Case 327

HISTORY

A 58-year-old man who was an active smoker was admitted twice to the intensive care unit (ICU) of a tertiary referral thoracic center for severe hypercapnic acute respiratory failure and persistent bilateral chest radiograph opacities that were unchanged over the course of the two ICU admissions within a 3-month period (Fig 1). He had obesity (body mass index, 36 kg/m2), stage 3 vascular chronic renal insufficiency, and hebephrenic schizophrenia treated with haloperidol, carbamazepine, and cyamemazine. He reported chronic dyspnea on exertion, which worsened for 6 months. At the second ICU admission, he was afebrile, with a blood pressure of 160/72 mm Hg and pulse oximetry of 93% on 6 L/min oxygen therapy through a nonrebreathing mask. Physical examination showed signs of respiratory failure with wheezing and active abdominal expiration, bilateral pulmonary crackles without chest pain, hemoptysis, clubbing, or signs of cardiac failure. He had no peripheral lymphadenopathy and no enlarged spleen. Blood gases (on 6 L/min oxygen) showed respiratory acidosis (pH, 7.15 [normal range, 7.38-7.42]; Pao2 level, 67 mm Hg [normal range, 80-100 mm Hg]; Paco2 level, 102 mm Hg [normal range, 38-42 mm Hg]; Hco3- level, 29 mmol/L [normal range, 22-27 mmol/L]). Noninvasive ventilation was initiated. Imaging performed during the second ICU hospitalization included noncontrast chest CT (Fig 2), MRI of the chest without contrast enhancement (Fig 3), and fluorine 18 fluorodeoxyglucose PET/CT (Fig 4).

Management of Acutely Decompensated Pulmonary Hypertension

Pulmonary arterial hypertension is a severe life-threatening condition associated with increased pulmonary vascular resistance and resulting right heart dysfunction. Admission to intensive care unit with acutely decompensated right heart failure is a significant negative prognostic event with a high risk of multisystem organ dysfunction and death. Presentations are heterogenous and may combine signs of both diastolic and systolic dysfunction complicating management. Renal dysfunction is often present, but other organ systems can be involved resulting in findings such as acute hepatic dysfunction or bowel wall congestion and ischemia. The goals of therapy are to rapidly reverse ventriculo-arterial decoupling and reduce right ventricular afterload to prevent progression to refractory or irreversible right heart failure. Triggering events must be investigated for and addressed urgently if identified. Volume status management is critical and both noninvasive and invasive testing can aid in prognostication and guide management, including the use of inotropes and vasopressors. In cases of refractory right heart dysfunction, consideration of urgent lung transplantation and mechanical circulatory support is necessary. These patients should be managed at expert centers in an intensive care setting with a multidisciplinary team of practitioners experienced in the management of right heart dysfunction given the high short- and long-term mortality resulting from acute decompensated right heart failure.

Clinical relevance and prognostic value of renal Doppler in acute decompensated precapillary pulmonary hypertension

AIMS

We aim to evaluate the clinical relevance and the prognostic value of arterial and venous renal Doppler in acute decompensated precapillary pulmonary hypertension (PH).

METHODS AND RESULTS

The renal resistance index (RRI) and the Doppler-derived renal venous stasis index (RVSI) were monitored at admission and on Day 3 in a prospective cohort of precapillary PH patients managed in intensive care unit for acute right heart failure (RHF). The primary composite endpoint included death, circulatory assistance, urgent transplantation, or rehospitalization for acute RHF within 90 days following inclusion. Ninety-one patients were enrolled (58% female, age 58 ± 16 years). The primary endpoint event occurred in 32 patients (33%). In univariate logistic regression analysis, variables associated with RRI higher than the median value were non-variable parameters (age and history of hypertension), congestion (right atrial pressure and renal pulse pressure), cardiac function [tricuspid annular plane systolic excursion (TAPSE) and left ventricular outflow tract- velocity time integral], systemic pressures and NT-proBNP. Variables associated with RVSI higher than the median value were congestion (high central venous pressure, right atrial pressure, and renal pulse pressure), right cardiac function (TAPSE), severe tricuspid regurgitation, and systemic pressures. Inotropic support was more frequently required in patients with high RRI (P = 0.01) or high RVSI (P = 0.003) at the time of admission. At Day 3, a RRI value <0.9 was associated with a better prognosis after adjusting to the estimated glomerular filtration rate.

CONCLUSION

Renal Doppler provides additional information to assess the severity of patients admitted to the intensive care unit for acute decompensated precapillary PH.

Functional respiratory complaints among COVID-19 survivors: a prospective cohort study

Background

Dyspnoea is a common persistent symptom after COVID-19. Whether it is associated with functional respiratory disorders remains unclear.

