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J L Beaumont

Publications and source records attributed to J L Beaumont.

At least 19 recordsLinked to original sources
PubMed1997

A multicenter evaluation of the routine use of a new white cell-reduction apheresis system for collection of platelets.

BACKGROUND: Residual white cells (WBCs) cause serious side effects in platelet transfusion. An in-line WBC-reduction system based on fluidized particle bed technology was recently developed as a modification of an existing plateletpheresis system. STUDY DESIGN AND METHODS: In an investigational phase, three flow profiles were evaluated using prototype software in five centers, each using their standard conditions. In the confirmatory phase, the released software was tested in three centers. WBCs were counted in two full Nageotte grids (dilution 1-in-5). RESULTS: With the prototype software, WBC levels were always below 1 x 10(6) per procedure (median, 25,000/procedure; n = 314). One profile proved to be superior to the other two with respect to platelet yield and residual WBCs, and it was incorporated in the released WBC-reduction system, together with a built-in process control. Median residual WBCs in these WBC-reduction system components not rejected by the process control were 19,000 per procedure (n = 211/225 total), with 99.5 percent of the platelet components having less than 1 x 10(6) WBCs. CONCLUSION: The protocol selected in the initial phase, now available as a WBC-reduction system, results in platelet concentrates with very low residual WBC levels. This satisfies even the most stringent criteria for WBC reduction in platelets, without the platelet loss typically seen with conventional fiber filtration.

Blood Platelets↗
PubMed1995

[Normolipemic plane xanthoma, monoclonal gammopathy, anti-lipoprotein activity, hypocomplementemia].

INTRODUCTION: Normolipaemic plane xanthomatosis is classically associated with a monoclonal gammapathy. CASE REPORT: We observed this association in a 69-year-old woman. This case was particular since anti-lipoprotein activity due to a monoclonal IgG immunoglobulin was found in the serum with abnormal complement fractions. The paraproteinaemia remained stable after a 2-year follow-up. CONCLUSION: This association is remarkable. The anti-lipoprotein activity of the monoclonal protein should be emphasized in light of the immunological processes involved in the pathogenesis of this association.

Aged↗
PubMed1994

[Transfusional strategy in neurosurgery: preoperative hemodilution by erythrocytapheresis].

Autologous blood transfusion techniques have been devised in order to decrease the risk of homologous transfusion-related complications. In neurosurgery, preoperative autologous blood collection is difficult because of the rather short time interval before surgery, as well as the risk of increasing cerebral oedema or intracranial hypertension. Therefore erythrocytapheresis has been performed the day before surgery as a preoperative haemodilution in 33 patients, using a discontinuous flow cell separator (PCS + Heamonetics). Patients with anaemia, unstable cardiovascular condition, infections, malignant tumor with a bad prognosis, or a poor peripheral venous status were not included. The mean volume of collected red cells was 526 +/- 176 mL, allowing a minimal colloid perfusion adjusted on this volume, with a simultaneous restitution of plasma and platelets. For a mean peroperative estimated blood loss of 1,040 +/- 52 mL, a homologous blood transfusion was avoided in 29 patients (88%). Four patients who underwent meningioma surgery received homologous red cells units in addition to their autologous blood. Two patients did not require any transfusion. Finally, 88% of autologous red cells units were readministered and 8 units were not retransfused. Preoperative erythrocytapheresis has proven to be a very simple and well tolerated technique. It can be considered for elective neurosurgery, when the time delay before surgery is short and when the blood loss is anticipated as to be moderate. It may also be associated with iterative autologous blood donation programme or the peroperative use of a cell saver.

Adolescent↗
PubMed1994

[Does preoperative erythroapheresis avoid homologous transfusion?].

The risk of transfusion-related viral infections promotes techniques intended to reduce such a risk. Preoperative erythroapheresis is an autologous blood collection technique which minimizes the inconvenience of repeated predeposit autologous donations. Erythroapheresis has been performed in 451 patients, 24 to 72 hours before surgery using a discontinuous flow cell separator (PCS+Haemonetics). The mean collected red cells volume was 485 ml (250-900) and was replaced by hydroxy-ethyl-starch (ELOHES). Homologous blood transfusion was avoided in 431 patients (95,6%). This technique is indicated for surgery with an expected blood loss between 1000 and 1500 ml or when the patient cannot be included in a preoperative blood donation programme. Preoperative erythrocytapheresis is a simple and well tolerated procedure. To have recourse to apheresis techniques allows to increase the number of autologous transfused patients.

Adolescent↗
PubMed1994

Familial xanthomatous hypercholesterolemia: abnormal exogenous lipid metabolism evidenced by the vitamin A test.

