993 resultados para Fluxometria por laser-Doppler


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OBJETIVO: descrever os resultados do tratamento da síndrome de transfusão feto-fetal grave com a ablação vascular placentária a laser em um centro universitário do Brasil. MÉTODOS: estudo observacional retrospectivo que incluiu pacientes tratadas na Universidade Estadual de Campinas entre 2007 e 2009. A ablação vascular placentária foi realizada em casos de transfusão feto-fetal grave (estágios II, III e IV de Quintero) diagnosticados até a 26ª semana de gravidez. As principais variáveis avaliadas foram a idade gestacional no parto, a sobrevida (alta do berçário) de pelo menos um gêmeo e o comprometimento neurológico nos sobreviventes. Regressão logística foi utilizada para investigar a influência do comprimento do colo uterino, da idade gestacional e do estágio da doença (antes da cirurgia) sobre o parto/abortamento e o óbito fetal após a intervenção, sobre o parto pré-termo extremo e a sobrevida. RESULTADOS: em toda a amostra, pelo menos uma criança sobreviveu em 63,3% dos casos (19/30). Entre as gestantes que não tiveram parto/abortamento após à cirurgia, a sobrevida de pelo menos um gêmeo foi 82,6% (19/23). Nesse subgrupo (n=23), a idade gestacional média no parto foi 31,9 semanas e o comprometimento neurológico ocorreu em um neonato (1/31; 3,2%). O comprimento do colo uterino influenciou na ocorrência de parto/abortamento após a cirurgia (valor de p=0,008). Entre sete pacientes (7/30; 23,3%) que apresentaram essa complicação, cinco (5/7; 71,4%) tinham medidas do colo uterino menores do que 15 mm. Entre as 23 gestantes que não tiveram parto/abortamento após a cirurgia, os estágios mais avançados da doença (III e IV) aumentaram o risco de parto antes de 32 semanas (valor de p=0,025) e diminuíram a chance de sobrevida de ambas as crianças (valor de p=0,026). CONCLUSÕES: os resultados são semelhantes aos descritos na literatura. Na presente amostra, os principais fatores associados a piores resultados foram o colo uterino curto (menor do que 15 mm) e os estágios mais avançados da doença (III e IV) no momento em que o tratamento foi realizado.

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PURPOSE: To evaluate the effectiveness, recurrence rate, and complications of carbon-dioxide laser vaporization in the treatment of Bartholin's gland cysts. METHODS: A retrospective study including 127 patients with symptomatic Bartholin' gland cysts submitted to carbon-dioxide laser vaporization at our institution from January 2005 to June 2011. Patients with Bartholin's gland abscesses and those suspected of having neoplasia were excluded. All procedures were performed in an outpatient setting under local anaesthesia. Clinical records were reviewed for demographic characteristics, anatomic parameters, intraoperative and postoperative complications, and follow-up data. Data were stored and analyzed in Microsoft Excel® 2007 software. A descriptive statistical analysis was performed, and its results were expressed as frequency (percentage) or mean±standard deviation. Complication, recurrence, and cure rates were calculated. RESULTS: The mean age of the patients was 37.3±9.5 years-old (range from 18 to 61 years-old). Seventy percent (n=85) of them were multiparous. The most common symptom was pain and 47.2% (n=60) of patients had a history of previous medical and/or surgical treatment for Bartholin's gland abscesses. Mean cyst size was 2.7±0.9 cm. There were three (2.4%) cases of minor intraoperative bleeding. Overall, there were 17 (13.4%) recurrences within a mean of 14.6 months (range from 1 to 56 months): ten Bartholin's gland abscesses and seven recurrent cysts requiring reintervention. The cure rate after single laser treatment was 86.6%. Among the five patients with recurrent disease that had a second laser procedure, the cure rate was 100%. CONCLUSIONS: At this institution, carbon-dioxide laser vaporization seems to be a safe and effective procedure for the treatment of Bartholin's gland cysts.

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PURPOSE: To establish reference values for the first trimester uterine artery resistance index (UtA-RI) and pulsatility index (UtA-PI) in healthy singleton pregnant women from Northeast Brazil. METHODS: A prospective observational cohort study including 409 consecutive singleton pregnancies undergoing routine early ultrasound screening at 11 - 14 weeks of gestation was performed. The patients responded to a questionnaire to assess maternal epidemiological characteristics. The left and right UtA-PI and UtA-RI were examined by color and pulsed Doppler by transabdominal technique and the mean UtA-PI, mean UtA-RI and the presence of bilateral protodiastolic notching were recorded. Quartile regression was used to estimate reference values. RESULTS: The mean±standard deviation UtA-RI and UtA-PI were 0.7±0.1 and 1.5±0.5, respectively. When segregated for gestation age, mean UtA-PI was 1.6±0.5 at 11 weeks, 1.5±0.6 at 12 weeks, 1.4±0.4 at 13 weeks and 1.3±0.4 at 14 weeks' gestation and mean UtA-RI was 0.7±0.1 at 11 weeks, 0.7±0.1 at 12 weeks, 0.6±0.1 at 13 weeks and 0.6±0.1 at 14 weeks' gestation. Uterine artery bilateral notch was present in 261 (63.8%) patients. We observed that the 5th and 95th percentiles of the UtA-PI and UtA-RI uterine arteries were 0.7 and 2.3 and, 0.5 and 0.8, respectively. CONCLUSION: Normal reference range of uterine artery Doppler in healthy singleton pregnancies from Northeast Brazil was established. The 95th percentile of UtA-PI and UtA-RI values may serve as a cut-off for future prediction of pregnancy complications studies (i.e., pre-eclampsia) in Northeast Brazil.

