Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 9 de 9
Filter
Add more filters










Database
Language
Publication year range
1.
Brachytherapy ; 18(5): 658-667, 2019.
Article in English | MEDLINE | ID: mdl-31235445

ABSTRACT

PURPOSE: To develop a treatment planning platform for episcleral Collaborative Ocular Melanoma Study plaque therapy in an established treatment planning software and to improve an existing quality assurance (QA) process for nonuniformly loaded plaques that measures air kerma strengths (AKSs) and loading profile. MATERIALS AND METHODS: Treatment planning is performed in Pinnacle using scripts that let the planner choose plaque size and notching. Scripts load seed positions for each plaque and five source groups corresponding to available stock seeds that can be placed into each seed position. Contours are loaded that display the model eye and the plaque itself. Plaque QA is performed using a modification of our previous pinhole apparatus by replacing x-ray film exposure with an optical camera and scintillating film system. The captured image is processed to remove background and to correct the intensity of seeds on the plaque periphery. Measured total optical counts provide an estimate of total plaque AKS. RESULTS: Treatment planning of eye plaques using Pinnacle, in conjunction with our stock inventory of seeds, is established as standard practice at our center. Planned plaques can vary from uniformly loaded to asymmetrically loaded notched plaques. Using the optical camera system for assessment of the seed loadings has decreased QA time from 40 min/plaque to 10 min/plaque. Total AKS of each plaque can be measured using the optical camera with an accuracy of 10%. CONCLUSIONS: Treatment planning is performed on a Health Canada-approved software that accommodates nonuniform plaque loading. Optical imaging of the plaque provides absolute total AKS and the relative seed arrangement in the plaque.


Subject(s)
Brachytherapy/methods , Eye Neoplasms/radiotherapy , Melanoma/radiotherapy , Radiotherapy Planning, Computer-Assisted/methods , Brachytherapy/instrumentation , Brachytherapy/standards , Canada , Eye Neoplasms/diagnostic imaging , Humans , Image Processing, Computer-Assisted/methods , Melanoma/diagnostic imaging , Optical Imaging/methods , Quality Assurance, Health Care , Radiotherapy Dosage , Software
2.
Science ; 362(6421): 1391-1395, 2018 12 21.
Article in English | MEDLINE | ID: mdl-30442767

ABSTRACT

Magnetic reconnection is an energy conversion process that occurs in many astrophysical contexts including Earth's magnetosphere, where the process can be investigated in situ by spacecraft. On 11 July 2017, the four Magnetospheric Multiscale spacecraft encountered a reconnection site in Earth's magnetotail, where reconnection involves symmetric inflow conditions. The electron-scale plasma measurements revealed (i) super-Alfvénic electron jets reaching 15,000 kilometers per second; (ii) electron meandering motion and acceleration by the electric field, producing multiple crescent-shaped structures in the velocity distributions; and (iii) the spatial dimensions of the electron diffusion region with an aspect ratio of 0.1 to 0.2, consistent with fast reconnection. The well-structured multiple layers of electron populations indicate that the dominant electron dynamics are mostly laminar, despite the presence of turbulence near the reconnection site.

3.
Ann R Coll Surg Engl ; 98(3): e37-9, 2016 Mar.
Article in English | MEDLINE | ID: mdl-26890846

ABSTRACT

INTRODUCTION: A clear cell sarcoma-like gastrointestinal tumour (CCSLGT) is a rare malignant soft tissue sarcoma. In the literature, they are sometimes referred to as malignant gastrointestinal neuroectodermal tumours, clear cell sarcomas or osteoclast rich tumours of the gastrointestinal tract. CASE HISTORY: We present a case of a CCSLGT arising from the ascending colon of a previously well 22-year-old man presenting with abdominal pain and anaemia. Computed tomography of the abdomen and pelvis showed a 7 cm irregular mass in the right flank that seemed to emerge from the proximal transverse colon. A laparoscopic right hemicolectomy was undertaken to remove the mass. Microscopic pathological examination of the specimen revealed sections of spindle to oval cells with monomorphic nuclei and scant cytoplasm. The cells were arranged in a striking perivascular growth pattern with microcytic breakdown and pseudopapillary formation. Immunohistochemistry analysis showed that the tumour cells removed expressed S100 protein, and were negative for smooth muscle actin, desmin, CD34, CD117, DOG1, HMB-45 and MNF116. Additionally, cytogenetic testing identified EWSR1 gene rearrangement, which was observed by interphase fluorescence in situ hybridisation. CONCLUSIONS: A complex tumour, a CCSLGT can be thought of in simple terms as a gastrointestinal tract tumour that is S100 protein positive, osteoclast rich, HMB-45 negative and compromises a t(12;22)(q13;q12) gene translocation. These simplified CCSLGT characteristics seem to be described and classified under different aliases in the literature, which makes it difficult to accurately predict the appropriate diagnostic and therapeutic modality required to provide the best clinical care. Given that this case report describes the fourth CCSLGT of primary colonic origins, it may aid future targeted therapies as well as offering epidemiological evidence on prevalence and prognosis.


