants may increase this risk as they were found at high levels in all samples. Unfortunately, these compounds could not be taken into account when calculating the estrogenic activity due to the lack of activity data for them. For future investigations, it will be important to assess the estrogenicity provided by these flame retardants. Due to the significant concentrations of EDCs detected in both rivers, further studies in this region are required.
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Affiliation(s)
- S Esteban
- Deparment of Preventive Medicine, Public Health, Inmunology and Medical Microbiology, Faculty of Health Sciences, Rey Juan Carlos University, Avda. Atenas, s/n. 28922 Alcorcón, Madrid, Spain
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Torres B, Ruoho AE. N-terminus regulation of VMAT2 mediates methamphetamine-stimulated efflux. Neuroscience 2013; 259:194-202. [PMID: 24321511 DOI: 10.1016/j.neuroscience.2013.11.059] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Revised: 10/28/2013] [Accepted: 11/28/2013] [Indexed: 10/25/2022]
Abstract
The 20 amino acid (AA) N-terminus of the vesicular monoamine transporter 2 (VMAT2) was examined as a regulator of VMAT2 function. Removal of the first 16 or 19 AAs of the N-terminus resulted in a molecule with reduced ability to sequester [(3)H]-5HT. A glutathione-S-transferase-construct of the N-terminus underwent phosphorylation in the presence of PKC at serines 15 and 18. These putative phosphorylation sites were examined for effects on function. Phospho-mimetic substitution of serines 15 and 18 with aspartate in the full-length VMAT2 resulted in reduced [(3)H]-5HT sequestration and reduced methamphetamine (METH)-stimulated efflux of preloaded [(3)H]-5HT. In contrast, mutation of serines 15 and 18 to alanines maintained intact net substrate sequestration but eliminated METH-stimulated efflux of pre-accumulated [(3)H]-5HT. In summary, these data suggest a model in which the VMAT2 N-terminus regulates monoamine sequestration.
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Affiliation(s)
- B Torres
- University of Wisconsin, Madison, Department of Neuroscience, 1300 University Avenue, Madison, WI 53706, USA
| | - A E Ruoho
- University of Wisconsin, Madison, Department of Neuroscience, 1300 University Avenue, Madison, WI 53706, USA.
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Petronijevic N, Sopta J, Doknic M, Radonjic N, Petronijevic M, Pekic S, Maric N, Jasovic-Gasic M, Popovic V. Chronic risperidone exposure does not show any evidence of bone mass deterioration in animal model of schizophrenia. Prog Neuropsychopharmacol Biol Psychiatry 2013; 46:58-63. [PMID: 23811489 DOI: 10.1016/j.pnpbp.2013.05.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Revised: 05/27/2013] [Accepted: 05/29/2013] [Indexed: 11/26/2022]
Abstract
BACKGROUND It has been shown that bone mass is centrally regulated. Thus schizophrenia being a disease of the central nervous system is an interesting model for studying bone. Most second generation antipsychotic drugs including risperidone are used in the treatment of schizophrenia. Weight gain and metabolic disturbances are common side effects. OBJECTIVE The aims of this study were to investigate bone mass, body composition and light microscopic pathology examinations of femur in an animal model of schizophrenia (pharmacologically induced by postnatally administered phencyclidine-PCP) and to further examine the effects of chronic treatment with risperidone on these parameters in rats. METHODS Four groups of male rats were studied:1) control group-NaCl postnatally administered, n=9; 2) PCP group-postnatal PCP administration to rat pups (on day 2,6,9 and 12), n=6; 3) risperidone group-rats treated with risperidone alone for 9weeks from day 35 (NaCl-RSP group, n=7); 4) PCP rats treated with risperidone for 9weeks from day 35 (PCP-RSP group, n=7). Bone mass and body composition were measured in vivo by dual X ray absorptiometry (areal DXA and fat mass). Light microscopic analysis of the femoral metaphysis was performed in all groups after sacrificing the animals. RESULTS Postnatal phencyclidine (PCP) administration