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1.
Clin Toxicol (Phila) ; 59(4): 320-325, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-32901533

RESUMO

INTRODUCTION: Calls to poison control about exposure to household cleaners have increased during the COVID-19 pandemic. This dynamic may reflect increased exposure from public health efforts as well as health misinformation shared on social media. METHODS: We analyzed the dynamics of calls to the Regional Center for Poison Control and Prevention serving Massachusetts and Rhode Island (MARI PCC) and tweets discussing treating COVID-19 with house cleaners from January 20, 2020 to May 5, 2020. We obtained publicly available tweets discussing the use of household cleaners to "cure COVID" from the same time period with geographic co-ordinates indicating that they were emitted from the Greater Boston Area. RESULTS: Our main finding is that public health efforts were followed by a sustained increase in calls after March 15, 2020 (10 ± 2 calls per day before to 15 ± 2.5 after) while misinformation on social media was associated with intermittent spikes in calls. Overall, calls significantly increased during the study period by 34% as compared to the previous 8 years, mostly reporting unintentional ingestions with no serious effects. The daily volume of tweets and retweets was significantly correlated with daily call rates to MARI PCC for the surrounding 7-10 days. CONCLUSIONS: Health misinformation on social media about using household cleaning agents to treat COVID-19 and public health efforts lead to different dynamics in PCC calls. Public health efforts were followed by a sustained increase in calls after March 15, 2020 while misinformation on social media was followed by intermittent spikes in calls. This analysis is the first to link the geospatial dynamics of social media and public health interventions to poison center calls about exposure to household cleaners.


Assuntos
COVID-19/terapia , Comunicação , Detergentes , Centros de Controle de Intoxicações , Mídias Sociais , Amônia/administração & dosagem , Amônia/efeitos adversos , Amônia/intoxicação , Boratos/administração & dosagem , Boratos/efeitos adversos , Boratos/intoxicação , Boston , COVID-19/psicologia , Detergentes/administração & dosagem , Detergentes/efeitos adversos , Detergentes/intoxicação , Humanos , Massachusetts , Fenol/administração & dosagem , Fenol/efeitos adversos , Fenol/intoxicação , Centros de Controle de Intoxicações/estatística & dados numéricos , Distribuição de Poisson , Rhode Island , Mídias Sociais/estatística & dados numéricos , Mídias Sociais/tendências , Hipoclorito de Sódio/administração & dosagem , Hipoclorito de Sódio/efeitos adversos , Hipoclorito de Sódio/intoxicação
2.
J Trace Elem Med Biol ; 62: 126569, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32563862

RESUMO

Boron is an essential trace element in cellular metabolism; however, the molecular mechanism of boron in the heart is unclear. In this study, we examined the effect of sodium tetraborate (as boron source) as a possible protective agent or competitive inhibitor of cardiac hypertrophy in an in vitro murine model. We evaluated different previously reported sodium tetraborate concentrations and it was found that 13 µM improves viability without affecting the cellular structure. We demonstrated that cardiomyocytes pretreated with sodium tetraborate prevents cellular damage induced by isoproterenol (cardioprotective effect) by increasing proliferation rate and inhibiting apoptosis. In addition, the reduction of the expression of the α1AR and ß1AR adrenergic receptors as well as Erk1/2 was notable. Consequently, the expression of the early response genes c-myc, c-fos and c-jun was delayed. Also, the expression of GATA-4, NFAT, NKx2.5 and myogenin transcription factors involved in sarcomere synthesis declined. In contrast, cardiomyocytes, when treated simultaneously with sodium tetraborate and isoproterenol, did not increase their size (cytoplasmic gain), but an increase in apoptosis levels was observed; therefore, the proliferation rate was reduced. Although the mRNA levels of α1AR and ß1AR as well as Erk1/2 and Akt1 were low at 24 h, their expression increased to 48 h. Notably, the mRNA of expression levels of c-myc, c-fos and c-jun were lower than those determined in the control, while the transcription factors GATA-4, MEF2c, Nkx2.5, NFAT and CDk9 were determined in most cells. These results suggest that pretreatment with sodium tetraborate in cardiomyocytes inhibits the hypertrophic effect. However, sodium tetraborate attenuates isoproterenol induced hypertrophy damage in cardiomyocytes when these two compounds are added simultaneously.


