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M Mallaret

Publications and source records attributed to M Mallaret.

33 records · Page 2Linked to original sources
PubMedDate not supplied

[Potentializing of tricyclics and serotoninergics by thyroid hormones in resistant depressive disorders].

In response to the increase of resistant depressive disorders and in spite of improved treatments, numerous studies were conducted in the last thirty Years aiming at assessing the pre-morbid thyroid state of depressed patients resistant to well conducted tricyclic treatments. "Minimal" thyroid abnormalities were evidenced as well as central thyroid disorders which may not be detected by peripheral-i.e plasmatic- dosages. Regarding the premorbid thyroid status, the hypothesis of subclinical hypothyroidism was considered by many Authors. It is marked by four grades including T3 and T4 decreased levels, basal TSH concentration abnormalities as well as increased TSH response to TRH stimulation, and the presence of antimicrosomal and antithyroglobulin antibodies. Although, there are different views on the existence or not of these abnormalities, we'll focus our attention on a metaanalysis including six studies. It shows in a population with a resistant depression, 52% of patients with subclinical hypothyroidism, against 8 to 17% in patients with simple depression and 5% in the overall population.Similarly, antithyroid antibody levels (group IV hypothyroidism) were significantly higher in depressed patients (9% to 20% against 7,5% in the overall population). For many Years, a central hypothyroidism was hypothesized on the basis of an exhausted T3-T4 transference mechanism and a lowered TRH hypothalamic biodisponibility.In the last Years, new data emerged on the role of transthyretin, a cerebral carrier T4 protein, whose concentration in the CSF was found significantly lower in depressed patients than in a control group, the lowest levels being observed in the most severely depressed. This decreased level of transthyretin would result in a lower central T4 biodisponibility-hence, in view of a T4-T3 desiodation insufficiency, a T3 deficit is observed. A low transthyretin level associated or not to subclinical hypothyroidism could be a factor of depressive vulnerability on one hand, of resistance to tricyclic treatment on the other one. Conversely, subclinical hypothyroidism could be a predictive factor of a good response to a potentializing strategy. The pharmacological mechanisms involved in this potentializing phenomenon are now well known: they consist in an interaction between depression, adrenergic receptors and thyroid hormones biodisponibility. The decreased norepinephrine level observed in depressive patients is associated, in case of increased thyroid hormones biodisponibility, with a higher sensitivity of adre-nergic receptors, mostly betaadrenergic. This seems to underly the recovery process. According to some Authors, the serotoninergic system might be involved in the potentialization of tricyclics by thyroid hormones. We know that in animals with hypothyroidism, the serotonin synthesis is decreased and that the administration of T3 increases the brain levels of serotonin and its 5HIA catabolite. In addition, T3 could correct the down-regulation induced by serotoninergics on beta-adrenergic receptors. On the basis of numerous studies carried out on the potentializing of tricyclics, we suggest practical modalities of treatment - which until today did not materialize in every day practice in the absence of a clear consensus based on statistically reliable data: after four to six weeks of inefficient tricyclic or serotoninergic treatment on a correct dosage testified by plasmatic dosages, it is recommended to initiate a T3 treatment on a effective posology (25 to 50 micrograms per day), which must be reached in 2 or 3 days, except in case of rare and transitory side effects (sweating, shaking, tachycardia, nervousness, anxiety). If the treatment is not rapidly efficient, it must be discontinued in case there is no improvement after 3 weeks. Until today, there is no consensus about the duration of a T3 treatment. It is important to take into account the predictive criteria of good or bad response to a T3 potentialization, since they have direct consequences on the management of depressed patients. For example, a high degree of chronic evolution with resistance to numerous treatments, associated disorders according to the DSM IV axis I and a comorbidity of addiction, point to a bad prognosis of a potentialization treatment. In addition, we'll examine the few recent studies on the potentializing of serotoninergic antidepressant drugs by thyroid hormones.

Animals↗
PubMedDate not supplied

In vitro transmission and antigenicity of a retrovirus isolated from a multiple sclerosis patient.

