Biomedical subjects

G Agnani

Publications and source records attributed to G Agnani.

At least 37 records · Page 2Linked to original sources

PubMed1994

Evidence of non-deficient low-density lipoprotein receptor patients in a pool of subjects with clinical familial hypercholesterolemia profile.

For this study, we selected 41 adult patients with the classic clinical diagnosis of heterozygous familial hypercholesterolemia (FH), which is characterized by a low-density lipoprotein (LDL) cholesterol level above the 95th percentile, xanthomas, and/or personal or familial cardiovascular history. We used an indirect immunocytofluorimetric assay to classify these 41 subjects according to LDL receptor function on lymphocytes. We found that LDL receptor activity was normal in nine patients. A large study of plasma lipid, lipoprotein, and apolipoprotein levels found no significant difference between patients with and without LDL receptor defect. Familial defective apolipoprotein (apo) B-100 (FDB) and LDL-binding defects were not found in the nine patients without LDL receptor defect. These results suggest that other defects in the regulation of lipoprotein metabolism are capable of giving rise to a clinical and biochemical disorder indistinguishable from classic FH.

Adult↗

PubMed1993

Cholesterol efflux from fibroblasts to discoidal lipoproteins with apolipoprotein A-I (LpA-I) increases with particle size but cholesterol transfer from LpA-I to lipoproteins decreases with size.

To understand the role of different discoidal lipoproteins in cellular cholesterol efflux, defined discoidal lipoproteins containing 2, 3, or 4 apolipoproteins (apo) A-I per particle (Lp2A-I, Lp3A-I, and Lp4A-I) were prepared from mixtures of apoA-I and phospholipids with or without cholesterol. Each particle had a slow pre beta migration on agarose gel electrophoresis which further decreased as the number of apoA-I increased. Incubation of cholesterol-labeled human fibroblasts with the different LpA-I at an equimolar concentration in apoA-I showed that the best acceptors of cellular cholesterol were Lp4A-I, followed by Lp3A-I and Lp2A-I. Cholesterol efflux to these particles was positively correlated to the number of apoA-I, to the ratio of phospholipids to apoA-I, and to the size of particles, three interrelated parameters. To follow the subsequent movement of cellular cholesterol after it became associated with LpA-I, cholesterol- and apoA-I-labeled LpA-I were incubated with plasma which resulted in parallel modifications of each labels electrophoretic migration with time. However, [3H]cholesterol-labeled LpA-I transferred from pre beta to alpha migration with a precursor-product relationship while 125I-LpA-I progressively shifted from pre beta to alpha migration. The change in electrophoretic migration of 125I-LpA-I is independent of cholesterol and appears related only to a modification of apoA-I charge. Lp2A-I was fastest in changing its electrophoretic migration to alpha, followed by Lp3A-I and then Lp4A-I.(ABSTRACT TRUNCATED AT 250 WORDS)

Apolipoprotein A-I↗

PubMed1993

[Ivemark syndrome: 2 case reports].

Ivemark Syndrome is a multiple organ syndrome associated with splenic abnormalities, complex cardiac pathology and an abnormality of the abdominal viscera. The incidence in our department is 1/6000 deliveries and the teratogenic effect seems to occur between the 30th and 40th days of intrauterine life, but the cause is unknown. The principal warning signal is bradycardia. Prenatal diagnosis can be made by ultrasound. The prognosis depends on the degree of malformation of the heart.

Abnormalities, Multiple↗

PubMed1992

Thrombin cleavage of apolipoprotein Bh of rabbit LDL: structural comparisons with human apolipoprotein B-100.

