Search PubMed⌕ Search

Biomedical subjects

S Aronson

Publications and source records attributed to S Aronson.

At least 91 records · Page 5Linked to original sources
PubMed1984

Injuries to the bronchi and lungs caused by laser-ignited endotracheal tube fires.

A CO2 laser attached to an operating room microscope was used to produce extraluminal and intraluminal ignition of various endotracheal tubes in dogs. Extraluminal ignition was produced in Silastic and red rubber endotracheal tubes. The red rubber tube ignited before the tube lumen was penetrated. The Silastic tube failed to ignite while the cuff was inflated. When the cuff was deflated, ignition occurred before the lumen was penetrated. No lung or bronchial injuries were detected in the red rubber or Silastic endotracheal tube extraluminal fires. Intraluminal fires were produced in Silastic, red rubber, and polyvinylchloride (PVC) endotracheal tubes. Microscopic examination of the bronchi and lungs revealed severe injuries in dogs intubated with the PVC and red rubber endotracheal tubes. No injuries to the bronchi and lungs were detected in the Silastic tube group, although the potentially toxic effects of silica ash require further investigation.

Animals↗
PubMed1981

Growth disturbance after physial injury of distal femur and proximal tibia studied by roentgen stereophotogrammetry.

Longitudinal growth determined by roentgen stereophotogrammetry was registered in three patients with physial injuries in distal femur and in two patients with physial injuries in proximal tibia during 18 months. The injuries in distal femur were classified as Type I, Type I kII and Type IV and in proximal tibia as Type I kII and Type IV in the different cases according to Salter and Harris. Markers of tantalum balls were implanted into the metaphysis and bony epiphysis of distal femur and proximal tibia permitting regular determination of longitudinal growth. Significant growth disturbances was registered in four patients. The Salter-Harris classification was difficult to use to predict growth disturbance after physial injuries around the knee. The roentgen stereophotogrammetric method was found useful to determine normal growth rate and after physial injuries to reveal growth disturbance leading to complete or partial growth arrest resulting in leg length discrepancy or angular deformity. This method facilitates preoperative planning if surgery is needed.

Adolescent↗
PubMed1975

Postirradiation syndrome and eeg findings in children with acute lymphoblastic leukaemia.

Out of 12 children with acute lymphoblastic leukaemia treated with craniospinal irradiation during primary haematologic remission, 8 developed a postirradiation syndrome characterized by fever and tiredness. The symptoms lasted 1-2 weeks and subsided spontaneously. Longitudinal EEG studies revealed no acute disturbances during the irradiation therapy but in all cases studied, moderate to severe diffuse general slowing developed during the postirradiation syndrome. Complete normalization of the EEG occurred in all children at follow-up. It is concluded that the described EEG abnormalities constitute an integral part of the postirradiation syndrome.

Adolescent↗
PubMedDate not supplied

The influence of intravenous Albunex injections on pulmonary arterial pressure, gas exchange, and left ventricular peak intensity.

Contrast ultrasonography may be used to assess regional tissue perfusion. The purpose of this study was to evaluate the safety and efficacy of a new, commercially prepared ultrasound contrast agent (Albunex) in dogs. The injections were administered from peripheral intravenous (IV), right atrial (RA), and pulmonary artery (PA) sites. Acute pulmonary hemodynamic and gas exchange effects of low-dose (0.5, 1.0, 2.0 ml) Phase I injections, and high-dose (2.0, 5.0, 10, 20 ml) Phase II injections of Albunex were evaluated in nine dogs. Immediately before and after each injection, pulmonary artery pressure (PAP) and oxygen tension (PO2) were determined. In addition, left ventricular cavity opacification was assessed visually and by videodensitometric off-line analysis. Visual assessment was performed by four blinded observers who graded on a scale of 0 to 3 (0 = no contrast enhancement of the left ventricular (LV) cavity; 1 = weak or suboptimal contrast enhancement; 2 = optimal or excellent contrast enhancement; and 3 = attenuation of the ultrasound signal following a contrast injection). Peak pixel intensity was also determined with videodensitometric analysis. Results showed that significant changes in PAP or PO2 were not noted after Albunex injections, regardless of injection site or dose range. The average change in PAP after Albunex injection was 1.0 mm Hg +/- 1.2 mm Hg (NS), and the average change in PO2 after Albunex injections was 6.2 mm Hg +/- 6.7 mm Hg (NS). The left ventricular cavity peak pixel intensity was dependent on both injection site (PA = RA > IV) and dose range (2.0 = 1.0 > 0.5).(ABSTRACT TRUNCATED AT 250 WORDS)

