Inclusion of echocardiographic measure of right ventricular function in the non-invasive French pulmonary arterial hypertension risk stratification method

Background

Although preserved right ventricular (RV) function is consistently associated with better survival in pulmonary arterial hypertension (PAH), the French risk assessment method has not yet considered echocardiographic criteria of RV function.

Purpose

In the present study, we tested the value of tricuspid annular plane systolic excursion (TAPSE) measured by echocardiography for non-invasive PAH risk assessment.

Methods

We retrospectively studied a cohort of 306 incident PAH patients treated in two French expert centers who underwent follow-up TAPSE measurement from echocardiographic apical 4-chamber view in addition to previously validated invasive and non-invasive risk stratification variables. The primary composite outcome was 3-year lung transplantation free survival after follow-up assessment.

Results

At re-evaluation, 66% of patients were in NYHA functional class I-II and mean pulmonary arterial pressure, cardiac index, N-Terminal pro brain natriuretic peptide (NTproBNP), and 6-minute walk distance (6MWD) were 40±16 mmHg, 3.5±1.1 L/min/m2, 270 [interquartile range (IQR) 896] ng/L and 401 (IQR 213) meters, respectively. The primary outcome occurred in 58 (19%) patients. In multivariable Cox regression analysis, NYHA functional class I-II (p=0.02), NTproBNP <300 ng/L or BNP <50 ng/L (p=0.02), 6MWD >440m (p=0.049) and TAPSE≥17 mm (p=0.02) were associated with lung transplantation free survival. TAPSE provided similar information over 6MWD when both were used alternatively to stratify PAH patients at low risk (log-rank<0.001); Harrell's c-index 0.73.

Conclusion

Three dichotomized low-risk criteria (TAPSE, 6MWD and NTproBNP or BNP plasma levels) allow non-invasive risk assessment in PAH.

Funding Acknowledgement

Type of funding sources: None. 3-years transplant-free survival

Turnover Study of Heparin Cofactor II in Healthy Man

Heparin cofactor II (HC II) is a heparin-dependent inhibitor of thrombin, distinct from antithrombin III (AT III). This study was designed to evaluate its metabolism in healthy subjects. Purified HC II was labelled with 125I by the lactoperoxidase-glucose oxidase technique. The biological activity of the HC II was unchanged after labelling as was its migratory pattern by crossed immunoelectrophoresis in the presence of heparin or dermatan sulfate.

Three healthy volunteers were injected with 10 uCi and the plasma radioactivity was measured daily. The data were approximated by a sum of two exponential terms and the metabolism of HC II was described by a two compartment mamillary system.

The mean values of fractional catabolic rate, intravascular fraction and half-life of the elimination phase were respectively: 0.44 d-1, 0.60 and 2.53 d. These parameters are of the same order of magnitude as those reported in the literature for AT III. The plasma HC II concentration in the 3 subjects ranged from 61 to 82 ug/ml as estimated using our purified preparation. Accordingly, the absolute catabolic rate ranged from 1.17 to 1.36 mg · kg-1 · d-1.

Chapitre I - Troubles vésico-sphintériens des syndromes parkinsoniens

Lower urinary tract dysfunction is frequent in Parkinson's disease and other Parkinsonian syndromes and can cause urinary incontinence complicating a urgency-frequency syndrome or on the contrary, dysuria. These disorders are a frequent urological presenting complaint due to their impact on the patient's quality of life. Urologists must be aware of the different natural histories of diseases such as Parkinson's disease and Parkinsonian syndromes such as multisystem atrophy, which often have a severe course and are marked by resistance to neuropharmacological treatments. These various diseases can also directly induce urinary symptoms, independently of urological complications. Inversely, the development of urinary disorders, especially obstructive symptoms, in a patient with Parkinsonian syndrome may require review of the neurological diagnosis. Finally, therapeutic management is complex due to the difficulty of using pharmacological treatments, and the risk of deterioration after surgical treatment of obstructive uropathy.

Lattice melting and rotation in perpetually pulsating equilibria

Systems whose potential energies consists of pieces that scale as r;{-2} together with pieces that scale as r;{2} , show no violent relaxation to Virial equilibrium but may pulsate at considerable amplitude forever. Despite this pulsation these systems form lattices when the nonpulsational "energy" is low, and these disintegrate as that energy is increased. The "specific heats" show the expected halving as the "solid" is gradually replaced by the "fluid" of independent particles. The forms of the lattices are described here for N18 and they become hexagonal close packed for large N . In the larger N limit, a shell structure is formed. Their large N behavior is analogous to a gamma=53 polytropic fluid with a quasigravity such that every element of fluid attracts every other in proportion to their separation. For such a fluid, we study the "rotating pulsating equilibria" and their relaxation back to uniform but pulsating rotation. We also compare the rotating pulsating fluid to its discrete counterpart, and study the rate at which the rotating crystal redistributes angular momentum and mixes as a function of extra heat content.

[Manufacture of DNA chips in a laboratory for internal use: legislation and quality assurance]

Manufacturing and using DNA chips in a laboratory, while respecting legality and good practices, require a review of the regulatory framework and relevant documentation for implementing a quality assurance system. Using DNA chips, either as a research tool, or as an in vitro diagnostic medical device, does not come within the same regulations: none in the first case, and european directive 98/79/CE in the second one. It is the same for research practice, for which the law to be enforced has been primarily conditioned to ethics, while carrying out medical analyses has been framed in France by the GBEA. The regulatory approach laid down in the GBEA is a first step for implementing a quality assurance system, but this must be extended to the manufacturing process of DNA chips. International standards (ISO 9001: 2000, ISO/IEC 15189...) provide documentation to meet this last requirement, but also enable one to carry on the quality approach up to the certification of the laboratory or its accreditation.

A fluorescence microplate assay using yopro-1 to measure apoptosis: application to HL60 cells subjected to oxidative stress

A new one-step labeling procedure using the membrane permeant fluorescent probe yopro-1 in association with fluorescence microtitration for the rapid determination of apoptosis is reported. Programmed cell death was induced by the pro-apoptotic agents etoposide and staurosporine, and measured in nonadherent HL60 cells and adherent phorbol 12-myristate 13-acetate (PMA)-treated HL60 cells. Cell viability was controlled by trypan blue exclusion and calcein-AM staining. To confirm results of fluorescence microplate assay, apoptosis was measured by flow cytometry analysis using the same fluorescent probe, and results showed corresponding data between both procedures. Development of apoptosis was confirmed by the presence of PARP (poly(ADP-ribose) polymerase cleavage and nuclear DAPI (4,6-diamidino-2-phenylindole) staining, two well-known methods used to investigate apoptosis. The fluorescence microplate assay was also applied to measure apoptosis in cells exposed to an oxidative stress induced by tert-butylhydroperoxide (t-BHP), and results confirmed the potential of the fluorescence microplate assay in measuring events of apoptosis, especially in adherent, cultured, living cells.