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OBJETIVO: Avaliar resultados obstétricos e neonatais em gestantes com fetos pequenos para a idade gestacional após 35 semanas segundo a contagem de eritroblastos (EB) no sangue de cordão umbilical.MÉTODOS: A contagem de EB por 100 leucócitos no sangue do cordão umbilical foi obtida de 61 gestantes com fetos pequenos para a idade gestacional e Doppler umbilical normal. Estas foram divididas em 2 grupos: EB≥10 (grupo estudo, n=18) e EB<10 (grupo controle, n=43). Resultados obstétricos e neonatais foram comparados entre os grupos. Para a análise estatística, foram utilizados teste do χ2e t de Student, com nível de significância adotado de 5%.RESULTADOS: A média±desvio padrão de EB por 100 leucócitos foi de 25,0±13,5 para o grupo estudo e de 3,9±2,2 para o grupo controle. Os grupos EB≥10 e EB<10 não diferiram estatisticamente em relação à idade materna (24,0 versus 26,0 anos), primiparidade (55,8 versus 50%), comorbidades (39,5 versus 55,6%) e idade gestacional no parto (37,4 versus 37,0 semanas). O grupo EB≥10 apresentou maior taxa de cesárea (83,3 versus 48,8%, p=0,02), sofrimento fetal (60 versus 0%, p<0,001) e pH<7,20 (42,9 versus11,8%, p<0,001). O peso de nascimento e o percentil de peso para a idade gestacional foram significativamente menores no grupo EB≥10 (2.013 versus 2.309 g; p<0,001 e 3,8 versus 5,1; p=0,004; respectivamente). Não houve nenhum caso de Apgar de 5º minuto abaixo de 7.CONCLUSÃO: A contagem de EB acima de 10 por 100 leucócitos no sangue do cordão umbilical foi capaz de identificar maior risco de parto cesárea, sofrimento fetal e acidose de nascimento em fetos pequenos para a idade gestacional com dopplervelocimetria de artéria umbilical normal.

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This study investigated the surface hardening of steels via experimental tests using a multi-kilowatt fiber laser as the laser source. The influence of laser power and laser power density on the hardening effect was investigated. The microhardness analysis of various laser hardened steels was done. A thermodynamic model was developed to evaluate the thermal process of the surface treatment of a wide thin steel plate with a Gaussian laser beam. The effect of laser linear oscillation hardening (LLOS) of steel was examined. An as-rolled ferritic-pearlitic steel and a tempered martensitic steel with 0.37 wt% C content were hardened under various laser power levels and laser power densities. The optimum power density that produced the maximum hardness was found to be dependent on the laser power. The effect of laser power density on the produced hardness was revealed. The surface hardness, hardened depth and required laser power density were compared between the samples. Fiber laser was briefly compared with high power diode laser in hardening medium-carbon steel. Microhardness (HV0.01) test was done on seven different laser hardened steels, including rolled steel, quenched and tempered steel, soft annealed alloyed steel and conventionally through-hardened steel consisting of different carbon and alloy contents. The surface hardness and hardened depth were compared among the samples. The effect of grain size on surface hardness of ferritic-pearlitic steel and pearlitic-cementite steel was evaluated. In-grain indentation was done to measure the hardness of pearlitic and cementite structures. The macrohardness of the base material was found to be related to the microhardness of the softer phase structure. The measured microhardness values were compared with the conventional macrohardness (HV5) results. A thermodynamic model was developed to calculate the temperature cycle, Ac1 and Ac3 boundaries, homogenization time and cooling rate. The equations were numerically solved with an error of less than 10-8. The temperature distributions for various thicknesses were compared under different laser traverse speed. The lag of the was verified by experiments done on six different steels. The calculated thermal cycle and hardened depth were compared with measured data. Correction coefficients were applied to the model for AISI 4340 steel. AISI 4340 steel was hardened by laser linear oscillation hardening (LLOS). Equations were derived to calculate the overlapped width of adjacent tracks and the number of overlapped scans in the center of the scanned track. The effect of oscillation frequency on the hardened depth was investigated by microscopic evaluation and hardness measurement. The homogeneity of hardness and hardened depth with different processing parameters were investigated. The hardness profiles were compared with the results obtained with conventional single-track hardening. LLOS was proved to be well suitable for surface hardening in a relatively large rectangular area with considerable depth of hardening. Compared with conventional single-track scanning, LLOS produced notably smaller hardened depths while at 40 and 100 Hz LLOS resulted in higher hardness within a depth of about 0.6 mm.

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Left ventricular diastolic dysfunction plays an important role on heart failure progression. In order to obtain additional reference values of left ventricular diastolic parameters and investigate influence of common variables, peak E wave (peak E), peak A wave (peak A), E/A ratio (E/A), E wave deceleration time (EDT) and isovolumic relaxation time (IRVT) were studied in 40 clinically healthy dogs, by pulsed wave Doppler. The following values were obtained: peak E = 0.747 ± 0.117 m/s, peak A = 0.487 ± 0.062 m/s, E/A = 1.533 ± 0.198, EDT = 88.7 ± 9.2 ms and IRVT = 0.080 ± 0.009 s. Some parameters were influenced by heart rate (peak E, peak A and IRVT), by age (peak A and E/A) and by body weight (TRIV). Gender influence was absent. Values obtained can be used as reference for canine specimens but its interpretation should consider on the influence of related variables.