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Biomedical subjects

D Blanchard

Publications and source records attributed to D Blanchard.

At least 217 records · Page 12Linked to original sources
PubMed1982

[Non-invasive study of aortic insufficiency by Doppler echocardiography].

The possibilities of diagnosis and quantification of aortic regurgitation by pulsed Doppler analysis of blood flow in the aortic arch were examined in 60 patients aged between 9 and 67 years old. Aortic flow curves were recorded from the suprasternal area with the sample volume positioned at the junction of the horizontal part of the aortic arch and the descending aorta. Normal flow curves are characterised by an anterograde systolic wave with a brief proto-diastolic reflux. In aortic regurgitation holodiastolic reflux is observed. An index of regurgitation may be calculated from the ratio of the amplitude of end diastolic reflux measured on the R wave of th ECG and the maximal amplitude of anterograde systolic flow. This ratio eliminates the factor related to the incident angle between the ultrasound beam and the direction of blood flow. The values of this ratio were compared to the semi quantitative assessment of aortic regurgitation from ascending aortic angiography. The only false negatives were observed in patients with negligible regurgitation (grade I). One false positive result was obtained in a patient in whom it was difficult to obtain the recording and in whom the value of the ratio was very low (0,02). Global specificity was 91 p. 100 and sensitivity was 82 p. 100. The sensitivity for average or severe regurgitation was 100 p. 100. The correlation coefficient between the Doppler index or regurgitation and the semi quantitative angiographic estimation was 0,69. In patients with pure aortic regurgitation the correlation reached 0,85 (p less than 0,001). The differences between the different groups then became highly significant.

Adolescent↗
PubMed1982

[Doppler echocardiographic diagnosis and evaluation of tricuspid regurgitation].

The reliability of pulsed Doppler echocardiography in the diagnosis and quantification of tricuspid regurgitation was assessed by analysis of blood flow in the inferior vena cava in 28 patients. The inferior vena caval flow was sampled in the retrohepatic portion of the vessel from the subxiphoid region. Recordings from 10 normal patients were used to define criteria of normality. This was characterised by two anterograde components (one systolic and one diastolic); atrial contraction gave rise to an end diastolic retrograde component. In tricuspid incompetence, retrograde systolic blood flow was recorded. A Doppler index was calculated from the ratio of the maximal amplitude of systolic reflux to the maximal amplitude of anterograde diastolic flow. In the absence of tricuspid regurgitation, this index approximated 0. The average of this ratio over 10 consecutive beats was compared with the semi quantitative assessment of tricuspid regurgitation from selective right ventricular angiography. There were no false positive results, specificity was, therefore, 100 p. 100. Six minimal regurgitations were not detected: sensitivity was therefore 74 p. 100. All moderate and severe regurgitations were detected, and the sensitivity for these cases was 100 p. 100. There was a close correlation (R = 0,89, p less than 0,01) between the Doppler index and the degree of regurgitation assessed by selective right ventricular angiography.

Adolescent↗
PubMed1981

Non-invasive diagnosis of mitral regurgitation by Doppler echocardiography.

The value of Doppler echocardiography for the non-invasive diagnosis of mitral regurgitation was studied blindly in 161 consecutive invasively investigated adult patients. Regurgitation was graded from 0 to 3 at selective left ventricular angiography. The Doppler echocardiographic examination was considered to be positive when a disturbed systolic flow was found within the left atrium behind the aorta or the anterior leaflet of the mitral valve. The test was considered to be negative in the absence of a regurgitant jet. The level of the signal to noise ratio was checked by the recording of the ventricular filling flow. The study was performed in 131 cases from the left side of the sternum and in 101 cases from the apex. There were no false positives and thus the specificity was 100 per cent. The 20 false negatives were all in patients with grade 1 regurgitation. Thus only some (33%) instances of mild regurgitation were misdiagnosed, and the sensitivity for moderate to severe mitral regurgitation was 100 per cent.

Adolescent↗
PubMed1980

Effect of long-term treatment with circulating thymic factor on murine lupus.