Assuntos
Boratos/farmacologia , Cardiomegalia/induzido quimicamente , Cardiomegalia/metabolismo , Cardiotônicos/farmacologia , Miócitos Cardíacos/efeitos dos fármacos , Animais , Apoptose/efeitos dos fármacos , Boratos/administração & dosagem , Boratos/efeitos adversos , Cardiotônicos/efeitos adversos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Regulação da Expressão Gênica/efeitos dos fármacos , Isoproterenol/administração & dosagem , Isoproterenol/efeitos adversos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Camundongos Endogâmicos BALB C , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Receptores Adrenérgicos alfa 1/genética , Receptores Adrenérgicos beta 2/genética , Transdução de Sinais/efeitos dos fármacos , Fatores de Transcrição/metabolismo
7.
J Endod ; 44(11): 1731-1735, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30266467

RESUMO

INTRODUCTION: Intraorifice barriers (IOBs) are usually used before internal bleaching for coronal sealing and the prevention of cervical resorption. The aim of this study was to investigate the effect of different IOBs on the fracture resistance (FR) of endodontically treated anterior teeth bleached with various bleaching agents (BAs). METHODS: After performing root canal treatment for 72 extracted bovine upper incisors, the coronal 3 mm of gutta-percha was removed, and samples were classified into 3 based on the type of IOB: calcium-enriched mixture, mineral trioxide aggregate, and resin-modified glass ionomer. After applying IOBs, samples of each group were subdivided into 4 based on the BA: carbamide peroxide 45% (CP), hydrogen peroxide 35% (HP), sodium perborate (PB), and distilled water as the control. At the end of bleaching, the access cavities were restored with composite resin. The FR was measured with a universal testing machine at a crosshead speed of 5 mm/min. The data were analyzed using 2-way analysis of variance and least significant difference post hoc tests (P < .05). RESULTS: The effect of BAs on the FR was significant (P < .05); however, the effect of the IOB and the interactive effect of these variables were not significant (P > .05). The FR in the HP and PB groups was significantly different from the control (P < .05) but that of CP was not significantly different from the control (P > .05). CONCLUSIONS: Mineral trioxide aggregate and calcium-enriched mixture act similarly to resin-modified glass ionomer as an IOB. CP, unlike HP and PB, did not significantly decrease the FR.


Assuntos
Clareadores/efeitos adversos , Força Compressiva/efeitos dos fármacos , Análise do Estresse Dentário , Materiais Restauradores do Canal Radicular , Clareamento Dental/efeitos adversos , Fraturas dos Dentes/etiologia , Dente não Vital , Animais , Boratos/efeitos adversos , Cálcio , Peróxido de Carbamida/efeitos adversos , Bovinos , Cimentos de Ionômeros de Vidro , Peróxido de Hidrogênio/efeitos adversos , Técnicas In Vitro , Tratamento do Canal Radicular , Fraturas dos Dentes/prevenção & controle
10.
J Nucl Med ; 58(10): 1666-1671, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28385795

