[Risk factors of early drop-out during induction of high-dose buprenorphine substitution therapy. A study of 1085 opiate addicts]. / Facteurs de risques de rupture précoce de prise en charge lors de l'induction d'un traitement substitutif par buprénorphine haut dosage. Etude chez 1085 dependants aux opiacés.

BACKGROUND: The revelation of an acceptable rate of users still treated one year after initiation of a substitution program with high-dose buprenorphine (HDB) has contributed in the validation of the interest of the molecule in this indication. However the frequency of early drop-outs (after the first consultation), when treatment is set-up, is frequently evoked, although undocumented, by general practitioners. OBJECTIVE: During analysis of a survey on the follow-up of opiate addicts starting substitution therapy with HDB, we attempted to assess the frequency of early drop-outs and identify the contributing factors. METHOD: Among the 1085 patients included in the study and in whom induction therapy had been prescribed, 656 were assessed after 12 months' follow-up. RESULTS: Age, precariousness, lack of social support and partial access to care (lack of health insurance, previous contact with the prescriber) were significantly associated with early drop-out. The consumption of psychoactive products and their administration mode, during the 30 days prior to the first consultation of those loss to follow-up, also differed from those of patients who remained within the care system. CONCLUSION: Knowledge of the factors related to frequent early drop-out during induction of HDB substitution therapy, and bearing this in mind, would permit the organisation of more attentive management and hence reduce the drop-out rate.

Comparison of high dose buprenorphine treatments of opiate dependent outpatients in four healthcare networks.

AIMS: The aim of this study was to compare the various clinical practices in four health care networks and to access how the variations in treatment effected the outcome in opiate-dependent patients. METHODS: A retrospective study was carried out with 71 participating general practitioners. These were chosen from a group of 354 practitioners from four health care networks. Each practitioner could enroll up to 5 patients who were currently undergoing treatment with high-dose buprenorphine(HDB). The patients treatment had to have been initiated between the 1(st) of February 1996 and the 31(st) of October 1996, and excluded any patients who had lapsed on their treatment during the first month. Patients were selected until a total of 75 cases were enrolled from each network. Data were then collected retrospectively between June and December 1997. Information collected concerned the initial stage of treatment, the stabilizing stage or level of treatment and followed up data on the most recent prescriptions. RESULTS: The final patient maintenance totals were high for all four care networks (82.7 to 96% of patients were still being followed by their doctor at the final evaluation). A positive outcome as indicated by reduction of risk and decreased social vulnerability was also observed in all networks. Additionally, in each network there was a clear correlation between prescription practices and patient behavior. For example, the prescription of HDB at a daily dose of less than 6.2mg was associated with a higher rate of benzodiazepine use; and prescription of several daily doses of HDB was associated with a higher percentage of injecting patients. CONCLUSION: This retrospective study provides evidence that general practitioner care of drug-dependent patients as outpatients, within a health care network helps to stabilize patient visits, allows treatment of associated comorbidities and favors social rehabilitation. The prescription of HDB as a single daily dose, individually adapted for each patient, optimizes the outcome and reduces misuse.

[Follow-up of opioid addicts treated with high-dose buprenorphine in a health care network. National retrospective study. Experience of French general physicians]. / Suivi de patients pharmacodépendants aux opiacés traités par buprénorphine haut dosage à partir de réseaux de soins. Etude rétrospective nationale. Expérience de médecins généralistes français.

AIMS: This study was designed to examine the profile of drug-dependent outpatients treated by general practitioners working in a health care network and to evaluate the impact of treatment with high-dose buprenorphine on their medical and social status. METHODS: A retrospective study was undertaken by 71 general practitioners, selected at random from physicians in four health care networks. Data for the period between June and December 1997 concerning the initial prescription, the first stabilization prescription and the most recent prescription, was collected retrospectively. RESULTS: Among the outpatients included in this study, high-dose buprenorphine treatment resulted in a clear reduction in the use of heroin (69.9%) and benzodiazepine (57.1%). It also reduced associated risks of infection and social vulnerability. CONCLUSION: This retrospective study seems to show that care by general practitioners proceeds satisfactorily. The majority of opiate-dependent outpatients were compliant with treatment and successfully reintegrated into society. This method of treatment will be effective if specialised training is given to the general practitioners within the framework of a health care network.

Dynamics of antibody transfer from mother to fetus through the yolk-sac cells in the rat.

In rodents, maternal immunoglobulins are transported intact by the yolk-sac visceral epithelium from mother to fetus. The main purpose of the present paper is to study the dynamics of the uptake and transport of immunoglobulins by the rat yolk-sac using a new experimental design. The results show the rapid binding of IgG to the cell membrane microvilli since only 30 sec were sufficient for this attachment to occur. The endocytic process also appears to be very fast as localization of IgG in clusters, pits and microvesicles were observed after 5 min of contact between the yolk-sac and the IgG solution. Moreover, the antibodies were detected in the intracellular spaces within 15 min of incubation.

A new experimental method for the dynamic study of the antibody transfer mechanism from mother to fetus in the rat.