Prism adaptation to rightward optical deviation improves postural imbalance in left-hemiparetic patients

Left-hemiparetic patients show predominant postural imbalance as compared to right-hemiparetic patients. The right hemisphere is crucial for generating internal maps used for perceptual and premotor processing of spatial information. Predominant postural imbalance with right-brain damage could thus result from a distortion of an internal postural map. Well-known manifestations of distorted internal maps due to right-hemisphere lesions, such as hemineglect, may show improvement following prism adaptation shifting the visual field to the right. We therefore investigated the effect of prism adaptation on postural imbalance in left-hemiparetic patients. Three groups of five patients were either adapted to prisms deviating the visual field to the right or left or exposed to neutral prisms while performing reaching movements of the right arm. Postural imbalance was reduced only following prism adaptation to the right. Thus, brief adaptation (i.e., 3 min) to rightward-shifting prisms can dramatically improve postural imbalance. This result shows that the effect of exposure to prisms that horizontally shift the visual field to the right in a reaching task generalizes to the postural system, and it suggests an interaction between horizontal and vertical reference frames. This also supports the theory that predominant postural imbalance in patients with right-brain damage may be partly related to a distortion of an internal postural map.

Integrins of the beta1 family influence keratinocyte-lymphocyte interaction

Data from the literature indicate that ICAM-1 molecules play an important role in keratinocyte interactions with lymphocytes via the lymphocyte function-associated-1 lymphocyte-adhesion molecule. We examined the role of beta1 integrins in keratinocyte-lymphocyte adhesion under different activation conditions. Among the beta1 integrins expressed on keratinocytes and lymphocytes detected by indirect immunofluorescence microscopy and flow cytofluorometry, primarily the alpha2 and the alpha3 subunits on both cell types were involved in keratinocyte-lymphocyte adhesion. Moreover, the highest adhesion level was observed when both cell types were activated by IFN-gamma for keratinocytes and phorbol 12-myristate 13-acetate for lymphocytes, suggesting that the former involved the protein kinase C pathway. Keratinocyte activation, characterized by the expression of ICAM-1, a decrease of beta1 integrins, and the absence of alpha5beta1 integrin, was required for optimal lymphocyte adhesion. Thus, beta1 integrins remaining at the surface of IFN-gamma-treated keratinocytes could be activated by this cytokine, and could synergize with ICAM-1 and lymphocyte function-associated-1 molecules to consolidate keratinocyte-lymphocyte adhesion.

T lymphocytes from Sézary syndrome patients express beta1 integrins whose beta(1-6)-branched N-linked oligosaccharides reflect their adhesive capacity

Sézary syndrome (Sz), characterized by slowly progressing clonal proliferation of CD4+, CD45 RO+ T cells, has several forms that are distinguished according to the epidermotropic properties of the pathological cells. In a recent paper (Derappe C, Haentjens G, Lemaire S, Feugeas JP, Lebbe C, Pasqualetto V, Bussel A, Aubery M, Néel D. Leukemia 1996;10:138), we observed that T lymphocytes from most of the Sézary patients [Szbeta(1-6)+] expressed high levels of beta(1-6)-GlcNAc-branched N-linked oligosaccharides while T lymphocytes from other patients [Szbeta(1-6)-] did not. Because this observation suggests the possibility of two forms of Sz, distinguished according to the expression rate of these glycans, we looked for a possible relationship between this expression rate and T-cell adhesiveness. Using an original protocol (Braut-Boucher F, Pichon J, Rat P, Adolphe M, Aubery M, Font J. J Immunol Methods 1995;178:41), we observed that T lymphocytes obtained from the Szbeta(1-6)+ patients adhered less to normal keratinocyte monolayers than T lymphocytes from Szbeta(1-6)- patients and normal donors. As assessed by FACS analysis, all the integrin-subunits studied were more expressed on Szbeta(1-6)-, especially alpha4, alpha5, beta1 and beta2, than on Szbeta(1-6)+ and normal lymphocytes. Although these results suggest that beta1- and beta2-integrin expression is involved in the adhesive properties of these T-cells, other factors, such as glycosylation, may also contribute. To demonstrate this possibility, we sought the presence of beta(1-6)-GlcNAc-branched N-linked oligosaccharides on beta1 integrins expressed by T lymphocytes from Sz patients. Immunoblot experiments, performed using the specific lectin from Phaseolus vulgaris (Leukoagglutinin form), showed that only the beta1 integrin subunit expressed by T lymphocytes from Szbeta(1-6)+ patients carried these glycans, supporting the concept of the involvement of T-cell glycosylation in the evolution of Sz.

Urinary disturbances in striatonigral degeneration and Parkinson's disease: clinical and urodynamic aspects

Although urinary disturbances are more frequent in multiple system atrophy (MSA) than in Parkinson's disease (PD), the striatonigral degeneration (SND) type of MSA is difficult to distinguish from PD, especially when the latter is associated with orthostatic hypotension or urinary symptoms. The pattern of urinary symptoms and urodynamic dysfunction was analyzed in 15 SND and 35 PD patients with urinary complaints. In SND, dysuria with or without chronic retention, frequently associated with a hypoactive detrusor and low urethral pressure, permitted early and reliable diagnosis. In PD, urgency to void, with or without difficulty voiding, but without chronic retention, associated with detrusor hyperreflexia and normal urethral sphincter function, predominated. In clinical practice, the study of urinary symptoms and bladder function may help to distinguish SND from PD in patients with urinary disturbances.