RESUMO

We report the safety, biodistribution, and internal radiation dosimetry, in humans with thyroid cancer, of 18F-tetrafluoroborate (18F-TFB), a novel PET radioligand for imaging the human sodium/iodide symporter (hNIS). Methods: Serial whole-body PET scans of 5 subjects with recently diagnosed thyroid cancer were acquired before surgery for up to 4 h after injection of 184 ± 15 MBq of 18F-TFB. Activity was determined in whole blood, plasma, and urine. Mean organ-absorbed doses and effective doses were calculated via quantitative image analysis and using OLINDA/EXM software. Results: Images showed a high uptake of 18F-TFB in known areas of high hNIS expression (thyroid, salivary glands, and stomach). Excretion was predominantly renal. No adverse effects in relation to safety of the radiopharmaceutical were observed. The effective dose was 0.0326 ± 0.0018 mSv/MBq. The critical tissues/organs receiving the highest mean sex-averaged absorbed doses were the thyroid (0.135 ± 0.079 mSv/MBq), stomach (0.069 ± 0.022 mSv/MBq), and salivary glands (parotids, 0.031 ± 0.011 mSv/MBq; submandibular, 0.061 ± 0.031 mSv/MBq). Other organs of interest were the bladder (0.102 ± 0.046 mSv/MBq) and kidneys (0.029 ± 0.009 mSv/MBq). Conclusion: Imaging using 18F-TFB imparts a radiation exposure similar in magnitude to many other 18F-labeled radiotracers. 18F-TFB shows a biodistribution similar to 99mTc-pertechnetate, a known nonorganified hNIS tracer, and is pharmacologically and radiobiologically safe in humans. Phase 2 trials for 18F-TFB as an hNIS imaging agent are warranted.


Assuntos
Boratos/farmacocinética , Ácidos Bóricos/farmacocinética , Regulação Neoplásica da Expressão Gênica , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Segurança , Simportadores/metabolismo , Neoplasias da Glândula Tireoide/diagnóstico por imagem , Neoplasias da Glândula Tireoide/metabolismo , Boratos/efeitos adversos , Boratos/metabolismo , Ácidos Bóricos/efeitos adversos , Ácidos Bóricos/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Radiometria , Distribuição Tecidual
12.
J Prosthet Dent ; 115(5): 606-10, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26775247

RESUMO

STATEMENT OF PROBLEM: Various Locator abutments and attachments are available commercially for use in overdenture patients. Patients are advised to use cleansing agents to keep their overdentures clean. The effect of different cleansing agents on attachments with different retention is not known. PURPOSE: The purpose of this in vitro study was to evaluate the retention of 3 Locator abutment attachments after they were soaked in 3 different cleansing solutions. MATERIAL AND METHODS: An implant analog with a diameter of 4.1 mm was embedded into acrylic resin, and 1 Locator abutment was placed onto the analog. Seven specimens of clear, pink, and blue Locator attachments (n=7) were soaked in 3 different denture-cleansing solutions (NaOCl, sodium perborate, sodium perborate-sodium bicarbonate) for a time simulating 6 months of clinical use. The control group was soaked in tap water. A testing machine was used to test the attachments' retention. The retention of the attachments after they were soaked in denture cleansers was compared among the groups with repeated-measures analysis of variance followed by the Tukey HSD test (α=.05). RESULTS: The retention of the clear attachments was significantly less after they had been soaked in sodium bicarbonate-containing denture cleanser (P=.001). The retention of the pink Locator attachments was no different after they had been soaked in the different solutions, and the retention of the blue Locator attachments decreased significantly after they had been soaked in the NaOCl and sodium bicarbonate cleansing agents (P=.002). CONCLUSIONS: Attachments of different colors and retention were affected differently by cleansing agents.


Assuntos
Higienizadores de Dentadura/efeitos adversos , Retenção de Dentadura , Revestimento de Dentadura , Boratos/efeitos adversos , Dente Suporte , Humanos , Técnicas In Vitro , Bicarbonato de Sódio/efeitos adversos , Hipoclorito de Sódio/efeitos adversos
13.
Beijing Da Xue Xue Bao Yi Xue Ban ; 44(6): 946-9, 2012 Dec 18.
Artigo em Chinês | MEDLINE | ID: mdl-23247464