Mice from three different strains (NZB, B/W, and Swan) which spontaneously develop a lupus-like disease and show a premature decline of their secretion of the circulating thymic factor, Facteur Thymique Sérique (FTS), were treated repeatedly with FTS and followed for the evolution of their autoimmune disease. The autoimmune sialoadenoitis (Sjögren's syndrome) appearing in NZB and B/W mice, evaluated here by a scintigraphic method, was completely prevented or even cured by FTS treatment. The increase in anti-erythrocyte autoantibody production was transiently delayed in aged NZB mice. Conversely, antiDNA antibody production either remained unaffected or was accelerated (in B/W mice) by FTS treatment. These results demonstrate that the restoration of the failing thymic secretion does influence autoantibody production, in a manner depending primarily on the autoantigen eliciting the autoimmune response. However, caution is urged in the application of this approach to human lupus without further studies.

Age Factors↗
PubMed1980

Thymic function in NZB mice. III. Impairment of the activity of specific suppressor cells involved in the regulation of antibody production against sheep red blood cells.

Spleen cells from DBA/2 mice immunized with high numbers of sheep red blood cells specifically suppress the primary anti-SRBC antibody response of syngeneic recipients specifically suppress the primary anti-SRBC antibody response of syngeneic recipients after in vivo transfer. Such suppressive activity of the immune spleen cells is mediated by null cells, or by T cells resistant to the cytotoxic activity of anti-Thy 1.2 antiserum plus complement. The primary anti-SRBC antibody response is much higher in NZB mice than in DBA/2 mice, and the suppressive activity of syngeneic immune spleen cells is much lower in NZB than in DBA/2 recipients. Immune spleen cells from DBA/2 donors do not provide more effective suppression than NZB spleen cells in NZB recipients. Conversely, immune spleen cells from NZB donors strongly suppress the anti-SRBC primary response of DBA/2 recipients to the same extent as DBA/2 immune spleen cells. Finally, NZB mice generate specific suppressor cells but their primary antibody response is not sensitive to this suppressor activity.

Animals↗
PubMed1980

Receptors for peanut agglutinin (Arachus hypogea) in childhood acute lymphoblastic leukemia: possible clinical significance.

The presence of lymphocyte receptors for peanut agglutinin in significant numbers (greater than 15%) was identified on leukemic cells from T-cell acute lymphoblastic leukemia (T-ALL) (3/4), B-cell ALL (B-ALL) (2/4), null cell ALL (8/17), and on normal fetal thymic lymphocytes but not on normal human peripheral blood lymphocytes. Peanut agglutinin (PNA) binding was blocked specifically on leukemia lymphoblasts and thymic lymphocytes by the addition of galactose to the medium. When all immunologic subgroups of ALL are combined, preliminary data suggest that of the 13 ALL patients having greater than 15% PNA-positive lymphoblasts, 8 had relapsed, whereas none of the 12 ALL patients with less than 15% PNA-positive cells have recurrent disease at this time. It is likely that analysis of PNA receptors on ALL lymphoblasts may be a useful adjunct to the existing clinical and immunologic prognostic indicators.

Adolescent↗
PubMedDate not supplied

Squirrel monkey (Saimiri sciureus) B lymphocytes: secretion of IgG directed to Plasmodium falciparum antigens, by primed blood B lymphocytes restimulated in vitro with parasitized red blood cells.