Subject(s)
Colonic Neoplasms , Sarcoma, Clear Cell , Adult , Colon, Ascending/chemistry , Colon, Ascending/pathology , Humans , Immunohistochemistry , Male , Osteoclasts , S100 Proteins , Young Adult
4.
Pharmazie ; 70(3): 177-82, 2015 Mar.
Article in English | MEDLINE | ID: mdl-25980178

ABSTRACT

In this work, starch acetate and propanoate derivatives with moderate degree of substitution were synthesized and characterized for employment as matrix formers for sustained release from tablets. Matrix tablets were prepared from cospray-dried and simple physical mixtures of starch/starch derivatives and theophylline as a model drug. The release was rapid for matrix tablets prepared from simple physical mixtures. On the other hand, tablets prepared from cospray-dried mixtures with starch acetate and starch propanoate showed much slower and extended release. Scanning electron micrographs of tablet surfaces revealed enhanced inter-particulate bonding and plastification for cospray-dried agglomerates in comparison with physical mixtures.


Subject(s)
Excipients/chemical synthesis , Starch/chemistry , Delayed-Action Preparations , Desiccation , Esters/chemistry , Starch/analogs & derivatives , Tablets , Theophylline/administration & dosage , Theophylline/chemistry , Vasodilator Agents/administration & dosage , Vasodilator Agents/chemistry
5.
Iran Red Crescent Med J ; 13(6): 428-30, 2011 Jun.
Article in English | MEDLINE | ID: mdl-22737507

ABSTRACT

BACKGROUND: Because of the low prevalence of Human T Lymphotropic Virus type I (HTLV-I) in comparison with Khorasan Province, considering HTLV-I as an etiology of spastic paraparesia, it may be neglected in evaluation of spastic paraparesis in the other regions of Iran. Some reports of spastic paraparetic patients due to HTLV-I infection in West Azarbaijan, caused us to reconsider the importance of HTLV-I epidemiology in the other areas of the country. METHODS: All spastic paraparetic patients who referred to Motahari and Imam Khomeini educational hospitals of Urmia from September 2004 to September 2007 were assessed for HTLV-I infection antibodies. RESULTS: In our 3 years study, 11 cases were diagnosed as Human T Lymphotropic Virus type I Associated Myelopathy/Tropical Spastic Paraparesis (HAM/TSP, 2 males and 9 females).The mean age of patients at the time of diagnosis was 45.8 years. Dorsal and cervical MRI of all patients was normal. Serum Enzyme-Linked Immuno-Sorbent Assay (ELISA) and Western blot (WB) for anti HTLV-I antibody in all patients was positive. Four patients underwent for lumbar puncture in which were normal in respect of cells and biochemistry, but positive for anti-HLTLV-I antibodies. CONCLUSION: HAM/TSP detection in West Azarbaijan in spite of its long distance from Khorasan Province shows the importance of anti-HTLV-I Ab assay in the blood and CSF of every spastic paraparetic patient all over the country.

6.
J Contemp Dent Pract ; 6(3): 78-85, 2005 Aug 15.
Article in English | MEDLINE | ID: mdl-16127475

ABSTRACT

BACKGROUND: Periodontitis is a bacterial infection, which has been classified as a local chronic inflammation. This, as well as cardiovascular disease, may share common risk factors such as smoking, diabetes, behavioral factors, aging, and male gender. The aim of this study was to evaluate the association between hyperlipidemia and periodontitis. MATERIALS AND METHODS: The levels of plasma lipids in 40 subjects with periodontitis (CPITN score III or IV, pocket depth 4 mm) with mean age 32.3 +/-1.2 years were measured and compared with those obtained from 40 age and sex matched controls. Both groups were systemically healthy according to their medical history. RESULTS: Total cholesterol (CHL) and triglycerides (TG) were significantly higher in the case group (P=0.045 and P=0.016, respectively). HDL and LDL cholesterols were higher in patients but did not have any significant differences with controls. The frequency of persons with pathologic values of TG and CHL were significantly higher in cases compared with controls. CONCLUSIONS: These results showed hyperlipidemia may be associated with periodontitis in healthy people. However, it is unclear whether periodontitis causes an increase in levels of serum lipids or hyperlipidemia is a risk factor for both periodontitis and cardiovascular disease.


