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Biomedical subjects

M A Richard

Publications and source records attributed to M A Richard.

42 records · Page 3Linked to original sources
PubMed1988

Fatty acid-binding protein, a potential regulator of energy production in the heart. Investigation of mechanisms by electron spin resonance.

The catabolic system, translocating then beta-oxidizing fatty acids in the mitochondria and considered as the major energy generator in the heart, was shown in the present study to be strongly regulated by fatty acid-binding protein (FABP), a self-aggregated and exclusive protein for the binding and transport of fatty acids in the cardiac cell cytoplasm. The mechanism behind this regulation was investigated by using new techniques in this field: i.e. electron spin resonance (ESR) and spin-labeling for the simultaneous analysis of partitioning and beta-oxidation of fatty acids in the isolated cardiac mitochondria. The step of this catabolic system which is controlled by FABP was shown to be the acylcarnitine transfer into the mitochondria. Two of the multi-self-aggregated FABP molecular species, namely those existing at FABP concentrations around 1.1 and 2.2 g.liter-1, were found to act as specific translocators delivering acylcarnitine to the mitochondrial beta-oxidative system. The energy production in the heart might thus be critically dependent on optimized FABP concentrations in the cardiac cells.

Animals↗
PubMedDate not supplied

Role of fatty acid-binding protein in cardiac fatty acid oxidation.

Although abundant in most biological tissues and chemically well characterized, the fatty acid-binding protein (FABP) was until recently in search of a function. Because of its strong affinity for long chain fatty acids and its cytoplasmic origin, this protein was repeatedly claimed in the literature to be the transcytoplasmic fatty acid carrier. However, techniques to visualize and quantify the movements of molecules in the cytoplasm are still in their infancy. Consequently the carrier function of FABP remains somewhat speculative. However, FABP binds not only fatty acids but also their CoA and carnitine derivatives, two typical molecules of mitochondrial origin. Moreover, it has been demonstrated and confirmed that FABP is not exclusively cytoplasmic, but also mitochondrial. A function for FABP in the mitochondrial metabolism of fatty acids plus CoA and carnitine derivatives would therefore be anticipated. Using spin-labelling techniques, we present here evidence that FABP is a powerful regulator of acylcarnitine flux entering the mitochondrial beta-oxidative system. In this perspective FABP appears to be an active link between the cytoplasm and the mitochondria, regulating the energy made available to the cell. This active participation of FABP is shown to be the consequence of its gradient-like distribution in the cardiac cell, and also of the coexistence of multispecies of this protein produced by self-aggregation.

Animals↗
PubMedDate not supplied

[Cutaneous adverse effects during selective serotonin reuptake inhibitors therapy: 2 cases].

BACKGROUND: Selective serotonin reuptake inhibitors are widely used in the treatment of depressive and obsessive-compulsive disorders because of their low-frequency adverse effects. We report two cases of cutaneous adverse effects during selective serotonin reuptake inhibitors therapy. CASE REPORTS: A man who complained of chronic anal idiopathic pruritus was treated with citalopram (Seropram(R)) 10 mg b.i.d. Six days after the beginning of the antidepressive treatment, he developed an extensive papular and purpuric erythema with keratinocytes necrosis and dermal leucocytoclastic vasculitis. Cutaneous lesions remained for several weeks, as the half-life of citalopram is very long (33 to 36 hours) but did not relapse. A women developed painful papular and purpuric erythema mainly located in sun-exposed sites, during therapy with paroxetine (Deroxat(R)) 20 mg b.i.d., which had been introduced one month before to treat depression. Cutaneous lesions healed spontaneously in 2 weeks after the discontinuation of paroxetine and with sun avoidance and didn't relapse. DISCUSSION: Adverse cutaneous effects of selective serotonin reuptake inhibitors are rare but the knowledge of these reactions is important because toxic epidermal necrolysis and Stevens-Johnson syndrome had been reported during fluoxetine (Prozac(R)) and fluvoxamine (Floxyfral(R)) treatment. Different serotonin uptake blockers could be involved in the same allergic reaction, suggesting cross reactivity, although these drugs have different chemistry structures. It is advisable to substitute after an adverse effect a medication from one of the other classes of antidepressants.

Aged↗
PubMedDate not supplied

[Extracorporeal photochemotherapy in therapy-refractory subacute lupus].

BACKGROUND: Extracorporeal photopheresis is a leukapheresis therapy that uses psoralen and ultraviolet A irradiation. We report the case of a woman with a refractory sub acute lupus which dramatically but transitionally responded to extracorporeal photopheresis. CASE REPORT: This women, born in 1960, developed erythematous and squamous patches located on face and neckline, associated with hyperpigmented and atrophic lesions on the arms and shoulders. Investigations confirmed the diagnosis of subacute lupus without systemic disease. All lesions progressed, despite all conventional therapies leading to major aesthetic prejudice. Extracorporeal photopheresis was initiated, and after two months, all lesions, including atrophic and healing lesions had regressed, but laboratory abnormalities did not change. Extracorporeal photopheresis was well tolerated. However, treatment was discontinued nine months later, since the cutaneous lesions relapsed. COMMENTS: Extracorporeal photopheresis could be efficient in the treatment of cutaneous autoimmune diseases through several immunomodulatory mechanisms. Extracorporeal photopheresis is a potent alternative agent in the therapy of refractory dermatological diseases

Adult↗