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Biomedical subjects

L Meunier

Publications and source records attributed to L Meunier.

At least 19 recordsLinked to original sources

[Long-term effects of environmental endocrine disruptors on male fertility].

Several epidemiologic studies have demonstrated during the last 50 years an increased incidence in testis cancer, male genital tract malformations (cryptorchidism and hypospadias) and a decrease in sperm quality in men. These three pathologies seem to be linked and to belong to the testicular dysgenesis syndrome (TDS). It was suggested that TDS is a consequence of intra-uterine exposure to environmental compounds that disrupt the metabolism of native hormones. Such substances are so called endocrine disruptors (EDs). EDs are present in our daily environment such as food and water (through the use of pesticides), cosmetics, house-care products etc. Experimental models have been carried out to (i) establish a link between EDs exposure and SDT and (ii) identify the mechanisms that are involved in. After a brief definition of EDs and having underlined the importance of the window of exposure to EDs, several mechanisms will be described such as (i) intergenerational transmission (epigenetic), (ii) programmed cell death of testicular cells, (iii) modification of the androgenic signal and (iv) role of the germ cells-nourishing cells. To conclude, we will try to propose some biomarkers that would be useful to identify the potential link between fetal exposure to anti-androgenic EDs and male testicular pathology.

Androgen Antagonists↗

[Tumoral and pilotropic mycosis fongoides without mucin: evolution towards a pustulous erythroderma].

INTRODUCTION: Pilotropic mycosis fongoides is a particular form of the disease, because of its clinical and histological aspects, its poor prognosis and its resistance to treatment. We report a case of pilotropic mycosis fongoides without mucinosis, immediately tumoral, the fatal progression of which was marked by the occurrence of pustular erythroderma. OBSERVATION: In 1998 a 69 year-old man presented with infiltrated erythro-squamatous plaques and nodules on the limbs associated with follicular lesions predominating on the cervical-cephalic area. Histological explorations revealed a pilotropic infiltrate with atypical CD4+ CD8 CD30 T-cells, without epidermotrophism or mucinosis. Study of genetic rearrangements found a clone lymphocyte T-cell in the skin. Diagnosis of pilotropic mycosis fongoides at the tumoral stage was made and, despite various treatments, the disease developed towards fatal pustular erythroderma. DISCUSSION: At the onset of its progression, pilotropic mycosis fongoides is sometimes difficult to distinguish from classical mycosis fongoides, during which follicular involvement is often seen. However it is important to differentiate these entities because of the poor prognosis of pilotropic mycosis fongoides. Development of tissue micro dissection techniques and lymphocyte T-cell clones from human skin would help to separate these cutaneous T-cell lymphoma sub-groups. Our case report is original because of the absence of dermal mucinosis combined with an immediately tumoral form and the progression towards generalized pustulosis. It also underlines the poor prognosis and resistance to treatment of pilotropic mycosis fongoides.

Aged↗

Transcriptional response of Choristoneura fumiferana to sublethal exposure of Cry1Ab protoxin from Bacillus thuringiensis.

Bacillus thuringiensis is a microbial control agent active against Choristoneura fumiferana, a lepidopteran defoliator of North American forests. Although the B. thuringiensis insecticidal crystal protoxins have a relatively narrow host range, there is concern about their impact on non-target species where intoxication effects may not be overt. Larval toxicity effects can be assessed at the molecular level by determining altered transcriptional profiles in response to sublethal protoxin exposure in sensitive insects. Subtraction hybridization libraries were created using two larval populations, control and protoxin-fed and were characterized by sequencing 1091 clones. Differential mRNA expression of selected clones, as measured by quantitative polymerase chain reaction, identified a number of metabolic and stress-related genes that were either transcriptionally enhanced or repressed after protoxin exposure.

Animals↗

[Narrow band UVB phototherapy in the treatment of widespread lichen planus].