Familial xanthomatous hypercholesterolemia is a metabolic disorder associated with high LDL levels attributed to a familial defect in LDL receptor activity. We have previously shown that hyperlipoproteinemia of WHHL rabbits, considered to be a model for heritable hypercholesterolemia, was at least partly of exogenous origin. We have though studied retinyl palmitate (RP) levels 12 h after a standardized mixed meal as a simple test to detect abnormalities of intestinal-derived lipoprotein clearance in 22 familial hypercholesterolemic patients with xanthomatosis (13 of them treated by simvastatin, an HMGCoA reductase inhibitor, and 9 not treated), as compared to a control group (n = 12). Total and LDL cholesterol, plasma triglyceride and apo B levels were significantly higher in patients when compared to controls. Mean RP levels appeared higher in familial hypercholesterolemic patients, when compared to controls, with 6 among 22 patients showing clearly high vitamin A levels and 4 borderline values, whereas high triglyceride levels (> 2 g/l) were detected in only 1 patient. No patients within the group with high vitamin A levels showed an apo E2/E2 phenotype. Vitamin A levels correlated with plasma triglycerides in the whole group of subjects (r = 0.50, p < 0.05). No difference was observed in vitamin A distribution between treated and untreated hypercholesterolemic patients. Our results indicate that the clearance of RP-labeled intestinal lipoproteins is delayed in some xanthomatous familial hypercholesterolemic patients as compared with that of controls. These findings suggest that familial xanthomatous hypercholesterolemia may be heterogenous concerning physiopathological mechanisms inducing hyperlipidemia.

Adult↗
PubMed1994

[Cholestatic viral hepatitis A in adults. Clinical, biological and histopathological study of 9 cases].

OBJECTIVES: We report here 9 cases of acute viral hepatitis A leading to hospitalization between June 1989 and October 1992. The main feature was a marked and protracted cholestasis. RESULTS: Jaundice lasted an average of 77 +/- 39 days (range: 30-120) and total serum bilirubin concentrations were 265 +/- 184 mumol/L (range: 51-560). IgM anti-HAV was present in the serum for 6.3 +/- 5.5 months (median: 4, range: 2-19). Histopathological examination of the liver was performed in 6 patients and most showed intralobular cholestasis and portal tract inflammation associated with dystrophy and paucity of bile ducts. Acute renal failure was noted in one patient. In three patients, whose pruritus was not relieved by cholestyramine, plasma exchange was an effective therapy. CONCLUSION: These case reports confirm the severity of viral hepatitis A in adults and emphasize the importance of vaccination.

Acute Kidney Injury↗
PubMed1993

Lp(a) levels and antiestrogen antibodies in women with and without thrombosis in the course of oral contraception.

Several reports have shown that lipoprotein(a) is associated with ischemic diseases. Two characteristics might explain this association. Firstly, Lp(a) is an LDL-like lipoprotein which may be implicated in the atherosclerotic process and secondly, Lp(a) possesses an additional apolipoprotein(a) whose structure is close to that of plasminogen and might confer to the molecule prothrombotic properties. It seemed of interest to see whether Lp(a) was a risk factor in oral contraceptive users with thrombotic complications, a group of young women with presumably little or no atherosclerosis. Three groups of women were compared: 25 of them served as controls and did not use oral contraceptives (OC) (group 1); 25 women were healthy current users of OC (group 2); 35 women suffered thrombotic complications in the course of OC (group 3). Mean levels of Lp(a), estimated by RID, were not found to be significantly different in the 3 groups: 19 +/- 18, 20 +/- 23 and 16 +/- 22 mg/dl, respectively. Levels above 30 mg/dl were similarly distributed. Among the other risk factors studied, antiestrogen antibodies were absent in group 1, present in 24% of group 2 and 71.4% of group 3 (P < 0.01). Serum cholesterol levels were similar in the 3 groups: 209 +/- 33, 220 +/- 41, 213 +/- 45 mg/dl respectively. Mean serum triglyceride levels were higher in group 2 than in group 1 (61 +/- 18 and 83 +/- 32, P < 0.01), and higher in group 3 than in group 2 (116 +/- 66 and 83 +/- 32, P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Hyperhomocyst(e)inemia, anti-estrogen antibodies and other risk factors for thrombosis in women on oral contraceptives.

Hyperhomocyst(e)inemia was shown to be associated with vascular occlusion in atherosclerotic patients. We have conducted a study to determine if hyperhomocyst(e)inemia was also related to the vascular events observed in women on oral contraceptives, presumably having little or no atherosclerosis. Two hundred women receiving oral contraceptives were included in the study: 100 were healthy controls and 100 had documented vascular occlusion. Determination of serum homocyst(e)ine and anti-estrogen antibody levels wore performed under blind conditions. They were evaluated in logistic regression models in which age and smoking were also included. Women with vascular occlusion had higher levels of homocyst(e)ine (P less than 0.001) and of anti-estrogen antibodies (P less than 0.001) when compared to controls. They were also older (P less than 0.001) and more frequently smokers (P less than 0.05). The above mentioned variables were, in isolation, independent predictors of vascular occlusion. Moreover, a model assessing those variables and their interactions indicated that the levels of anti-estrogen antibodies and smoking increased the predictability in older women, as well as the levels of age-adjusted homocyst(e)ine. The study suggests that the above factors can identify women at risk and that determination of anti-estrogen antibodies and homocyst(e)ine levels may help to detect women predisposed to vascular occlusions when taking oral contraceptives.