Congenital lumbosacral lipomas

Congenital lumbosacral lipomas can be responsible for progressive defects. The general feeling is that tethering of roots, filum, or cord probably explains this evolution, and that untethering of these structures could prevent late deterioration. Like the vast majority of neurosurgeons, we too have routinely and systematically operated on lumbosacral lipomas, even in the absence of neurological deficits. This policy stemmed from our belief that spontaneous neurological deterioration was frequent, recovery from preoperative deficits rare, and surgery both efficient and benign in nature. After 22 years of experience, we felt that it was necessary to review our series of 291 lipomas (38 lipomas of the filum and 253 of the conus) operated on from 1972 to 1994. To reassess the value of prophylactic surgery, we attempted an accurate evaluation of (1) the risk of pathology, (2) the risks involved in surgery, (3) the postoperative outcome with respect to preoperative deficits, and (4) the postoperative outcome in asymptomatic patients at 1 year and at maximum follow-up. Special attention was paid to 93 patients whose postoperative follow-up was more than 5 years (average 8.7, median 8, range 5-23 years). Of these 93 patients, 39 were asymptomatic preoperatively (7 with lipoma of the filum and 32 with lipoma of the conus). Lipomas of the filum and of the conus are entirely different lesions and were studied separately. In 6 cases prenatal diagnosis had been possible. The mean age at surgery was 6.4 years. Low back skin stigmata were present in 89.4% of cases. Preoperative neurological deficits existed in 57% of the patients and were congenital in 22%. Clinical signs and symptoms recorded were pain in 13.3% of the patients and/or neurological deficits affecting sphincter (52%), motor (27.6%) and sensory (22.4%) functions. Deficits were progressive in 22.4% of cases, slowly progressive in 58.8% of these and rapidly progressive in the remaining 41.2%. In 36 patients (13.2%) the lipomas were seen to grow either subcutaneously or intraspinally. Among these patients, 21 were infants, 2 were obese adolescents, and 10 were pregnant women. The metabolism of the fat within the lipomas was studied in 11 patients and found to be similar to that at other sites. Lipomas were associated with various other malformations, either intra- or extraspinal. These associated anomalies were rare in the case of lipomatous filum (5.2%) but frequent with lipomas of the conus, except for intracranial malformations (3.6%). Therapeutic objectives were spinal cord untethering and decompression, sparing of functional neural tissue and prevention of retethering. Procedures used to achieve these goals were subtotal removal of the lipoma, intraoperative monitoring, duroplasty, and sometimes closure of the placode. Histologically, lipomas consisted of normal mature fat. However, 77% of them also included a wide variety of other tissues, originating from ectoderm, mesoderm, or entoderm. This indicates that lipomas are either simple or complex teratomas. The results of the study are as follows. (1) Surgery was easy and safe when performed for treatment of lipomas of the filum (no complications), but difficult and hazardous in the case of lipomas of the conus (20% local, 3.9% neurological complications). (2) All types of deficit could be improved by surgery, which was beneficial in all cases of lipoma of the filum and 50% of cases of lipoma of the conus. (3) In asymptomatic patients long-term surgical results depended on the anatomical type of the lipoma. They were excellent in lipomas of the filum. In lipomas of the conus they were good in the short term but eroded with time. At more than 5 years of follow-up only 53.1% of the patients were still free of symptoms. (4) Reoperations were performed in 16 patients (5.5%), 5 (31.2%) of whom improved postoperatively, while in 7 (43.7%) progression stopped, in 3 (18.7%) deterioration continued and in 1 (6.2%) the condition was wor

Altered collagen of human pathological fibroblasts impairs the synthesis of fibronectin

Human fibroblasts with mutated type I collagen have marked defective adhesive capacities on exogenous type I collagen and exogenous fibronectin in comparison to normal fibroblasts. This defective cell adhesion could be partly explained by the decreased level of cell surface receptors of the beta 1-integrin family, i.e., the alpha 2 integrin subunit for type I collagen and the alpha 5 integrin subunit for fibronectin, observed in pathological fibroblasts. However, it appeared that the presence of altered collagen interfered both with fibronectin biosynthesis and with its surface expression. Using a binding assay on immobilized fibronectin, we demonstrated that the mutated collagen had a weaker binding to fibronectin. In addition, the pathological fibroblasts plated on a mixture of normal exogenous type I collagen and fibronectin exhibited the same maximal level of adhesion as control fibroblasts. These results indicate that fibroblasts with the mutated collagen exhibit a decreased binding to normal fibronectin, a modification of synthesis and surface expression of fibronectin, and, finally, altered adhesive capacities.

The effects of ribavirin on the GTP level and the VIP receptor dynamic of human IGR39 cells

GTP is one of the major cellular molecules involved in fundamental functions of cell life. Ribavirin, and antiviral and antitumoral agent, the primary site of action of which is the IMP deshydrogenase, was used in order to depress the intracellular GTP level. Consequential effects were tested on the property and dynamic of the VIP receptor on human melanoma IGR 39 cells. A concentration of 100 microM of Ribavirin reduced the intracelluar GTP level by more than 60% and induced a reversible growth arrest. Nevertheless this drug displayed no effect on: i) the VIP binding parameters (Kd and Bmax) of both high and low affinity receptors; ii) the cycling of the VIP receptor; iii) the based and VIP-stimulated cAMP production and iv) the subcellular GTP distribution. We show that Ribavirin, in the range of concentrations used, is very efficient to inhibit GTP synthesis in the human melanoma cell line IGR 39 and its growth, without affecting VIP receptor functions.

"Pure" striatonigral degeneration and Parkinson's disease: a comparative clinical study

Striatonigral degeneration (SND) is difficult to diagnose in vivo. The purpose of this study was to detect the best indicators for an early and reliable diagnosis of the disease. Eighteen patients clinically diagnosed as having SND were selected with rigorous inclusion criteria and compared to 18 patients with Parkinson's disease (PD) matched for age and disease duration. Apart from dysautonomia, the principal discriminant clinical features that distinguished SND from PD were the early appearance of the following symptoms and signs: (a) severe and atypical progressive parkinsonism characterized by bilateral bradykinesia and rigidity, slowness of gait, postural instability, and falls, and poor or absent response to adequate levodopa treatment; (b) increased tendon reflexes associated or not with frank pyramidal signs, severe dysarthria, and less consistently, dysphagia, stridor, antecollis, and stimulus-sensitive myoclonus, which, when present, are highly suggestive of the disease.

