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1.
Int Endod J ; 48(10): 994-1000, 2015 Oct.
Article in English | MEDLINE | ID: mdl-25307251

ABSTRACT

AIM: To evaluate the characteristic artefact patterns associated with teeth root filled with Gutta-percha when scanned with four cone-beam CT devices. METHODOLOGY: Whilst using soft tissue simulation, ten root filled human premolars were placed in empty sockets in a dry human skull. Subsequently, the skull was scanned using 3D Accuitomo 170(®) , WhiteFox(®) , Cranex 3D(®) and Scanora 3D(®) following clinical protocols with the highest resolution and artefact reduction. After proper image registration in OnDemand3D(®) software (Cybermed, Seoul, Korea), each image slice was evaluated by three trained and calibrated dentomaxillofacial radiologists, which scored absence (0) and presence (1) of cupping artefact, hypodense halos and streak artefacts. Kappa test was performed for intra- and interobserver agreement. RESULTS: A moderate to perfect agreement for each observer (intra-observer κ = 0.5-1.0) was found. Agreement between the different observers was moderate to almost perfect for the different artefact patterns (interobserver κ = 0.55-0.9). Cupping artefact was the most prevalent (70%), followed by a hypodense halo (35%) and streak artefacts (16%). The Chi-squared test revealed significantly more streaks in axial slices (P < 0.0001), with some CBCT systems yielding significantly inferior results to others (P < 0.05). The dedicated EndoMode and artefact reduction did not improve the result significantly. CONCLUSIONS: The variation of artefact expression was significantly different amongst CBCT machines for root filled teeth. Continuous efforts are needed to improve CBCT reconstruction algorithms, with a specific focus on reducing artefacts induced by dense dental materials, whilst striving for enhanced image quality at low-radiation doses.


Subject(s)
Artifacts , Bicuspid/diagnostic imaging , Cone-Beam Computed Tomography/instrumentation , Root Canal Obturation , Tooth Root/diagnostic imaging , Gutta-Percha , Humans , In Vitro Techniques , Reproducibility of Results , Skull/diagnostic imaging , Software
2.
Hist Cienc Saude Manguinhos ; 5(1): 99-113, 1998.
Article in Portuguese | MEDLINE | ID: mdl-11625435

ABSTRACT

Based on articles from major newspapers in Rio de Janeiro and Sao Paulo, the text examines the written press's discourse on acupuncture and the process of its legitimization, institutionalization, and legalization in Brazil. The topic is analyzed from a sociological perspective, focusing on three different periods: the 1970s, the 1980s, and the first half of the 1990s.


Subject(s)
Acupuncture Therapy/history , Newspapers as Topic/history , Brazil , History, 20th Century
3.
Toxicon ; 32(5): 595-603, 1994 May.
Article in English | MEDLINE | ID: mdl-8079371

ABSTRACT

The antimyotoxic and antihemorrhagic effects of Eclipta prostrata (EP) and three of its constituents (wedelolactone, WE; stigmaterol, ST; and sitosterol, SI) were investigated. The myotoxicity of crotalid venoms (Bothrops jararaca, Bothrops jararacussu and Lachesis muta), purified myotoxins (bothropstoxin, BthTX; bothropasin; and crotoxin), and polylysine was quantified in vitro by the release rate of creatine kinase (CK) from rat or mouse extensor digitorum muscles, and in vivo by the plasma CK activity in mice. The in vitro myotoxicity of the crotalid venoms and myotoxins was neutralized by simultaneous exposure of the muscles to an aqueous extract of EP or to WE. ST and SI were less effective than WE, but interacted synergistically with it. Both the EP extract and WE failed to neutralize the in vitro myotoxic effects of polylysine. The in vivo myotoxicity of venoms and myotoxins was neutralized by their preincubation with the EP extract or WE. Intravenous administration of the plant extract or WE attenuated the increase in plasma CK activity induced by subsequent intramuscular injections of the crotalid venoms or the myotoxins. EP and WE inhibited the hemorrhagic effect of B. jararaca venom, as well as the phospholipase A2 activity of crotoxin and the proteolytic activity of B. jararaca venom. The data provide direct evidence for antimyotoxic and antihemorrhagic effects of EP and WE against the crotalid venoms responsible for most cases of envenomation by snakebites in Brazil. These effects are interpreted as consequences of antiproteolytic and antiphospholipase A2 activities of EP and its constituents.


Subject(s)
Crotalid Venoms/antagonists & inhibitors , Hemorrhage/prevention & control , Muscles/enzymology , Plant Extracts/pharmacology , Animals , Coumarins/pharmacology , Creatine Kinase/blood , Creatine Kinase/drug effects , Crotalid Venoms/toxicity , Mice , Muscles/drug effects , Rats , Sitosterols/pharmacology , Stigmasterol/pharmacology
4.
Planta Med ; 60(2): 99-100, 1994 Apr.
Article in English | MEDLINE | ID: mdl-8202573

ABSTRACT

Fifteen compounds, isolated from plants reputed as snake venom antidotes, belonging to different classes of natural products, were shown to protect mice to a significant degree against the lethal action of the venom of Bothrops jararaca snakes. Administration was by the oral route, one hour prior to envenomation. The substances are nitrogen-free, low-molecular-weight compounds for which some kind of biodynamic activity has previously been reported. The fact that they are mostly trivial, naturally-occurring compounds should explain why plants used as snake-bite antidotes are so widely distributed over the plant kingdom.


Subject(s)
Antidotes , Crotalid Venoms/antagonists & inhibitors , Medicine, Traditional , Plants, Medicinal , Animals , Bothrops , Mice , Plant Extracts/pharmacology
5.
Planta Med ; 60(2): 99-100, 1994 Apr.
Article in English | MEDLINE | ID: mdl-17236028

ABSTRACT

Fifteen Compounds, isolated from plants reputed as snake venom antidotes, belonging to different classes of natural products, were shown to protect mice to a significant degree against the lethal action of the venom of BOTHROPS JARARACA snakes. Administration was by the oral route, one hour prior to envenomation. The substances are nitrogen-free, low-molecular-weight compounds for which some kind of biodynamic activity has previously been reported. The fact that they are mostly trivial, naturally-occurring compounds should explain why plants used as snake-bite antidotes are so widely distributed over the plant kingdom.

6.
Toxicon ; 27(9): 1003-9, 1989.
Article in English | MEDLINE | ID: mdl-2799833

ABSTRACT

Ethanolic extracts of the aerial parts of Eclipta prostrata L. (Asteraceae) neutralized the lethal activity of the venom of South American rattlesnake (Crotalus durissus terrificus) when mixed in vitro before i.p. injection into adult Swiss mice. Samples of ethanolic extract corresponding to 1.8 mg of dry extract per animal neutralized up to four lethal doses of the venom (LD50 = 0.08 micrograms venom/g animal). Three substances isolated from the plant--wedelolactone (0.54 mg/animal), sitosterol (2.3 mg/animal) and stigmasterol (2.3 mg/animal)--were able to neutralize three lethal doses of the venom. Aqueous extracts of the plant inhibited the release of creatine kinase from isolated rat muscle exposed to the crude venom. The protection conferred against the myotoxic effects of the venom could be demonstrated also in vivo, when the venom was preincubated with the extract prior to injection into mice.


Subject(s)
Crotalid Venoms/antagonists & inhibitors , Plant Extracts/pharmacology , Animals , Chromatography, High Pressure Liquid , Creatine Kinase/metabolism , In Vitro Techniques , Mice , Muscles/drug effects , Muscles/enzymology , Muscular Diseases/chemically induced , Muscular Diseases/prevention & control , Rats
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