Georgios Stamatas - Academia.edu (original) (raw)

Papers by Georgios Stamatas

Research paper thumbnail of Visual versus spectroscopic analysis of skin color reactions: separation of contributing chromophores

Skin reactions to stimuli such as UV irradiation include vascular changes and stimulation of mela... more Skin reactions to stimuli such as UV irradiation include vascular changes and stimulation of melanin production. Both reactions alter the color appearance of the skin. Skin color reactions were evaluated visually by a trained dermatologist and using a diffuse reflectance spectrometer in the visible range. Our results provide strong evidence that mixed vascular and pigment reactions cannot be visually separated.

Research paper thumbnail of Infant stratum corneum water content

International Journal of Cosmetic Science

Research paper thumbnail of Age and body site effects on the stratum corneum lipid composition

International Journal of Cosmetic Science

Research paper thumbnail of Objective evaluation of feature orientation in a two-dimensional image - Applications on skin imaging

Biophotonics 2007: Optics in Life Science, 2007

Research paper thumbnail of The Structural and Functional Development of Skin During the First Year of Life: Investigations Using Non-invasive Methods

Textbook of Aging Skin, 2010

ABSTRACT

Research paper thumbnail of Update on Infant Skin with Special Focus on Dryness and the Impact of Moisturizers

Treatment of Dry Skin Syndrome, 2012

ABSTRACT

Research paper thumbnail of Spectroscopic Techniques in Dermatokinetic Studies

Dermatokinetics of Therapeutic Agents, 2011

Research paper thumbnail of Mineral Oil in Skin Care: Safety Profile

Lipids and Skin Health, 2014

Research paper thumbnail of Photobiology of Infant Skin

Research paper thumbnail of Soy Application for Daily Defense Against Sun Irradiation

Research paper thumbnail of Formulating for the Unique Needs of Baby Skin

Research paper thumbnail of Modern Technology for Imaging and Evaluation of Acne Lesions

Pathogenesis and Treatment of Acne and Rosacea, 2014

Research paper thumbnail of Skin Barrier Impairment in Diaper Dermatitis Measured In Vivo

Purpose: - Diaper dermatitis is a common infant skin condition. Skin irritation in diaper dermati... more Purpose: - Diaper dermatitis is a common infant skin condition. Skin irritation in diaper dermatitis is thought to be a direct result of the impairment in skin barrier due to the conditions of the diapered skin including occlusion, moisture, friction, and alkaline skin pH that favors proteolytic enzyme activity. The purpose of this study was to build on the current understanding of diaper dermatitis and to define non-invasive measurable parameters that relate to the pathophysiology of this skin condition. Methods: - The study protocol was approved by an IRB committee. Sixteen infants were recruited with mild or moderate diaper dermatitis and twenty infants without any clinical skin symptoms as controls. All infants were 3-24 months of age and informed consent was obtained from their primary care givers. The skin sites examined with non-invasive bioinstrumentation were: a) a control non-irritated site outside of the diaper (upper thigh), b) a control non-irritated site on the buttock...

Research paper thumbnail of Keeping Infant Skin Healthy through Proper Cleansing

Keeping the skin clean is essential to the overall good health of an individual. This statement i... more Keeping the skin clean is essential to the overall good health of an individual. This statement is even more relevant in the case of infants, since infant skin structure, function, and composition are still developing, underscoring the need for special care. Skin cleansing essentially means removing unwanted substances, including irritants from sources such as saliva, nasal secretions, urine, feces, and dirt. These irritants include salts, lipolytic and proteolytic enzymes, infectious microbial species, as well as potential allergens. Keeping the diaper area clean helps prevent skin barrier breakdown and therefore rash (diaper dermatitis) and infection (candidiasis). Keeping hands clean, particularly in the case of babies with their hand-to-mouth behaviors, can help reduce or prevent oral transmission of microbial contaminants. Special attention should also be paid to the facial area, where vulnerable skin can be irritated by milk, saliva, and nasal mucosa, all of which have high pH...

Research paper thumbnail of Geometrical and topological analysis of in vivo confocal microscopy images reveals dynamic maturation of epidermal structures during the first years of life

Journal of biomedical optics, 2015

Reflectance confocal microscopy is successfully used in infant skin research. Infant skin structu... more Reflectance confocal microscopy is successfully used in infant skin research. Infant skin structure, function, and composition are undergoing a maturation process. We aimed to uncover how the epidermal architecture and cellular topology change with time. Images were collected from three age groups of healthy infants between one and four years of age and adults. Cell centers were manually identified on the images at the stratum granulosum (SG) and stratum spinosum (SS) levels. Voronoi diagrams were used to calculate geometrical and topological parameters. Infant cell density is higher than that of adults and decreases with age. Projected cell area, cell perimeter, and average distance to the nearest neighbors increase with age but do so distinctly between the two layers. Structural entropy is different between the two strata, but remains constant with time. For all ages and layers, the distribution of the number of nearest neighbors is typical of a cooperator network architecture. Th...

