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1.
J Heart Valve Dis ; 20(3): 265-71, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21714415

RESUMO

BACKGROUND AND AIM OF THE STUDY: The study aim was to evaluate the available literature comparing mitral valve repair (MVRep) versus mitral valve replacement (MVR) in the elderly population, and to provide a pooled analysis regarding this issue. METHODS: Medline, Embase, Cochrane, trial registries, conference proceedings and reference lists were searched for trials of MVRep versus MVR surgery in the elderly population. The primary outcome was 30-day mortality, while secondary outcomes were postoperative complications and length of hospital stay. Pooled odds ratios were calculated for categorical outcomes and weighted mean differences for continuous outcomes. RESULTS: Four studies retrieved were deemed appropriate for inclusion. The outcome measures used for the analysis clearly showed a benefit of MVRep in the elderly population with reduced mortality (pooled Odds Ratio (OR) = 3.97; p = 0.003) and reduced postoperative complications (pooled OR = 2.35; p = 0.003). There was no significant difference between the two groups with regards to duration of hospital stay (weighted mean difference = 0.22; p = 0.18). CONCLUSION: With the demonstration of clear advantages of MVRep over MVR in the elderly population, a randomized trial between the two techniques is not ethically justifiable. As there are clear advantages to MVRep, it is recommended that this should be the primary treatment offered in mitral valve pathology, irrespective of the patient's age.


Assuntos
Envelhecimento , Procedimentos Cirúrgicos Cardíacos , Doenças das Valvas Cardíacas/cirurgia , Implante de Prótese de Valva Cardíaca , Valva Mitral/cirurgia , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Procedimentos Cirúrgicos Cardíacos/mortalidade , Inglaterra , Medicina Baseada em Evidências , Feminino , Doenças das Valvas Cardíacas/mortalidade , Implante de Prótese de Valva Cardíaca/efeitos adversos , Implante de Prótese de Valva Cardíaca/mortalidade , Humanos , Tempo de Internação , Masculino , Razão de Chances , Seleção de Pacientes , Medição de Risco , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento
2.
Fish Physiol Biochem ; 34(4): 299-306, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18958586

RESUMO

A feeding trial of 120 days was conducted to study the effect of graded levels of dietary phosphorus on haematology, serum protein concentrations and HSP70 expression in fingerlings of the Indian major carp, Catla (Catla catla). Eight isonitrogenous and isoenergetic purified diets were formulated to contain graded levels of dietary phosphorus (dP), i.e., T(1), 0.1%; T(2), 0.3%; T(3), 0.5%; T(4), 0.7%; T(5), 0.9%; T(6), 1.1%; T(7), 1.3%; or T(8), 1.5%. Four hundred and eighty fish (average weight 4.23 +/- 0.016 g) were equally distributed into 24 tanks forming eight treatments with three replicates each. The fish were fed daily at the rate of 3.5% body weight in two instalments. At the end of feeding trial fish were sampled to study total RBC and WBC count, haemoglobin, serum lysozyme activity, serum total protein, albumin (A), globulin (G) concentration and HSP70 expression. Total RBC count, haemoglobin concentration and serum lysozyme activity did not vary significantly in response to different dietary phosphorus concentrations. Total WBC count was found to be significantly (P < 0.05) higher in T(1 )relative to all other treatments. Serum albumin and A/G ratio was found to be significantly lower in fish of T(1) and T(2) in relation to T(7) group (P < 0.05). Serum globulin and total protein levels remained unaffected by variations in dietary phosphorus. HSP70 expression was observed in T(1) group (0.1% dP) in gills and brain tissue, but not in liver and muscle tissues. No HSP70 expression was observed in fish of T(4) (0.7% dP) and T(8) (1.5% dP) treatments. These prima facie results suggest that dietary phosphorus had only minor influence on the haemato-biochemical parameters studied; however dietary phosphorus deficiency caused organ specific induction of HSP70 in catla fingerlings.


