O objetivo deste trabalho foi avaliar a taxa de oxigenação (%SpO2) do tecido pulpar em pacientes com tumores malignos intraoral e de orofaringe, tratados através de radioterapia (RT). As mensurações da %SpO2 foram realizadas com o oxímetro de pulso (OP), o qual gera valores relativos à quantidade de oxigênio viável circulante no tecido pulpar, o que o caracteriza como um método fisiométrico de avaliação do status da polpa dental. Foram selecionados 20 pacientes, sendo avaliados dois dentes de cada um (n=40), independente do quadrante e da área de irradiação, em quatro tempos distintos: I- antes da RT; II- no início da RT com dose de radiação entre (30Gy 35Gy); III- ao final da RT (60Gy 70Gy) e IV- depois de 4 5 meses do início do tratamento oncológico. As médias obtidas nos quatro tempos avaliados foram de 93%, 83%, 77% e 85% de SpO2, respectivamente. Através do teste t de Student (p0.01) foram encontradas diferenças estatisticamente significantes entre o Tempo I e todos os outros três tempos, o Tempo III também mostrou diferença quando comparado ao Tempo II e, não houve diferença estatística entre os Tempos II e IV. É possível concluir que as taxas de %SpO2 antes da RT são maiores do que aquelas obtidas trans e pós RT e, como os valores no Tempo IV ficam próximos aos obtidos no Tempo II, pode haver uma recondutibilidade sanguínea normal posterior a radiação ionizante. / The aim of this study was to evaluate pulp oxygenation level (%SpO2) in patients with malignant intraoral and oropharyngeal tumors treated by radiotherapy (RT). Pulp oxygenation level was measured by pulse oximetry, which shows the amount of oxygen circulating in viable pulp tissue and is a physiometric method for assessment of dental pulp status. Twenty patients were selected and two teeth of each of them (n = 40) were analyzed, regardless of the quadrant and the area irradiated, at four different times: I- before RT; IIat the beginning of RT with radiation doses between 30Gy 35Gy; III- at the end of RT (60Gy 70Gy) and IV- after 4-5 months of the beginning of the cancer treatment. Mean %SpO2 in the different times was 93%, 83%, 77% and 85%, respectively. Students t test (p0.01) showed statistically significant differences between Time I and the other three times. Time III was also different when compared to Time II, and there was no statistical difference between Times II and IV. It was concluded that %SpO2 before RT was greater than that observed during and after therapy and, as values obtained in Time IV were close to those of Time II, pulp tissue may show normal blood flow after radiation therapy.

Abstract Patent foramen ovale (PFO) is a common finding in the general population and is present in approximately one quarter of adults. The potential role of PFO in the pathogenesis of ischaemic brain infarction of unknown aetiology in young adults has been investigated during the past 15 years, and associations with other diseases have been proposed. The most plausible mechanism of stroke associated with PFO is paradoxical embolism, but there is uncertainty about this because a venous source of emboli is seldom identified. If the theory of venous emboli is relevant, prothrombotic states should be associated with PFO and ischaemic stroke. Relatively little is known about the risk factors of cryptogenic brain infarction, although this subgroup of stroke is relatively common. As the present diagnostic methods for detecting PFO have certain limitations, new non-invasive, simple and reliable methods would be useful. Two new methods examined here, the dye dilution method and ear oximetry, were both found to be feasible and to be highly specific and sensitive in relation to the present gold standard, contrast transoesophageal echocardiography. A case-control study among adult patients with PFO and cryptogenic brain infarction showed the presence of a prothrombotic state, particularly factor V Leiden and prothrombin G2021OA gene mutation, to be associated with an increased risk of stroke, and migraine was also identified as a risk factor. Associations with the classical risk factors for venous thrombosis and Valsalva manoeuvre-like activities at the onset of stroke were also observed. The results lend support to the theory that paradoxical embolism is one of the pathogenic mechanisms behind cryptogenic brain infarction with associated PFO. In another case-control study among adult patients with cryptogenic brain infarction but without associated PFO, prothrombotic states were not identified as risk factors, except that an association was found between elevated factor VIII activity and stroke. The major independent risk factors for such cryptogenic strokes were current cigarette smoking, hypertension and a low level of high density lipoprotein cholesterol.

Pulse oximeters are used in operating rooms and recovery rooms as a monitoring device for oxygen in the respiratory system of the patient. The advantage of pulse oximeters over other methods of oxygen monitoring is that they are easy to use and they are non-invasive, which means it is not necessary break the skin to extract blood for information to be obtained. The standard for the measurement of partial pressure of CO2 and O2 is an arterial blood gas analysis (ABG). However routine monitoring using this method on a continuous basis is impractical since it is slow, painful and invasive. Measuring carbon dioxide is critical to preventing ailments such as carbon dioxide poisoning or hypoxia. The problem is, currently there is no known effective non-invasive method for accurately measuring carbon dioxide in the body to properly assess the adequacy of ventilation. The objective of this study was to experimentally use spectroscopy in the visible spectrum and the principles of operation of a pulse oximeter to incorporate a method of non-invasive real-time carbon dioxide monitoring that is as quick and easy to use.

Background. Premature infants are at risk for many complications. Among these, growth failure and intermittent hypoxia (IH) can independently impact the outcomes of other comorbidities. Recent data suggest that IH may directly affect postnatal growth. Our study aims to evaluate the impact of IH on growth velocity in preterm infants. Methods. This prospective cohort study utilized inpatient oximetry, nutrition, and growth data to evaluate the relationship between IH and growth velocity. Enrolled infants were dichotomized by high- versus low-exposure to IH. This relationship was explored in both unadjusted analyses and generalized linear models with repeated measures. Results. The study population included 19 preterm infants, with average birth gestational age of 29 weeks, each contributing one or more measures of weekly data. Infants in the high-exposure cohort had lower birth weight, higher rates of bronchopulmonary dysplasia, and longer duration of respiratory support and caffeine treatment. The unadjusted analysis revealed a marginally significant trend towards higher IH rates during weeks of slower growth. The logistic regression with repeated measures analysis also supported increased odds of slower growth associated with higher IH rates, but this relationship was also only marginally significant. Conclusion. Our study suggests a relationship between exposure to IH and slower growth velocity in preterm infants. The prospectively collected data allowed for accurate measures of IH, growth, and nutrition, but the small sample size likely contributed to the lack of significance of our results.

京都大学 / 0048 / 新制・課程博士 / 博士(社会健康医学) / 甲第19969号 / 社医博第74号 / 新制||社医||9(附属図書館) / 33065 / 京都大学大学院医学研究科社会健康医学系専攻 / (主査)教授 小池 薫, 教授 福田 和彦, 教授 木村 剛 / 学位規則第4条第1項該当 / Doctor of Public Health / Kyoto University / DFAM

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