Biomedical subjects
E Mahé
Publications and source records attributed to E Mahé.
CD30+ T-cell lymphoma in a patient with psoriasis treated with ciclosporin and infliximab.
There is a known relationship between the use of immunosuppressive therapies and the development of lymphoproliferative malignancies. These lymphomas are mainly B-cell nonHodgkin's lymphomas associated with Epstein-Barr virus. Most cases concern classical immunosuppressive treatments including ciclosporin and methotrexate. A relationship between the new antitumour necrosis factor (TNF)-alpha agents and lymphoproliferative malignancies is debated. Patients with psoriasis on immunosuppressive therapies, mainly ciclosporin, are considered to have a low risk of developing lymphoid proliferation. We report a patient with erythrodermic psoriasis treated with ciclosporin and infliximab who developed a CD30+ T-cell lymphoma. This lymphoma regressed after stopping these treatments. In this case, the anti-TNF-alpha agent may have played a role in association with ciclosporin in the development of the lymphoproliferative disorder. Whereas the combination of anti-TNF-alpha therapies with methotrexate has been well studied, their combination with ciclosporin has been evaluated only in a few patients. Psoriatic patients who may require anti-TNF-alpha treatment have often been or will be treated with ciclosporin. The combination of ciclosporin and anti-TNF-alpha warrants further investigation.
[Seizures during interferon alpha therapy: three cases in dermatology].
INTRODUCTION: Interferon alpha has many side effects. Among them the risk of occurrence of seizures is not well known by dermatologists. We report three cases of seizures that occurred in patients treated with interferon alpha in two dermatological diseases: mycosis fungoides and melanoma. OBSERVATIONS: A 68 year-old man, treated for mycosis fungoides, and two men aged 47 and 52 years, treated for melanoma, were under interferon alpha. After 11 months, 3 weeks and 9.5 months, respectively, the three patients had seizures without any past history of epilepsy. Anamnesis and assessment of each patient (brain CT, biological results) suggested the responsibility of interferon alpha. After withdrawal of the treatment, no relapse was observed after 3 months, 6 months and 1 year later, respectively. DISCUSSION: Seizures during treatment with interferon alpha have already been reported. According to the series their prevalence would be of 1 to 4 p. 100. Their pathophysiology is not well known, but apparently interferon alpha lowers the epileptogenic threshold by affecting the central nervous system either directly or through cytokines or neuromediators. The risk of occurrence of seizures must be known by the prescribing physician who must systematically search for past history of epilepsy or risk factors for seizures. This rare but existing side effect raises the problem of information to be supplied to the patient by the prescribing physician.
[Cutaneous necrosis is predictive of cancer in adult dermatomyositis].
INTRODUCTION: Adult dermatomyositis is associated with cancer in 15 p. 100 to 50 p. 100 of cases and, hence, investigations should be systematically performed to search for cancer. A number of predictive factors have been reported. The aim of our study was to search for predictive factors of cancer, among adults with dermatomyositis. METHODS: We prospectively assessed 26 adults presenting with dermatomyositis, hospitalised in our department of dermatology from January 1993 to June 2000. The parameters assessed were: association with a cancer, age, gender, cutaneous necrosis, muscular weakness, electromyographic abnormalities, erythrocyte sedimentation rate, and muscular enzyme levels. RESULTS: Mean age was of 52 years and sex ratio (M/F) was of 0.53. Cancers were diagnosed in eight cases (31 p. 100) (mean age: 59.5 years; sex ratio=1; cancer localization: lung (2), breast (2), ovary, endometrium, bladder, and melanoma). Five patients in the cancer group had cutaneous necrosis and only 2 in the without cancer (p=0.01; PPV=71.4 p.100). Elevation of muscular enzyme was also associated with cancer. CONCLUSION: Our report demonstrates that cutaneous necrosis is closely associated with cancer and it suggests that in selected patients with dermatomyositis and cutaneous necrosis, more exhaustive and repeated investigations should be performed to search for cancer. The interest of elevation in muscular enzyme as a predictive factor of cancer is discussed.
[Cutaneous lymphangitic carcinomatosis and acquired ichtyosis associated with prostatic carcinoma].
BACKGROUND: Prostatic adenocarcinoma is exceptionally associated with cutaneous lesions. We describe a patient with cutaneous lymphangitis and paraneoplastic ichtyosis related to prostatic cancer. CASE REPORT: A 92 year-old man had been treated for five years for a prostatic carcinoma. An angiomatous lesion developed with in 3 months near the right breast. Physical examination revealed axillary node enlargement, a large skin angiomatous lesion, and ichtyosis. The skin biopsy of the angiomatous skin lesion demonstrated its prostatic origin with carcinomatous metastases in the lymphatic vessels. The ichtyosis was considered as paraneoplastic. DISCUSSION: Cutaneous metastases from prostatic carcinoma are rare. Less than 1 p. 100 of cutaneous metastases are of prostate origin despite the high frequency of this cancer in the general population. The clinical aspects - angiomatous lesion and paraneoplastic ichtyosis - are exceptional.