Research paper thumbnail of Multicellular agent-based modeling and simulation of stratum corneum maturation, morphology and turnover

International Journal of Cosmetic Science

Research paper thumbnail of Development of a Non-Invasive Optical Method for Assessment of Skin Barrier to External Penetration

Biomedical Optics and 3-D Imaging, 2012

ABSTRACT Confocal Raman Microspectroscopy was used to compute the concentration profiles of topic... more ABSTRACT Confocal Raman Microspectroscopy was used to compute the concentration profiles of topically applied caffeine through the skin. Parameters relating to the skin barrier function were calculated from the caffeine concentration profiles.

Research paper thumbnail of Infant skin physiology and development during the first years of life: a review of recent findings based on in vivo studies

International journal of cosmetic science, 2011

Infant skin is often presented as the cosmetic ideal for adults. However, compared to adult skin ... more Infant skin is often presented as the cosmetic ideal for adults. However, compared to adult skin it seems to be more prone to develop certain pathological conditions, such as atopic dermatitis and irritant contact dermatitis. Therefore, understanding the physiology of healthy infant skin as a point of reference is of interest both from the cosmetic as well as from the clinical point of view. Clinical research on healthy infants is, however, limited because of ethical considerations of using invasive methods and therefore until recently data has been scarce. Technical innovations and the availability of non-invasive in vivo techniques, such as evaporimetry, electrical impedance measurement, in vivo video and confocal microscopy, and in vivo fibre-optic based spectroscopy, opened up the field of in vivo infant skin physiology research. Studies incorporating such methods have demonstrated that compared to adult, infant skin continues to develop during the first years of life. Specifica...

Research paper thumbnail of Optical non-invasive approaches to diagnosis of skin diseases

The journal of investigative dermatology. Symposium proceedings / the Society for Investigative Dermatology, Inc. [and] European Society for Dermatological Research, 2002

A number of noninvasive approaches have been developed over the years to provide objective evalua... more A number of noninvasive approaches have been developed over the years to provide objective evaluation of the skin both in health and in disease. The advent of computers, as well as of lasers and photonics, has made it possible to develop additional techniques that were impossible a few years ago. These approaches provide the dermatologist with sensitive tools to measure the skin's condition in terms of physiologic parameters (e.g., color, erythema and pigmentation, induration, sebaceous and stratum corneum lipids, barrier function, etc.). Yet, a typical dermatologic diagnosis relies primarily on the trained eyes of the physician and to a lesser extent on information from other senses, such as touch and smell. The trained senses of the dermatologist backed by his/her brain form a powerful set of tools for evaluating the skin. The golden rule in diagnosis remains the histologic examination of a skin biopsy, a rather invasive method. These tools have served the profession well. The...

Research paper thumbnail of The Infant Skin Barrier: Can We Preserve, Protect, and Enhance the Barrier?

Dermatology Research and Practice, 2012

Infant skin is different from adult in structure, function, and composition. Despite these differ... more Infant skin is different from adult in structure, function, and composition. Despite these differences, the skin barrier is competent at birth in healthy, full-term neonates. The primary focus of this paper is on the developing skin barrier in healthy, full-term neonates and infants. Additionally, a brief discussion of the properties of the skin barrier in premature neonates and infants with abnormal skin conditions (i.e., atopic dermatitis and eczema) is included. As infant skin continues to mature through the first years of life, it is important that skin care products (e.g., cleansers and emollients) are formulated appropriately. Ideally, products that are used on infants should not interfere with skin surface pH or perturb the skin barrier. For cleansers, this can be achieved by choosing the right type of surfactant, by blending surfactants, or by blending hydrophobically-modified polymers (HMPs) with surfactants to increase product mildness. Similarly, choosing the right type of oil for emollients is important. Unlike some vegetable oils, mineral oil is more stable and is not subject to oxidation and hydrolysis. Although emollients can improve the skin barrier, more studies are needed to determine the potential long-term benefits of using emollients on healthy, full-term neonates and infants.

Research paper thumbnail of Visual versus spectroscopic analysis of skin color reactions: separation of contributing chromophores

Skin reactions to stimuli such as UV irradiation include vascular changes and stimulation of mela... more Skin reactions to stimuli such as UV irradiation include vascular changes and stimulation of melanin production. Both reactions alter the color appearance of the skin. Skin color reactions were evaluated visually by a trained dermatologist and using a diffuse reflectance spectrometer in the visible range. Our results provide strong evidence that mixed vascular and pigment reactions cannot be visually separated.