INTRODUCTION: UVA phototherapy, acitretin and oral corticosteroids are currently the front-line treatment of disseminated cutaneous lichen planus. We studied the efficacy of narrow band UVB therapy in this indication. PATIENTS AND METHODS: We retrospectively studied the dossiers of patients suffering from disseminated cutaneous lichen planus, treated with narrow band phototherapy in the Phototherapy Unit of the University hospital in Montpellier, from May to November of the year 2001. Disseminated lichen planus was defined as lichen involving at least 20p. 100 of the skin surface. Twenty patients were included. UVB were applied thrice weekly using a Philips TL01 cubicle (311-313 nm). The protocol was that used for the treatment of psoriasis. We defined 4 types of response: complete response (disappearance of more than 90p. 100 of the lesions), partial response (disappearance of at least 50p. 100) poor response (improvement in 20 to 50p. 100) and failure (less than 20p. 100 reduction in the lesions). Assessment of relapses in the long term was made using a telephone survey among the patients treated or their physicians. RESULTS: Complete response was obtained in 11 out of the 20 patients (55p. 100) and partial response in 4 (20p. 100), corresponding to 75p. 100 of the responders. Response was obtained with a median delay of 3 months, ranging from 2 to 6 months, following a median of 30 sessions (12 to 50) and accumulated dose of UVB of 36 +/- 4.8 joules/cm2. The phototype, gender, age and duration of evolution before treatment did not influence the response. The relapse rate was and estimated 18p. 100 (2/11) 42 months after treatment had been stopped. DISCUSSION: In our opinion, these results underline the efficacy of narrow band UVB in the treatment of disseminated cutaneous lichen planus. They confirm those of earlier studies and are superimposable with those of oral UVA phototherapy.

Adult↗

High plasma proteasome levels are detected in patients with metastatic malignant melanoma.

BACKGROUND: Proteasomes, nonlysosomal proteolytic structures, are implicated in cell growth and differentiation. An abnormal expression has been described in haematopoietic malignancies and in some solid tumours. OBJECTIVES: To study the plasma proteasome levels in patients with malignant melanoma (MM) using an enzyme-linked immunosorbent assay (ELISA) technique, and to compare them with the values obtained in a normal population and in patients with severe psoriasis or chronic idiopathic urticaria (CIU). METHODS: Plasma proteasome level was measured using a sandwich ELISA test in normal donors (n = 14), and in patients with stage I/II (n = 13), stage III (n = 6) and stage IV (n = 10) MM, severe psoriasis (n = 13) and CIU (n = 6). Tissue proteasome expression was also detected by immunohistology using a monoclonal antibody in paraffin-embedded samples of normal tissue, psoriasis skin and MM. RESULTS: In normal donors, mean +/- SEM plasma proteasome concentration was 2138 +/- 221 ng mL(-1). Patients with stages III and IV MM exhibited a significantly higher value (3373 +/- 470 ng mL(-1) and 8931 +/- 1232 ng mL(-1), respectively). Values in patients with stage I/II MM and CIU were not significantly different from those in normal volunteers. Patients with severe psoriasis also exhibited increased values (3398 +/- 374 ng mL(-1)) but to a lesser extent than in patients with stage IV MM. There was a significant correlation of proteasome levels with serum lactate dehydrogenase in the MM group. Tissue expression as demonstrated by immunohistochemistry paralleled these findings. The strongest expression was seen on MM slides and to a lesser extent in psoriasis samples, the weakest expression being observed in normal skin. CONCLUSIONS: Proteasomes are strongly expressed in cutaneous MM; high levels of circulating proteasomes are detected in patients with metastatic MM with a high melanoma burden, and at a lesser extent in psoriatic patients, which suggests proteasomes represent a marker more of nonspecific inflammation than of early cancer.

Adult↗

[Iatrogenic syncopes and malaises].