A non-isotopic, highly sensitive, fluorimetric, cell-cell adhesion microplate assay using calcein AM-labeled lymphocytes

A simple and sensitive cell-cell adhesion microplate assay was established using the cytoplasmic fluorescent dye, calcein AM. The procedure involves three steps: the labeling of lymphocytes with an adequate concentration of calcein AM (20 microM) during a short incubation period (30 min); the adhesion of 2 x 10(5) labeled lymphocytes per well to confluent keratinocyte or fibroblast monolayers grown in microtiter plates for 90 min; and, finally, measurement of the fluorescent signal utilizing a new system of cold-light microfluorimetry (Rat, 1993). During the adhesion assay, the release of calcein from labeled lymphocytes is low and the method permits the detection of as few as 1000 adherent cells. This non-radioactive procedure takes less than 4 h to perform and has proven to be as accurate and reliable as the common method using radioactive isotopes. In addition to its simplicity, the use of a fluorescent molecular probe in conjunction with cold-light microfluorimetry (CLF) offers many advantages of safety and economy, and can readily be adapted to the different cell types that participate in cell-cell adhesion.

A new three-dimensional culture of human keratinocytes: optimization of differentiation

Many attempts have been made to obtain reconstructed human epidermis comprised of keratinocytes and extracellular-matrix constituents (essentially collagen) in the presence or absence of fibroblasts. A simple model of cultured human keratinocytes, grown at the air-liquid interface of a noncoated artificial membrane, has been developed. This culture system offers many advantages: easy control of environmental factors and routine examination using optical or electronic microscopy, immunohistochemistry and indirect immunofluorescence techniques. This model enables the analysis of well-known differentiation markers and also integrins, a family of cell-surface molecules involved in cell-cell and cell-extracellular matrix interactions, whose receptors are expressed on all basal keratinocytes. In our culture system, the expression of the different integrin subunits (alpha 2, alpha 3, alpha 5, alpha 6, beta 1) was studied as a function of the differentiation state in two different media (K-SFM or DMEM/Ham's F12) supplemented with 5% fetal calf serum and adjusted to 1.5 mmol/L calcium. The most significant data are the preponderant expression of the alpha 2 and alpha 3 subunits in the basal and suprabasal layers, with membrane expression differing according to the culture medium; terminal differentiation was obtained in DMEM/Ham's F12. The use of membrane inserts represents a significant technological advance in culturing keratinocytes and is an easy-to-handle and valid model for determining the influence of physiological or pharmacological factors on cell proliferation or differentiation.

Inhibition of vasoactive intestinal peptide (VIP) binding on human melanoma cells IGR39 by nitric oxide: cGMP is not involved

Nitric oxide (NO) and the NO generating agent nitroprusside (SNP), inhibit the binding of [125I] vasoactive intestinal peptide (VIP) to its receptor at the surface of IGR39 human melanoma cells. Cysteine (10 mM) increases the sensitivity of the system to SNP while N-acetylcysteine (10 mM) decreases it. The NO gas as well as SNP inhibits the [125I]VIP binding capacity. These observations sustain an effect of SNP-generated NO rather than an effect of the SNP molecule per se or the cyanoferrate portion of the molecule. The inhibitory effect of NO is time and concentration dependent and is fully reversible. Affinity constants of high and low affinity VIP receptors of SNP-treated IGR39 cells are not modified while maximal binding capacity (Bmax) of both receptor types are decreased to the same extent. Production of cGMP by SNP-treated cells is time and concentration dependent and the maximum amount of cGMP obtained reaches 13 times the basal level. The cAMP production is not affected by SNP. However, the SNP effects on the [125I]VIP binding are not mimicked by the membrane permeant cGMP analogs dibutyryl cGMP and 8-bromo cGMP even at concentrations as high as 0.5 mM. Taken altogether, these data demonstrate a regulatory action of NO on VIP binding capacity of IGR39 melanoma cells which is not cGMP mediated. They also evidence a new step which could be involved in the NO-VIP interaction.

A monoclonal antibody inhibits adhesion to fibronectin and vitronectin of a colon carcinoma cell line and recognizes the integrins alpha v beta 3, alpha v beta 5, and alpha v beta 6

Using whole viable human colon carcinoma HT29 cells as immunogen, we produced a monoclonal antibody (mAb) termed 69-6-5. The antibody was functionally selected on its anti-cell-spreading activity. By immunoprecipitation of surface radiolabeled cell lysates from HT29-D4 cells (an HT29 cell clone), mAb 69-6-5 recognized a molecular complex resembling integrin heterodimers. Sequential immunodepletions with mAb to the integrin alpha v subunit demonstrated that this complex was composed of alpha v-containing integrins. Accordingly, mAb 69-6-5 reacted with integrin alpha v beta 3 immunopurified from melanoma cells and integrins alpha v beta 5 and alpha v beta 6 immunopurified from pancreatic carcinoma cells. In cell adhesion assays, the 69-6-5 mAb was able to inhibit strongly in a dose-dependent manner arginine-glycine-aspartic acid-mediated adhesion of HT29-D4 cells to vitronectin, fibronectin, or ProNectin F but not to laminin or collagen. Immunoprecipitations with beta chain-specific antisera indicated that these cells express integrins alpha v beta 5 (receptor for vitronectin) and alpha v beta 6 (receptor for fibronectin) but neither alpha v beta 1 nor alpha v beta 3. In summary, these results indicated that mAb 69-6-5 reacts with several alpha v integrins and that it can effectively interfere with the adhesive functions of at least alpha v beta 5 and alpha v beta 6, which represent the major receptors on HT29-D4 cells responsible for their adhesion on vitronectin and fibronectin.

Glycosylation of VIP receptors: a molecular basis for receptor heterogeneity

Apparent molecular weights of VIP-binding proteins differ greatly according to species and to tissue. In this study, we used plasma membranes from various species (human, rat, pig) and tissues (melanoma, intestine, liver), which display major 125I-VIP-labeled components with molecular weights ranging from M(r) = 51,800 to 66,800. With the exception of porcine receptor, the various VIP receptors had similar apparent molecular weights after removal of their N-linked carbohydrates. In addition to differences in the amount of asparagine-linked glycans, our results also revealed differences in the composition of the oligosaccharide chains, which can also account for the heterogeneity in the molecular weights of the VIP receptor.

