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Biomedical subjects

B Guillot

Publications and source records attributed to B Guillot.

At least 37 records · Page 2Linked to original sources
PubMed2005

[Eruptive pseudoangiomatosis in infant and newborns].

INTRODUCTION: Eruptive pseudoangiomatosis was first described in children in the form of an acute non-pruritic macular or papular rash that fades on application of a glass test and resolves within several days. Viral aetiology is suspected but has never been demonstrated to date. OBSERVATIONS: We discuss seven cases of infants presenting this disease: 5 boys and 2 girls aged 8 days to 16 months. The rash presented typical clinical features in all cases and affected the face and limbs in 6 of the 7 subjects. In one child, involvement of the face and back was observed with sparing of the limbs. The rash occurred after an episode of rhinolaryngeal infection in 3 cases and after gastrointestinal infection in 1 case. Spontaneous resolution was seen within 3 to 10 days in 6 patients although a longer course lasting over 9 months was observed in one infant. In another patient, the rash appeared after surgery for mesoblastic nephroma. In one child, a similar rash was seen in both parents. Screening for infectious agents was negative for the two children from whom samples were obtained. DISCUSSION: This series of paediatric cases of eruptive pseudoangiomatosis is characterised by the very young age of one of the children, coexistence of the condition with a renal tumour in another child, the familial nature of the rash in a third child and unusually long disease duration in the final child. However, this series did not allow identification of the causative infectious agent or agents. Probably, as with other syndromes such as Giannotti-Crosti syndrome or "gloves and socks" syndrome, eruptive pseudoangiomatosis forms a clinical picture common to a non-specific viral infection.

Age of Onset↗
PubMed2005

Nickel-elicited systemic contact dermatitis from a peripheral intravenous catheter.

Nickel-elicited systemic contact dermatitis is a well-known entity, although it is far less common than allergic contact dermatitis. In most of the cases, the main way of nickel administration is oral. Clinical manifestations are miscellaneous including pompholyx, diffuse exanthema, flexural dermatitis or baboon syndrome. Systemic nickel dermatitis induced by venous catheters is very uncommon, but it is probably underdiagnosed. We report here 2 patients with diffuse recurrent maculopapular rash corresponding to nickel-elicited systemic contact dermatitis. They were both perfused during the last episode with the assistance of a peripheral polyurethane venous catheter during or just before the cutaneous eruption. At the base of the catheter, there was a small metallic eyelet on which dimethylglyoxime test was positive, indicating a release of nickel. Then, we measured nickel release in normal use conditions and found high nickel levels, although the manufacturer denied that nickel could be released. This diagnosis is important to know because such exanthema often occurred during postoperative or postpartum period. Its frequency is probably underestimated because it is often considered as a cutaneous drug reaction. To our knowledge, only 2 cases have been reported in the literature.

Adult↗
PubMed2005

The expression of cytotoxic mediators is altered in mononuclear cells of patients with melanoma and increased by interferon-alpha treatment.

BACKGROUND: The role of cytotoxic cells in the control of cancer is now well established. OBJECTIVES: To evaluate the expression of perforin and granzyme A in cytotoxic cells of patients with melanoma and to look for a link between this expression and natural tumour progression; to check if interferon (IFN)-alpha administration increased expression of cytotoxic mediators; and to evaluate if this increase was correlated with the antitumoral effect of IFN-alpha. METHODS: To determine in patients with melanoma the expression of the cytotoxic mediators perforin and granzyme A in peripheral blood natural killer (NK) and T cells, we used flow cytometry before and after IFN-alpha administration. RESULTS: Compared with healthy volunteers, we observed in 82 patients a low percentage of NK cells harbouring perforin [75% (95% confidence interval (CI) 70-79) vs. 92% (95% CI 89-95), P < 0.001] and granzyme A [48% (95% CI 41-55) vs. 73% (95% CI 66-81), P < 0.001]. By contrast, a high percentage of T cells, and particularly of CD56+ T cells, expressed perforin [56% (95% CI 41-71) vs. 28% (95% CI 18-38), P < 0.001], whereas a low percentage of CD56+ T cells expressed granzyme A [30% (95% CI 24-36) vs. 54% (95% CI 43-65), P < 0.001]. In untreated patients, the percentage of CD56+ T cells expressing granzyme A was higher in progressors than in nonprogressors [49% (95% CI 39-58) vs. 16% (95% CI 0-33), P = 0.003]. We followed cytotoxic mediator expression in 17 patients treated with IFN-alpha. IFN-alpha administration increased granzyme A expression in NK cells [44% (95% CI 27-61) and 65% (95% CI 54-76) before and after treatment, respectively, P = 0.010], rather than perforin expression, whereas expression of both perforin [46% (95% CI 30-62), and 58% (95% CI 44-73), P = 0.112] and especially granzyme A [27% (95% CI 14-40) vs. 45% (95% CI 26-64), P = 0.016] was increased in CD56+ T cells after IFN-alpha administration. Yet, this effect was not correlated with the clinical response to IFN-alpha. CONCLUSIONS: Thus, the expression of cytotoxic mediators is altered in cytotoxic cells of patients with melanoma, and increased under IFN-alpha administration.

Adult↗
PubMed2005

Clinical variants of the preprotuberant stage of dermatofibrosarcoma protuberans.