Methods

We assessed the proportion and characteristics of patients with “functional respiratory complaints” (FRCs) (as defined by Nijmegen Questionnaire>22) among 177 post-COVID-19 individuals who benefited from outclinic evaluation in the COMEBAC study (i.e., symptomatic and/or ICU survivors at 4 months). In a distinct explanatory cohort of 21 consecutive individuals with unexplained post-COVID-19 dyspnoea after routine tests, we also analysed the physiological responses to incremental cardio-pulmonary exercise testing (CPET).

Findings

In the COMEBAC cohort, 37 had significant FRCs (20.9%, IC95: 14.9–26.9). The prevalence of FRCs ranged from 7.2% (ICU patients) to 37.5% (non-ICU patients). The presence of FRCs was significantly associated with more severe dyspnoea, lower 6-minute walk distance, more frequent psychological and neurological symptoms (cognitive complaint, anxiety, depression, insomnia and post-traumatic stress disorders) and poorer quality of life (all p<0.01). In the explanatory cohort, 7/21 patients had significant FRCs. Based on CPET, dysfunctional breathing was identified in 12/21 patients, 5/21 had normal CPET, 3/21 had deconditioning and 1/21 had evidence of uncontrolled cardiovascular disease.

Interpretation

FRCs are common during post-COVID-19 follow-up, especially among patients with unexplained dyspnoea. Diagnosis of dysfunctional breathing should be considered in those cases.

Funding

Assistance Publique-Hôpitaux de Paris.

Interest of TAPSE/sPAP ratio for noninvasive pulmonary arterial hypertension risk assessment

BACKGROUND

Although ventriculoarterial coupling is associated with better survival in pulmonary arterial hypertension (PAH), existing PAH risk assessment method has not considered echocardiographic criteria of right ventricular to pulmonary artery coupling. We aimed to test the prognostic value of the echocardiographic tricuspid annular plane systolic excursion/systolic pulmonary artery pressure (TAPSE/sPAP) ratio for noninvasive PAH risk assessment.

METHODS

We retrospectively studied a cohort of 659 incident PAH patients from 4 independent French PH centers (training cohort: n = 306, validation cohort n = 353) who underwent follow-up TAPSE/sPAP measurement in addition to previously validated noninvasive risk stratification variables. The primary composite outcome was 3-year all-cause mortality or lung transplantation from re-evaluation.

RESULTS

Mean age was 55 ± 17 years-old with a majority of female (66%). The three main PAH causes were connective tissue disease (26%), idiopathic (24%) and porto-pulmonary (19%). The primary composite outcome occurred in 71 (23%) patients. Multivariable Cox regression analysis retained 3 noninvasive low-risk criteria as associated with the primary composite outcome: NYHA I-II (p = 0.001), NTproBNP <300 ng/L or BNP <50 ng/L (p = 0.004), and TAPSE/sPAP >0.33 mm/mmHg (p = 0.004). The more the low-risk criteria achieved at follow-up, the better the event-free survival both in the training and validation cohort (log-rank p < 0.001). In the training cohort, the c-index for these 3 criteria, for COMPERA 2.0 and for the noninvasive French Pulmonary Hypertension Network method were 0.75, 95%CI(0.70-0.82), 0.72 95%CI(0.66-0.75), 0.71 95%CI(0.62-0.73), respectively.

CONCLUSION

The 3 following dichotomized low-risk criteria: TAPSE/sPAP >0.33 mm/mmHg, NYHA I-II and NTproBNP <300 ng/L or BNP <50 ng/L allow to identify low-risk PAH patients at follow-up.

COVID-19 in Patients with Pulmonary Hypertension: A National Prospective Cohort Study

Rationale: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is associated with pulmonary endothelial dysfunction. There are limited data available on the outcomes of coronavirus disease (COVID-19) in patients with pulmonary hypertension (PH), a disease characterized by pulmonary endothelial dysfunction. Objectives: To describe characteristics and outcomes of patients with precapillary PH and COVID-19. Methods: We prospectively collected characteristics, management, and outcomes of adult patients with precapillary PH in the French PH network who had COVID-19 between February 1, 2020, and April 30, 2021. Clinical, functional, and hemodynamic characteristics of PH before COVID-19 were collected from the French PH registry. Measurements and Main Results: A total of 211 patients with PH (including 123 with pulmonary arterial hypertension, 47 with chronic thromboembolic PH, and 41 with other types of PH) experienced COVID-19, and 40.3% of them were outpatients, 32.2% were hospitalized in a conventional ward, and 27.5% were in an ICU. Among hospitalized patients (n = 126), 54.0% received corticosteroids, 37.3% high-flow oxygen, and 11.1% invasive ventilation. Right ventricular and acute renal failure occurred in 30.2% and 19.8% of patients, respectively. Fifty-two patients (all hospitalized) died from COVID-19. Overall mortality was 24.6% (95% CI [confidence interval], 18.8-30.5) and in-hospital mortality 41.3% (95% CI, 32.7-49.9). Nonsurvivors were significantly older, more frequently male and suffering comorbidities (diabetes, chronic respiratory diseases, systemic hypertension, chronic cardiac diseases, and/or chronic renal failure), and had more severe PH at their most recent evaluation preceding COVID-19 diagnosis (in terms of functional class and 6-minute-walk distance; all P < 0.05). Use of pulmonary arterial hypertension therapy was similar between survivors and nonsurvivors. Conclusions: COVID-19 in patients with precapillary PH was associated with a high in-hospital mortality. The typical risk factors for severe COVID-19 and severity of PH were associated with mortality in this population.

