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Biomedical subjects

Isabelle Thomas

Publications and source records attributed to Isabelle Thomas.

12 recordsLinked to original sources
PubMed2005

Persistent B19 infection in immunocompetent individuals: implications for transfusion safety.

Recent reports suggested that parvovirus B19 (B19) might persist in immunocompetent individuals such as blood donors, but only cross-sectional data were available. Serial samples from a cohort of multitransfused patients with hemoglobinopathies and a cross-sectional population of pregnant women were tested for B19 markers. Of 76 red cell recipients, 6 (8%) had persistent viral DNA for 1 to 3 or more years, depending on the sensitivity of the genomic amplification assay. All patients also carried B19-specific immunoglobulin G (IgG). In contrast, 0.8% of 500 pregnant women carried both detectable B19 DNA and specific IgG. These results demonstrate that persistence of low levels of B19 DNA suggested by cross-sectional studies is frequent in multitransfused patients and that the virus may remain detectable several years after infection in nonimmunodeficient individuals.

Adolescent↗
PubMed2005

Understanding spatial concentrations of road accidents using frequent item sets.

This paper aims at understanding why road accidents tend to cluster in specific road segments. More particularly, it aims at analyzing which are the characteristics of the accidents occurring in "black" zones compared to those scattered all over the road. A technique of frequent item sets (data mining) is applied for automatically identifying accident circumstances that frequently occur together, for accidents located in and outside "black" zones. A Belgian periurban region is used as case study. Results show that accidents occurring in "black" zones are characterized by left-turns at signalized intersections, collisions with pedestrians, loss control of the vehicle (run-off-roadway) and rainy weather conditions. Accidents occurring outside "black" zones (scattered in space) are characterized by left turns on intersections with traffic signs, head-on collisions and drunken road user(s). Furthermore, parallel collisions and accidents on highways or roads with separated lanes, occurring at night or during the weekend are frequently occurring accident patterns for all accident locations. These exploratory results show the potentiality of the frequent item set method in addition to more classical statistical techniques, but also suggest that there is no unique countermeasure for reducing the number of accidents.

Accidents, Traffic↗
PubMed2005

Highly pathogenic H5N1 influenza virus in smuggled Thai eagles, Belgium.

We report the isolation and characterization of a highly pathogenic avian influenza A/H5N1 virus from Crested Hawk-Eagles smuggled into Europe by air travel. A screening performed in human and avian contacts indicated no dissemination occurred. Illegal movements of birds are a major threat for the introduction of highly pathogenic avian influenza.

Acetamides↗
PubMed2005

Body dysmorphic disorder: more than meets the eye.

Body dysmorphic disorder is a relatively common yet long unrecognized problem affecting mainly adolescents and young adults of both sexes. It is an obsessive disease of such intensity that it interferes with daily activities. Patients typically focus on imagined major defects in the face, nose, skin or hair. Patients often seek multiple physician assessment, but body dysmorphic disorder may be disabling and even life-threatening as a result of depression and suicidal ideation. Treatment with serotonin reuptake inhibitors and cognitive behavioral therapy may be beneficial in many patients.

Adolescent↗
PubMed2004

Palmoplantar hyperhidrosis: a therapeutic challenge.

Excessive sweating from the palms and soles, known as palmoplantar hyperhidrosis, affects both children and adults. Diagnosis of this potentially embarrassing and socially disabling condition is based on the patient's history and visible signs of sweating. The condition usually is idiopathic. Treatment remains a challenge: options include topical and systemic agents, iontophoresis, and botulinum toxin type A injections, with surgical sympathectomy as a last resort. None of the treatments is without limitations or associated complications. Topical aluminum chloride hexahydrate therapy and iontophoresis are simple, safe, and inexpensive therapies; however, continuous application is required because results are often short-lived, and they may be insufficient. Systemic agents such as anticholinergic drugs are tolerated poorly at the dosages required for efficacy and usually are not an option because of their associated toxicity. While botulinum toxin can be used in treatment-resistant cases, numerous painful injections are required, and effects are limited to a few months. Surgical sympathectomy should be reserved for the most severe cases and should be performed only after all other treatments have failed. Although the safety and reliability of treatments for palmoplantar hyperhidrosis have improved dramatically, side effects and compensatory sweating are still common, potentially severe problems.