Subject(s)
Hyperlipidemias/complications , Periodontitis/complications , Adult , Case-Control Studies , Cholesterol/blood , Female , Humans , Hyperlipidemias/blood , Male , Periodontitis/blood , Triglycerides/blood
7.
Nitric Oxide ; 12(3): 129-40, 2005 May.
Article in English | MEDLINE | ID: mdl-15797841

ABSTRACT

Nitric oxide (NO) is the smallest known gaseous signaling molecule released by mammalian and plant cells. To investigate the pathophysiologic role of exogenous NO gas (gNO) in bacterial and mammalian cell cultures, a validated in vitro delivery method is required. The system should be able to deliver gNO directly to bacterial and/or cell cultures in a continuous, predictable, and reproducible manner over a long period of time (days). To accomplish this, a gas delivery system was designed to provide optimal growth conditions for bacteria and/or mammalian cells. Parameters for cell exposure, such as concentration of gNO, nitrogen dioxide (NO(2)), oxygen (O(2)), temperature, and relative humidity (RH) were continuously monitored and evaluated. Uptake of gNO into various media was monitored by measuring the nitrite concentration using the Griess reagent technique. A selection of standard growth media [saline, tryptic soy broth (TSB), Middlebrook 7H9 (MB 7H9), and Dulbecco's modified Eagle's medium (DMEM)] exposed to various concentrations of gNO revealed a steady and consistent transfer of gNO into the aqueous phase over a 48-h period. Validation of optimal growth conditions within the device, as compared to a conventional incubator, were accomplished by growing and observing viability of Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and human fibroblast cultures in the absence of gNO. These results indicate that an optimal growth environment for the above tested cells was accomplished inside the proposed delivery system. Dose-dependent toxicological data revealed a significant bacteriostatic effect on P. aeruginosa and S. aureus with continuous exposure to 80 ppm gNO. No toxic effects were observed on dermal fibroblast proliferation at concentrations up to 400 ppm gNO for 48 h. In conclusion, the designed gNO exposure system is capable of supporting cellular viability for a representative range of prokaryote and eukaryotic cells. The exposure system is also capable of obtaining toxicological data. Therefore, the proposed device can be utilized to continuously expose cells to various levels of gNO for up to 72 h to study the in vitro effects of gNO therapy.


Subject(s)
Anti-Bacterial Agents/administration & dosage , Drug Delivery Systems , Nitric Oxide/administration & dosage , Anti-Bacterial Agents/pharmacology , Bacteria/drug effects , Cell Culture Techniques , Cell Proliferation , Fibroblasts/drug effects , Humans , Nitric Oxide/pharmacology
8.
J Org Chem ; 66(21): 6926-31, 2001 Oct 19.
Article in English | MEDLINE | ID: mdl-11597211

ABSTRACT

A range of dihydroisoquinolinium salts containing alcohol, ether, and acetal functionalities in the nitrogen substituent has been prepared and tested as asymmetric epoxidation catalysts, providing ee's of up to ca. 60%.

9.
Ecotoxicol Environ Saf ; 8(2): 152-61, 1984 Apr.
Article in English | MEDLINE | ID: mdl-6201332

ABSTRACT

Interest has arisen in heavy-metal contamination of the environment, mostly because of potential hazards to the health of animals and human (directly and/or indirectly). High levels of heavy metals in soil, plants, and the atmosphere are often related to industries, highways , chemical dumping, impure chemical fertilizers, and pesticides containing metals. An important source of heavy metals, especially lead, is from the combustion of leaded gasoline used for transportation. Other heavy metals associated with transportation include nickel, which is also added to gasoline and is contained in engine parts, zinc, and cadmium from tires, lubricating oils, and galvanized parts such as fuel tanks.


Subject(s)
Environmental Pollution/analysis , Metals/analysis , Vehicle Emissions/analysis , Cadmium/analysis , Lead/analysis , Nickel/analysis , Plants/metabolism , Poaceae/analysis , Snow , Soil Pollutants/analysis , Water Pollutants, Chemical/analysis , Wind , Zinc/analysis
SELECTION OF CITATIONS
SEARCH DETAIL
...