Respiratory symptoms and radiologic findings in post-acute COVID-19 syndrome

Rationale

The characteristics of patients with respiratory complaints and/or lung radiologic abnormalities after hospitalisation for coronavirus disease 2019 (COVID-19) are unknown. The objectives were to determine their characteristics and the relationships between dyspnoea, radiologic abnormalities and functional impairment.

Methods

In the COMEBAC (Consultation Multi-Expertise de Bicêtre Après COVID-19) cohort study, 478 hospital survivors were evaluated by telephone 4 months after hospital discharge, and 177 who had been hospitalised in an intensive care unit (ICU) or presented relevant symptoms underwent an ambulatory evaluation. New-onset dyspnoea and cough were evaluated, and the results of pulmonary function tests and high-resolution computed tomography of the chest were collected.

Results

Among the 478 patients, 78 (16.3%) reported new-onset dyspnoea, and 23 (4.8%) new-onset cough. The patients with new-onset dyspnoea were younger (56.1±12.3 versus 61.9±16.6 years), had more severe COVID-19 (ICU admission 56.4% versus 24.5%) and more frequent pulmonary embolism (18.0% versus 6.8%) (all p≤0.001) than patients without dyspnoea. Among the patients reassessed at the ambulatory care visit, the prevalence of fibrotic lung lesions was 19.3%, with extent <25% in 97% of the patients. The patients with fibrotic lesions were older (61±11 versus 56±14 years, p=0.03), more frequently managed in an ICU (87.9 versus 47.4%, p<0.001), had lower total lung capacity (74.1±13.7 versus 84.9±14.8% pred, p<0.001) and diffusing capacity of the lung for carbon monoxide (D_LCO) (73.3±17.9 versus 89.7±22.8% pred, p<0.001). The combination of new-onset dyspnoea, fibrotic lesions and D_LCO <70% pred was observed in eight out of 478 patients.

Conclusions

New-onset dyspnoea and mild fibrotic lesions were frequent at 4 months, but the association of new-onset dyspnoea, fibrotic lesions and low D_LCO was rare.

New-onset dyspnoea is a frequent complaint 4 months after #COVID19 and is generally multifactorial, and the combination of new-onset dyspnoea, fibrotic lesions and D_LCO <70% pred is rarely observedhttps://bit.ly/3q4hyyM

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 &lt;300 ng/L or BNP &lt;50 ng/L (p=0.02), 6MWD &gt;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&lt;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

Pulmonary Hypertension in Patients with Common Variable Immunodeficiency

PURPOSE

Common variable immunodeficiency (CVID) is known to cause infectious, inflammatory, and autoimmune manifestations. Pulmonary hypertension (PH) is an unusual complication of CVID with largely unknown characteristics and mechanisms.

METHODS

We report the clinical, functional, hemodynamics, radiologic and histologic characteristics, and outcomes of CVID-associated PH patients from the French PH Network.

RESULTS

Ten patients were identified. The median (range) age at CVID diagnosis was 36.5 (4-49) years and the median delay between CVID and PH diagnosis was 12 (0-30) years. CVID-associated PH affected predominantly women (female-to-male ratio 9:1). Most patients were New York Heart Association functional class III with a severe hemodynamic profile and frequent portal hypertension (n = 6). Pulmonary function tests were almost normal in 70% of patients and showed a mild restrictive syndrome in 30% of patients while the diffusing capacity for carbon monoxide was decreased in all but one patient. High-resolution computed tomography found enlarged mediastinal nodes, mild interstitial infiltration with reticulations and nodules. Two patients had a CIVD-interstitial lung disease, and one presented with bronchiectasis. Pathologic assessment of lymph nodes performed in 5 patients revealed the presence of granulomas (n = 5) and follicular lymphoid hyperplasia (n = 3). At last follow-up (median 24.5 months), 9 patients were alive, and one patient died of Hodgkin disease.

CONCLUSION

PH is a possible complication of CVID whose pathophysiological mechanisms, while still unclear, would be due to the inflammatory nature of CVID. CVID-associated PH presents as precapillary PH with multiple possible causes, acting in concert in some patients: a portal hypertension, a pulmonary vascular remodeling, sometimes a pulmonary parenchymal involvement and occasionally an extrinsic compression by mediastinal lymphadenopathies, which would be consistent with its classification in group 5 of the current PH classification.