Administration, Topical↗
PubMed2004

Melanoma within the seborrheic keratosis.

Seborrheic keratoses (SKs) are common benign nonmelanocytic epidermal tumors with characteristic clinical features, which are thought to allow a straightforward diagnosis in most situations. As a result, it is an accepted practice to destroy them without histopathologic confirmation. However, systematic reviews of histologic specimens reveal an erroneous clinical diagnosis or associated malignant tumors in a number of cases, including malignant melanomas. We describe a patient with a clinically typical-appearing SK, which was biopsied and histologically proven to be a malignant melanoma arising in the SK. Our report is a reminder that the reliability of clinical diagnosis of SKs needs to be questioned. In addition, a biopsy of SKs is not only warranted but necessary in order to identify a malignant melanoma that would otherwise be misdiagnosed or even completely missed.

Aged↗
PubMed2004

Ocular melanoma metastatic to skin: the value of HMB-45 staining.

BACKGROUND: Cutaneous metastatic disease is an important finding that may represent the first sign of systemic cancer, or, if already known, that may change tumor staging and thus dramatically altered therapeutic plans. Although cutaneous metastases are relatively frequent in patients with cutaneous melanoma, they are less so from ocular melanoma. OBJECTIVE: To demonstrate the value of HMB-45, staining in the detection of ocular melanoma metastatic to skin. METHODS: The immunohistochemical stain HMB-45 a monoclonal antibody directed against intact human melanoma cells, was employed on a skin biopsy specimen from a cutaneous tumor. RESULTS: HMB-45 staining was positive in the atypical hyperchromatic cells of the deep dermis. CONCLUSION: HMB-45 may be of value in the detection of ocular melanoma metastatic to skin. Cutaneous metastatic disease is a somewhat common and extremely important diagnosis. Although cutaneous metastases from cutaneous melanoma are relatively frequent, those from ocular melanomas are less so. Use of histochemical staining, especially the HMB-45 stain, allows confirmation of the diagnosis.

Antigens, Neoplasm↗
PubMed2003

The local spatial autocorrelation and the kernel method for identifying black zones. A comparative approach.

This article aims to determine the location and the length of road sections characterized by a concentration of accidents (black zones). Two methods are compared: one based on a local decomposition of a global autocorrelation index, the other on kernel estimation. After explanation, both methods are applied and compared in terms of operational results, respective advantages and shortcomings, as well as underlying conceptual elements. The operationality of both methods is illustrated by an application to one Belgian road.

Accidents, Traffic↗
PubMed2002

The use of nucleic acid amplification techniques to increase the viral safety of blood.

Despite recent significant improvements in the viral safety of blood and blood products there remains a small risk of contamination mainly due to the existence of a window period before the appearance of antibodies. Nucleic acid amplification technologies (NAT) permit a direct detection of the viral genome itself with an extreme sensitivity and specificity, without depending anymore on the delayed appearance of antibodies. These technologies can be applied to detect most blood-borne viruses. However, the usefulness and strategies will largely depend on different features specific to the type of the virus, such as pathogenicity, prevalence of the infection, viral load during preseroconversion, doubling time of the virus and infectious dose. Many studies have already been conducted in different parts of the world, and the results proving the feasibility of the NAT screening are more than encouraging. However, some problems still remain to be solved in theroutine application of these technologies.

Belgium↗
PubMedDate not supplied

Cutaneous paraneoplastic syndromes: uncommon presentations.

Paraneoplastic syndromes are a group of clinical manifestations associated with a malignancy, but not directly related to the primary tumor itself or to its metastases. Characteristically, they follow a course parallel to the tumor, resolve with successful treatment of the primary tumor, and tend to recur with its relapse or the onset of metastases. The mechanism by which they occur is not well understood, but may be related to the production of bioactive substances by or in response to the tumor, such as polypeptide hormones, hormone-like peptides, antibodies or immune complexes, cytokines, or growth factors.

Biopsy, Needle↗