The yolk-sac is known to be a route for the transport of passive immunity from mother to fetus in the rat. The main purpose of the present paper is to describe an experimental system for ultrastructurally studying the kinetics of the uptake and transport of immunoglobulin by rat yolk-sac. This system has the advantage of enabling the membrane to be externalized and then exposed to protein under controlled environmental conditions whilst at the same time maintaining the conceptus in connection with the in situ placenta. Preliminary investigations have utilized homologous anti-horseradish peroxidase (HRP) IgG (detected as antibody by application of HRP) or HRP alone. Comparison has been made with the localization of endogenous IgG transmitted in vivo after immunization of the female rat with HRP. The results show the rapid binding of IgG to membrane since only 30 sec were sufficient for this attachment to occur. Moreover, the endocytic process also appears to be very fast as localization of IgG in clusters or patches, caveolae or pits and even rare microvesicles is observed within 8 min. On the other hand, no binding of HRP to microvilli was observed and, unlike IgG, HRP became located in the apico-tubulocanalicular system.

Estrogen binding properties of a haptoglobin-hemoglobin complex isolated from human fetus.

A haptoglobin-hemoglobin complex purified from human fetus was found to be able to bind estradiol in the presence of hydrogen peroxide. Bound estradiol was copurified with the complex during the purification process: ion exchange, gel filtration and hydroxyapatite chromatographies. The hormone-labelled complex was also precipitated with an anti-adult haptoglobin. The binding resisted to denaturation and solvent extraction suggesting a covalent bond between protein and hormone.

Complement fixing activity and immunoglobulin classes of antinuclear antibodies occurring in systemic lupus erythematosus and rheumatoid arthritis.

The sera of 88 patient suffering from systemic lupus erythematosus (SLE) or rheumatoid arthritis (RA) containing antinuclear antibodies (ANA) were studied for: I) the complement fixing capacity of these ANAs: II) their immunoglobulin class. The results showed that: I) ANAs bind complement to a significant extent in 2 patients with SLE out of 3, but not in RA; II) the ANAs which bind complement belong partially or totally to the IgG class, while most of the ANAs from SLE not fixing complement belong to other classes; III) the ANAs from RA were most often from the IgM class and, surprisingly, they did not bind complement; IV) the occurrence of IgM ANA in SLE patients seems to be associated with clinical manifestations of arthritis. This double test (identification of ANA class and complement binding capacity), appears to be a valuable aid in the cases where diagnosis between RA and SLE is questionable.

Purification and characterization of a haptoglobin-hemoglobin complex isolated from human fetuses.

A haptoglobin-hemoglobin complex was purified from human fetuses (10-week-old pregnancies). The yield was 12% and the purification factor was about 450. The purified complex appears to have a molecular weight of 850,000 daltons. It cross-reacts with human adult haptoglobins. Its electrophoretic mobility was reduced from alpha 2- to beta-globulin when compared with the adult molecule.

Purification and characterization of an estrogen-binding peroxidase from human fetuses.

A peroxidase found under two forms with a molecular weight of 220,000 and 170,000 respectively, was purified from human fetuses. The purification procedure included ammonium sulfate precipitation, ion exchange chromatography, gel filtration and hydrophobic interaction chromatography. The purification factor approximated 400. These two forms of peroxidase were found to be immunologically identical as shown when utilizing immunodiffusion. They were able to bind estradiol in the presence of H2O2. This bond resisted to denaturation and solvent extraction therefore suggesting a covalent binding of estradiol to the enzyme.

[Behavior of some microorganisms cultivated in the presence of irradiated maize starch]. / Comportement de quelques microorganismes cultivés en présence d'extraits d'amidon irradié.

The bactericidal effect of water soluble radiolysis products of Maize starch on Escherichia coli cultures declines when the initial population grows. This toxicity varies with the culture environment and the bacterial species: Bacillus subtilis, Lactobacillus plantarum, Streptococcus faecalis, Enterobacter sp. Moreover, for the eucaryote cell Saccharomyces cerevisiae, wild strain or muting "small colonies", only the generating time is altered by the active parts of radiolysis products. The results are analysed with regard to the hypothesis that the hydrogen peroxide is responsible for this toxicity.

Toxicity of radiolytic products from 60 Co-treated starch on microorganisms.

The radiolytic products of a 60Co-irradiated starch are sensitive to the action of catalase, peroxidase and ferrous ions: extracts of irradiated starch so treated loss their toxicity for Escherichia coli. After eliminating the reductones, the toxic activity is attributed to the peroxides and more especially to hydrogen peroxide. Artificial reconstitution of an irradiated starch extract confirms this conclusion and reveals a secondary toxic action of formaldehyde.

[The mechanism is action of hydrogen peroxide on bacterial metabolism]. / Mode d'action du peroxyde d'hydrogène sur le métabolisme bactérien

Hydrogen peroxide oxidizes glutathione and lipoïc, pyruvic and alpha-ketoglutaric acids in vitro. This work with Escherichia coli shows that the oxidative decarboxylation of pyruvic acid by the peroxide in vivo takes into account its toxicity.