RESUMO

OBJECTIVE: To study the change in properties of heat-polymerized acrylic resin after using one denture cleanser. METHODS: In the study, 20 disk-shaped (50.0 mm×0.5 mm) and 40 rectangular (34.0 mm×13.5 mm×1.3 mm) specimens prepared from heat-polymerized acrylic resin were randomly divided into four groups. The specimens were exposed to one of the three treatments as follows: Group 1 was without any treatment, Group 2 was exposed to air, Group 3 to distilled water, and Group 4 to Polident. The 4 exposures lasting 8 hours were conducted daily and repeated for 30 days. The color stability of heat-polymerized acrylic resin was determined by visual methods. The flexural strength and bonding strength of acrylic resin were measured using a universal testing machine. All the results were analyzed using ANOVA. RESULTS: The flexural strength test of acrylic resin demonstrated significant differences between Group 4 and Group 1 (P<0.05), there were no significant differences among Group 1, Group 2 and Group 3. No significant differences were found in other properties of the test materials. CONCLUSION: Long-term use of polident could alter the physical and mechnical properties of heat-polymerized acrylic resin. It may be related to the accelerating aging of resins caused by certain chemicals in denture cleansers. Polident may have some adverse effects on denture materials for decreasing flexural strength of heat-polymerized acrylic resin after 30-day immersion.


Assuntos
Resinas Acrílicas/química , Boratos/efeitos adversos , Materiais Dentários/química , Higienizadores de Dentadura/efeitos adversos , Sulfatos/efeitos adversos , Boratos/farmacologia , Higienizadores de Dentadura/farmacologia , Polímeros , Estresse Mecânico , Sulfatos/farmacologia
14.
Dent Traumatol ; 28(3): 238-42, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22099532

RESUMO

OBJECTIVES: To compare the fracture resistance of bovine teeth after intracoronal bleaching with sodium percarbonate (SPC) or sodium perborate (SP) mixed with water or 20% hydrogen peroxide (HP). MATERIALS AND METHODS: Fifty extracted bovine teeth were divided into four experimental groups (G1-G4) and one control (n = 10) after endodontic treatment. Following root canal obturation, a glass ionomer barrier was placed at the cemento-enamel junction. After that, the pulp chambers were filled with: G1 - SP with water; G2 - SP with 20% HP; G3 - SPC with water; and G4 - SPC with 20% HP. No bleaching agent was used in the control group. Coronal access cavities were sealed with glass ionomer and specimens were immersed in artificial saliva. The bleaching agents were replaced after 7 days, and teeth were kept in artificial saliva for an additional 7 days, after which the pastes were removed and the coronal access cavities were restored with glass ionomer. Crowns were subjected to compressive load at a cross head speed of 0.5 mm min(-1) applied at 135° to the long axis of the root by an EMIC DL2000 testing machine, until coronal fracture. Data were statistically analysed by anova and Tukey test. RESULTS: No differences in fracture resistance were observed between the experimental groups (P > 0.05). However, all experimental groups presented lower fracture resistance than the control group (P < 0.05). CONCLUSION: SPC and SP led to equal reduction on fracture resistance of dental crowns, regardless of being mixed with water or 20% HP.


Assuntos
Clareadores/efeitos adversos , Boratos/efeitos adversos , Carbonatos/efeitos adversos , Coroas , Peróxido de Hidrogênio/efeitos adversos , Clareamento Dental/efeitos adversos , Fraturas dos Dentes , Animais , Bovinos , Clareamento Dental/métodos , Fraturas dos Dentes/etiologia
15.
J Clin Pediatr Dent ; 35(3): 289-94, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21678672

RESUMO

OBJECTIVES: External root resorption is the complication of intra-coronal bleaching done with 30% H2O2 alone or mixed with sodium perborate but not with sodium perborate mixed with water. The study was done to comparatively evaluate the H2O2 leakage from three H2O2 liberating bleaching agents. STUDY DESIGN: Fifty one single rooted human teeth were used. After root canal therapy gutta percha was removed below cemento-enamel junction. Three bleaching agents: sodium perborate mixed with water, sodium perborate mixed with 30% H2O2 and 30% H2O2 alone were used. Teeth without defect, with cervical root defect and with mid root defect constituted group A, group B and group C. According to various bleaching agents groups were subdivided into subgroup 1, 2 and 3. H2O2 leakage was measured with the help of spectrophotometer RESULTS: Almost all teeth showed H2O2 leakage. It was maximum in B1 followed by C1, B2, A1, A2, C2, B3, A3 and C3. CONCLUSION: Sodium perborate mixed with water was found to be the best bleaching agent.