Characteristics and outcomes of asthmatic patients with COVID-19 pneumonia who require hospitalisation

Background

Viral respiratory infections are the main causes of asthma exacerbation. The susceptibility of patients with asthma to develop an exacerbation when they present with severe pneumonia due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is unknown. The objective of this study was to investigate the characteristics and outcomes of asthmatic patients with coronavirus disease 2019 (COVID-19) pneumonia who required hospitalisation during the spring 2020 outbreak in Paris, France.

Methods

A prospective cohort follow-up was carried out from 15 March to 15 April 2020 in Bicêtre Hospital, University Paris-Saclay, France. All hospitalised patients with a SARS-CoV-2 infection who reported a history of asthma were included.

Results

Among 768 hospitalised patients, 37 (4.8%) reported a history of asthma, which had been previously confirmed by a pulmonologist in 85% of cases. These asthmatic patients were mainly female (70%) and nonsmokers (85%), with a median age of 54 years (interquartile range (IQR) 42–67 years). None of them presented with an asthma exacerbation. 22 (59%) had major comorbidities and 31 (84%) had a body mass index ≥25 kg·m⁻². The most common comorbidities were obesity (36%), hypertension (27%) and diabetes (19%). All patients had a confirmed diagnosis of COVID-19 pneumonia on computed tomography of the chest. Eosinopenia was a typical biological feature with a median count of 0 cells·mm⁻³ (IQR 0–0 cells·mm⁻³). 11 patients (30%) were admitted into the intensive care unit, with three deaths (8.1%) occurring in the context of comorbidities.

Conclusion

Asthma patients were not overrepresented among those with severe pneumonia due to SARS-CoV-2 infection who required hospitalisation. The worst outcomes were observed mainly in patients with major comorbidities.

Asthmatic patients were not overrepresented among those with severe pneumonia due to SARS-CoV-2 infection who required hospitalisation. None presented with an asthma exacerbation. Worst outcomes were observed mainly in patients with major comorbidities.https://bit.ly/303djG6

Respiratory virus-associated infections in HIV-infected adults admitted to the intensive care unit for acute respiratory failure: a 6-year bicenter retrospective study (HIV-VIR study)

Introduction

Acute respiratory failure is the main reason for admission to the intensive care unit (ICU) in HIV-infected adults. There is little data about the epidemiology of respiratory viruses in this population.

Methods

HIV-infected adults admitted to two intensive care units over a 6-year period for an acute respiratory failure and explored for respiratory viruses with multiplex polymerase chain reaction (mPCR) were retrospectively selected. Objectives were to describe the prevalence of respiratory viruses, coinfections with non-viral pathogens, and hospital outcome.

Results

A total of 123 episodes were included. An HIV infection was newly diagnosed in 9% of cases and 72% of the population were on antiretroviral therapy. Real-time mPCR tests identified at least one respiratory virus in the respiratory tract of 33 (27%) patients, but with a non-viral copathogen in two-thirds of cases. Rhinovirus was predominant, documented in 15 patients, followed by Influenza and Respiratory Syncytial Viruses (both n = 6). The prevalence of respiratory virus-associated infection did not vary along with the level of the CD4 T-cell deficiency, except for Rhinovirus which was more prevalent in patients with a CD4 lymphocyte count below 200 cells/µL (n = 13 (20%) vs. n = 2 (4%), p < 0.01). In multivariate analysis, respiratory virus-associated infection was not associated with a worse prognosis.

Conclusions

Viruses are frequently identified in the respiratory tract of HIV-infected patients with acute respiratory failure that requires ICU admission, but with a non-viral copathogen in two-thirds of cases. Rhinovirus is the predominant viral specie; its prevalence is highest in patients with a CD4 lymphocyte count below 200 cells/µL.

Diagnosis and management of respiratory viruses in critically ill adult patients: an international survey of knowledge and practice among intensivists

In this survey endorsed by the European Society of Intensive Care Medicine (ESICM), we aimed to describe the practice patterns of intensivists worldwide, regarding their diagnosis and management of respiratory viruses in lower respiratory tract infections. There were 229 respondents from 53 countries, mainly in Europe (78%). Our main findings are that a majority of intensivists (i) searched for respiratory viruses in case of severe community-acquired LRTI in adults, whatever the season and the medical history and clinical presentation; (ii) had access to large-panel respiratory mPCR; (iii) used them as first-line diagnostic test in routine practice; (iv) had some knowledge about the panel of the mPCR that they use, but markedly less about the cost. However, we observed strong heterogeneity regarding how intensivists took into account mPCR results for infection control (confinement measures) and patient care (antiviral treatment and antibiotics management).

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.