Albumins↗
PubMedDate not supplied

Pitfalls in quantitative contrast echocardiography: the steps to quantitation of perfusion.

Current methods used clinically to assess myocardial perfusion are invasive and expensive. As the technology of ultrasound imaging improves, CE may provide a relatively inexpensive, noninvasive means of quantitating myocardial perfusion. Issues regarding stability of microbubble contrast agents must be studied more closely under physiologic conditions. As such, encapsulated microbubbles may provide more stability under physiologic pressures than free gas microbubbles. Introducing high concentrations of contrast, either by hyperconcentrating the contrast agent or by increasing the injection rate, may provide greater stability under physiologic conditions. Further, before quantitative statement of tissue perfusion can be made, the relationship between tracer concentration and system response must be established. Further, a "linear" postprocessing ultrasound setting does not eliminate this requirement as data must still undergo nonlinear transformation during log compression and time-gain compensation. Additionally, issues regarding "electronic thresholding" must be explored more extensively in vivo. Commercial ultrasound scanners, in their present form, may not offer adequate sensitivity for absolute quantitative studies. Further development of modified ultrasound systems may provide sufficient sensitivity for quantitative perfusion imaging. CE offers a potentially powerful tool in the clinical management of patients with ischemic heart disease. Conventional coronary angiography provides information on the size of a lesion, but accompanying tissue perfusion distal to the lesion cannot be determined. Doppler ultrasonography determines velocity of blood flow in large vessels but does not offer the potential to quantitate tissue perfusion. Clearly, CE has a place in the future of diagnostic imaging. The recent work of Ito et al. demonstrated the qualitative potential of CE in the identification of "areas at risk" in patients who had undergone thrombolysis or percutaneous transluminal coronary angioplasty after an acute myocardial infarction. With further improvement in the ultrasound imaging techniques and microbubble stability, CE may offer an inexpensive, noninvasive means of assessing myocardial perfusion.

Albumins↗
PubMedDate not supplied

In vitro calculation of flow by use of contrast ultrasonography.

Contrast echocardiography has been used for qualitative assessment of cardiac function, and its potential for quantitative assessment of blood flow is being explored. With the development of an ultrasound contrast agent capable of passage through the microcirculation, a mathematical model based on classic dye dilution theory, and a digital ultrasound acquisition system, absolute quantitation of myocardial perfusion may be feasible. This study validates the mathematical model in a simple in vitro tube system. Flow was delivered at variable rates through an in vitro tube system while a longitudinal section was imaged with a modified commercial ultrasound scanner. Albunex contrast agent was injected, and videointensity data were captured and analyzed off line. Time-intensity curves were generated, and flow was calculated by use of a mathematical model derived from classic dye dilution mathematics. For 39 different flow rates, ranging for 9.2 to 110 ml/seconds, a correlation coefficient of r = 0.928 (p < 0.001) with a slope of 0.97 was calculated. We conclude that (1) contrast ultrasonography is capable of quantitative determination of flow in an in vitro system, and (2) a mathematical model based on dye dilution theory can be used to calculate flow with accuracy and precision.

Albumins↗
PubMedDate not supplied

Advances in contrast echocardiography: intraoperative perfusion assessment.

Contrast ultrasound techniques provide on-line assessments of regional tissue perfusion. Intraoperative clinical studies of cardiac revascularization and renal transplantation have been performed and are currently under active clinical investigation. The potential to diagnose and manage patients through the use of contrast ultrasound techniques is just beginning to be realized. With continued development of the contrast agents and improved computer-aided software analyses programs, the future of the real-time perfusion imaging looks bright.

Cardiac Surgical Procedures↗