Evaluation of six markers of haemostatic system in normal pregnancy and pregnancy complicated by hypertension or pre-eclampsia

OBJECTIVE

To establish the plasma evolution of prothrombin fragments 1+2 (F 1+2), thrombin-antithrombin III complexes (TAT), fibrin fragment D-Dimers (DD), von Willebrand factor antigen (vWf), Type 1 plasminogen activator inhibitor antigen (PAI) and blood platelet count during normal pregnancy and to compare these values with those obtained in hypertensive or pre-eclamptic pregnancies.

DESIGN

Cross-sectional study.

SUBJECTS

Forty-seven healthy pregnant women with gestational age ranging between 5 and 40 weeks, and fourteen women with gestational age ranging between 25 and 38 weeks presenting with either gestational hypertension (n = 4) or pre-eclampsia (n = 10). Numbers of nulliparous women in the control, hypertension and pre-eclampsia groups were 13/47 (28%), 1/4 (25%) and 9/10 (90%), respectively.

RESULTS

All six markers increased with gestational age in normal pregnant women (P < 0.01). Using the upper limit of 95% prediction interval obtained from regression curves as normality threshold, TAT showed the best sensitivity (71% vs < 30% for F1+2, DD, vWf, PAI and platelet count).

CONCLUSION

TAT appears to be an interesting marker for detecting haemostatic system alterations in pregnancies complicated by hypertension or pre-eclampsia. A large prospective study to determine its clinical usefulness for such complicated pregnancies is currently in progress.

Modifications of the binding properties of the human VIP receptor of IGR39 cells by sulfhydryl reagents

The effects of specific sulfhydryl reagents, N-ethylmaleimide (NEM), p-chloromercuribenzoic acid (PCMB) and 5-5'-dithiobis(2-nitrobenzoic acid) (DTNB), were tested on the vasoactive intestinal peptide (VIP) receptor binding capacity of the human superficial melanoma-derived IGR39 cells. On intact cell monolayers NEM and PCMB inhibit the specific [125I]VIP binding in a time and dose-dependent manner while DTNB has no effect at any concentration tested. Inhibitory effects of NEM and PCMB on high and low affinity VIP receptor are not identical. With NEM-treated cells, only low affinity sites remained accessible to the ligand. Their affinity constant is not modified. With PCMB-treated cells, the binding capacity of high affinity sites is reduced by 56% while the binding capacity of low affinity sites is not significantly affected. For both types of binding sites, the affinity constants remain in the same range of that of untreated cells. On cells made permeable by lysophosphatidylcholine, DTNB is able to inhibit the specific [125I]VIP binding in a time and dose-dependent manner. The three sulfhydryl reagents stabilize the preformed [125I]VIP receptor complex whose dissociation in the presence of native VIP is significantly reduced. Labeling of free SH groups with tritiated NEM after preincubation of cells with DTNB and VIP made possible the characterization of reacting SH groups which probably belong to the receptor. Taken together, these data allow us to define three classes of sulfhydryl groups. In addition, it is shown that high and low affinity sites have different sensibility to sulfhydryl reagents.

Modulation of the expression of the VIP receptor by serum factors on the human melanoma cell line IGR39

IGR39 cells, isolated from a human superficial melanoma, display at their surface high and low affinity receptors for the vasoactive intestinal peptide (VIP). When grown in DME medium supplemented with 10% fetal calf serum, cells display 1.6 x 10(5) high affinity (Kd 0.74 nM) and 5.6 x 10(5) low affinity (Kd 55 nM) VIP binding sites per cell. When cultured in a chemically defined medium containing EGF, transferrin, and selenium, IGR39 cells display many neurite-like extensions. Following these morphological changes, the specific [125I]VIP binding is increased four- to fivefold after 6 days in culture. This phenomenon is reversible and is the result of an increased number of VIP binding sites available at the cell surface, without modification of their affinities. The molecular mass of the binding sites is also unchanged whatever cell culture conditions. Increase in [125I]VIP binding is inversely correlated to the serum concentration in the culture medium. When added to the chemically defined medium, sera from various origins as well as some serum substitutes reduce [125I]VIP binding to the same extent as that of the serum. The total cAMP production by VIP-stimulated IGR39 cells is enhanced by a factor of six to seven when cells are cultured in serum-free medium, in good correlation with the increase of VIP binding capacity. These data suggest that factor(s) present in fetal calf serum inhibit(s) the expression of VIP receptor, thus demonstrating the importance of a strict control of cell culture conditions for in vitro studies.

Prothrombin fragment 1 + 2, thrombin-antithrombin III complexes and D-dimers in acute deep vein thrombosis: effects of heparin treatment

Plasma levels of prothrombin fragment 1 + 2 (F 1 + 2), of thrombin-antithrombin III complexes (TAT) and of D-dimers were evaluated at several time intervals in 15 patients affected by acute proximal deep vein thrombosis, complicated or not by pulmonary embolism, and treated by conventional heparin therapy for 9 d. The mean levels of the three markers remained significantly increased throughout the period of observation, except for F 1 + 2 on day 9, when compared to normal values established in a population of normal healthy blood donors. However, whereas heparin significantly decreased the plasma levels of F 1 + 2 and of TAT complexes in less than 3 d. D-dimer levels were not significantly altered. Significant correlations were observed between the plasma levels of the three markers but they were not correlated to the actual intensity of heparin treatment evaluated as the activated partial thromboplastin time prolongation. These results indicate that heparin improves the hypercoagulable state associated with a deep vein thrombosis within the first days of treatment as indicated by TAT and F 1 + 2. They also account for the performances of D-dimer assay for the diagnosis of deep vein thrombosis in patients already receiving heparin, a common situation in routine hospital practice.

Suramin-induced differentiation of the human colic adenocarcinoma cell clone HT29-D4 in serum-free medium

The clonal cell line HT29-D4 was able to grow in a completely defined medium containing EGF, selenous acid, and transferrin in the presence of the anti-helminthic drug suramin. In the absence of suramin, the kinetics of cell growth and the cell density obtained were dependent on the external EGF concentration. In the presence of suramin, cell density reached a plateau independent of EGF concentration above 50 ng/ml. At the morphological level, suramin allowed hemicyst formation in the cell monolayer. The cells were polarized with a well-ordered brush border facing the culture medium and mature junctional complexes that divided the cell membrane in two distinct domains. The carcinoembryonic antigen was found to be restricted to the apical membrane domain while the major histocompatibility molecules HLA-ABC were segregated within the basolateral domain. The electrical parameters of suramin-treated cells grown on permeable filters were measured and demonstrated that the cell monolayer was electrically active. These properties were never found in the absence of the drug. Moreover, the vasoactive intestinal polypeptide (VIP) was able to induce a dramatic increase in cAMP only when it was added, in agreement with the localization of the VIP receptor, in the lower compartment of the culture chamber. In conclusion we described for the first time conditions allowing the growth of functionally differentiated human colic cell monolayers in chemically defined medium. This model will contribute to a better understanding of suramin action and of the mechanisms involved in cell polarization.

