In previous work, we postulated that mean aortic flow velocity (MAFV) might be a direct measure of cardiac index. To investigate the assumptions inherent in this relation, we measured body surface area, aortic cross-sectional area (two-dimensional ultrasonography) and MAFV (Doppler ultrasonography) in 70 normal children. For a direct check of the relation, we simultaneously measured cardiac index (Fick technique) and MAFV (Doppler ultrasonography) in 25 children after cardiac surgery. In the normal group, we found that body surface area was directly proportional to aortic cross-sectional area (R 0.94), and MAFV at rest was the same in the ascending and descending aorta (t test, p < 0.05). In the intensive care patients, MAFV in the descending aorta was directly proportional to cardiac index over a wide clinical range [MAFV (cm/s) = CI (L/min/m2).7.7-1.2]. The assumptions made when deriving the relation between MAFV and cardiac index appear to be valid whether measured in the ascending or descending aorta. However, the scatter of results limits its clinical value. Mean aortic flow velocity is probably of greater use as a trend indicator and has the potential for continuous display using an esophageal Doppler probe when measured in the descending aorta.

Adolescent↗

PubMedDate not supplied

High-energy resolution X-ray, gamma and electron spectroscopy with cryogenic detectors.

Cryogenic detectors offer remarkably better energy resolutions than those achievable with conventional semiconductor or scintillation detectors. With the additional asset of a detection efficiency close to unity for low-energy X-ray photons and electrons, these detectors have the potential to perform X-ray, gamma and electron spectroscopy of a hitherto unknown quality, in particular at low energies. Two types of cryogenic detectors are described and the results of prototype detectors are presented.

Calorimetry↗

PubMedDate not supplied

Protein meals and postprandial thermogenesis.

In North America the consumption of meat far exceeds that of fish. Because the palatability of the food has been shown to influence the thermogenic response to feeding, a study was designed to compare the metabolic response to 195-g beef steak and 250-g cod fillet containing both 43 g of proteins in a first experiment and to 250 g of both nutrients in a second experiment. The subjects who participated in this study gave a higher rating of palatability (obtained on a 10-cm visual analog scale) when the beef steak (7.4) was consumed compared to the cod fillet (3.0). Measurements of oxygen consumption during the cephalic phase (0 to 40 min) indicated a larger thermogenic response to the beef than to the fish meal. These findings suggest that the thermic response to feeding during the cephalic phase are related to the sensory stimulation of the meal. During the gastrointestinal phase (40 to >180 min) the response was not influenced by the type of food and was related instead to the amount of proteins ingested. Plasma amino acid determinations indicated differences between the beef and fish feeding. Plasma histidine and glutamine was higher after beef feeding. The meaning of these findings does not seem to be related at this time to the results obtained on postprandial thermogenesis. The increases in plasma insulin that were observed during both phases of feeding were similar for the beef and the fish meals. Despite a marked increase of insulin, plasma glucose remained unchanged after feeding either meals, suggesting an enhanced gluconeogenesis and an increased glucose utilization.

Adult↗

PubMedDate not supplied

A new absolute method for the standardization of radionuclides emitting low-energy radiation.

Microcalorimeters (or bolometers) operated at temperatures below 100 mK allow individual counting of photons and electrons with a very low energy detection threshold. The physics is based on the pulse temperature increase of the target (or absorber) of the detector due to the complete absorption of both electrons and photons. Since this target can be constructed with a perfect 4-pi geometry, a bolometer offers potentially a new method for absolute activity measurements of radionuclides emitting low-energy radiation. In this paper we present our first results of a feasibility study of activity standardization of a 55Fe solution with a prototype 4-pi bolometer.

Journal Article↗

PubMedDate not supplied

[Hydatidosis involving the heart and liver simultaneously. A case report with successful surgery].

Explore the source record for details and available documents.

Adult↗

PubMedDate not supplied

Peripheral arterial trauma in children. A fifteen year review.

A 15 year retrospective evaluation of peripheral vascular trauma in infants and children was undertaken. Forty-eight affected limbs in 47 patients (mean age 5.1 years) were explored for peripheral arterial injury. There were 40 iatrogenic, five penetrating and three blunt injuries. Thrombectomy alone, thrombectomy with autogenous saphenous vein patch angioplasty, direct angioplasty, segmental resection with end-to-end anastomosis and interposition-bypass grafting were the most common reparative procedures used. Circulation was normal within 24 hours of surgery in 35 of the 45 limbs (77.8%) whose patency was restored. In patients less than three years or 12.5 kg with iatrogenic injuries, patency rate was significantly lower (p 0.05). Four children died of congenital heart disease. All six children with failed vascular reconstruction suffered late sequelae.

Adolescent↗

PubMedDate not supplied