[Pyoderma gangrenosum].
GENERAL CHARACTERISTICS: Rare cause of cutaneous ulceration, pyoderma gangrenosum is among the group of neutrophilic dermatites characterized by the richness of the mature neutrophilic polynuclear dermal infiltrate. The primary lesion is a pustule sitting on an inflammatory base; extremely painful, it rapidly ulcerates. The lesion rapidly extends to more than 10 cm in diameter, has a regular, sharp border and a peripheral roll of flesh exhibiting purulent channels on the inside and a red granulous surface often covered with a pustular coating. Little is known of this disease. CONCOMITANT AFFECTIONS: In more than 50% of cases, pyoderma gangrenosum is associated with other diseases, which must be systematically searched for. These may be digestive, essentially inflammatory enterocolitis with frequent development of peristomal ulceration, rheumatismal affections notably rheumatoid arthritis, hematological affections (benign monoclonal gammapathy, chronic myeloid hemopathy). FROM A PARACLINICAL POINT OF VIEW: There are no specific examinations. A cutaneous biopsy should be performed in all cases, notably to eliminate other causes of ulceration. Since concomitant disease can be subsequently revealed, it is essential to renew the paraclinical investigations, even after the disease has healed. NO CODIFIED TREATMENT: Treatment of the cause, if it can be cured, may be sufficient to permit regression of the lesions. Local treatments to provoke budding and hence avoid surinfection are mandatory. In the progressive and extensive forms, systemic treatment, notably high dose corticosteroids, is indicated. Surgery, a priori, is excluded.
[A new antiviral for genito-anal condylomas].
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[Doxycycline prophylaxis after tick bites].
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[Papular filariasis].
UNLABELLED: 'River blindness' is the main problem of onchocerciasis. Despite a high prevalence of onchocerciasis in endemic countries, cases of imported cutaneous or ocular onchocerciasis in France are rare. CASE REPORT: We report the case of a chronic papular onchodermatitis with voluminous lymphadenopathy in a Cameroonian child, resolving with a treatment of ivermectin. CONCLUSION: The main symptom of cutaneous onchocerciasis is pruritus, which symptom may alert physicians when dealing with patients who come from endemic countries for onchocerciasis. Cutaneous aspects may vary depending on length of exposure to antigens and immune responses by the host against microfilariae. Nowadays, onchocerciasis is treated with a single dose of ivermectin, which is sufficient for eye and cutaneous symptoms. However, this therapy is efficient only against microfilariae, and treatments have to be repeated many times to avoid relapses linked to persistence of adult worms.
Oral lichenoid eruption due to methacrylate allergy.
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Endoscopic evaluation of the gastrotolerance of short-term antalgic treatment with low dose k-diclofenac: a comparison of ibuprofen and aspirin.
In a short-term gastro-duodenal endoscopic study in 12 healthy volunteers, the gastrotoxicity was not different after intake of diclofenac-K 12.5 mg (0.33) or ibuprofen 200 mg (0.42, P=0.66) but significantly higher after aspirin 500 mg (2.67, P=0.002).
[Large hairy pigmented spots in neurofibromatosis type 1: an atypical form of neurofibromas].
INTRODUCTION: Large hairy pigmented spots have been observed in patients with neurofibromatosis type 1. In this study we tried to determine the nature and the frequency of these hairy pigmented spots in neurofibromatosis type 1. PATIENTS AND METHODS: In patients with neurofibromatosis type 1, hairy pigmented spots with a diameter more than 3 cm were systematically notified. Realisation of the biopsy of the spot was proposed to the patient. RESULTS: Among 614 patients with neurofibromatosis type 1, seven (1.1 p. 100) had a large hairy pigmented spot. Biopsy was realized in six cases. In five cases, diagnosis was superficial and plexiform neurofibroma, the 6(th) case was a Becker's nevus. CONCLUSION: Large hairy pigmented spot is a rare aspect of superficial and plexiform neurofibroma during neurofibromatosis type 1. A biopsy may be useful if it is necessary for the disorder diagnosis.
Cyclosporine in childhood psoriasis.
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PEP trial. Pulmonary Embolism Prevention.
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Conserved aromatic residues in the transmembrane region VI of the V1a vasopressin receptor differentiate agonist vs. antagonist ligand binding.