Urinary bladder diverticula and the Ehlers-Danlos syndrome in children

Two large bladder diverticula that induced severe micturition disturbances were surgically removed in a 5-year-old boy with Ehlers-Danlos syndrome (EDS). One year after surgery, a new, asymptomatic diverticulum developed. This case is discussed in the light of nine similar cases that have already been published. It is concluded that EDS diverticula form a distinct group characterized by postoperative recurrence. They are not due to vesicourethral obstruction but probably result from an anomaly of the vesical wall. They are responsible for micturition difficulties and urinary tract infections. Their unavoidable recurrence means that surgery should be restricted only to symptomatic patients.

In vitro covalent binding of the pyrethroids cismethrin, cypermethrin and deltamethrin to rat liver homogenate and microsomes

Phenobarbital-induced rat liver homogenate and microsomes were used to study covalent binding of 14C-labelled (at the alcohol moiety) cismethrin, 14C-labelled (at the alcohol and acid moieties) cypermethrin, and 14C-labelled (at the alcohol and acid moieties) deltamethrin. Covalent binding was dependent on pyrethroid concentration. With liver homogenate, inhibition of esterases by tetraethylpyrophosphate and of mitochondrial respiration by rotenone or potassium cyanide only slightly altered the covalent binding level. With microsomes, inhibition of cytochrome P-450 and mixed function oxidases by carbon monoxide and piperonyl butoxide reduced the covalent binding so far as to be nearly absent. Eighty percent inhibition of epoxide hydrolase decreased the covalent binding by 50%. The comparison of data between alcohol and acid labelling of the same pyrethroid suggested that, in vitro, the whole molecule is bound to proteins and that hydrolysis can occur afterwards. The experiments stress the role of cytochrome P-450-dependent monoxygenases in the covalent binding process.

A human melanoma-derived cell line (IGR39) with a very high number of vasoactive-intestinal-peptide (VIP) receptors. 1. Molecular characterization of the binding site

Using mono[125I]iodinated vasoactive intestinal peptide (125I-VIP), a very high number of specific binding sites for VIP were identified at the surface of the human melanoma cell line IGR39. The Scatchard analysis of competitive displacement experiments between native VIP and 125I-VIP was consistent with the existence of two classes of VIP-binding sites. IGR39 cells possess 0.54 x 10(6) high-affinity sites with a dissociation constant (Kd) of 0.66 nM and 1.3 x 10(6) sites of moderate affinity with a Kd of 4.7 nM. Pharmacological studies indicated that the order of potency in inhibiting 125I-VIP binding of the VIP/secretin family peptides was VIP much greater than peptide histidine methioninamide greater than human growth-hormone-releasing factor(1-44) greater than secretin. Glucagon has no effect on the binding of the labelled peptide. By means of photoaffinity labelling a polypeptide of Mr 63,000 was characterized. The labelling of this species was completely abolished by native VIP. The order of potency of VIP-related peptides in inhibiting 125I-VIP cross-linking to its receptor was the same as in the competition experiments. The glycoprotein nature of the VIP-binding sites of IGR39 cells has been investigated by affinity chromatography on wheat-germ-agglutinin-Sepharose.

A human melanoma-derived cell line (IGR39) with a very high number of vasoactive-intestinal-peptide (VIP) receptors. 2. Effect of VIP on cAMP production and on cell-surface VIP-binding sites

Vasoactive intestinal peptide (VIP) stimulated in a dose-dependent manner the accumulation of cAMP in human melanoma-derived cell line IGR39. The maximal effect (about 100 times the basal level) was observed with 10 nM VIP. Half-maximum cAMP production was obtained at 0.78 nM VIP. VIP-related peptides were also potent in stimulating the cAMP production in IGR39 cells. The order of potency was VIP much greater than peptide histidine-methioninamide greater than human growth-hormone-releasing factor(1-44) greater than secretin greater than glucagon. Using the same conditions, IGR37 cells, a metastasic counterpart of IGR39 cells, displayed a weak stimulation of cAMP production. After exposure of IGR39 cells to 10 nM VIP, the cAMP response to a new stimulation by VIP was strongly reduced. This desensitization of IGR39 cells to VIP was rapid (t1/2 less than 2 min) and homologous. Preincubation of IGR39 cells in the presence of native VIP induced disappearance of the VIP-binding sites at the cell surface. This phenomenon was dependent on time and VIP concentration. Maximum effect (loss of 80% of binding capacity) was obtained after exposure of the cells at 37 degrees C with a VIP concentration of 1 microM. The t1/2 of maximum disappearance was less than 2 min and the concentration of VIP giving half-maximum decrease in binding of mono[125I]iodinated VIP (125I-VIP) was 8 nM. This phenomenon was also reversible since 85% of the VIP-binding capacity could be restored in less than 1 h by incubating IGR39 cells in a VIP-free medium. The IGR39 cell line should be a useful model for further study of the structure and function of the human VIP receptor.

Solubilization of the active vasoactive intestinal peptide receptor from human colonic adenocarcinoma cells

The non-ionic detergent n-octyl-beta-D-glucopyranoside was used to solubilize the VIP (vasoactive intestinal peptide) receptor from human colonic adenocarcinoma cell line HT29-D4. The binding of monoiodinated 125I-VIP to the solubilized receptor was specific, time-dependent, and reversible. Scatchard analysis of data obtained from competitive displacement of monoiodinated 125I-VIP by native VIP suggested the presence of two classes of VIP binding sites with Kd values of 0.32 and 46.7 nM. The binding capacities of these two classes were 1.7 x 10(10) and 30.2 x 10(10) sites/mg of proteins, respectively. The solubilized receptor retained the specificity of the human VIP receptor towards the peptides of the VIP/secretin/glucagon family. The order of potency in inhibiting monoiodinated 125I-VIP binding was VIP (IC50 = 1.0 x 10(-9) M) much greater than peptide histidine methionine amide (IC50 = 10(-7) M) greater than growth hormone-releasing factor (IC50 = 3 x 10(-7) M) greater than secretin (IC50 greater than 10(-6) M); glucagon had no effect on VIP binding. The reducing agent dithiothreitol inhibited in a dose-dependent manner the binding of 125I-VIP. Covalent cross-linking experiments between the solubilized receptor and 125I-VIP showed that after sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography two major and one minor polypeptides of Mr 67,000, 72,000, and 83,000 were specifically labeled. When analyzed by gel filtration, the n-octyl-beta-D-glucopyranoside-solubilized 125I-VIP-receptor complex was resolved into two major peaks with molecular mass in the range of 60-70 and 270-300 kDa. Thus, the soluble form of the VIP receptor was probably a multimeric complex in which disulfide bonds may play an important role to hold the receptor in an active configuration.

