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T Jansen

Publications and source records attributed to T Jansen.

At least 91 records · Page 5Linked to original sources
PubMed1998

A rigorous complexity analysis of the (1 + 1) evolutionary algorithm for separable functions with Boolean inputs.

Evolutionary algorithms (EAs) are heuristic randomized algorithms which, by many impressive experiments, have been proven to behave quite well for optimization problems of various kinds. In this paper a rigorous theoretical complexity analysis of the (1 + 1) evolutionary algorithm for separable functions with Boolean inputs is given. Different mutation rates are compared, and the use of the crossover operator is investigated. The main contribution is not the result that the expected run time of the (1 + 1) evolutionary algorithm is theta (n ln n) for separable functions with n variables but the methods by which this result can be proven rigorously.

Algorithms↗
PubMed1997

Advances and perspectives in acne therapy.

Acne is one of the most common diseases in dermatology. It is of considerable esthetic significance, which explains the mental stress in affected patients. Although acne almost always heals spontaneously in early adulthood, treatment measures can shorten the course, reduce the severity of the disease, and avoid complications such as scarring. Treatment has changed substantially in recent years. In accordance with pathogenic principles, effective treatment is possible. In most patients, a combination of drugs aimed at correcting abnormal keratinization and reducing the proliferation of Propionibacterium acnes is sufficient to control the disease. For more severely affected patients with no response to this approach, therapy to suppress sebum production is indicated. Of all therapeutic modalities available, only oral isotretinoin alters the natural course of the disease. In acne inversa, surgical management should be undertaken as early as possible.

Acne Vulgaris↗
PubMed1997

Ophthalmologic examination in systemic toxicity studies: an overview.

The procedures of ophthalmologic examination used by the authors during systemic toxicity studies in laboratory animals are presented in this paper. The present international guidelines with respect to the requirements for ophthalmological examination are given in an overview. A list of proposed keywords is included which may be used in describing ocular changes.

Animals↗
PubMed1997

Characterization of pulmonary and myocardial beta-adrenoceptors with S-1'-[fluorine-18]fluorocarazolol.

UNLABELLED: S-1'-[18F]fluorocarazolol was administered to healthy volunteers to assess its potential for noninvasive measurement of regional pulmonary and myocardial beta-adrenoceptor densities. METHODS: High-specific activity fluorocarazolol was intravenously injected on two separate occasions within a 1-wk interval. The initial injection was without pretreatment, but before the second injection, the volunteers either inhaled salbutamol (2 x 200 micrograms aerosol) or they ingested pindolol (3 x 5 mg during a 12-hr interval). Twenty-eight PET time frames of 31 planes were acquired over a period of 60 min after each injection. Blood samples were drawn and analyzed for the presence of fluorocarazolol and radioactive metabolites. RESULTS: Uptake of fluorocarazolol in the target tissues was hardly affected by salbutamol but was strongly depressed by pindolol. Pulmonary and myocardial tissue-to-plasma concentration ratios of fluorocarazolol reached plateau values of 11.6 +/- 0.6 (lungs) and 18.1 +/- 1.0 (heart) at 45-50 min postinjection. These values were reduced to 2.0 +/- 0.4 and 2.0 +/- 0.6 after treatment with pindolol. CONCLUSION: These data indicate that: 1. Pulmonary and myocardial uptake of radioactivity after intravenous administration of S-1'-[18F]fluorocarazolol represents radioligand binding to beta-adrenoceptors. 2. Pulmonary binding occurs mainly in alveoli rather than in airway smooth muscle under these conditions. 3. Binding kinetics do not preclude quantification of receptors with compartment models.

Adrenergic beta-Agonists↗
PubMed1997

Acne conglobata and Klinefelter's syndrome.

Acne conglobata has been reported to be more common and more severe in XYY chromosomal aberration than in normal subjects. Whereas only exceptional cases have been observed in the more common XXY Klinefelter karyotype. We report a 17-year-old male with both Klinefelter's syndrome and acne conglobata, spreading from face to upper arms, trunk, buttocks and upper legs. The serum level of testosterone was normal, whereas luteinizing hormone and follicle-stimulating hormone were elevated. Skin lesions responded well to a combined therapeutic regimen including oral isotretinoin and prednisolone. An overview of severe acne in relation to chromosomal abnormalities is given and diagnostic and therapeutic options discussed.

Acne Vulgaris↗
PubMed1996

[Eruptive vellus hair cysts].

Eruptive vellus hair cysts are rare epidermal cysts with vellus hairs, which appear in children or young adults. A 21-year-old patient is reported who developed asymptomatic comedo-like papules on his face, neck and chest. Histopathologically, epidermoid cysts with a fine stratum granulosum, laminated keratinous material and numerous vellus hairs were found in the mid-dermis. Evaluation of immediate family members revealed that the patient's father was similarly affected. Eruptive vellus hair cysts and steatocystoma multiplex are clinically similar, but have distinctive histopathological features and should be regarded as distinct entities.

Adult↗
PubMed1996

Diffuse sebaceous gland hyperplasia. A case report and an immunohistochemical study with cytokeratins.

We report a 43-year-old woman with sebaceous gland hyperplasia that occurred in a diffuse pattern of aggregated papular lesions involving her entire face, neck, and upper chest. Comedones, pustules, and inflammatory papules were absent. The eruption was accompanied by marked seborrhea. Histopathological examination showed enlargement of sebaceous acini, an increased number of immature sebocytes in foci, and a dilated follicular infundibulum. Immunohistochemical investigation showed cytokeratin 14 (CK 14) expression in the keratinocytes of the infundibulum, the isthmus, and sebaceous duct and in the mature and immature sebocytes; CK 17 expression in the keratinocytes of the sebaceous duct; CK 1 expression in the keratinocytes of the infundibulum; and an enhanced expression of the proliferation cell antigen Ki-67 (MiB1) in the immature sebocytes. With CK 18 and CK 19, no staining was observed. Oral therapy with isotretinoin (13-cis-retinoic acid) resulted in remarkable improvement in < or = 3 months. Histopathological and immunohistochemical examination after therapy showed markedly reduced sebaceous glands, a decrease in the staining of MiB1-positive immature sebocytes, and enhanced expression of CK 19 in immature sebocytes and sebaceous duct cells. Diffuse sebaceous gland hyperplasia is a rare variant of seboglandular proliferative disorders that is distinct from the well-known circumscribed type.

Administration, Oral↗