Rabbit plasma low density lipoprotein (LDL) contains one major apolipoprotein of apparent molecular weight of 320 kDa, designated apolipoprotein (apo) Bh, while another component termed apoB1 of apparent molecular weight of 220 kDa is found in chylomicrons. The fragments generated by thrombin digestion of the protein moieties of rabbit and human LDL were separated by polyacrylamide gradient gel electrophoresis and compared. As in the human species, the enzyme produced limited cleavage patterns of rabbit LDL apoB. Within the first 2 h, two fragments (Tr1 and Tr2, with apparent molecular weights 280,000 and 44,000, respectively) appeared. Longer incubations led to the production of two additional peptides, Tr3 and Tr4 (apparent molecular weights 180,000 and 96,000, respectively). Ten monoclonal antibodies, developed against rabbit LDL and designated P01 to P10, were found to react with rabbit apoB. Some also cross-reacted with human apoB. Epitope mapping, performed with these antibodies, showed that Tr3 and Tr4 were derived from the further degradation of Tr1. The rabbit is one of the most frequently used animals in atherosclerosis research. Its LDL receptor has been characterized and there exists a strain of homozygous LDL receptor-deficient rabbits referred to as WHHL rabbits. Despite this, little has been done to characterize the structure of rabbit apoB; only a short region has been sequenced and shown to be the carboxyl-terminal region, the rabbit apoB1. The molecular weight of human apoB (550,000) is much larger than rabbit apoBh. In both species, a primary and secondary thrombin cleavage occur, but the size of the fragments produced is very different between the two species. Identification of the thrombolytic fragments of the rabbit apoB have afforded the opportunity to compare the structures of both apoB species.

Animals↗

PubMed1991

Isolation and characterization of human Lp-B lipoprotein containing apolipoprotein B as the sole apolipoprotein.

A sequential immunoaffinity chromatography procedure was developed to isolate from whole normolipidemic human plasma a subpopulation of apoB containing particles (Lp-B) which is virtually free of non apoB protein. The absence of non apoB protein in Lp-B was assessed by enzyme immunoassay against apolipoproteins A-I, A-II, A-IV, E, C-III and (a). Electron microscopy and fractionation of the isolated particles by gel filtration demonstrated that these particles were heterogeneous in size. However, most of them had diameters between 18 and 26 nm. These particles were found to be rich in cholesterol (molar ratio cholesterol/apoB = 2246 +/- 995) poor in triacylglycerol (molar ratio triacylglycerol/apoB = 555 +/- 518) and had a phospholipids/apoB molar ratio of 713 +/- 348. Most of the cholesterol was esterified (66% +/- 5%). Lp-B particles bound to the apoB, E receptor of HeLa cells with a lower affinity than LDL prepared by ultracentrifugation (1.030 kg/l less than d less than 1.053 kg/l). (KD = 18.9 vs 10.5 nmol/l).

Apolipoproteins B↗

PubMed1991

[Interaction between LDL receptor and lipoproteins containing apo B].

The physiocochemically defined lipoproteins such as VLDL, LDL are comprised of subpopulations with different lipid and apolipoprotein composition. In order to determine the respective roles of different apolipoproteins (B, C-III, E) in their metabolism, four species (LpB, LpB:E, LpB: C-III and LpB: C-III: E) have been separated by sequential immunoaffinity chromatography. We examined the binding characteristics of each lipoprotein to HeLa cells and expressed the results in relation to the number of moles of apo B. LpB particles which contained apo B as their sole apolipoprotein had lower affinity for the LDL receptor that did total LDL but an apparently higher number of binding sites. The presence of apo E of phenotype E3 or E4 on one particle increased the affinity for the receptor. The apparent number of binding sites decreased probably due to the fact that a particle containing multiple copies of apo E bound to more than one molecule of receptor. Interaction with several LDL receptors would also explain the higher binding affinity which we observed. When the apo E phenotype was E2/E2, the LpB: E particle did not bind to the receptor. We showed also that apo C-III, when present, diminished the binding of apo B containing lipoproteins. These data suggest that apolipoproteins E and C-III impaired the interaction of apo B with the LDL receptor. It is likely that in LpB: E only apo E (in the case of E3 or E4 phenotype) participates in the LDL receptor binding.