Syncope or presyncope related to adverse drug reactions are well-known. On the other hand, little is known about the specific role of different drugs. Over one six year period, 1611 patients were referred in our hospital for syncope or presyncope, including 688 in the cardiology department. Among these patients, 420 were 70 years old or more. The search for an adverse drug reaction was systematic, with the help of the French method for causality of adverse drug reaction: knowledge of "extrinsic" criteria (bibliographical data relating to the drug involved); moreover, score on the basis of "intrinsic", chronological and symptomatic criteria. Seventy five patients (11% of the group with syncope leading to admission in cardiology department) were thus retained: score = I2, "possible adverse drug reaction", for 28 patients (37%); score = I3, "probable adverse drug reaction", for 47 patients (63%). Score I4, "definite adverse drug reaction" was not used since it required the readministration of the drug to prove the iatrogenic effect. Average age was 78 years, with a female majority of 69%. Seventy two patients (96%) had previous cardiovascular disease, 37 (50%) previously experienced syncope or presyncope. In addition to the basic assessment, a Holter recording was performed among 56 patients, finding a drug-induced arrhythmia in three cases. In the majority of the patients (59 patients, 79%), the adverse drug reaction consisted of hypotension, clinically obvious in 49 cases. In ten cases, vasovagal syndrome facilitated by the drugs was diagnosed by a tilt-test. The other side effects were eight rhythm disorders and eight severe metabolic disorders. The treatments were always multiple. The involved drug was a cardiovascular therapy in 66% of the cases. The other drug classes were primarily represented by uroselective alpha 1-adrenergic blocking drugs (12%) and psychotropic ones (22%). Among the cardiovascular treatments, ACE inhibitors and diuretics, generally in association, were involved (59%). This study confirms the role for antihypertensive drugs in iatrogenic syncope, its great frequency in elderly patients but also the responsibility of another drug class less often reported, the uroselective alpha 1-adrenergic blocking drugs.

Aged↗

[Simvastatin-induced lichen planus pemphigoides].

INTRODUCTION: Simvastatin is a competitive inhibitor of the 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase which is effective in the treatment of various hyperlipidemia. We report a case of lichen planus pemphigoides induced by simvastatin treatment. CASE REPORT: A 63-year-old man was treated for two months with simvastatin for hypercholesterolemia. One month later he developed a pruriginous and bullous lichenoid eruption. Histological and direct immunofluorescent features were consistent with the diagnosis of lichen planus pemphigoides. The Western blot analysis revealed antibodies directed against BP 180 kDa antigens. All the lesions progressively disappeared after treatment was discontinued. DISCUSSION: Lichen planus pemphigoides may be due to the intake of drugs such as cinnarizine, captopril, ramipril and furosemide. Simvastatin may induce various drug eruptions such as pruritus, eczematous rash, cheilitis, angio-oedema and urticaria, porphyria cutanea tarda, lupus-like syndrome, dermatomyositis and lichenoid eruption. With the increasing use of HMG-CoA reductase inhibitors, an association between simvastatin and lichen planus pemphigoides should be kept in mind.

Blotting, Western↗

Simultaneous RT/PCR detection and differentiation of arabis mosaic and grapevine fanleaf nepoviruses in grapevines with a single pair of primers.

The movement protein genes from several isolates of ArMV and GFLV of different geographical origins were amplified by RT/PCR using degenerate primers, cloned and sequenced. A single pair of degenerate primers was designed from these sequences to allow the simultaneous amplification of parts of the movement protein genes of ArMV and GFLV. Their use in an immunocapture-RT/PCR for the detection of ArMV or GFLV in infected grapevines proved to be ten times more sensitive than the corresponding ArMV or GFLV ELISA tests. A Sph1 restriction site found in the sequences corresponding to the amplified products from the GFLV isolates, but not in the amplified products from the ArMV isolates, allowed the differentiation between ArMV and GFLV in the infected grapevines by a Sph1 restriction digestion of the amplified products.

Animals↗

[Lymphangioma in a patient with Maffuci syndrome of the lower legs].

Maffucci syndrome is a rare dysembryoplasia associating cartilage tumors similar to enchondromas in Ollier's disease and vessel tumors. We report the case of a 50-year-old woman with Maffucci syndrome involving the lower legs who developed a variety of vascular proliferations. This patient had capillary hemangiomas, cavernous angiomas, and lymphangiomas facing the cartilage tumefactions on the thigh. Regular clinical surveillance is required for such patients due to the risk of degeneration of the enchondromas and the angiomas, but also due to the possible occurrence of other malignant tumors besides the cartilage and vessel tumors.

