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S Bas

Publications and source records attributed to S Bas.

50 records · Page 3Linked to original sources
PubMed1984

Pulsed Doppler echocardiographic indices for assessing mitral regurgitation.

Pulsed Doppler indices were devised in order to grade the severity of mitral regurgitation on a quantitative basis. Indices were obtained by mapping the regurgitant jet by recording abnormal systolic Doppler signals detected on a "yes/no" basis using a 3 MHz pulsed Doppler velocimeter associated with a cross sectional real time ultrasonic scanner. Combined information from two echographic planes was used to take into account the geometrical three dimensional configuration of the jet. The following dimensions of the jet were measured: (a) the length and the height in the long axis view of the left atrium (long axis regurgitant index (LARI), 0.5 X length X height); (b) the width at the annulus in the short axis view (short axis regurgitant index (SARI); (c) the total regurgitant index (TRI) calculated as the product of LARI multiplied by SARI. Sixteen normal subjects and 94 patients including 46 cases of mitral regurgitation confirmed by angiography (32 of whom proceeded to surgery) were investigated. The diagnostic sensitivity was 91% and the specificity 94%. The jet was detected in 76% of cases. Indices were correlated with independently performed angiographic grading on a three point scale. The best linear correlation was obtained for the TRI; mean values were significantly increased for each grade of severity. Correlations with invasive procedures showed an 87% success rate for the Doppler prediction of the involved regurgitant leaflet(s) and of the anatomical site of the lesion at the annulus. In addition, an abnormal diastolic signal was found in five of the eight patients with ruptured chordae and also a decreased percentage of systolic shortening of the annulus diameter in patients with mitral regurgitation compared with those without.

Adult↗
PubMed1984

Quantification of left to right shunt in atrial septal defect using systolic time intervals derived from pulsed Doppler velocimetry.

Systolic time intervals derived from Doppler velocimetry measurements were used instead of direct pulmonary to systemic flow ratio measurements in adults with atrial septal defect to quantify left to right atrial shunts. Thirteen normal subjects and 25 patients with uncomplicated atrial septal defect confirmed by cardiac catheterisation were studied. The pulmonary to systemic flow ratio (Qp:Qs) expressing the shunt size was determined by the Fick method; in normal subjects the Qp:Qs ratio was assumed to be equal to 1.0. The pulsed Doppler analogue velocity recording of flow in the pulmonary artery and the ascending aorta was taken as indicating the ejection time of each ventricle and the Q wave of the electrocardiogram as indicating the onset of systole. From these measurements the ratios of the pre-ejection periods to the ejection times (haemodynamic ratio) were calculated for each ventricle and the ratios of each variable (pre-ejection period, ejection time, and haemodynamic ratio) were calculated for both ventricles. Significant differences were found between the normal subjects and the patients with atrial septal defect for all these ratios. When the Doppler findings and the Fick measurements of Qp:Qs were compared the best linear correlation coefficient was for the left to right haemodynamic ratio. It is concluded that the use of a ratio involving several variables, such as the pre-ejection period and the ejection time for both ventricles, improves the reliability of this method, which appears to be applicable in adults.

Adult↗
PubMed1983

Fatty acid utilization and purine nucleotide binding in brown adipose tissue of genetically obese (ob/ob) mice.

The activities of the main enzymes involved in fatty acid utilization i.e. palmitoyl CoA synthetase as well as peroxisomal and mitochondrial beta-oxidation were measured in brown adipose tissue homogenates of lean and ob/ob mice kept at 23 degrees C or acclimated at 4 degrees C. The proton conductance pathway, i.e. the number of purine nucleotide (GDP) binding sites and the percentage of 32,000 polypeptide in brown adipose tissue mitochondria were also measured. In the ob/ob mice at 23 degrees C, the specific activities of the palmitoyl CoA synthetase and of the beta-oxidation as well as the number of GDB binding sites were lower than in the lean mice by 26%, 43% and 37%, respectively. The percentage of 32,000 polypeptide, however, was the same in both groups. In the ob/ob mice at 23 degrees C, the lower homogenate beta-oxidation specific activity was due to the fact that the peroxisomal and mitochondrial specific activities were 44% and 37% lower, respectively. Cold acclimation at 4 degrees C was found to cause an increase of the palmitoyl CoA synthetase specific activity, of the palmitoyl CoA synthetase and peroxisomal beta-oxidation total activities and of the number of GDP binding sites, in both lean and ob/ob mice. Cold acclimation increased the percentage of 32,000 polypeptide in the ob/ob mice only.

Adipose Tissue, Brown↗
PubMed1983

Peroxisomal and mitochondrial palmitoyl coenzyme A beta-oxidation activities in rat white adipose tissue and their regulation in hypothyroidism.