Assuntos
Infiltração Dentária/induzido quimicamente , Cavidade Pulpar/efeitos dos fármacos , Peróxido de Hidrogênio/administração & dosagem , Clareadores Dentários/administração & dosagem , Clareamento Dental/métodos , Raiz Dentária/efeitos dos fármacos , Boratos/administração & dosagem , Boratos/efeitos adversos , Relação Dose-Resposta a Droga , Humanos , Peróxido de Hidrogênio/efeitos adversos , Reabsorção da Raiz/induzido quimicamente , Reabsorção da Raiz/prevenção & controle , Clareadores Dentários/efeitos adversos , Colo do Dente/efeitos dos fármacos , Coroa do Dente/efeitos dos fármacos , Descoloração de Dente/terapia
16.
Biol Trace Elem Res ; 144(1-3): 253-63, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21607703

RESUMO

The objective of this pilot study was to determine whether 15 days of dietary supplementation with calcium fructoborate could acutely modulate inflammatory and lipid blood markers in individuals diagnosed with primary osteoarthritis. During 2 weeks, a placebo-controlled, randomized, double-blind study was conducted on 116 subjects that were initially recruited. Seventy-two subjects started the study, being divided into four groups, and only 60 completed the study as designed. The aim was to compare the effects of calcium fructoborate to placebo on subjects diagnosed with knee primary osteoarthritis. The obtained outcomes were inflammation biomarkers (C-reactive protein, fibrinogen, and erythrocyte sedimentation rate) and lipid markers (triglycerides, total cholesterol, LDL cholesterol, and HDL cholesterol). No serious adverse events were reported. The calcium fructoborate showed beneficial effect on the inflammatory markers for all groups subjected to the treatment when compared with the placebo group and slight changes in the lipid metabolism. This study suggests that short-term (2 weeks) calcium fructoborate supplementation in patients with osteoarthritis symptoms has a favorable prognosis on inflammation diseases.


Assuntos
Boratos/uso terapêutico , Suplementos Nutricionais , Dislipidemias/sangue , Dislipidemias/dietoterapia , Frutose/análogos & derivados , Inflamação/sangue , Inflamação/dietoterapia , Osteoartrite/sangue , Osteoartrite/dietoterapia , Idoso , Idoso de 80 Anos ou mais , Sedimentação Sanguínea , Boratos/efeitos adversos , Proteína C-Reativa/análise , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Método Duplo-Cego , Feminino , Fibrinogênio/análise , Frutose/efeitos adversos , Frutose/uso terapêutico , Humanos , Metabolismo dos Lipídeos/efeitos dos fármacos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Resultado do Tratamento , Triglicerídeos/sangue
17.
Ter Arkh ; 81(8): 70-2, 2009.
Artigo em Russo | MEDLINE | ID: mdl-19799205

RESUMO

AIM: To examine efficacy and tolerance of the drug Bora-Bora in patients with osteoarthrosis. MATERIAL AND METHODS: Bora-Bora and nimesulid were given to 20 patients with a verified diagnosis of osteoarthrosis (OA). 20 control patients received nimesulid alone. Treatment efficacy was evaluated by quantitative parameters of articular syndrome, indices of periarticular muscles affection estimated before the treatment, 2, 6 and 8 weeks after the start of the treatment. Ultrasonic investigation of the joints and periarticular tissues was conducted before and after the treatment course. RESULTS: The response to Bora-Bora was seen on day 10 of therapy. Bora-Bora attenuated pain syndrome in the joints and periarticular tissues, improved joint function more effectively than nimesulid (p < 0.05). Bora-Bora is a good anelgetic. It is well tolerated and can be recommended for OA treatment.