We have recently isolated an apparently novel retrovirus (LM7) from a patient with multiple sclerosis (MS). We present here results showing that (1) LM7 retrovirus can be transmitted in vitro to a normal human leptomeningeal cell culture and that (2) specific antibody against this retroviral strain can be detected in MS cases. Our results suggest that, if this virus is an endogenous retrovirus, it is different from human endogenous elements already described.

Antibodies, Viral↗
PubMedDate not supplied

Determination of buprenorphine and norbuprenorphine in urine and hair by gas chromatography-mass spectrometry.

Buprenorphine, which is used in France as a substitution drug for opioid addiction, is widely abused, and several fatal cases have been reported. In order to confirm a recent intoxication or to establish retrospectively chronic abuse, a simple and reliable gas chromatographic-mass spectrometric method was developed and validated for quantitation of buprenorphine and its active metabolite norbuprenorphine in urine and hair. Two milliliters of urine or 50 mg of pulverized hair was submitted to a pretreatment (enzymatic hydrolysis for urine and decontamination with dichloromethane followed by incubation in 0.1 M HCI for hair). Buprenorphine-d4 was chosen as the internal standard. Selective solid-phase extraction with Bond Elut Certify columns provided recoveries higher than 85% for urine and 43% for hair. By using a mixture of MSTFA/TMSIM/TMCS (100:2:5), buprenorphine and norbuprenorphine produced stable silylated derivatives. The detection was carried out with a quadrupole mass detector working in El selected ion monitoring mode. Ions at m/z 450 and 468 were chosen for the quantitation of buprenorphine and norbuprenorphine, respectively (m/z 454 was used for the internal standard). Limits of quantitation were 0.25 and 0.20 ng/mL, respectively, for buprenorphine and norbuprenorphine in urine and 0.005 ng/mg for the two compounds in hair. Calibration curves were linear from 0 to 50 ng/mL in urine and from 0 to 0.4 ng/mg in hair. Between-day and within-day precisions were less than 8.4% in hair and 6.1% in urine for both molecules in all cases. This method was applied to urine and hair samples collected from patients in a withdrawal treatment program and demonstrated its good applicability in routine analysis and its benefit for clinicians. This technique, which requires instruments already available to many toxicology laboratories, offers an attractive alternative to more sophisticated techniques.

Adult↗
PubMedDate not supplied

[Adverse effects and medication errors: incidence and role of the organization of drug distribution].

The true incidence of adverse drug events is controversial and there are few data concerning the percentage of potentially preventable adverse drug events. Over 2 months, in two internal medicine units, we asked the staff to report adverse drug events. All incidents were evaluated: adverse drug events (preventable and non-preventable) and potential adverse drug events (non-intercepted potential adverse drug events and intercepted potential adverse drug events). The severity, the stage in the process at which the error occurred and the type of error were evaluated by a physician reviewer. Over the 240 admissions, the incidence of adverse drug events is 18 per 1000 patient-days. The system design caused 77 per cent of the incidents. The medication errors occurred at all stages from ordering to administration. Adverse drug events resulting in medication errors (n = 22) were more serious than non-preventable adverse drug events (n = 26) (p = 0.003). A prevention strategy by pharmacovigilance centres (Centres Régionaux de Pharmacovigilance) should target all stages of the drug delivery process.

Drug-Related Side Effects and Adverse Reactions↗
PubMedDate not supplied

[Vasculitis after anti-influenza vaccination. Report of 5 cases].

We describe five cases of vasculitis noted a few days after influenza vaccination. This complication has occurred in four women, and the mean age was 76 years. Although cutaneous biopsy has confirmed leucocytoclasic vasculitis in only one case, the clinical characteristics were evocative in the other cases. No systemic complication were noted. Spontaneous retrocession was noted in four patients and following corticosteroids once. To our knowledge only few cases of vasculitis has been previously reported after influenza vaccination. The mechanisms are unknown but preservatives may have some responsibilities.

Aged↗
PubMedDate not supplied

[Macrolides and drug interactions: review of the literature].

Clarithromycin, azithromycin and dirithromycin have recently been introduced in France. We list the different drug-interactions with these three new drugs and with erythromycin, josamycin, roxithromycin, midecamycin and spiramycin.

Drug Interactions↗