Enchondromatosis↗

[Septic embolism complicating an aorto-duodenal fistula].

INTRODUCTION: Aorto-duodenal fistulas are rare complications of aortal prostheses. We report a case revealed by septic embolism. OBSERVATION: A 63 year-old man with past history of obliterating arteriopathy of the legs and bifemoral aortal bypass was hospitalized in a dermatology unit because of bilateral ecchymotic and purpural lesions of the soles of the feet and fever. Hemocultures were positive for E. coli and alpha hemolytic streptococci. The search for a deep infectious area was negative. Gastro-esophageal fibroscopy revealed an aorto-duodenal fistula showing a fresh blood clot in the second duodenum. DISCUSSION: Aorto-duodenal fistulas are rare complications of aortal prostheses, the high mortality of which is often related to late diagnosis. The initial symptoms such as fever, abdominal pain, palpable mass and digestive bleeding are inconstant and the clinical profile polymorphous. Any suspicion of septic embolism in a patient with an aortal vascular prosthesis must lead to the search for prosthetic infection and an aorto-duodenal fistula, notably in the presence of osteomyelitis at distance from the prosthesis. A scan and/or scintigraphy with normal polynuclears do not eliminate the diagnosis of an aortal-duodenal fistula and a gastro-esophageal fibroscopy should be performed.

Abdominal Pain↗

Complete nucleotide sequences of the RNAs 2 of German isolates of grapevine fanleaf and Arabis mosaic nepoviruses.

The RNAs 2 of an Arabis mosaic virus (ArMV) and a grapevine fanleaf virus (GFLV) isolate, originating from South West of Germany near Neustadt an der Weinstrasse (NW), were sequenced. They are 3820 and 3775 nucleotides long respectively, and both contain one open reading frame encoding a polypeptide of 1110 amino acids. Their 5' non-coding regions contain conserved and repeated sequences, which are able to form stem-loop structures. Nucleotide sequence comparisons between the full-length RNAs 2 revealed homology levels of 84 and 82% between the ArMV-NW and the ArMV-L and -U, respectively, 90% between GFLV-NW and GFLV-F13, and 72% between ArMV-NW and GFLV-NW. Amino acid sequence comparisons showed that the greatest difference was found between the 2A proteins of the different ArMV isolates, the 2A protein of the ArMV-NW showing more similarity to the 2A protein of GFLV-NW than to those of ArMV-L2 or -U2.

Amino Acid Sequence↗

Clonal variation of gene expression as a source of phenotypic diversity in parasitic protozoa.

Within a cellular clone, individual cells can express different members of a gene family. If the difference in expression is transmitted to daughter cells, 'phenotypic clones' are formed. Such clonal phenotypic variation has evolved independently in phylogenetically distant parasitic protozoa under similar selective pressure: the need for phenotypic diversity at several steps of their life cycle. Here, I review clonal phenotypic variation processes, outline their role in parasite biology and argue that clonal phenotypic variation is complementary to sexual reproduction as a source of phenotypic diversity.

Animals↗

Transient protection by peripheral benzodiazepine receptors during the early events of ultraviolet light-induced apoptosis.

The peripheral benzodiazepine receptor (PBR) is a mitochondrial protein involved in the formation of mitochondrial permeability transition (PT) pores which play a critical role during the early events of apoptosis. PBRs are located in many tissues and are strongly expressed in the superficial layers of human epidermis. PBRs play a protective role against free radical damage and PBR ligands modulate apoptosis. To investigate the role of PBR during the early events of ultraviolet (UV)-mediated apoptosis we compared the effects of UVB on PBR-transfected Jurkat cells and their wild type counterparts devoid of any PBR expression. Results indicate that early after UVB exposure (up to 4 h), PBR-transfected cells were more resistant to apoptosis and exhibited a delayed mitochondrial transmembrane potential drop, a diminished superoxide anions production, and a reduced caspase-3 activation. Taken together these findings suggest that PBR may regulate early death signals leading to UV induced apoptosis.

Apoptosis↗