Despite their opposite effects on signal transduction, the nonapeptide hormone arginine-vasopressin (AVP) and its V1a receptor-selective cyclic peptide antagonist d(CH2)5[Tyr(Me)2]AVP display homologous primary structures, differing only at residues 1 and 2. These structural similarities led us to hypothesize that both ligands could interact with the same binding pocket in the V1a receptor. To determine receptor residues responsible for discriminating binding of agonist and antagonist ligands, we performed site-directed mutagenesis of conserved aromatic and hydrophilic residues as well as nonconserved residues, all located in the transmembrane binding pocket of the V1a receptor. Mutation of aromatic residues of transmembrane region VI (W304, F307, F308) reduced affinity for the d(CH2)5[Tyr(Me)2]AVP and markedly decreased affinity for the unrelated strongly hydrophobic V1a-selective nonpeptide antagonist SR 49059. Replacement of these aromatic residues had no effect on AVP binding, but increased AVP-induced coupling efficacy of the receptor for its G protein. Mutating hydrophilic residues Q108, K128 and Q185 in transmembrane regions II, III and IV, respectively, led to a decrease in affinity for both agonists and antagonists. Finally, the nonconserved residues T333 and A334 in transmembrane region VII, controlled the V1a/V2 binding selectivity for both nonpeptide and cyclic peptide antagonists. Thus, because conserved aromatic residues of the V1a receptor binding pocket seem essential for antagonists and do not contribute at all to the binding of agonists, we propose that these residues differentiate agonist vs. antagonist ligand binding.
Correlation between binding affinity and necrosis-inducing activity of mutant AVR9 peptide elicitors.
The race-specific peptide elicitor AVR9 of the fungus Cladosporium fulvum induces a hypersensitive response only in tomato (Lycopersicon esculentum) plants carrying the complementary resistance gene Cf-9 (MoneyMaker-Cf9). A binding site for AVR9 is present on the plasma membranes of both resistant and susceptible tomato genotypes. We used mutant AVR9 peptides to determine the relationship between elicitor activity of these peptides and their affinity to the binding site in the membranes of tomato. Mutant AVR9 peptides were purified from tobacco (Nicotiana clevelandii) inoculated with recombinant potato virus X expressing the corresponding avirulence gene Avr9. In addition, several AVR9 peptides were synthesized chemically. Physicochemical techniques revealed that the peptides were correctly folded. Most mutant AVR9 peptides purified from potato virus X::Avr9-infected tobacco contain a single N-acetylglucosamine. These glycosylated AVR9 peptides showed a lower affinity to the binding site than the nonglycosylated AVR9 peptides, whereas their necrosis-inducing activity was hardly changed. For both the nonglycosylated and the glycosylated mutant AVR9 peptides, a positive correlation between their affinity to the membrane-localized binding site and their necrosis-inducing activity in MoneyMaker-Cf9 tomato was found. The perception of AVR9 in resistant and susceptible plants is discussed.
Solid-phase synthesis, conformational analysis, and biological activity of AVR9 elicitor peptides of the fungal tomato pathogen Cladosporium fulvum.
The race-specific peptide elicitor AVR9 of the fungal pathogen Cladosporium fulvum specifically induces a hypersensitive response in tomato genotypes carrying the complementary resistance gene Cf-9. The total chemical syntheses of this 28-residue AVR9 peptide containing three disulfide bonds, and of three mutant peptides [R8K]AVR9, [F10A]AVR9 and [F21A]AVR9, have been accomplished. The syntheses were carried out using a stepwise solid-phase approach based on tBoc chemistry. The disulfide bridges were formed by air oxidation. The correctness of the chemical structure of all folded synthetic peptides was confirmed by combined NMR and MS analyses. The biological activity and a number of physicochemical properties of folded synthetic AVR9 are identical to those of native fungal 28-residue AVR9. The overall conformations of the folded synthetic mutant peptides were comparable to that of synthetic wild-type AVR9 as demonstrated by NMR spectroscopy. Mutant [R8K]AVR9 showed a threefold higher, and mutant [F10A]AVR9 a threefold lower necrosis-inducing activity when compared to synthetic wild-type AVR9. However, mutant [F21A]AVR9 showed hardly any necrosis-inducing activity. Affinity for polyclonal antibodies raised against native fungal AVR9 is positively correlated with the necrosis-inducing activity of the synthetic AVR9 peptides ([R8K]AVR9 > wild-type AVR9 > [F10A]AVR9 > [F21A]AVR9).
Properties of a new radioiodinated antagonist for human vasopressin V2 and V1a receptors.
A vasopressin receptor antagonist, [1-(beta-mercapto-beta,beta-pentamethylenepropionic acid), 2-o-ethyl-D-tyrosine, 4-valine, 9-tyrosylamide] arginine vasopressin (d(CH2)5[o-ethyl-D-Tyr2,Val4,Tyr-NH9(2)]AVP), has been prepared. This antagonist is a potent antiantidiuretic, antivasopressor and antioxytocic peptide with pA2 values of 7.69-7.94 and affinities of 1.12-11.0 nM. When radioiodinated at the phenyl moiety of the tyrosylamide residue at position 9, this peptide was demonstrated to bind to vasopressin V2 and V1a receptors with a dissociation constant of 0.22-0.75 nM. This ligand is a good tool for further studies on human vasopressin V2 receptor localization and characterization, when used in combination with a selective vasopressin V1a ligand.