Adult↗
PubMed1991

Oral contraceptives, sex steroid-induced antibodies and vascular thrombosis: results from 1318 cases.

The role of antiethinyl estradiol antibodies (anti EE Ab) and associated risk factors was evaluated in 1318 cases of venous or arterial thrombosis in oral contraceptives (OC) users, and compared to 61 non-users and 124 healthy current users. Anti EE Ab were absent in non-users and present in 33% of healthy users and 72% of those with thrombosis, either arterial or venous. Age, duration of use, hyperlipidaemia and smoking were factors associated with thrombosis only in women with an arterial disease. While the two predominant factors, anti EE Ab and smoking may be risk factors in their own right, the combination of both was found in 47.7% of women with thrombosis. It is proposed that thrombosis associated with OC use may be explained by an immunological disease in which anti EE Ab and their complexes with the circulating synthetic hormones may be harmful to the vessels, as also suggested by the type of lesions already described in OC users. The determination of anti EE Ab in healthy users may identify a group at risk of thrombosis.

Adult↗
PubMed1990

Circulating IgA-Lp complexes in Watanabe heritable hyperlipidemic and cholesterol fed NZW rabbits.

Auto-immune immunoglobulin-lipoprotein complexes (Ig-Lp), as well as other modified lipoproteins, are activators of the transformation of macrophages into foam cells which may be the first step in atherogenesis. In humans circulating Ig-Lp have been demonstrated in autoimmune hyper- or dyslipidemia (AIH, DIH) and found to be associated with conditions related to atherosclerosis. Thus Ig-Lps may be significant and potentially primary atherogenic factors. In order to test this hypothesis we compared the distribution of Ig-Lps in 14 WHHL homozygote rabbits and in 15 normal fed and 8 cholesterol-fed NZW rabbits, all males aged 4-6 months. The Ig-Lps were detected by ELISA using 2 different capture anti-Lp and 4 indicator antibodies specific for either total Igs or the IgA, IgM or IgG classes. Some Ig-Lp of all classes were found in normal fed NZW. As compared with these normal levels, IgA-Lp are increased 2.5-fold in both the WHHL and the cholesterol-fed NZW rabbits (P = 0.0002). During cholesterol feeding the increase of IgA-Lp and total cholesterol and their decrease after returning to a normal diet were parallel in NZW rabbits, but their variation was mainly independent. IgM-Lp was also increased, but to a much lesser extent, in WHHL and in cholesterol-fed NZW. IgG-Lp was not increased in WHHL and only moderately increased in some of the cholesterol-fed NZW. The WHHL and the cholesterol-fed NZW rabbits did not differ by the IgA-Lp content of the serum, but the level of IgM-Lp was higher in the former.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Retinyl palmitate labeled intestinally derived lipoproteins accumulate in the circulation of WHHL rabbits.

The behavior of native retinyl palmitate labeled intestinally derived lipoproteins and their remnants was studied in 8 NZW and 8 WHHL (5 homo- and 3 heterozygote) normal-fed rabbits and in 3 cholesterol-fed NZW, after 1 month of cholesterol feeding, and 3 and 5 months after resuming normal feeding. Palmitate labeled lipoproteins were produced by the intestine after administration of 50,000 IU of Vitamin A, together with olive oil via gastric intubation. Blood was drawn before and 3,6,9,12,24, and in some instances, 48 h later. Retinol (R) and retinyl palmitate (RP) were measured in whole serum and in the chylomicron, d less than 1006, d greater than 1006 less than 1019, d greater than 1019 less than 1063, d greater than 1063 less than 1210 g/ml lipoprotein fractions and in the infranatant. The R content of the serum was almost all concentrated in the infranatant, it did not change during the vitamin A test and was similar in WHHL, and normal- or cholesterol-fed NZW rabbits. In the normal-fed NZW the RP content of the serum increased within 6 h after giving the vitamin A fat meal (peak value less than 200 microgram/100 ml) and then decreased. In the WHHL homozygotes, the RP increased to a much greater degree (peak value 600-1820 micrograms) and for a much longer time, as it was still increased in the 5 cases studied after 24 h, and in 3 cases studied after 48 h. Similar RP curves were obtained in NZW rabbits, after 1 month of cholesterol feeding.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