Blood B lymphocytes obtained from Plasmodium falciparum-immune Saimiri monkeys were assayed for their in vitro differentiation in immunoglobulin-secreting cells upon restimulation with P. falciparum-parasitized Saimiri red blood cells. Selected culture conditions enabled appropriately stimulated blood B cells to secrete 3F11/G10+ IgG, detected in the supernatants by means of a dot immunobinding assay. Primed blood B lymphocytes from P. falciparum-immune Saimiri monkeys were thus able to secrete IgG when restimulated by parasitized red blood cells in the presence of T cell- and monocyte-derived cytokines (recombinant human cytokines). These primed blood B cells, which were able to differentiate, were shown to secrete antibodies reactive with P. falciparum-infected red blood cells, as detected by means of an indirect immunofluorescence assay, and reactive with P. falciparum-infected red blood cell extracts, as detected by means of Western blot analysis. Furthermore, due to the possibility of discriminating between IgG subtypes in the squirrel monkey (3F11/G10+::3A2/G6+ IgG [associated with protection against the blood stages of P. falciparum] vs. 3F11/G10+::3E4/H8+ IgG [usually not functionally associated with protection]), we have attempted to estimate the respective proportions of each IgG subtype. In defined culture conditions, Saimiri monkey blood B cells preferentially secrete 3F11/G10+::3E4/H8+ IgG in response to parasitized red blood cells. We therefore discuss the conditions that would render this assay suitable for the selection, among P. falciparum blood stage antigens, of those that have major B-cell epitopes.

Animals↗
PubMedDate not supplied

Partial characterization of the human erythrocyte receptor for rabbit haemorrhagic disease virus.

An important, well known property of the rabbit haemorrhagic disease virus is its ability to agglutinate human red blood cells. Accordingly, red cells from human adult donors were agglutinated despite their blood group ABO status, and treatments with proteases or glycosidases did not prevent agglutination. However, we discovered that the cells from human umbilical cords or foetuses were not agglutinated. In order to identify the viral receptor on human erythrocytes, glycolipids and glycoproteins from adult red cells were separated and tested for their potency in inhibiting agglutination. The bulk of the biological activity was associated with the highly glycosylated glycolipids (polyglycosylceramides), whereas a lower but significant activity was also associated with neutral glycolipids. No activity was found in the lipid-free sialoglycoprotein fractions. All these data strongly suggest that the RHDV receptor on human red cells corresponds to a development antigen which is not expressed on foetal cells and is mainly carried by glycolipids. Faint activity was also found in membranes from sheep red cells, suggesting that a similar glycolipid component is carried by these animal cells.

Animals↗
PubMedDate not supplied

Manual thromboaspiration and dilation of thrombosed dialysis access: mid-term results of a simple concept.

PURPOSE: To report the feasibility, safety, and effectiveness of manual thromboaspiration as a single means of declotting dialysis access. MATERIALS AND METHODS: Between April 1994 and December 1996, 59 consecutive conduits (43 polytetrafluoroethylene [PTFE] grafts, 16 native fistulas) were declotted with 8-F or 7-F angulated catheters. Unmasked stenoses were dilated. Clinical and paraclinical nephrologic surveillance (poor flow, palpation, difficulties with cannulation, increased compression times, increasing venous pressures) led to redilations and stent placements. Rethromboses were treated with further declotting by aspiration. The results are presented according to the life-table method. RESULTS: The initial success of 43 of 43 PTFE grafts (mean procedure time, 119 min +/- 29 [standard deviation]) led to a primary patency rate of 85% +/- 5% (SE) at 1 month, 33% +/- 8% at 6 months, and 24% +/- 12% at 1 year. A graft was ligated 6 days after declotting for acute bleeding in one patient given high-dose warfarin. The secondary patency rates were 86% +/- 7% at 6 months and 86% +/- 9% at 1 year, with a mean duration of patency of 5.7 months between two radiologic interventions performed to maintain or to restore patency, and 19 stents were placed at a mean follow-up of 3 months. The success rate was 81% for native fistulas, with primary patency rates of 81% +/- 10% at 1 month, 74% +/- 14% at 6 months, and 60% +/- 27% at 1 year; secondary patency rates of 81% +/- 12% at 6 months and 81% +/- 18% at 1 year. CONCLUSION: Thromboaspiration is a safe and effective method for declotting dialysis access, yielding a low rethrombosis rate during the first month. Overall radiologic management with reintervention on average every 6 months results in high secondary patency rates at 1 year (81%-86%).

Adult↗
PubMedDate not supplied

Wallstents and Craggstents in hemodialysis grafts and fistulas: results for selective indications.