The vasoactive intestinal peptide (VIP) receptor: recent data and hypothesis

Vasoactive intestinal peptide (VIP) is a neuropeptide with a broad range of biological activities in various tissues. After interaction with its membrane receptor, VIP generally induces a very large increase in the intracellular cyclic AMP level. Receptors for VIP have been described in numerous tissues and cell lines. The first results on VIP receptor structure have been obtained by covalent cross-linking using bifunctional reagents. The molecular mass of the different components characterized in this way differs greatly according to the species and the tissue used. This heterogeneity may reflect either a difference in the length of the cross-linked polypeptide backbone or differently glycosylated forms of the same polypeptide. The VIP binding site of intact human adenocarcinoma cells (HT29 cells) is an Mr 64,000 glycoprotein with 20kDa of N-linked oligosaccharide side chains containing sialic acid. The structure of the VIP binding site from HT29 cell is compared, first to the structure of the VIP receptor from other tissues, particularly that from rat liver, and second to the structure of the hepatic glucagon binding site. Recently, solubilization of the VIP receptor in an active form has provided a new way of studying this receptor. The HT29 cell line is an appropriate model to study the dynamics of the VIP receptor. After binding to its receptor, VIP is rapidly internalized, probably by receptor-mediated endocytosis. This internalization leads to a decrease in the cell surface receptor number and simultaneously to a homologous desensitization of adenylate cyclase. VIP is then degraded in the lysosomes, while most of the receptors are recycled back to the cell surface. The presence of an intracellular pool of unoccupied VIP receptors has been demonstrated after inactivation of the cell surface receptors by chymotrypsin. The kinetics of the receptor reappearance at the cell surface, after inactivation by chymotrypsin or after receptor-mediated endocytosis, indicate 2 possible intracellular pathways for occupied and unoccupied VIP receptors.

Restricted localization of functional vasoactive intestinal peptide (VIP) receptors in in vitro differentiated human colonic adenocarcinoma cells (HT29-D4)

HT29-D4, a clone of the human colonic adenocarcinoma cell line (HT29), possesses at its cell surface specific binding sites for the vasoactive intestinal peptide (VIP) (KD = 0.5 nM). Their molecular weight was previously estimated to 117 kDa and 64 kDa. This clone underwent functional and structural differentiation when grown in a glucose-free galactose-containing medium. The [125I]VIP binding capacity of cells grown in this medium gradually declined while the cell density increased and reached a value close to zero when cell monolayer was able to form hemicysts. At this time, cells presented numerous tight junctions and desmosomes and a well organized brush border. Binding capacity could be recovered when the post-confluent monolayers were previously disaggregated with EDTA. Neither the affinity for VIP nor the molecular weight of the [125I]VIP cross-linked polypeptides were modified in these cells compared to cells grown in glucose-containing medium. However, surface receptor number of differentiated cells was twice that of undifferentiated cells. Leakproof differentiated cell monolayers grown on permeable substratum produced cAMP in response to VIP only when the peptide was present in the lower chamber of the culture wells. Taking these data altogether, we conclude that the localization of functional VIP receptors is restricted to the basolateral domain in differentiated post-confluent HT29-D4 cells.

Monoclonal antibodies to scorpion toxins. Characterization and molecular mechanisms of neutralization

Two mAb specific for the potent toxin II of the scorpion Androctonus australis Hector have been produced. One of them shows both high affinity binding to the toxin (Kd) = 0.8 nM) and in vivo and in vitro neutralizing properties. The mechanism by which the antibody neutralizes toxin binding to its receptor was shown to be of the competitive type, the epitope overlapping or being close to the receptor-binding region of the toxin. Several residues of the toxin clustered in the C-terminal region were shown likely to be part of the discontinuous epitope recognized by the antibody. The positive charge of the N epsilon-Lys-58 seems to play a pivotal role in the binding of the toxin to both the mAb and the sodium channel receptor.

Monoclonal antibodies to scorpion toxins. Characterization and molecular mechanisms of neutralization

Two mAb specific for the potent toxin II of the scorpion Androctonus australis Hector have been produced. One of them shows both high affinity binding to the toxin (Kd) = 0.8 nM) and in vivo and in vitro neutralizing properties. The mechanism by which the antibody neutralizes toxin binding to its receptor was shown to be of the competitive type, the epitope overlapping or being close to the receptor-binding region of the toxin. Several residues of the toxin clustered in the C-terminal region were shown likely to be part of the discontinuous epitope recognized by the antibody. The positive charge of the N epsilon-Lys-58 seems to play a pivotal role in the binding of the toxin to both the mAb and the sodium channel receptor.