Assuntos
Carpas/fisiologia , Regulação da Expressão Gênica/efeitos dos fármacos , Proteínas de Choque Térmico HSP70/metabolismo , Fósforo na Dieta/farmacologia , Animais , Análise Química do Sangue , Proteínas Sanguíneas/metabolismo , Western Blotting , Carpas/sangue , Carpas/metabolismo , Contagem de Eritrócitos , Hemoglobinas/metabolismo , Contagem de Leucócitos , Muramidase/sangue
3.
J Thorac Cardiovasc Surg ; 156(6): 2124-2132.e31, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30075959

RESUMO

OBJECTIVE: Aortic valve replacement (AVR) can be performed either through full median sternotomy (FS) or upper mini-sternotomy (MS). The Mini-Stern trial aimed to establish whether MS leads to quicker postoperative recovery and shorter hospital stay after first-time isolated AVR. METHODS: This pragmatic, open-label, parallel randomized controlled trial (RCT) compared MS with FS for first-time isolated AVR in 2 United Kingdom National Health Service hospitals. Primary endpoints were duration of postoperative hospital stay and the time to fitness for discharge from hospital after AVR, analyzed in the intent-to-treat population. RESULTS: In this RCT, 222 patients were recruited and randomized (n = 118 in the MS group; n = 104 in the FS group). Compared with the FS group, the MS group had a longer hospital length of stay (mean, 9.5 days vs 8.6 days) and took longer to achieve fitness for discharge home (mean, 8.5 days vs 7.5 days). Adjusting for valve type, sex, and surgeon, hazard ratios (HRs) from Cox models did not show a statistically significant effect of MS (relative to FS) on either hospital stay (HR, 0.874; 95% confidence interval [CI], 0.668-1.143; P = .3246) or time to fitness for discharge (HR, 0.907; 95% CI, 0.688-1.197; P value = .4914). During a mean follow-up of 760 days (745 days for the MS group and 777 days for the FS group), 12 patients (10%) in the MS group and 7 patients (7%) in the FS group died (HR, 1.871; 95% CI, 0.723-4.844; P = .1966). Average extra cost for MS was £1714 during the first 12 months after AVR. CONCLUSIONS: Compared with FS for AVR, MS did not result in shorter hospital stay, faster recovery, or improved survival and was not cost-effective. The MS approach is not superior to FS for performing AVR.


Assuntos
Valva Aórtica/cirurgia , Doenças das Valvas Cardíacas/cirurgia , Implante de Prótese de Valva Cardíaca/métodos , Esternotomia/métodos , Idoso , Idoso de 80 Anos ou mais , Valva Aórtica/diagnóstico por imagem , Valva Aórtica/fisiopatologia , Análise Custo-Benefício , Inglaterra , Feminino , Doenças das Valvas Cardíacas/diagnóstico por imagem , Doenças das Valvas Cardíacas/fisiopatologia , Implante de Prótese de Valva Cardíaca/efeitos adversos , Implante de Prótese de Valva Cardíaca/economia , Custos Hospitalares , Humanos , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Alta do Paciente , Recuperação de Função Fisiológica , Esternotomia/efeitos adversos , Esternotomia/economia , Fatores de Tempo , Resultado do Tratamento
4.
Eur J Cardiothorac Surg ; 32(2): 362-9, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17580118

RESUMO

Though rare in incidence, chylothorax can lead to significant morbidity and mortality. Its occurrence corresponds to increased mortality following esophagectomy. Leakage of chyle and lymph leads to significant loss of essential proteins, immunoglobulins, fat, vitamins, electrolytes and water. The presence of chylomicrons and a triglyceride level >110 mg/dl in the aspirated pleural fluid confirms the diagnosis of chylothorax. Identifying the aetiology using different diagnostic tests is important in planning treatment. While therapeutic thoracentesis provides relief from respiratory symptoms, the nutritional deficiency will continue to persist or deteriorate unless definitive therapeutic measures are instituted to stop leakage of chyle into the pleural space. Definitive therapy consists of obliteration and prevention of recurrence of chylothorax. Aggressive surgical therapy is recommended for post-traumatic or post-surgical chylothorax.