PURPOSE: To report the value of selective placement of self-expandable stents (Wallstent and Craggstent) for the treatment of limitations and, occasionally, of complications of dilation in hemodialysis access, and especially for delaying restenosis. MATERIALS AND METHODS: This is a retrospective study of a 7-year period, during which 41 Wallstents and 11 Craggstents were placed in 26 polytetrafluoroethylene (PTFE) grafts, 15 native fistulas, and nine central veins of 47 patients. The indications were stenosis recoil (n = 13), recurrent restenosis within 6 months (n = 33), restenosis after 6 months (n = 3), and acute angioplasty-induced rupture (n = 1). Restenosis after stent placement necessitated redilation and percutaneous declotting and 10 additional stent placements. RESULTS: Two initial misplacements were corrected immediately. Primary patency rates for PTFE grafts were 58% +/- 10% at 6 months and 23% +/- 10% at 1 year, respectively. Secondary patency rates were 100% at 6 months and 88% +/- 8% at 1 year, respectively. For native fistulas, primary patency rates were 47% +/- 12% at 6 months and 20% +/- 18% at 1 year. Secondary patency rates were 95% +/- 6% at 6 months and 79% +/- 14% at 1 year. It was necessary to reintervene after stent placement to maintain or to restore patency every 9 months for PTFE grafts and every 7.3 months for native fistulas. When stents were placed for treatment of early recurring restenosis, the mean interval between radiologic interventions (redilations or declottings) performed to maintain or to restore patency before stent placement was multiplied by 2.1 after stent placement for both grafts (3.2 months increased to 6.9, P < .01) and native fistulas (2.9 months increased to 6.2, P < .02). CONCLUSIONS: Wallstents and Craggstents are valuable for the treatment of failure of regular dilation and they double the intervals between reinterventions for early (< 6 months) recurring stenoses in PTFE grafts and native fistulas.

Adult↗
PubMedDate not supplied

Growth response to enteral feeding by children with cerebral palsy.

This study evaluated the growth of 51 children with cerebral palsy after the initiation of enteral tube feedings. The children were divided into three groups according to how soon after their central nervous system (CNS) insult they were started on enteral feedings. Group 1 consisted of 14 children who were within a year of their CNS insult; they were underweight for age, but had normal length as well as weight for length. Within 6 months of initiating enteral tube feedings, most children in this group had normalized their weights. Group 2 consisted of 27 children who were within 8 years of their CNS insult; they were stunted and were underweight for both their age and their length. Within 6 months of initiating enteral feeds, the group increased both weight and weight for length to near normal, but their gains in length reached a plateau at 90% of ideal for age. Group 3 consisted of 10 children who were more than 8 years after their CNS insult. This group was severely malnourished but had some improvement in their weight for age and for length but, length for age showed no significant change. We conclude that the earlier adequate nutritional management of children with severe cerebral palsy is initiated, the more readily the nutritional deficits will reverse.

Adolescent↗
PubMedDate not supplied

Efficacy and safety of nicardipine in 29,104 patients with hypertension.

The efficacy and safety of nicardipine were assessed in 29,104 hypertensive patients (mean age, 64 years) during a 90-day multicenter clinical trial. By treatment day 90, blood pressure was controlled in 60% of the patients taking nicardipine alone. The efficacy of nicardipine combined with another antihypertensive agent was examined in 6,479 of the patients. When nicardipine was added to their treatment regimen, blood pressure was controlled by day 90 in 63% of the patients taking beta-blockers, in 58% of those on diuretics, in 50% of those on angiotensin converting enzyme inhibitors, and in 49% of those taking centrally acting antihypertensive agents. Nicardipine was well tolerated; only 11% of the 29,104 patients discontinued treatment because of side effects. Most adverse reactions were transient and were related to vasodilation, and included peripheral edema in 7% of the patients, flushing in 7%, and headache in 4%. The results indicate that nicardipine is suitable as initial therapy in arterial hypertension.

Age Factors↗