Stephan El Gammal

A model to assess the efficacy of moisturizers--the quantification of soap-induced xerosis by image analysis of adhesive-coated discs (D-Squames).

Clinical grading of dry skin syndromes (xerosis) is beset by many variables which limit its reliability. Removing scales onto adhesive coated discs (D‐Squames®) has provided a means for objective measurement of xerotic slates. Using image analysis we have modified the basic procedure to assure greater accuracy and reproducibility. The distribution of grey values on the discs was determined, from which a single value of the degree of scaling was calculated. We term this the sealing index.

High Frequency Ultrasound for High Resolution Skin Imaging

High frequency and broadband ultrasound in the frequency range above 20 MHz is an efficient modality for the non invasive and high resolution imaging of skin structures and skin diseases like skin tumors and inflammatory processes. However, special system designs and signal processing strategies have to be applied to account for the strong and frequency dependent attenuation of high frequency ultrasound in tissue. In this paper the design of an ultrasound imaging system with a minimum spatial resolution of about 9 , utilizing the frequency range from 30 to 150 MHz, is presented. This system enables the high resolution visualization of the uppermost skin layers, which is of great interest in dermatology and cosmetics. To quantify the imaging properties of the system reference measurements were performed by imaging a glass plate and a wire phantom. Furthermore, image processing techniques for the analysis of three dimensional data sets were adapted to investigate the topology of skin structures like skin layers. Results from in vivo measurements on healthy skin and skin tumors are presented. Übersicht Hochfrequenter und breitbandiger Ultraschall im Frequenzbereich oberhalb von 20 MHz stellt eine leistungsfähige Modalität zur nichtinvasiven und hochauflösenden Abbildung von Hautstrukturen und Hauterkrankungen wie Hauttumoren und entzündlichen Prozessen dar. Es müssen jedoch spezielle Systemkonzepte und Signalverarbeitungstechniken angewandt werden, um der starken und frequenzabhängigen Dämpfung des hochfrequenten Ultraschalls im Gewebe Rechnung zu tragen. In dieser Arbeit wird der Entwurf eines Ultraschallabbildungssystems, das den Frequenzbereich von 30 bis 150 MHz nutzt, mit einer kleinsten räumlichen Auflösung von etwa 9 vorgestellt. Dieses System erlaubt die hochauflösende Darstellung der obersten Hautschichten, was von großem Interesse in der Dermatologie und der Kosmetik ist. Zur Quantifizierung der Abbildungseigenschaften des Systems wurden Referenzmessungen durch Abbildung einer Glasplatte und eines Drahtphantoms durchgeführt. Femer wurden Bildverarbeitungstechniken für die Analyse dreidimensionaler Datensätze adaptiert, um die Topologie von Hautstrukturen (Hautschichten, Haarfollikel) zu untersuchen. Es werden Ergebnisse von Messungen in vivo an gesunder Haut und an Hauttumoren vorgestellt. Für die Dokumentation Hochfrequenter Ultraschall / Ultraschallabbildung / Medizin / Dermatologie / Haut / B/D-scan