Assuntos
Quilotórax/terapia , Adulto , Algoritmos , Colesterol/análise , Quilo/metabolismo , Quilotórax/etiologia , Humanos , Sistema Linfático/anatomia & histologia , Derrame Pleural/metabolismo , Prognóstico , Procedimentos Cirúrgicos Torácicos/métodos , Tórax/anatomia & histologia
5.
Cancer Res ; 39(6 Pt 1): 1934-6, 1979 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-109189

RESUMO

The abilities of the racemic trans-3,4-, 5,6-, and 8,9-dihydrodiols of 7,12-dimethylbenz(a)anthracene to initiate skin tumors in mice were determined by using a two-stage system of tumorigenesis. The 7,12-dimethylbenz(a)anthracene trans-3,4-dihydrodiol was found to be much more active as a tumor initiator than the parent hydrocarbon. The 7,12-dimethylbenz(a)anthracene trans-5,6- and 8,9-dihydrodiols were essentially inactive as skin tumor initiators. Our results suggest that the 3,4-dihydrodiol of 7,12-dimethylbenz(a)anthracene is a proximal carcinogen and that the "bay region" diol-epoxide may be the ultimate carcinogenic form of DMBA.


Assuntos
9,10-Dimetil-1,2-benzantraceno , Benzo(a)Antracenos , Papiloma/induzido quimicamente , Neoplasias Cutâneas/induzido quimicamente , 9,10-Dimetil-1,2-benzantraceno/análogos & derivados , 9,10-Dimetil-1,2-benzantraceno/toxicidade , Animais , Benzo(a)Antracenos/análogos & derivados , Feminino , Camundongos , Neoplasias Experimentais/induzido quimicamente , Relação Estrutura-Atividade , Acetato de Tetradecanoilforbol/administração & dosagem
6.
Cancer Lett ; 97(1): 33-7, 1995 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-7585475

RESUMO

Nineteen synthetic chalcones and ten structurally related compounds were investigated for their cytotoxic, tumour reducing and antioxidant activities. Methyl and hydroxy substituted chalcones were found to be cytotoxic in vitro whereas only hydroxy substituted chalcones could reduce ascites tumour in animals. Although most of the compounds analysed showed antioxidant activity, hydroxy and methyl substituted compounds were found to be the most potent antioxidants.


Assuntos
Antineoplásicos , Antioxidantes , Chalcona/farmacologia , Animais , Ascite , Carcinoma de Ehrlich , Chalcona/análogos & derivados , Linfoma , Camundongos , Relação Estrutura-Atividade , Superóxidos/metabolismo , Células Tumorais Cultivadas/efeitos dos fármacos
7.
Invest Radiol ; 35(1): 8-24, 2000 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10639032

RESUMO

RATIONALE AND OBJECTIVES: To investigate the effect of substituent lipophilicity, substituent position, and overall charge on the hepatobiliary clearance and tolerance of a series of aromatic ring-containing macrocyclic Gd chelates to select a candidate compound for evaluation as a hepatobiliary imaging agent. METHODS: Hepatobiliary clearance was studied in rats. Tissue distribution and tolerance were studied in mice. Imaging was performed in cats, rabbits, and Rhesus monkeys using T1-weighted pulse sequences or T1-weighted breath-hold pulse sequences. RESULTS: All the compounds were excreted bimodally. Gd-2,5-BPA-DO3A (15d) was found to have the optimal combination of hepatobiliary clearance (47% in rats, 29% in mice) and tolerance (minimum lethal dose 5.0 mmol/kg). Initial imaging studies in cats demonstrated the feasibility of Gd-2,5-BPA-DO3A for hepatic imaging. In rabbits with implanted VX-2 adenocarcinoma as a model for metastatic liver disease, Gd-2,5-BPA-DO3A provided sustained hepatic signal intensity (SI) enhancement and lesion conspicuity over a 120-minute imaging time course. In Rhesus monkeys with normal liver function, Gd-2,5-BPA-DO3A afforded sustained hepatic SI enhancement and a time-dependent increase in gallbladder SI over the entire 90-minute imaging time course. CONCLUSIONS: Gd-2,5-BPA-DO3A provides dramatic and sustained SI enhancement of hepatic tissue in cats, rabbits, and Rhesus monkeys that was superior in all respects to the extracellular space MRI agent, Gd-HP-DO3A, that was employed as a control.


