Search PubMed⌕ Search

Biomedical subjects

D Weill

Publications and source records attributed to D Weill.

At least 55 records · Page 3Linked to original sources
PubMed1984

Assessment of erythrocyte deformability by constant flow filtration technique: analysis of factors influencing the initial pressure.

When filtering red blood cells (RBC) resuspended into buffer at constant flow, the pressure-time curve is dependent on erythrocyte deformability (E.D) and also on the plugging of pores by RBC or leukocytes (WBC). To understand the influence of these 3 factors, we used an apparatus with: 1) a constant flow syringe (Bioblock) (1.56 ml/mn); 2) a pressure transducer (Statham P23 ID); 3) a recorder (Gould); 4) a 5 micron polycarbonate filter (Nuclepore) housed in a lucite block according to USAMI & al. (1). Resuspensions of RBC from 4 to 14% haematocrit with 0 to 600 WBC/mm3 were investigated. Results indicate that: 1/ The first inflexion point of the pressure-time curve (initial pressure leading to calculation of beta) is related to the RBC's deformability; 2/beta is (in our experimental conditions) dependent on the WBC number; 3/beta seems very sensitive to deformability changes as shown by rapid increases induced by osmolarity changes.

Erythrocytes↗
PubMed1983

"Spontaneous" endothelial injury in the rat caudal artery.

Numerous spontaneous lesions, characterized principally by a gap in the internal elastic lamina, form with age in the caudal artery of the young, male Wistar rat. Such newly formed lesions were studied, with special reference to the state of the endothelium, using three techniques: "en face" examination of silver-stained caudal artery, [3H]thymidine autoradiography, and light and electron microscopy. In many, but perhaps not all cases, areas of endothelium are damaged or removed either simultaneously or shortly after the formation of the break in the internal elastic lamina and some underlying smooth muscle cells are damaged. Polymorphonuclear cells and monocytes are attracted to the site of injury. A repair process rapidly ensues including rapid regeneration of the endothelium and proliferation of smooth muscle cells in the underlying media and of some adventitial fibroblasts. This process results in the restitution of the endothelial monolayer and the laying down of one or several layers of longitudinal smooth muscle and collagen and elastic fibers in the subendothelial space. This demonstration of naturally occurring damage to fairly large areas of endothelium and the events which occur in the repair process is of interest in view of the "response-to-injury" theory of atherogenesis; observations are discussed in the light of previous studies performed on experimentally removed endothelium.

Animals↗
PubMed1983

[Preparation of leukocyte-poor erythrocyte concentrates using a simple aspiration technic].

Depletion of leukocytes from red blood cells can prevent transfusion reactions in HLA-sensitized patients. We describe a simple technique of aspiration of the buffy-coat after centrifugation of red blood cells concentrates, less than 6 days old. This method can remove 87% of the leukocytes. The average leukocyte count after aspiration is 2 x 10(8). This method is inexpensive and does not require any special equipment.

Blood Sedimentation↗
PubMed1983

From Virchow to red cells (the unended quest).

For Virchow vessel wall, coagulability and flow were the three eventual culprits of thrombogenesis. Pharmacological progress in the three fields has not been parallel. Strangely enough they have found possible therapy in the order of their description: first the vessel wall with vasodilators. Then 'coagulability' with anticoagulants, thrombolytics, antiaggregants. It is only more recently that new methods of investigation have allowed assessment and pharmacology of the main determinant of flow in microvessels: red cell deformability.

2,3-Diphosphoglycerate↗
PubMed1983

[Blood microfiltration methods].

Red cell deformability can be approached by filtration through narrow channels either at constant pressure or at constant flow. A very simplified constant pressure method is described, measuring relative flow of 8% hematocrit red cells resuspended in buffer. A constant flow method is also described, using again 8 to 10% hematocrit, which the authors consider as more physiological than the very low hematocrits used by others. Significant results are obtained after incubation with pentoxifylline.

Blood↗
PubMed1980

[HLA antigens and responsiveness to tetanic toxoid in man].

HLA-A, B, C and Bf antigens were studied in 153 blood donors who developped a titre of greater than or equal to 25 i.u./ml antitetanus antibodies following tetanus anti-toxin vaccination. Antigen frequency was compared with that of 412-464 normal blood donors living in the same area. Few significant differences were demonstrated: absence of Bw21 antigen and slight increase of Bf F antigen were observed in "good responders".

HLA Antigens↗
PubMed1980

Intimal lesions in rat caudal artery. Ablation, replacement, and receptor studies on the protective effects of estrogen.

The incidence of spontaneous lesions of the intima in the rat caudal artery is significantly higher in male than in female Wistar rats at 12 weeks of age. After gonadectomy at 5 weeks, lesions in both sexes at 12 weeks reach a level intermediate between those seen in age-matched intact males and females. After gonadectomy at 5 weeks, lesions in both male and female rats are unaffected by testosterone administration but are reduced to below female control levels by diethylstilbestrol. In contrast, diethylstilbestrol administration does not significantly reudce lesion incidence in intact male rats. Binding studies provided no evidence of estrogen-binding sites in cytosol from caudal arteries, but heart and kidney cytosols from both male and female rats contain a single class of high affinity (10(-10)M) binding sites with specificity characteristic of estrogen receptors. Longitudinal studies (4-11 weeks of age) provided no evidence for a change in receptor profile as a factor contributing to the increased lesion incidence in mature male rats.

Animals↗
PubMed1975

[Cylindrical osteotomy of the upper extremity of the tibia with advancement of the patellar ligament. Biomechanical treatment of gonarthrosis].

The authors recall briefly the applications of Pauwel's theories concerning surgery in cases of gonarthrosis, which must be surgery to relieve restrictions on movement and not surgery to restore shape. They describe briefly the main biomechanical principles which must guide the pre-operative investigations and report their experience with a technique proposed by Blaimont and perfected by Maquet, the advantage of which is the exactness of the surgical correction. The technique is also useful in cases of femoro-patellar arthrosis. Among 120 osteotomies carried out using this method, the authors obtained very good or good results in 85 per cent of cases, and fairly good or poor results in 15 per cent of the patients. This method makes it possible to avoid in the great majority of cases recourse to total prostheses of the knee.

Adult↗
PubMed1975

[The place of intertrochanteral valgus osteotomy (Pauwels II) in the surgical treatment of coxarthrosis. Biomechanical principles. Results. Apropos of a homogeneous series of 80 cases].

The authors report their experience of treating certain forms of coxarthrosis by valgus osteotomy (Pauwel's operation II). Their study was carried out on 80 patients in whom the disease was of sufficient duration. The authors recall the main principles of biomechanics that must be strictly applied following careful and detailed study of the radiological films and of the results of the pre-operative test: failure to do this will lead to failure in treatment. The cases that are usually improved by the Pauwels II operation are those arthroses with a flattened head or with gout, often dislocated. The authors describe the surgical technique and the postoperative treatment. They obtained very good or good results in 85 percent of cases, and unsatisfactory results in 15 percent of patients, mainly because of errors at beginning of the series. As with varus, osteotomy, these operations must be regarded as surgery to relieve restrictions on movement and not surgery to restore shape.

Adult↗
PubMed1975

[Serum IgE Statistical study of 2000 measurements].

In a statistical analysis of more than 2000 IgE estimations, the authors corroborate the importance of this determination for diagnosis of asthma, eczema and rhinitis. Serum IgE levels are also elevated in parasitic diseases, and may be elevated in some other cases in which there are several disorders, such as cirrhosis and leukemia.

Asthma↗