Assuntos
Anti-Inflamatórios não Esteroides/uso terapêutico , Boratos/uso terapêutico , Suplementos Nutricionais , Frutose/análogos & derivados , Osteoartrite/tratamento farmacológico , Sulfonamidas/uso terapêutico , Anti-Inflamatórios não Esteroides/administração & dosagem , Anti-Inflamatórios não Esteroides/efeitos adversos , Boratos/administração & dosagem , Boratos/efeitos adversos , Quimioterapia Combinada , Feminino , Frutose/administração & dosagem , Frutose/efeitos adversos , Frutose/uso terapêutico , Humanos , Masculino , Pessoa de Meia-Idade , Osteoartrite/diagnóstico por imagem , Radiografia , Índice de Gravidade de Doença , Sulfonamidas/administração & dosagem , Sulfonamidas/efeitos adversos , Resultado do Tratamento , Ultrassonografia
18.
Int Endod J ; 41(7): 556-60, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18355252

RESUMO

AIM: To evaluate and compare radicular peroxide diffusion from different concentrations of carbamide peroxide bleaching gels. METHODOLOGY; Fifty maxillary premolar teeth were separated into five groups (n = 10). Standardized endodontic access cavities were prepared in the occlusal surfaces, and the root canals were prepared using a step back technique and filled using the lateral compaction technique. The gutta-percha filling was removed 4 mm short of the cemento-enamel junction (CEJ) and a 2-mm-thick glass-ionomer cement base was placed. Outer root surfaces were sealed with wax and nail polish, leaving the coronal third of the tooth and the CEJ exposed. All teeth were immersed in a plastic tube containing 2 mL of distilled water, and the experimental groups were treated with a bleaching agent of either 10%, 17% or 37% carbamide peroxide (CP) or a mixture of 30% hydrogen peroxide (HP) and sodium perborate (SP) placed into the coronal pulp chamber of teeth and left for 24 h. Peroxide penetration was measured using the ferrothiocyanate method. Statistical analysis of data was conducted by using the Kruskal-Wallis Analysis of Variance and Mann-Whitney U test. RESULTS: Higher peroxide penetration occurred with the 30% HP-SP mixture than with the CP bleaching gels, and the 37% CP group also promoted greater peroxide penetration than the other CP groups (P < 0.05). There was no statistically significant difference between 10% and 17% CP groups (P > 0.05). CONCLUSION: Peroxide penetration of CP gels was significantly lower than that of a HP-SP mixture.


Assuntos
Extravasamento de Materiais Terapêuticos e Diagnósticos/etiologia , Clareamento Dental/efeitos adversos , Adulto , Boratos/administração & dosagem , Boratos/efeitos adversos , Peróxido de Carbamida , Difusão , Combinação de Medicamentos , Humanos , Peróxido de Hidrogênio/administração & dosagem , Peróxido de Hidrogênio/efeitos adversos , Oxidantes/administração & dosagem , Oxidantes/efeitos adversos , Peróxidos/administração & dosagem , Peróxidos/efeitos adversos , Reabsorção da Raiz/etiologia , Estatísticas não Paramétricas , Dente não Vital , Ureia/administração & dosagem , Ureia/efeitos adversos , Ureia/análogos & derivados
19.
Int Arch Occup Environ Health ; 81(3): 337-45, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17609973