Assuntos
Meios de Contraste , Imageamento por Ressonância Magnética , Animais , Sistema Biliar/anatomia & histologia , Gatos , Meios de Contraste/síntese química , Meios de Contraste/química , Gadolínio , Compostos Heterocíclicos , Fígado/anatomia & histologia , Neoplasias Hepáticas Experimentais/patologia , Macaca mulatta , Camundongos , Compostos Organometálicos/síntese química , Compostos Organometálicos/química , Coelhos , Ratos , Distribuição Tecidual
8.
Br J Ophthalmol ; 75(3): 179-80, 1991 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-2012789

RESUMO

A case of Norrie's disease in an identical twins is reported. No positive family history was obtained. The couple had no other children. The older of the twins died at the age of 9 months of uncertain cause. To the best of my knowledge this is the first case of Norrie's disease reported in Malaysia. And its occurrence in an identical twins is very rare.


Assuntos
Cegueira/congênito , Doenças em Gêmeos , Retina/anormalidades , Humanos , Recém-Nascido , Masculino , Retina/patologia , Descolamento Retiniano/congênito , Descolamento Retiniano/patologia , Síndrome , Gêmeos Monozigóticos
9.
Mutat Res ; 343(1): 25-30, 1995 May.
Artigo em Inglês | MEDLINE | ID: mdl-7753104

RESUMO

Inhibitory effects of eugenol, a compound present in many spices such as cloves, cardamom etc. and the extracts of Anacyclus pyrethrum and Spilanthes calva which are traditionally used in India during the preparation of chewable tobacco, on tobacco-induced mutagenesis were evaluated using Ames Salmonella/microsome assay. Eugenol significantly inhibited (P < 0.001) tobacco-induced mutagenicity at concentrations of 0.5 and 1 mg/plate. Anacyclus pyrethrum extract (1 mg/plate) produced 74.33% inhibition while the extract of Spilanthes calva at 2 mg/plate inhibited tobacco-induced mutagenesis by 86.4%. Eugenol and the plant extracts also inhibited the nitrosation of methylurea in a dose-dependent manner.


Assuntos
Antimutagênicos/farmacologia , Eugenol/farmacologia , Mutagênese/efeitos dos fármacos , Nicotiana , Extratos Vegetais/farmacologia , Plantas Tóxicas , Interações Medicamentosas , Testes de Mutagenicidade , Mutagênicos , Tabaco sem Fumaça
10.
Singapore Med J ; 32(3): 163-5, 1991 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-1876889

RESUMO

Immunoperoxidase staining was compared with flowcytometry for the enumeration of lymphocyte subsets. The percentages obtained for peripheral blood lymphocytes using immunoperoxidase (CD3 = 76 CD4 = 27.9, B = 10.7 CD4/CD8 = 1.8) differed significantly from those obtained by flowcytometry (CD3 = 65.7 CD4 = 39.4, CD8 = 25.6, B = 16.7, HLA DR = 11.9 CD4/CD8 = 1.54) for certain subsets (CD3, CD4, B). There was no significant difference in lymphocyte subsets between children and adults using the same method. These differences are probably due to the different methods used to prepare lymphocytes for analysis. Other factors that should also be considered are the presence of CD4 antigen on monocytes and CD8 on natural killer cells.