Apolipoproteins B↗

PubMed1991

[The reduction of prematurity by telephone follow-up].

Twice-daily check-up of the uterine contractions by the pregnant women is a recognized and accepted necessity. Using the "green" free-phone number to report the number of contractions, to answer the questions asked and to receive the instructions given has made it possible to reduce the prematurity rate and the duration of the consequent specific hospitalization. This new method of follow-up, applied to two identically recruited groups of pregnancies offers an undeniable low-cost improvement over the systems used previously.

Female↗

PubMed1991

[Artificially induced labor. Experience of the maternity unit of the Besançon teaching hospital].

The authors describe 190 cases in which labor was artificially induced between 29 and 42 weeks. They compare different methods (120 induced by oxytocin-like agents, 70 by prostaglandins) in some cases associated with mechanical methods. Various parameters were investigated, notably the Bishop score at the time labor was induced, the method of delivery and the impact on the offspring of these techniques.

Apgar Score↗

PubMed1991

[Influence of Chlamydiae serology and the presence of a pelvic inflammatory state on the results of in-vitro fertilization].

The authors investigated the influence of Chlamydiae serology and the presence of a pelvic inflammatory state on the outcome of in-vitro fertilization on the basis of an analysis of 116 stimulation cycles. The study included 71 female patients suffering from infectious sterility of tubular origin with distal lesions. Chlamydiae trachomatis serology was considered to be positive at IgG titers in excess of 1/64. When the serum test was positive, there was a significant reduction in the number of clinical pregnancies and the cleavage rate. The percentage of ectopic pregnancies (6 ectopic pregnancies out of 29 clinical pregnancies) was very high, particularly if the serum test was positive and a pelvic inflammatory state persisting after antibiotic treatment contraindicated microsurgery. Surgery was performed only in favorable cases and did not appear to have any negative impact on the outcome. The presence of a non-stabilized pelvic infectious state was correlated with a significant increase in the drop-out rate and the number of post-menopausal gonadotropin required to achieve stimulation. The fact that unexpected spontaneous pregnancies may occur after an unsuccessful attempt must be taken into account when sterilization or salpingectomy are envisaged in an attempt to improve the outcome.

Chlamydia Infections↗

PubMed1991

[Influence of the initial treatment of endometriosis and results obtained by in-vitro fertilization].

The authors have investigated the results obtained by in-vitro fertilization in cases of pelvic endometriosis. Fifty-eight (58) stimulation cycles have been analyzed in function of the previous curative treatment, which may have been a combine medico-surgical treatment or a conventional surgical treatment. Six pregnancies which progressed to full term were achieved in the 8 patients who had previously received medico-surgical treatment. Twenty punctures were performed. In patients who received an initial medical treatment, there were no pregnancies carried to full term and three clinical terminations of pregnancy for a total of 15 punctures. A celioscopy check-up revealed persistent endometriosis in 10 of the patients involved. No clinical pregnancy was observed following primary surgical treatment. In all these cases, there were lesions affecting the ovary and the numbers of ovocytes and embryos were significantly reduced.

Adult↗

PubMed1989

Antipeptide antibody against the human low-density-lipoprotein receptor. Characterization and cross-reactivity with bovine lymphocytes.

A dodecapeptide corresponding to the external N-terminal sequence of the human low-density-lipoprotein (LDL) receptor was synthesized. Antibodies raised in rabbits against the peptide were purified and were shown to react specifically with the peptide and with human LDL receptor of fibroblasts, HeLa cells and lymphocytes using binding studies and immunoblotting. By indirect immunogold analysis, antibodies bound to the LDL receptor of human lymphocytes could be revealed as clusters. Anti-receptor peptide immunoglobulins specifically bound to the human HeLa cell's LDL receptor with a lower affinity than LDL (Kd x 3). The anti-receptor peptide immunoglobulins and 125I-labelled-LDL competed with each other for the LDL-receptor sites. Antibodies failed to react with lymphocytes of subjects with the homozygous form of familial hypercholesterolaemia. Cross-reactivity with the dodecapeptide of the bovine LDL receptor was limited, but this cross-reactivity was confirmed by the binding of anti-receptor peptide immunoglobulins to the LDL receptor from bovine lymphocytes.