A peroxisomal fraction with catalase and CN- -insensitive palmitoyl CoA beta-oxidative activity different from the CN- -sensitive mitochondrial palmitoyl CoA beta-oxidative activity was purified from rat epididymal and perirenal white adipose tissue by differential and sucrose density gradient centrifugations. The degree of purification of this fraction as compared to the nuclei-free and fat-free homogenate was 10 and 34 for catalase and palmitoyl CoA beta-oxidative activity, respectively. The finding that it was devoid of urate oxidase activity suggests that white adipose tissue peroxisomes are anucleoid. The contributions of the peroxisomes and of the mitochondria to total beta-oxidative activity in white adipose tissue were 65 and 35%, respectively. Hypothyroidism induced a 2.0- and 2.4-fold decrease of mitochondrial and peroxisomal beta-oxidation specific activities, respectively. These results are discussed in terms of a possible thermogenic role for white adipose tissue peroxisomes.

Adipose Tissue↗
PubMed1983

Brown adipose tissue metabolism in streptozotocin-diabetic rats.

Defects of both diet-induced thermogenesis and cold tolerance have been reported for streptozotocin-diabetic rats. Since brown adipose tissue (BAT) is a major effector of both diet- and cold-induced thermogenesis in the rat, the possible cause of these defects was investigated by comparing BAT metabolism under basal conditions and during activation by nerve stimulation, norepinephrine (NE), or octanoate addition in both streptozotocin-diabetic rats and in controls. The following metabolic indices were measured in rat interscapular BAT (IBAT): 1) tissue composition, 2) heat production rate as measured by direct microcalorimetry, 3) redox state of flavoproteins linked to the acyl-coenzyme A dehydrogenase pathway as measured by reflection spectrometry, 4) redox state of NAD(P) as measured by surface-emitted fluorescence, and 5) fatty acid activation and beta-oxidation activities in IBAT homogenate. In streptozotocin-diabetic rats, IBAT was atrophied (DNA content unmodified, protein and lipid content decreased). The basal and NE-stimulated total heat production rates showed a 75% and 56% decrease, respectively. The specific activity of fatty acid beta-oxidation as measured by flavoprotein redox state or enzymatically was decreased by 52% and 59%, respectively. The basal redox level of NAD(P) was about 3 times higher than in the controls and NE stimulation resulted in oxidation in contrast to the reduction observed in control tissues. These results show that the metabolic capacity of IBAT from streptozotocin-diabetic rats is decreased and further suggest that the reduced capacity for beta-oxidation contributes significantly to the metabolic alteration.

Adipose Tissue, Brown↗
PubMed1979

Decarboxylation and carboxylation of pyruvate in the living mice.

Mice received intravenously [1- or 2-14C]acetate, [1-, 2- or 3-14C] or [2-14C]pyruvate and were killed 1, 3, 5 or 15 min later. The radioactivity of CO2 or HCO3- of liver or carcass as well as the radioactivity of blood glucose were measured. The ratio of the radioactivity found in these compounds after [3-14C] or [2-14C-A1pyruvate injection suggests that in the fed aminals: 1. the decarboxylation of the pyruvate was more rapid than its carboxylation, 2. most of the neosynthesized glucose was derived from pyruvate molecules which had undergone a decarboxylation followed by a condensation to citrate, 3. 1/4 to 1/3 of the pyruvate was carboxylated and 2/3 to 3/4 was decarboxylated in animals receiving a diet poor in fats.

Acetates↗
PubMedDate not supplied

Applications of pulsed Doppler flow mapping to left sided cardiac valvular lesions.

The flow mapping procedure has been developed in parallel to the standard pulsed Doppler procedure. It has a different purpose--picking up flow signals at the site of lesions rather than calibrating velocities--and has its own methodology, developed within the last six years. On the basis of invasive correlations performed in 267 cases of valvular heart disease, we review the three-fold purpose of the flow mapping technique: diagnosing lesions, relying on the presence of flow anomalies; assessing their severity, relying on the spatial spreading of these flow signals; and identifying the site of the lesion, which is a specific advantage, relying on the anatomical location of these flow signals and/or on the direction of the jets. For example, using this technique, it is now possible to easily differentiate a cusp tear from a leak of a bioprosthesis, to measure the size of the leaks, and to reconstruct the image of aortic or mitral stenotic areas. These optimal results are only obtained using an appropriate methodology which mainly includes a) the selection of adequate two-dimensional short axis planes in order to explore the diseased valve in its entirety, because of frequent assymetrical orifices, and to pick up the jets at their starting point, b) measurements of the abnormal areas, c) when jets are studied, a three dimensional approach is required in order to cope with the three dimensional nature of the jet and to make available the calculation of three dimensional indices of severity.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Flow Velocity↗
PubMedDate not supplied

Quantitative assessment of valvular regurgitations using the pulsed Doppler technique. Approach to the regurgitant lesion.