Assuntos
Citometria de Fluxo/métodos , Técnicas Imunoenzimáticas , Subpopulações de Linfócitos , Humanos , Contagem de Leucócitos/métodos
11.
Artigo em Inglês | MEDLINE | ID: mdl-6658505

RESUMO

A micro ELISA assay was established to diagnose systemic poisoning for the rapid administration of specific antivenom. Rabbit anti venom IgG was bound to the solid phase to enable detection of venom from both the Malayan Pit Viper (Agkistrodon rhodostoma) and the Common Cobra (Naja naja). This assay is read visually and takes 35 to 45 minutes to perform. It can detect 15.6 ng/ml of viper venom in 75 minutes and 7.8 ng/ml of cobra venom in 55 minutes. Tests on sera from snake bite patients showed detectable levels of snake venom in the serum even though administration of antivenom was not necessary. Furthermore, results from these clinical cases were obtained in less than 45 minutes. It was found that the most suitable washing media was saline/Tween, the assay could be performed at room temperature and plates stored for 6 months showed no loss of activity.


Assuntos
Anticorpos/análise , Mordeduras de Serpentes/diagnóstico , Animais , Reações Antígeno-Anticorpo , Venenos de Crotalídeos/imunologia , Venenos Elapídicos/imunologia , Humanos , Imunoglobulina G/análise , Coelhos , Fatores de Tempo
12.
Br J Oral Maxillofac Surg ; 23(2): 140-5, 1985 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-3158336

RESUMO

Orbital cellulitis is a rare condition, which usually develops as a complication of the infection of paranasal sinuses, namely ethmoidal, frontal and occasionally the maxillary sinuses. Maxillary sinusitis could result from dental infection. A case is presented illustrating how dental infection can proceed to maxillary sinusitis and orbital cellulitis. The clinical presentation and treatment are described. Possible complications are discussed.


Assuntos
Celulite (Flegmão)/etiologia , Infecção Focal Dentária/complicações , Doenças Orbitárias/etiologia , Infecções Estafilocócicas , Doenças Dentárias/complicações , Adolescente , Humanos , Masculino , Seio Maxilar , Dente Molar , Sinusite/complicações , Sinusite/etiologia
13.
Indian J Physiol Pharmacol ; 38(4): 306-8, 1994 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-7883300

RESUMO

Number of tumours (papillomas) produced by the application of 7,12-dimethyl benz (a) anthracene as initiator and croton oil promoter in mice were considerably inhibited (84%) by the prior application of eugenol. Moreover, there was considerable decrease in the number of tumour bearing animals and their onset. Eugenol inhibited superoxide formation and lipid peroxidation and the radical scavenging activity may be responsible for its chemopreventive action.


Assuntos
Eugenol/farmacologia , Neoplasias Experimentais/induzido quimicamente , Animais , Peróxidos Lipídicos/metabolismo , Peróxidos Lipídicos/farmacologia , Camundongos , Papiloma/induzido quimicamente , Neoplasias Cutâneas/induzido quimicamente , Superóxidos/metabolismo , Superóxidos/farmacologia
14.
Indian J Physiol Pharmacol ; 39(4): 347-53, 1995 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8582746

RESUMO

Using Salmonella typhimurium strains TA 100 and TA 1535, the mutagenicity and anti-mutagenicity of extracts of several spices were checked. Spices like pepper, pippali, ginger and mustard increased the number of revertants indicating their mutagenic potential. Garlic extract on the other hand was found to inhibit the mutagenicity produced by direct acting mutagens such as N-methyl N'-nitro-N-nitrosoguanidine and sodium azide. Asafoetida and turmetic extract were found to inhibit microsomal activation dependent mutagenicity of 2-acetamidofluorene. Similar results were also obtained using curcumin and eugenol which are phenolics present in turmeric and clove respectively. These results indicated that some of the spices may ameliorate the effect of environmental mutagens especially present in the food.