Wound healing and skin physiology

I. History of Wound Healing.- Theory and Practice of Wound Healing in the Past.- De rara medicatione vulnerum: An Historical Approach to Wound Care.- II. Morphology and Physiology.- Fetal Wound Repair.- Histological Examination of Skin Grafts.- Reepithelialisation of Wounds.- Pathophysiology of Wound Healing in Venous Leg Ulcers.- Collagen Metabolism and Wound Contraction.- The Role of the Connective Tissue Matrix in Wound Healing: Fibroblast and Collagen Interactions.- Modulation of Fibroblastic Cytoskeletal Features During Wound Healing and Fibrosis.- III. Microcirculation and Angiogenesis.- Measurement of Microcirculation.- Spatial Pattern of Cutaneous Perfusion in Wound Healing.- The Vascular Architecture of the Keloid: A Scanning Electron Microscope Study on Vascular Corrosion Casts.- Growth Factor Control of Wound Healing Angiogenesis.- Blood Flow in Ulcerated Tissue and Surrounding Skin: Healing Correlates with Return of the Venoarteriolar Reflex.- Three-Dimensional Reconstruction of Terminal Blood Spaces in the Proximal Tibia Metaphysis of the Growing Rat - A Model to Study Normal Angiogenesis.- IV. Biochemistry and Immunology.- Trace Elements in Normal and Impaired Wound Healing.- Plasmin-Mediated Pericellular Proteolysis by Keratinocytes: Extracellular Matrix Reorganisation vs Tissue Damage.- Reduced Migration Potential of Epithelial Cells from Explants of Chronic Decubitus Ulcers: The Cause of Impaired Wound Healing?.- Fibronectin and Its Role in Wound Healing.- Mechanisms of Action of Collagenase in Wound Repair.- Studies of Growth Factor and Matrix Proteinase Activities During Early Stages of Wound Healing.- Regulatory Aspects of Collagen Synthesis in Fibroblasts from Human Colon and Skin.- Platelet Released Factors Stimulate Rat Burn Wound Contraction.- V. Experimental Studies.- Biologic Activity of Tissue Flaps in the Treatment of Complicated Wounds.- Studies on Wound Healing in Axial Pattern Flaps of the Diabetic Rat.- Endogenous Growth Factor Pathways May Regulate Epidermal Hyperplasia in Chronic Venous Wounds: Modulation by Hydrocolloid Dressings.- Immunohistochemical Effect of a Hydrocolloid Occlusive Dressing (DuoDERM E) in Psoriasis Vulgaris.- The Treatment of Malum Perforans Pedis: Operative and Conservative Therapy.- Phosphocreatine Ameliorates Structural Integrity of Ischemic Skin Flaps.- Granulocyte Activity Is Enhanced by Culture Supernatants of Mononuclear Leukocytes Incubated with Tetrachlorodecaoxide.- Skin Reactions and Sensations Induced by Intradermal Injection of Substance P into Compound 48/80 Pretreated Skin.- Effect of Wound Fluid on Cultured Keratinocytes.- Strategies of Keratinocytes and Fibroblasts in Wound Closure Observed in an In Vitro Model.- Interleukin-2 Improves Transfusion-Suppressed Repair of Experimental Intestinal Anastomoses.- Neuropeptides and Merkel Cells in Tissue Expansion.- Congenital Factor XIII Deficiency as Cause of Therapy-Resistant Burn Wounds.- VI. Microbiology and Wound Infection.- The Microbiology of Wounds.- Pathogenesis of Wound Infections.- Interaction of Bacteria with Host Defence Cells: Mechanisms of Burn Wound Sepsis.- Streptococcus pyogenes Induced Necrosis and Ulcers of the Skin: The Possible Role of Streptococal Exotoxins.- Inhibition of Wound Healing by Topical Anti-microbial Agents.- Intra-arterial Application of Ceftizoxime Supports Wound Healing in Infected Ischemic Lesions of the Limbs.- VII. Noninvasive Measurement Techniques.- Noninvasive Measurement of Wound Healing of the Skin.- Computerized Wound Analysis - A New Method for Assessment of Healing.- A Color Image Analysis System (CD-CWA) for the Quantification of Wound Healing in Multicenter Trials.- Noninvasive Assessment of the Physical Properties of the Skin.- Noninvasive Evaluation of Skin Barrier Function.- A Cellstick Device for Wound Healing Research.- High-Resolution Ultrasound Imaging of Various Types of Wounds.- A 20 MHz Ultrasound Examination of Lipodermatosclerosis.- Physiological Changes in Aging Skin.- Diagnosis and Treatment of Venous Diseases and Leg Ulcer.- VIII. Surgery and Physical Therapy of Wounds.- Wound Healing in Oncologic Dermatosurgery.- Treatment of Keloids and Hypertrophic Scars with Cryosurgery and Silicon Gel Sheeting.- Surgery of Venous Leg Ulcers.- Treatment of Venous Leg Ulcers with a Soft Laser Light.- IX. Dressings and Agents Promoting Wound Healing.- Dressings as a New Concept for Topical Treatment of Ulcers.- The Effect of Allopurinol on Wound Contraction and Granulation Tissue Formation in the Rat.- Effects of Pale Ichthyol in a Model of Impaired Wound Healing.- Pretreatment of Photodamaged Forearm Skin with Topical Tretinoin Accelerates Healing of Full-Thickness Wounds.- Treatment of Chronic Wounds with Cultured Keratinocytes.- Influence of Agents Used for Topical Wound Treatment on Phagocyte Stimulation and Fibroblast Growth.- Both Wet and Moist Wound Environments Accelerate Cutaneous Healing.- Comparative Experimental Study on the Treatment of Open Wounds.- Comparison of Varihesive E with the Conventional Tulle Gras Dressing in Skin Graft Donor Sites Treatment of Infants.- Hydrocolloid Dressings in the Therapy of Cryolesions.- Treatment of Venous Leg Ulcers Using Occlusive Hydrocolloid Dressings (Varihesive E) Versus Conventional Phase-Adapted Wound Dressing.- Weekly treatment of Psoriatic Plaques with the Hydrocolloid Dressing DuoDERM E in Combination with Triamcinolone Acetonide.- Covering Tattoo Dermabrasion Wounds with a Hydrocolloid Dressing (Varihesive E).- A Prospective Randomized Study of the Efficacy of Hydrogel, Hydrocolloid, and Saline Moistened Dressings on the Management of Pressure Ulcers.- Pericapillary Fibrin in Venous Ulcers Treated with Hydrocolloid Dressings.