Amino Acid Sequence↗

PubMed1989

Determination of the LDL receptor binding capacity of human lymphocytes by immunocytofluorimetric assay.

The determination of the LDL receptor binding capacity of human blood lymphocytes was assessed by indirect immunocytofluorimetric assay. To produce the maximal synthesis of the LDL receptor, the cholesterol efflux was enhanced by incubation of lymphocytes with HDL3 subfractions. The binding capacity of the LDL receptor was measured by incubation at 4 degrees C either with LDL and rabbit anti-LDL immunoglobulins or with peptide receptor antibody (ARP-Ig) raised against the NH2-terminal sequence of the LDL receptor. Thereafter complexes were incubated with fluorescein-labelled anti-rabbit immunoglobulin (FITC-Ig). Fluorescence flow cytometry was used to quantify the number of fluorescent lymphocytes and results were expressed as the percentage of lymphocytes with a fluorescent intensity above the threshold. Using preimmune rabbit immunoglobulin and then FITC-Ig, only 5-10% of cells were fluorescent. Neither LDL nor ARP-Ig could bind to homozygous familial hypercholesterolemia (FH) lymphocytes. Normal lymphocytes preincubated with HDL3 could bind LDL or ARP-Ig, the number of fluorescent cells being 59 and 39.2% respectively. Subjects with confirmed or suspected heterozygous FH demonstrated cell fluorescence at about half the normal level.

Female↗

PubMed1989

Rat monoclonal antibodies to human apolipoprotein B: advantages and applications.

Eight monoclonal antibodies (Mabs) to human serum low density lipoprotein (LDL) were derived from the fusion of spleen cells, from LOU rats immunized with human LDL, and the rat myeloma line IR983F. These Mabs were characterized in terms of isotype, specificity, and affinity. Competitive experiments indicated that the epitopes that were recognized could be grouped into three patterns depending on their apparent affinity for apoB-containing lipoprotein particles such as LDL, very low density lipoproteins (VLDL), or intermediate density lipoproteins (IDL). Six epitopes have been mapped in relation to elements of the sequence of apolipoprotein B-100 (apoB-100) and some have been assigned to the middle part of the median thrombolytic fragment T3, a region not yet well targeted by mouse Mabs. The presence of lipids for the expression of the epitopes was studied and confirmed a lipid dependence for epitopes that are close to the T2/T3 cleavage site. The capacity of binding to the LDL receptor was also tested; among the Mabs we described, one inhibited the uptake and degradation of LDL to HeLa cells receptor. Finally, some antibodies were able to precipitate LDL in gel.

Animals↗

PubMed1987

Oestrone sulphate metabolism in normal human endometrium grown in organ culture.

Samples of human endometrium were maintained in organ culture for 6 days on growth medium. On Day 6, ultrastructural studies were performed on endometrial explants, demonstrating that human endometrium grown in organ culture preserved its normal structure. The effect of oestrone sulphate was studied on the endometrium explants. The endometrium was cultured on harvest medium for 4 days to ensure the complete removal of endogenous steroids, the tissues were then incubated with 10(-7) M oestrone sulphate for 24 h. The oestrone sulphatase known to interfere with oestrone sulphate metabolism was present in endometrial organ culture. By incubation with estrone sulphate for 24 h it was demonstrated that oestrone sulphate is hydrolysed to active oestrogens.

Endometrium↗

PubMed1987

[Hellp syndrome may precede the appearance of arterial hypertension in pregnancy toxemia].