Assuntos
Antimutagênicos/farmacologia , Mutagênicos/farmacologia , Mutagênicos/toxicidade , Especiarias/toxicidade , 2-Acetilaminofluoreno/antagonistas & inibidores , 2-Acetilaminofluoreno/toxicidade , Animais , Azidas/antagonistas & inibidores , Azidas/toxicidade , Masculino , Metilnitronitrosoguanidina/toxicidade , Testes de Mutagenicidade , Ratos , Salmonella typhimurium/efeitos dos fármacos , Salmonella typhimurium/genética , Azida Sódica
15.
Med J Malaysia ; 46(4): 388-91, 1991 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-1840452

RESUMO

Three clinical cases of fungal corneal ulcers are described to highlight the course, ocular morbidity and principles of treatment. A brief discussion of the diagnosis and management of ulcerative keratomycosis is presented.


Assuntos
Aspergilose/microbiologia , Aspergillus fumigatus , Aspergillus oryzae , Úlcera da Córnea/microbiologia , Micoses/microbiologia , Adulto , Úlcera da Córnea/terapia , Humanos , Masculino , Micoses/terapia
16.
Med J Malaysia ; 45(2): 144-7, 1990 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-2152019

RESUMO

The aim of this study was to determine the frequency and specificity of HLA-A and B antibodies in multiparous mothers in the Malaysian population. 1,100 maternal serum samples obtained during normal childbirth were screened against a panel of 100 lymphocytes with known HLA antigen types for HLA antibodies by the complement dependent lymphocyte microcytotoxicity dye exclusion test. From the total number of 1,100 samples of maternal serum that were screened for HLA antibodies only 205 specimens (18.6%) tested positive for antibodies. The percentage of maternal sera which contained HLA-B specificities (10.6%) were significantly higher than those which contained HLA-A specificities (3.0%). Sixty maternal serum samples (5.5%) had high enough titres to be utilised as tissue typing reagents. Thirty nine maternal serum samples (3.5%) contained monospecific HLA antibodies. In this study the most common monospecific HLA antibodies characterised included the following specificities: A2, B5, B17 and B40. Malaysian multiparous mothers of gravida 3, 4 and 5 had a higher frequency for producing HLA-antibodies.


Assuntos
Anticorpos/análise , Antígenos HLA-A/imunologia , Antígenos HLA-B/imunologia , Gravidez/imunologia , Feminino , Humanos , Malásia , Paridade
18.
Interact Cardiovasc Thorac Surg ; 16(6): 725-30, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23429568

RESUMO

OBJECTIVES: Many centres in the UK carry out routine chest X-ray (CXR) and/or electrocardiogram (ECG) when patients attend follow-up clinic after cardiac surgery. Current evidence to support this practice is weak. This study investigated the appropriateness of carrying out these investigations in the absence of clinical indication. METHODS: All patients attending routine 6- to 8-week follow-up clinic after cardiac surgery in this hospital were prospectively reviewed over a 6-month period (October 2011-April 2012). Two groups were identified for comparison. Group A comprised patients who had CXR and/or ECG requested routinely, and those in Group B had the investigations only when clinically indicated. A proforma was designed to screen each patient for cardiac and respiratory symptoms, predischarge CXR abnormalities and the presence of atrial fibrillation/flutter postoperatively. Management alterations based on the findings from the investigations were noted. Patients who had thoracic, major aortic, or heart transplant surgery were excluded from the audit. RESULTS: Three hundred and fifty patients were reviewed: 250 were in Group A and 100 in Group B. No patient had a significant management alteration in the absence of an indication for the tests. There were no differences in outcome between the two groups. In Group A, 111 (45%) patients had CXR and ECG done without indication and no abnormality was detected. In Group B, 52 patients had no indication for either tests and were thus not tested. None of these patients required readmission/intervention following discharge from clinic. Overall, 271 patients had CXR carried out, with only 83 being indicated. This led to a management alteration in 33 patients (12% overall, 40% if indicated). Two hundred and eighty-six patients had ECG carried out with 140 indicated. Management was altered in 122 patients (43% overall, 87% if indicated). The correlation between the clinical indication-based investigation and the resulting change in patient management was found to be significant (Goodman-Kruskal Gamma: 0.99, P = 0.000 for both investigations). CONCLUSIONS: There is a strong correlation between clinical indication for CXR and/or ECG and management alterations. These investigations should be performed during the routine follow-up of adult cardiac surgical patients using a patient-centred approach based on signs and symptoms.