HT 29, a model cell line: stimulation by the vasoactive intestinal peptide (VIP); VIP receptor structure and metabolism

HT 29, a cell line derived from a human colonic adenocarcinoma, is highly responsive to the vasoactive intestinal peptide (VIP) as shown by a more than 100-fold intracellular cAMP increase (Ka = 0.3 nM), the stimulations of protein kinase A (Ka = 0.1 nM) and the low-Km cAMP phosphodiesterase (Ka = 40 nM). Remarkably, adenylate cyclase, cAMP-dependent kinase and cAMP-specific phosphodiesterase are activated in a sequential manner. Binding studies with [125I]-labeled VIP indicate a high affinity site with a Kd value (0.5 nM) close to the activation constant value (Ka) of the three enzymes. The molecular structure of the VIP receptor was studied by immunological and chemical approaches. A monoclonal antibody (mAb 109-10-16) which partially decreased the binding of VIP to its receptor allowed the characterization of Mr = 53,000 and Mr = 48-49,000 polypeptides. More precise identification of protein components of the VIP receptor resulted from covalent cross-linking on intact HT 29 cells by four bifunctional reagents: dithiobis-(succinimidyl propionate) and its non-cleavable analog disuccinimidyl suberate, the photoactivable azido phenyl glyoxal and dimethylpimelimidate. Analysis by SDS-polyacrylamide gel electrophoresis demonstrated a major band of Mr = 67,000 regardless of which cross-linker was used. The same band and an Mr = 49,000 species were found in experiments using a crude membrane fraction of HT 29 cells. Assuming one molecule of VIP (Mr = 3326) linked per polypeptide, these observations suggest that an Mr = 64,000 species belongs to the VIP specific plasma membrane receptor. This protein contains an Mr = 20,000 N-linked sialic acid rich oligosaccharidic moiety.(ABSTRACT TRUNCATED AT 250 WORDS)

Photoaffinity labelling of the vasoactive-intestinal-peptide-binding site on intact human colonic adenocarcinoma cell line HT29-D4. Synthesis and use of photosensitive vasoactive-intestinal-peptide derivatives

N-Hydroxysuccinimidyl 4-azidobenzoate, a u.v.-sensitive heterobifunctional reagent, was used to synthesize photoreactive derivatives of the vasoactive intestinal peptide (VIP). Products of the reaction were purified by reverse-phase h.p.l.c. Three 4-azidobenzoyl-VIP (4-AB-VIP) derivatives were able to compete with monoiodinated 125I-VIP with an apparent KD of 2.5, 6.3 and 12.5 nM compared with 0.6 nM for native VIP. H.p.l.c.-purified mono[125I]iodinated VIP was used to synthesize 4-AB-125I-VIP derivatives. They were used to photoaffinity-label the VIP-binding site of HT29-D4 cells, a clone derived from the human colonic adenocarcinoma cell line HT29. Only one polypeptide, of Mr 70,000 +/- 5000 (mean +/- S.D.) was specifically labelled. The Mr of the component thus characterized was slightly higher than that of the major species (Mr 67,000) labelled after cross-linking experiments using 125I-VIP, conventional homobifunctional reagents and HT29 cells. Nevertheless, the specificity and extent of glycosylation of these two components were identical. These new photosensitive VIP derivatives should be useful tools with which to investigate further VIP-receptor structure and metabolism.

Cycloheximide induces accumulation of vasoactive intestinal peptide (VIP) binding sites at the cell surface of a human colonic adenocarcinoma cell line (HT29-D4). Evidence for the presence of an intracellular pool of VIP receptors

Incubation of monolayers of HT29-D4 cells (a clone of the human colonic adenocarcinoma cell line HT29) in the presence of 17.5 microM cycloheximide resulted in an increase in the number of vasoactive intestinal peptide (VIP) binding sites at the cell surface without any change in the affinity of receptor for its ligand. The increase in 125I-VIP-binding capacity was dose-dependent between 0.35 microM and 17.5 microM cycloheximide and was correlated with the inhibition of protein biosynthesis. At higher concentrations of drug (17.5-100 microM) a plateau corresponding to a twofold increase in VIP-binding capacity was reached independently of the extent of protein synthesis inhibition. We found that VIP receptors of HT29-D4 cells with such an enhanced binding capacity behaved like those of control cells with respect to receptor internalization and recycling (i.e. the cycle of occupied receptors was insensitive to cycloheximide). After inactivation of 90% of cell-surface VIP receptors by alpha-chymotrypsin, we observed a biphasic kinetic of reappearance of VIP-binding sites. 40% of VIP-binding sites reappeared very quickly (less than 5 min) and 100% within 17 h. The fast recovery of VIP receptors was probably due to the deployment of new binding sites from an intracellular pool. The rate and extent of recovery of these receptors were similar in control cells and in cycloheximide-treated cells. However, the slow recovery was inhibited in cycloheximide-treated cells probably because a pool of immature receptors was depleted by the drug before the alpha-chymotrypsin treatment. Our data are consistent with the existence of two different intracellular pathways of occupied and unoccupied VIP receptors.

The vasoactive intestinal peptide receptor on intact human colonic adenocarcinoma cells (HT29-D4). Evidence for its glycoprotein nature

We have previously shown that the mono [125I]iodinated vasoactive intestinal peptide (125I-VIP) could be covalently cross-linked on intact colonic adenocarcinoma cells (HT29). A major Mr 67,000 and a minor Mr 120,000 cross-linked polypeptides have been characterized [Muller, Luis, Fantini, Abadie, Giannellini, Marvaldi & Pichon (1985) Eur. J. Biochem. 151, 411-417]. The glycoprotein nature of these species was investigated using endo-beta-acetylglucosaminidase F (Endo F) treatment, enzymic and chemical desialylation and wheat germ agglutinin (WGA)-Sepharose affinity chromatography. Affinity-labelled VIP-binding proteins solubilized by Nonidet P-40 bound to WGA-Sepharose and could be eluted specifically with N-acetyl-D-glucosamine. Treatment with Endo F resulted in an increased electrophoretic mobility of both polypeptides. The major and the minor VIP-binding proteins were converted respectively into Mr 47,000 and 100,000 species, indicating removal of 20 kDa of N-linked oligosaccharides. Deglycosylation with trifluoromethanesulphonic acid also led to a 20 kDa loss in mass of the Mr 67,000 component, indicating the absence of additional O-linked sugars on this polypeptide. The presence of sialic acid on the major VIP-binding protein was demonstrated after treatment of intact cells with neuraminidase or by chemical desialylation with hydrochloric acid. We conclude from this study that the VIP receptor from intact HT29-D4 cells is a glycoprotein with N-linked oligosaccharide side chains containing sialic acid.

Intraspinal lipomas with spina bifida. Prognosis and treatment in 73 cases

The authors present a series of 73 cases of intraspinal lipomas in the lumbosacral region. Sixty-four patients were operated on, 43 of these under intraoperative monitoring of neural function. The results of this series and of major series published in the past 10 years demonstrate both the potential severity of these lesions (which are responsible for progressive neurological deficits in 56% of affected cases) and the benignity of their surgical treatment. The authors emphasize the usefulness of systematic early surgical treatment of these lesions.