Orthognathic surgery is frequently accompanied by intermaxillary fixation. Intermaxillary fixation impedes the maintenance of effective oral hygiene and prolonged fixation can result in periodontal disease. A potentia...Orthognathic surgery is frequently accompanied by intermaxillary fixation. Intermaxillary fixation impedes the maintenance of effective oral hygiene and prolonged fixation can result in periodontal disease. A potential shorter term effect is the generation of oral malodour. It is unclear, however, as to how the production of malodorous compounds in the oral cavity is altered post-surgery. Oral air concentration of sulphur containing compounds, short chain organic acids, ammonia, isoprene and acetone were measured using selected ion flow tube-mass spectrometry in a patient who had undergone orthognathic surgery with subsequent intermaxillary fixation. Total sulphide levels rose approximately 5-fold during fixation with metal ties, with smaller increases recorded for the other compounds measured with the exception of isoprene which remained close to baseline levels. Organic acid levels declined markedly once elastic ties had replaced metal ties, with a lesser reduction being observed in sulphide levels, with both declining further after the commencement of a chlorhexidinecontaining mouthwash. These data suggest that bacterial generation of a variety of malodorous compounds increases markedly following intermaxillary fixation. This single case also suggests that the use of elastic ties and effective oral hygiene techniques, including the use of chlorhexidine mouthwash, may help ameliorate such post-surgical effects.展开更多
Recently, biological technology and computer science are of great importance in medical applications. Since one’s breath biomarkers have been proved to be related with diseases, it is possible to detect diseases by a...Recently, biological technology and computer science are of great importance in medical applications. Since one’s breath biomarkers have been proved to be related with diseases, it is possible to detect diseases by analysis of breath samples captured by e-noses. In this paper, a novel medical e-nose system specific to disease diagnosis was used to collect a large-scale breath dataset. Methods for signal processing, feature extracting as well as feature & sensor selection were discussed for detecting diseases on respiratory, metabolic and digestive system. Sequential forward selection is used to select the best combination of sensors and features. The experimental results showed that the proposed system was able to well distinguish healthy samples and samples with different diseases. The results also showed the most significant sensors and features for different tasks, which meets the relationship between diseases and breath biomarkers. By selecting best combination of different sensors and features for different tasks, the e-nose system is shown to be helpful and effective for diseases diagnosis on respiratory, metabolic and digestive system.展开更多
Schizophrenia is a common and debilitating mental illness. The disorder is thought to be developmental in origin, with oxidative stress being implicated as possible pathophysiological mechanism. Breath alkanes provide...Schizophrenia is a common and debilitating mental illness. The disorder is thought to be developmental in origin, with oxidative stress being implicated as possible pathophysiological mechanism. Breath alkanes provide a non-invasive means to assess oxidative stress, with ethane levels reportedly increased in medicated patients with schizophrenia. It is possible, however, that the psychotropic medications used to treat the disorder result in elevated breath ethane levels. We have therefore measured the concentration of ethane and pentane, markers of oxidative stress, in the breath of currently unmedicated patients with schizophrenia. Alveolar breath samples were collected, applied to thermal desorption tubes, and analyzed using a combination of two-stage thermal de-sorption, gas chromatography and mass spectrometry. Compared to healthy controls ethane and pentane levels were found to be elevated in patients with schizophrenia, while levels of butane were normal. Our data support the notion that oxidative stress is increased in schizophrenia and that this is unlikely to be a consequence of antipsychotic medications. In addition, breath alkane analysis may represent a rapid and non-invasive means to monitor oxidative stress occurring in schizophrenia.展开更多
文摘Orthognathic surgery is frequently accompanied by intermaxillary fixation. Intermaxillary fixation impedes the maintenance of effective oral hygiene and prolonged fixation can result in periodontal disease. A potential shorter term effect is the generation of oral malodour. It is unclear, however, as to how the production of malodorous compounds in the oral cavity is altered post-surgery. Oral air concentration of sulphur containing compounds, short chain organic acids, ammonia, isoprene and acetone were measured using selected ion flow tube-mass spectrometry in a patient who had undergone orthognathic surgery with subsequent intermaxillary fixation. Total sulphide levels rose approximately 5-fold during fixation with metal ties, with smaller increases recorded for the other compounds measured with the exception of isoprene which remained close to baseline levels. Organic acid levels declined markedly once elastic ties had replaced metal ties, with a lesser reduction being observed in sulphide levels, with both declining further after the commencement of a chlorhexidinecontaining mouthwash. These data suggest that bacterial generation of a variety of malodorous compounds increases markedly following intermaxillary fixation. This single case also suggests that the use of elastic ties and effective oral hygiene techniques, including the use of chlorhexidine mouthwash, may help ameliorate such post-surgical effects.
文摘Recently, biological technology and computer science are of great importance in medical applications. Since one’s breath biomarkers have been proved to be related with diseases, it is possible to detect diseases by analysis of breath samples captured by e-noses. In this paper, a novel medical e-nose system specific to disease diagnosis was used to collect a large-scale breath dataset. Methods for signal processing, feature extracting as well as feature & sensor selection were discussed for detecting diseases on respiratory, metabolic and digestive system. Sequential forward selection is used to select the best combination of sensors and features. The experimental results showed that the proposed system was able to well distinguish healthy samples and samples with different diseases. The results also showed the most significant sensors and features for different tasks, which meets the relationship between diseases and breath biomarkers. By selecting best combination of different sensors and features for different tasks, the e-nose system is shown to be helpful and effective for diseases diagnosis on respiratory, metabolic and digestive system.
文摘Schizophrenia is a common and debilitating mental illness. The disorder is thought to be developmental in origin, with oxidative stress being implicated as possible pathophysiological mechanism. Breath alkanes provide a non-invasive means to assess oxidative stress, with ethane levels reportedly increased in medicated patients with schizophrenia. It is possible, however, that the psychotropic medications used to treat the disorder result in elevated breath ethane levels. We have therefore measured the concentration of ethane and pentane, markers of oxidative stress, in the breath of currently unmedicated patients with schizophrenia. Alveolar breath samples were collected, applied to thermal desorption tubes, and analyzed using a combination of two-stage thermal de-sorption, gas chromatography and mass spectrometry. Compared to healthy controls ethane and pentane levels were found to be elevated in patients with schizophrenia, while levels of butane were normal. Our data support the notion that oxidative stress is increased in schizophrenia and that this is unlikely to be a consequence of antipsychotic medications. In addition, breath alkane analysis may represent a rapid and non-invasive means to monitor oxidative stress occurring in schizophrenia.