It is now possible with pulsed Doppler to grade the severity of aortic, mitral and tricuspid regurgitations on a quantitative basis. "Indices" were devised, using the measurement of the spatial extent of abnormal Doppler signals. For aortic regurgitation: (1) at the aortic valvular orifice area, by measurement of the regurgitant aortic valvular area and calculation of the valvular regurgitant "index". (2) In the left ventricle outflow tract, by calculation of an "index" combining information from two echographic (short and long axis) planes. For mitral regurgitation: by calculation of the total regurgitant "index" combining information from examination of the annulus in short axis, and of the left atrium in long axis view. For tricuspid regurgitation: at the tricuspid annulus, by averaging the depth of the reversal wave on two samples recorded using various echographic approaches. A group of patients with aortic (42), mitral (55) and tricuspid (57) regurgitation proven by invasive procedures, was investigated with this procedure using a 3 MHz two dimensional pulsed Doppler echo device. Correlative coefficients between the Doppler grading and that provided by independently performed invasive procedures on a three point scale, ranged between 0.66 and 0.88, with significant differentiation of mean values of indices (P less than 0.01 to P less than 0.001) for each grade of severity. Success in the Doppler grading of severity of the regurgitations requires (1) a sampling as close as possible to the lesion, and optimally at ther very site of the lesion, (2) the largest explorable area at the site of the lesion, (3) the relevancy of the selected Doppler parameter in order to take into account, as much as possible, the three dimensional configuration of the regurgitant jet. Moreover, this mapping procedure provides a pathophysiological insight of the regurgitant lesion for left-sided regurgitations.

Adult↗
PubMedDate not supplied

Respective timing of maximal color Doppler jet areas and of peak velocity of jets in left-sided valvular lesions: clinical implications.

Time intervals between the R wave of the electrocardiogram and maximal dimension of jet areas of color Doppler and the R wave of the electrocardiogram and peak velocity of valvular jets of continuous-wave Doppler were compared by use of paired and correlative studies for a group of 55 patients with a total of 71 left-sided lesions. Mean values of both time intervals, mean difference, and its standard error were equal to zero for stenoses. Time intervals of 71% for mitral stenosis and 52% for aortic stenosis did not differ by more than 0.01 second; correlation coefficients were 0.96 for mitral stenosis and 0.85 for aortic stenosis. For regurgitations, differences in mean values and a mean difference with a standard error were found but remained unsignificant. However, the percentage of differences in time intervals below or equal to 0.01 second decreased to 35 for aortic regurgitation and 13 for mitral regurgitation, which showed the widest 95% range of differences. Correlation coefficients were 0.84 for the aortic regurgitation and 0.33 for mitral regurgitation. Thus the close relationship of time intervals suggests that standardized timing of area measurements at peak velocity is feasible for stenoses and remains under consideration for aortic regurgitation. Timing of measurements should remain empiric for mitral regurgitation.

Adolescent↗
PubMedDate not supplied

Production of neutrophil activating peptide-1 (NAP-1/IL-8) by blood and synovial fluid mononuclear cells from patients with arthritis.

As polymorphonuclear leukocytes (PMN) are predominant in inflammatory synovial fluids, we investigated the production of neutrophil-activating peptide-1 (NAP-1) by mononuclear cells (MC) from 15 synovial fluids and matched peripheral blood. MC were cultured for 24 h alone or with stimulants (ConA, LPS). NAP-1 was determined in the supernatants by a bioassay (elastase release from normal human PMN) and an immunoassay (sandwich ELISA with a mouse anti-NAP-1 mAb and an alkaline phosphatase labelled goat anti-NAP-1 pAb). The results showed a significant increase in NAP-1 production by synovial fluid MC when compared to peripheral blood MC. Both cell types produced more NAP-1 in the presence of added stimuli. The results obtained with the two methods of detection were in close agreement. No relationship was found between the amount of NAP-1 produced in 24 h and the number of synovial fluid leukocytes, the erythrocyte sedimentation rate, the diagnosis of the underlying arthritis or the treatment of the patients.

Adult↗
PubMedDate not supplied

Defective diet-induced but normal cold-induced brown adipose tissue adaptation in hypothalamic obesity in rats.

our weeks after bilateral ventromedial hypothalamic (VMH) lesions in the female rat reared at 23 degrees C, the weight of the interscapular brown adipose tissue (IBAT) was doubled as compared to appropriate controls. Tested in vitro, the tissue of the lesioned animals showed, per unit weight, a basal and a noradrenaline--or octanoate--stimulated heat output about half of that of the tissue from the controls. However, basal and stimulated heat outputs as well as beta-oxidative capacity of IBAT from lesioned animals and their appropriate controls were the same when calculated per whole fat pad. The lesioned animals were hyperphagic, with a gross energy intake 70% larger than that of the controls. Cold acclimation at 5 degrees C for 3 weeks was found to restore the basal and stimulated heat outputs per unit weight of IBAT of the lesioned animals to the level of that of their cold acclimated controls. The weight of the tissue did not change significantly in lesioned animals upon cold exposure whereas controls exhibited the expected hypertrophy. Calculated per whole fat pad, the stimulated heat output became 33% larger in lesioned animals than in appropriate controls. The total beta-oxidative capacity increased by 3 fold in controls and 4.8 fold in lesioned animals. Cold exposure was followed by a mean increase of gross energy intake of 43% in the controls and 31% in the lesioned animals as compared to their gross energy intake at 23 degrees C.(ABSTRACT TRUNCATED AT 250 WORDS)

Acclimatization↗