BACKGROUND: Some cases of dermatofibrosarcoma protuberans (DFSP) do not protrude above the skin. OBJECTIVES: To assess the prevalence of these DFSPs and further to describe their presentation and course. METHODS: One hundred and forty-three patients were retrospectively collected. They were asked to complete a standardized questionnaire indicating the history and appearance of the DFSP from the first skin changes identified to the time of diagnosis. RESULTS: Eighty-one DFSPs were described as protuberant ab initio, and 62 as initially nonprotuberant (npDFSP). The latter remained at this stage for a mean period of 7.6 years. Twenty-nine per cent of npDFSPs were 'morphoea-like', 19% were 'atrophoderma-like' and 42% were 'angioma-like'. Age at diagnosis was similar for both initial presentations. npDFSPs were most often misdiagnosed by physicians. CONCLUSIONS: Nearly half the patients first identified their early DFSP-related skin changes as patches. Both this frequency and the long duration at this preprotuberant stage should prompt dermatologists to consider the diagnosis of DFSP earlier, in order to make surgical treatment easier.

Adolescent↗
PubMed2004

Ultra-high-resolution X-ray structure of proteins.

The constant advances in synchrotron radiation sources and crystallogenesis methods and the impulse of structural genomics projects have brought biocrystallography to a context favorable to subatomic resolution protein and nucleic acid structures. Thus, as soon as such precision can be frequently obtained, the amount of information available in the precise electron density should also be easily and naturally exploited, similarly to the field of small molecule charge density studies. Indeed, the use of a nonspherical model for the atomic electron density in the refinement of subatomic resolution protein structures allows the experimental description of their electrostatic properties. Some methods we have developed and implemented in our multipolar refinement program MoPro for this purpose are presented. Examples of successful applications to several subatomic resolution protein structures, including the 0.66 angstrom resolution human aldose reductase, are described.

Aldehyde Reductase↗
PubMed2004

A prospective study of cutaneous adverse events induced by low-dose alpha-interferon treatment for malignant melanoma.

INTRODUCTION: alpha-Interferon is associated with numerous cutaneous side effects, but the accurate incidence of these complications is not clearly known. OBJECTIVES: A prospective study was designed to evaluate the incidence and clinical pattern of cutaneous side effects in a cohort of patients receiving adjuvant therapy with low-dose interferon for malignant melanoma. MATERIAL AND METHODS: A cohort of 33 patients with stage IIA and IIB melanoma treated with low-dose alpha-interferon (3 MIU 3 times a week for 18 months) were prospectively enrolled in a single-center study. The patients responded to a questionnaire on their medical history and were systematically examined for any cutaneous lesions before treatment and every 3 months afterwards. RESULTS: 29/33 patients (87%) experienced 1 or more cutaneous side effects. The most frequent was hair loss and occurred in 16 cases (48.4%). Hair discoloration was noted in 6 cases (18%). Eczematous reactions at injection sites or at remote sites were observed in 13 patients (39%). Pruritus occurred in 10 cases (30%). Xerostomia, Raynaud's phenomenon or livedo reticularis were observed in 10 patients, associated with an increase in circulating autoantibody titer in 2 cases. Some rare side effects were observed: urticaria (1 case) or angioedema (1 case), worsening of preexisting seborrheic dermatitis (3 cases), herpetic recurrence (2 cases), pityriasis versicolor (1 case), worsening of recurrent buccal aphthous ulcer (1 case) and vitiligo (1 case). CONCLUSION: Cutaneous adverse events during adjuvant immunotherapy of melanoma with low-dose alpha-interferon seem to be frequent but do not result in treatment discontinuation. A good awareness of these side effects may be useful for a more accurate survey and clinical management of patients receiving this treatment.

Adult↗
PubMed2004

Mucocutaneous side effects of antineoplastic chemotherapy.

All structures of the skin may be affected by side effects of antineoplastic chemotherapy. The most commonly described effects concern skin adnexes, especially hair with alopecia. Nails are also frequently involved. Eccrine sweat or sebaceous gland involvement is more rarely reported. Mucous membranes, particularly in the mouth, are frequently altered by several mechanisms; direct cytotoxicity, infection, and a decrease in polymorphonuclear or platelet counts. Among cutaneous side effects, hyperpigmentation is very common and may have different clinical patterns; generalised, figurated, or localised. Acral erythema is another cutaneous side effect that is relatively specific to chemotherapy and is often dose-related. Some cutaneous side effects are related to an interaction between chemotherapy and radiation, particularly phototoxicity, recall phenomenon, and radiation enhancement. Miscellaneous, less frequent, side effects are described; sclerodermiform dermatitis, Raynaud's phenomenon, and hypersensitivity syndrome. In some cases, cutaneous side effects are relatively specific to one type of drug. Capillary leak syndrome is most often related to taxanes. Hydroxyurea is responsible for some peculiar cutaneous side effects (ulcerations, pseudo-dermatomyositis), perhaps due to long-term administration of the drug. Although mucocutaneous side effects of chemotherapy are frequent and sometimes severe, interruption of the culprit drug is rarely mandatory. However, adaptation of the dosage or prevention of some of these side effects remains necessary. Antineoplastic chemotherapies are widely used in many therapeutic protocols and may be responsible for numerous mucocutaneous side effects, either specific or more unusual. In rare cases, the severity of these side effects may require interruption of therapy. They may involve skin adnexes, mucous membranes or the skin itself. This review discusses cytotoxic antineoplastic drugs only, not cytokines, monoclonal antibodies or transduction factors used in the treatment of cancer.

Alopecia↗