The "Hellp syndrome" describes the association of three biological abnormalities (hemolysis, liver abnormalities and thrombocytopenia) establishing the severity of arterial hypertension during pregnancy and requiring the interruption of pregnancy as much for the child as for the mother. This article reports a case of "Hellp syndrome" which was special in that the biological abnormalities preceded the occurrence of pre-eclampsia. The signs, diagnosis, prognosis and treatment of the "Hellp syndrome" are studied in this article.

Adult↗

PubMed1986

[Prostanoids of the peritoneal fluid and sterility with or without pelvic lesions (endometriosis, postinfectious adhesions)].

Peritoneal fluid levels of 6-keto-PGF1 alpha, TxB2, PGE2 and PGF2 alpha were measured in 62 infertile women undergoing coelioscopy. In 10 patients with mild endometriosis, the levels of all prostanoids were significantly enhanced as compared to control group (15 infertile patients without pelvic lesion). In 5 patients with moderate endometriosis, only PGF2 alpha exhibited a significant enhancement. The results confirmed the prostanoid component alteration of peritoneal fluid in infertile women with mild or moderate endometriosis, which however not has been found by all authors. In 6 patients with chronic salpingitis, no difference was found in prostanoid levels as compared to control group. The 26 patients with pelvic adhesions were distributed in 3 groups on the criterion of easy lysed or not adhesions. In group I (not lysed adhesions, 7 patients), no difference was found in prostanoid levels as compared to control group. In group II (mixed adhesions, 13 patients), the levels of all prostanoids, particularly 6-keto-PGF1 alpha, were significantly higher than that found in control group. In group III (easy lysed adhesions, 6 patients), the levels of 6-keto-PGF1 alpha, TxB2 and particularly PGF2 alpha were significantly enhanced as compared to control group. The results of this study suggest that prostanoids are implicated in physiopathology of endometriosis and pelvic adhesions and perhaps in mechanism of the associated infertility.

6-Ketoprostaglandin F1 alpha↗

PubMed1986

[Cesarean section for placenta praevia. Perinatal mortality and morbidity].

The severity of placenta praevia is well known and responsible of a non negligible perinatal mortality. This study relates to 65 children born after a cesarean section for placenta praevia and analyzes the fetal complications, their frequency, their prognosis as well as the obstetrical factors connected to this problem. Mortality is 3%, prematurity remains high and so is the anemia, but hypotrophy is rare. The main complications are infection essentially due to an overlapping placenta praevia, its hemorrhagic nature and the increasing number of hemorrhagic episodes and respiratory complications (respiratory distress, inhalation of amniotic fluid and hyaline membrane disease). From these fetal data, the authors propose a method of management of low placental insertions consisting essentially of bed rest as soon as the diagnosis in made on the sonogram, and extraction at the 35th week of amenorrhea. In case of hemorrhage, extraction must be performed earlier if obstetrical conditions, maternal as well as fetal, do not permit to undertake a conservative approach aimed essentially to decrease prematurity and its consequences.

Cesarean Section↗

PubMed1984

Estrone sulfatase activity in normal and abnormal endometrium.

We investigated the activity of estrone sulfatase in normal and pathological endometrium. In normal endometrium, the estrone sulfatase activity [pmol E1 X min-1 X (mg prot)-1] was 23.13 +/- 8.44 (mean +/- SD). An increase (p less than 0.01) of estrone sulfatase activity (62.81 +/- 21.97) was noted in mild endometrial hyperplasia. In focal hyperplasia (when the measurements were performed in the normal endometrial biopsies) such an increase was not noted (19.10 +/- 5.33). Estrone sulfatase activities of moderate hyperplasia (25.30 +/- 11.40) and endometrial neoplasia (30.30 +/- 9.57) were in the same range as in normal endometrium. Treatment with progestagen simultaneously reduced hyperplasia and estrone sulfatase activity. But when morphologically abnormal endometrium persisted after treatment, estrone sulfatase activity remained increased. The increase of estrone sulfatase activity appeared to be specific to mild endometrial hyperplasia. The role of estrone sulfatase in the pathogenesis of endometrial hyperplasia is discussed.

Adult↗