to rat pups caused a long lasting reduction of total bone mass versus control animals (aDXA 128±2mg/cm(2) vs 139±5mg/cm(2), p<0.05). Examination of the femoral bone revealed a decrease in the number and thickness of the metaphyseal trabecule and cortical thinning. There was a decrease in total and retroperitoneal fat. Nine weeks of administration of risperidone alone to rats, resulted in significant weight gain and had no effect on bone mass versus control animals (aDXA was 136±7mg/cm(2) vs 139±5mg/cm(2), p>0.05). Furthermore, there were no changes in the light microscopic analysis of femoral metaphysis in comparison with controls. When PCP rats were treated with risperidone, they did not change their body weight nor bone mass versus PCP alone (aDXA 126±2mg/cm(2) vs 128±2mg/cm(2), p>0.05) but intriguingly on examination of the femoral bone an increase in the number and thickness of the metaphyseal trabecule was found (trabecular thickness 0.6±0.1μm vs 0.35±0.1μm, p<0.01). CONCLUSION This study shows that in the PCP rat model of schizophrenia bone mass is reduced. When PCP rats were treated with risperidone bone mass remained unchanged but intriguingly and unexpectedly light microscopic examination of femoral metaphysis showed an increase in thickness of metaphyseal trabeculae. The mechanism of risperidone's action on bone remains to be clarified.
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Affiliation(s)
- Natasa Petronijevic
- Institute of Biochemistry, University of Belgrade, Serbia; School of Medicine, University of Belgrade, Serbia
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Baum BS, Schultz MP, Tian A, Shefter B, Wolf EJ, Kwon HJ, Shim JK. Amputee locomotion: determining the inertial properties of running-specific prostheses. Arch Phys Med Rehabil 2013; 94:1776-83. [PMID: 23542403 DOI: 10.1016/j.apmr.2013.03.010] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2012] [Revised: 02/21/2013] [Accepted: 03/13/2013] [Indexed: 12/01/2022]
Abstract
OBJECTIVES (1) To test the validity of a trifilar pendulum in estimating moments of inertia (MOIs) for running-specific prostheses (RSPs), (2) to measure inertial properties (mass, center of mass [CM] position, and MOIs) for 4 RSPs, (3) to verify the influence of the stiffness on the inertial properties of RSPs, and (4) to develop a predictive equation to estimate RSP CM positions. DESIGN An aluminum block with known MOIs was used for verifying the accuracy of the trifilar pendulum MOI measurements. MOI errors were investigated by systematically misaligning the block and pendulum principal axes across a range of 1 to 10cm. Mass, CM position, and MOI were tested across 4 RSP designs with 3 stiffness categories each. SETTING University biomechanics laboratory. SPECIMENS Four different RSP designs and 3 stiffness categories per design were examined. INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES MOI errors from known values and principal axis misalignments between RSPs and pendulum; mass, CM positions, and RSP principal axis MOIs; and predictive equation CM position errors. RESULTS The trifilar pendulum estimated MOIs within -6.21×10(-5)kg/m(2) (≤1% error) for a block with known MOIs. Misalignments of 1 to 5cm between the RSPs' and pendulum's CM yielded errors from .00002 to .00113 kg/m(2) (0.3%-59.2%). Each RSP's inertial properties are presented. MOIs about any axis varied <.004kg/m(2) across stiffness categories; MOIs differed up to .013kg/m(2) between different designs. The predictive CM equation erred between .010 and .028m when using average input values across an RSP design. CONCLUSIONS Trifilar pendulums can accurately measure RSP MOI. The RSP inertial properties differed slightly across stiffness categories within each design, but differed more substantially across different RSP designs. Using a predictive equation to estimate RSP CM positions can provide adequate data, but directly measuring CM positions is preferable.
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Affiliation(s)
- Brian S Baum
- Department of Kinesiology, University of Maryland, College Park, MD 20742, USA
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