Biomedical subjects

M H Schmid

Publications and source records attributed to M H Schmid.

24 records · Page 2Linked to original sources

PubMed1995

The concept of the acid mantle of the skin: its relevance for the choice of skin cleansers.

Whereas soap has long been the only cleansing agent, a new generation of cleansers, the so-called synthetic detergents or syndets, has been developed during the last decades. They offer a wide variety of formulations and are therefore becoming more and more important for cleansing of diseased and healthy skin. Among the syndets, especially those with a pH of about 5.5 seem to be relevant. In contrast to alkaline soap, they do not interfere with the cutaneous microflora, whose composition is linked to the skin surface pH. As their irritancy potential might be even lower than that of soap, the benefit-to-risk ratio of syndets appears favorable.

Acids↗

PubMed1994

Liposomes: a drug carrier system for topical treatment in dermatology.

During the last three decades, the value of liposomes as a drug delivery system has been examined. The interest in liposomes as carriers of active substances is based on their potential to enclose various types of biological materials and to deliver them to diverse cell types. Whereas experiments with systemically applied liposome-entrapped drugs often proved disappointing, recent work suggests that liposomes as vehicles for topical drug delivery may be superior to conventional preparations. The use of liposomes in ophthalmology for the diagnosis and treatment of different ocular diseases has been postulated recently. Dermatics based on liposomes as drug carrier systems have been tested for different types of ingredients, e.g., corticosteroids and local anesthetics. To understand more about the pharmacological potential of liposomes, it is important to investigate the interaction between liposomes and the epidermis. Analysis in this field suggests that only a compromised epidermal barrier enables intact liposomes to penetrate the skin. This is in accordance with clinical findings. A liposomal preparation of betamethasone dipropionate seems superior to a conventional commercial preparation in eczema but not in psoriasis vulgaris. However, one cannot rule out the follicular pathway as an alternate route. Many questions must be resolved before a complete understanding of liposomes as a drug carrier system in dermatology can be reached. However, examinations performed so far indicate that liposomes might be useful as vehicles for topical drug delivery in various diseases of the skin.

Administration, Topical↗

PubMed1994

Semimalignant ("pseudolymphomatous") cutaneous B-cell lymphomas.

Almost 50% of cutaneous B-cell lymphoproliferative infiltrates are derived from follicular center cells. Among these, about 25% show a rapidly progressive course, whereas about 75% account for flattening of the survival curve after about 7 years. This group is referred to as semimalignant ("pseudolymphomatous") cutaneous B-cell lymphoma (SM-CBCL). Clinical, histologic, and phenotypical criteria for their differentiation from B-cell pseudolymphoma and from CBCL have been investigated in 60 patients (11 CBCL, 30 SM-CBCL, 19 PSL). Semimalignant CBCL are different from malignant CBCL because they do not tend to disseminate to extracutaneous sites or to transform into high-grade malignant blast-type lymphomas; follicular center cell formation with CD21 positive dendritic reticulum cells is usually present; and normal survival time is not affected. On the other hand, SM-CBCL differ from PSL in that complete cure of the usually multiple and disseminated skin manifestations is not possible and that follicular center formation and the network of CD21-positive cells in conjunction with a kappa or lambda light chain restriction of cellular surface immunoglobulins is seen. If these and other criteria are taken together, differentiation of these various nosologic entities demanding different therapeutic approaches can be achieved with significant reliability.

Adolescent↗

PubMed1993

Liposomes for atopic dry skin: the rationale for a promising approach.

Atopic dry skin characterized by a defect of the barrier function as determined by transepidermal water-loss measurements at the ultrastructural level shows an increase in membrane-coating granules (MCGs). MCGs are lamellar, ovoid organelles appearing in the stratum spinosum and stratum granulosum. MCGs consist of stacks of small parallel disks that are extruded and fuse to continuous lamellae. Liposomes, i.e., unior multilamellar vesicles composed of alternating lipid and water phases are structurally similar. Moreover, they also can form continuous lamellae. While phospholipids are generally used for liposome production, skin lipids and in particular ceramides can also be used. These lipids also seem to be the major components of MCGs. Hence, it seems advisable to use liposomes made of such lipids in the treatment of atopic dry skin. Apart from the probable inherent effect liposomes of this type may also apply particularly well for the delivery of active components.

Body Water↗

PubMedDate not supplied

Evidence for the phagocytosis of intact oligolamellar liposomes by human keratinocytes in vitro and consecutive intracellular disintegration.

While there is evidence for the use of liposomes as drug carriers upon topical application to the skin, the underlying mechanisms are far from being clear. Therefore human keratinocytes grown in vitro were exposed to large oligolamellar liposomes. After attachment and invagination these particles can be found unchanged within the cytoplasm both inside and outside of lysosomes. If incorporated into lysosomes the structural lipids can be disintegrated and spread within the entire phagolysosome. Gold labeling adds further to the hypothesis of intact uptake of liposomes by the living cells of the human epidermis.

Cells, Cultured↗

PubMedDate not supplied

Pyoderma gangrenosum associated with the secondary antiphospholipid syndrome.

A 64-year-old woman with an 11-year history of systemic lupus erythematosus and amputation of her left lower leg as a consequence of arterial embolism, presented with two large, non-healing ulcers on her right shank. Pyoderma gangrenosum associated with secondary antiphospholipid syndrome was diagnosed based upon the typical clinical features and increased antibodies to cardiolipin. Although an aggressive therapy with corticosteroids and cyclosporine was started, her condition continued to worsen. She finally died as a result of sepsis. We discuss the difficulties in diagnosis and therapy of SLE combined with the antiphospholipid syndrome and pyoderma gangrenosum.

Adrenal Cortex Hormones↗