Assuntos
Procedimentos Cirúrgicos Cardíacos , Eletrocardiografia , Ambulatório Hospitalar , Complicações Pós-Operatórias/diagnóstico , Radiografia Torácica , Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Humanos , Assistência Centrada no Paciente , Cuidados Pós-Operatórios , Complicações Pós-Operatórias/diagnóstico por imagem , Valor Preditivo dos Testes , Estudos Prospectivos , Fatores de Tempo , Procedimentos Desnecessários
19.
Angle Orthod ; 82(1): 22-9, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21749248

RESUMO

OBJECTIVE: To determine in vitro the frictional properties, surface morphology, and load deflection rate with looped designs of two newly developed titanium aluminum nitride (TiAlN) and tungsten carbide/carbon (WC/C) physical vapor deposition (PVD) coated beta titanium orthodontic archwires coated with PVD. MATERIALS AND METHODS: Frictional properties with Tidy's protocol, surface evaluation before and after friction testing with the help of scanning electron microscopy (ESEM), and load deflection rate with different orthodontic loops on Instron universal testing machine were evaluated. RESULTS: The results clearly indicate reduced frictional properties for WC/C coated archwires when compared with uncoated and TiAlN coated archwires. There were no significant surface alterations upon ESEM evaluation of friction tested archwires. Low load deflection rate was exhibited by both coated archwires, the difference in load deflection rate between the coated and uncoated archwires was statistically significant. CONCLUSION: WC/C coated wires can be recommended for even sliding mechanics due to reduced frictional properties, better surface characteristics, and low load deflection rate compared with TiAlN coated and uncoated archwires.


Assuntos
Materiais Revestidos Biocompatíveis , Ligas Dentárias , Análise do Estresse Dentário , Desenho de Aparelho Ortodôntico , Fios Ortodônticos , Titânio , Fricção , Humanos , Teste de Materiais , Propriedades de Superfície
20.
Acta Biomater ; 7(4): 1913-27, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21111072

RESUMO

The present research was aimed at developing surface coatings on ß titanium orthodontic archwires capable of protection against fluoride-induced corrosion. Cathodic arc physical vapor deposition PVD (CA-PVD) and magnetron sputtering were utilized to deposit thin films of titanium aluminium nitride (TiAlN) and tungsten carbide/carbon (WC/C) coatings on ß titanium orthodontic archwires. Uncoated and coated specimens were immersed in a high fluoride ion concentration mouth rinse, following a specially designed cycle simulating daily use. All specimens thus obtained were subjected to critical evaluation of parameters such as electrochemical corrosion behaviour, surface analysis, mechanical testing, microstructure, element release, and toxicology. The results confirm previous research that ß titanium archwires undergo a degradation process when in contact with fluoride mouth rinses. The study confirmed the superior nature of the TiAlN coating, evident as many fewer changes in properties after fluoride treatment when compared with the WC/C coating. Thus, coating with TiAlN is recommended in order to reduce the corrosive effects of fluorides on ß titanium orthodontic archwires.


Assuntos
Técnicas Eletroquímicas/métodos , Fluoretos/química , Fios Ortodônticos , Titânio/química , Acústica , Morte Celular , Linhagem Celular Tumoral , Sobrevivência Celular , Corrosão , Módulo de Elasticidade , Etídio/metabolismo , Humanos , Micronúcleos com Defeito Cromossômico , Microscopia Eletrônica de Varredura , Propriedades de Superfície , Fatores de Tempo
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