Bildgebende Verfahren in der Dermatologie

Die hochfrequente Sonographie (> 20MHz) wird zur Bestimmung der raumlichen lateralen Ausdehnung und Tiefenausdehnung von Hautveranderungen verwendet. Echoreflexe entstehen im Wesentlichen an Gewebsgrenzen unterschiedlicher Impedanz und durch Gewebsinhomogenitaten. Aufgrund der Schallkopfgeometrie und der Physik entstehen verschiedene Bildartefakte, die bei Unkenntnis zu Fehlinterpretationen fuhren konnen. Ziel muss es deshalb sein, diese Artefakte als solche zu erkennen.

B—Scan—Sonography in Dermatological Routine Diagnostics

In dermatological routine diagnostics, as yet, only few technical procedures have been made available to support macroscopic diagnostics. Conventional sonographical instruments have not been suitable for this purpose, since they are of too low resolution or are producing only a one-dimensional amplitude image of reflecting signals. Only recently high-frequent ultrasound imaging systems with sufficient axial and lateral resolution as well as the possibility of a two-dimensional image display have been made available.

Sonography of the Skin

Sonography is the oldest noninvasive cross-sectional method to study the skin. Due to technical improvements and advances in signal and image processing in the past 30 years, high-resolution sonography has become a routine diagnostic tool in dermatology.

Hochfrequente Sonographie in der dermatologischen Onkologie

Moderne bildgebende Verfahren hatten in der Dermatologie lange Zeit eine nur untergeordnete Bedeutung. Dies mag in der Tatsache begrundet sein, das die Haut den Sinnesorganen des Untersuchers frei zuganglich ist und somit die Notwendigkeit fehlte, aufwendige Hilfsmittel zu deren Untersuchung zu verwenden. Die Erfolge nichtinvasiver bildgebender Methoden in anderen Fachgebieten der Medizin weckten schlieslich das Interesse, diese Diagnostikverfahren auch fur die Haut und deren pathologische Veranderungen einzusetzen. Im Bereich der Dermatoonkologie interessierten v. a. die Erhohung der diagnostischen Treffsicherheit sowie die Verbesserung der Therapieplanung bei Hautmalignomen. Insbesondere durch die in den letzten Jahrzehnten ansteigenden Erkrankungszahlen an bosartigen Hauttumoren wurde diese Entwicklung vorangetrieben [81], Eines der wichtigsten neueren Verfahren unter den nichtinvasiven Methoden ist die hochfrequente Sonographie der Haut.