RESUMO

OBJECTIVES: (1) To assess the relation between occupationally relevant exposures to dust of boric acid and magnitude of feel in the eye, nose, and throat during activity (pedaling) equal to light industrial work. (2) To compare feel from the dust of boric acid with that of the alkaline dusts calcium oxide and sodium tetraborate pentahydrate (sodium borate). (3) To chart how magnitude of feel changes with time in exposures up to 3/4 h. METHODS: Twelve subjects, six males and six females, participated in duplicate sessions of exposure to 2.5, 5, and 10 mg m(-3) of boric acid, 10 mg m(-3) of sodium borate, 2.5 mg m(-3) of calcium oxide presented as calcium oxide alone or diluted with hydrated calcium sulfate, and 0 mg m(-3) (blank). Exposures occurred in a plastic dome suspended over the head and closed around the neck with rubber dam. Measurements pre- and post-exposure included nasal secretion and nasal resistance. Measurements during exposure included rated magnitude of feel in the eye, nose, and throat, and respiration (Respitrace System). Six concentrations of carbon dioxide ranging from just below detectable to sharply stinging gave subjects references for their ratings. RESULTS: In general, feel increased for periods up to half an hour, then either declined or held at a plateau. Each material had a temporal signature. The nose led with the highest feel, followed by the throat, then the eyes. This hierarchy proved weakest for boric acid; at one level of exposure, magnitude in the throat overtook that in the nose. Accompanying measures implied that change of feel with time occurred neither because of an increase in dilution of the dissolved dusts in newly secreted mucus nor an increase of consequence in nasal resistance. Most likely, sensory adaptation determined the change. Boric acid of 10 mg m(-3) fell slightly and insignificantly below 10 mg m(-3) sodium borate in feel. Boric acid, though, showed a relatively flat dose-response relationship, i.e., a change in level caused little change in feel. CONCLUSIONS: The time-constant for feel from dusts lies on the order of tens of minutes. A flat concentration-response function for boric acid and a notable response from the throat suggests that perceived dryness, not mediated by acidity but perhaps by osmotic pressure, may account for the feel evoked at levels of exposure at or below 10 mg m(-3). More acidic dusts that could actually change nasal pH may trigger sensations differently.


Assuntos
Poluentes Ocupacionais do Ar/efeitos adversos , Boratos/efeitos adversos , Ácidos Bóricos/efeitos adversos , Compostos de Cálcio/efeitos adversos , Exposição Ocupacional/efeitos adversos , Óxidos/efeitos adversos , Adolescente , Adulto , Boratos/administração & dosagem , Ácidos Bóricos/administração & dosagem , Compostos de Cálcio/administração & dosagem , Poeira , Orelha Interna/fisiopatologia , Teste de Esforço , Feminino , Humanos , Masculino , Nariz/fisiopatologia , Óxidos/administração & dosagem , Faringe/fisiopatologia
20.
Dent Update ; 34(2): 98-100, 103-4, 107, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17432774

RESUMO

UNLABELLED: There is an increasing move towards more minimally invasive techniques in restorative dentistry. This series of two articles discusses conservative techniques for the treatment of discoloured teeth. A step-wise approach to treatment is promoted to encourage the most conservative solution to achieve satisfactory aesthetics. The first of these two articles will describe the use of bleaching, whilst part two will go on to describe microabrasion and the use of direct composite resin. CLINICAL RELEVANCE: Discoloured teeth are a common dental problem. Bleaching provides a simple conservative solution in many cases.


Assuntos
Clareamento Dental/métodos , Descoloração de Dente/tratamento farmacológico , Boratos/efeitos adversos , Boratos/uso terapêutico , Peróxido de Carbamida , Dispositivos para o Cuidado Bucal Domiciliar , Sensibilidade da Dentina/induzido quimicamente , Combinação de Medicamentos , Doenças da Gengiva/induzido quimicamente , Humanos , Peróxido de Hidrogênio/efeitos adversos , Peróxido de Hidrogênio/uso terapêutico , Oxidantes/efeitos adversos , Oxidantes/uso terapêutico , Peróxidos/efeitos adversos , Peróxidos/uso terapêutico , Recidiva , Reabsorção da Raiz/induzido quimicamente , Dente não Vital/terapia , Ureia/efeitos adversos , Ureia/análogos & derivados , Ureia/uso terapêutico
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