Research paper thumbnail of Infant stratum corneum water content

International Journal of Cosmetic Science

Research paper thumbnail of Age and body site effects on the stratum corneum lipid composition

International Journal of Cosmetic Science

Research paper thumbnail of Objective evaluation of feature orientation in a two-dimensional image - Applications on skin imaging

Biophotonics 2007: Optics in Life Science, 2007

Research paper thumbnail of The Structural and Functional Development of Skin During the First Year of Life: Investigations Using Non-invasive Methods

Textbook of Aging Skin, 2010

ABSTRACT

Research paper thumbnail of Update on Infant Skin with Special Focus on Dryness and the Impact of Moisturizers

Treatment of Dry Skin Syndrome, 2012

ABSTRACT

Research paper thumbnail of Spectroscopic Techniques in Dermatokinetic Studies

Dermatokinetics of Therapeutic Agents, 2011

Research paper thumbnail of Mineral Oil in Skin Care: Safety Profile

Lipids and Skin Health, 2014

Research paper thumbnail of Photobiology of Infant Skin

Research paper thumbnail of Soy Application for Daily Defense Against Sun Irradiation

Research paper thumbnail of Formulating for the Unique Needs of Baby Skin

Research paper thumbnail of Modern Technology for Imaging and Evaluation of Acne Lesions

Pathogenesis and Treatment of Acne and Rosacea, 2014

Research paper thumbnail of Skin Barrier Impairment in Diaper Dermatitis Measured In Vivo

Purpose: - Diaper dermatitis is a common infant skin condition. Skin irritation in diaper dermati... more Purpose: - Diaper dermatitis is a common infant skin condition. Skin irritation in diaper dermatitis is thought to be a direct result of the impairment in skin barrier due to the conditions of the diapered skin including occlusion, moisture, friction, and alkaline skin pH that favors proteolytic enzyme activity. The purpose of this study was to build on the current understanding of diaper dermatitis and to define non-invasive measurable parameters that relate to the pathophysiology of this skin condition. Methods: - The study protocol was approved by an IRB committee. Sixteen infants were recruited with mild or moderate diaper dermatitis and twenty infants without any clinical skin symptoms as controls. All infants were 3-24 months of age and informed consent was obtained from their primary care givers. The skin sites examined with non-invasive bioinstrumentation were: a) a control non-irritated site outside of the diaper (upper thigh), b) a control non-irritated site on the buttock...

Research paper thumbnail of Keeping Infant Skin Healthy through Proper Cleansing

Keeping the skin clean is essential to the overall good health of an individual. This statement i... more Keeping the skin clean is essential to the overall good health of an individual. This statement is even more relevant in the case of infants, since infant skin structure, function, and composition are still developing, underscoring the need for special care. Skin cleansing essentially means removing unwanted substances, including irritants from sources such as saliva, nasal secretions, urine, feces, and dirt. These irritants include salts, lipolytic and proteolytic enzymes, infectious microbial species, as well as potential allergens. Keeping the diaper area clean helps prevent skin barrier breakdown and therefore rash (diaper dermatitis) and infection (candidiasis). Keeping hands clean, particularly in the case of babies with their hand-to-mouth behaviors, can help reduce or prevent oral transmission of microbial contaminants. Special attention should also be paid to the facial area, where vulnerable skin can be irritated by milk, saliva, and nasal mucosa, all of which have high pH...

Research paper thumbnail of Geometrical and topological analysis of in vivo confocal microscopy images reveals dynamic maturation of epidermal structures during the first years of life

Journal of biomedical optics, 2015

Reflectance confocal microscopy is successfully used in infant skin research. Infant skin structu... more Reflectance confocal microscopy is successfully used in infant skin research. Infant skin structure, function, and composition are undergoing a maturation process. We aimed to uncover how the epidermal architecture and cellular topology change with time. Images were collected from three age groups of healthy infants between one and four years of age and adults. Cell centers were manually identified on the images at the stratum granulosum (SG) and stratum spinosum (SS) levels. Voronoi diagrams were used to calculate geometrical and topological parameters. Infant cell density is higher than that of adults and decreases with age. Projected cell area, cell perimeter, and average distance to the nearest neighbors increase with age but do so distinctly between the two layers. Structural entropy is different between the two strata, but remains constant with time. For all ages and layers, the distribution of the number of nearest neighbors is typical of a cooperator network architecture. Th...

Research paper thumbnail of Multicellular agent-based modeling and simulation of stratum corneum maturation, morphology and turnover

International Journal of Cosmetic Science

Research paper thumbnail of Development of a Non-Invasive Optical Method for Assessment of Skin Barrier to External Penetration

Biomedical Optics and 3-D Imaging, 2012

ABSTRACT Confocal Raman Microspectroscopy was used to compute the concentration profiles of topic... more ABSTRACT Confocal Raman Microspectroscopy was used to compute the concentration profiles of topically applied caffeine through the skin. Parameters relating to the skin barrier function were calculated from the caffeine concentration profiles.

Research paper thumbnail of Infant skin physiology and development during the first years of life: a review of recent findings based on in vivo studies

International journal of cosmetic science, 2011

Infant skin is often presented as the cosmetic ideal for adults. However, compared to adult skin ... more Infant skin is often presented as the cosmetic ideal for adults. However, compared to adult skin it seems to be more prone to develop certain pathological conditions, such as atopic dermatitis and irritant contact dermatitis. Therefore, understanding the physiology of healthy infant skin as a point of reference is of interest both from the cosmetic as well as from the clinical point of view. Clinical research on healthy infants is, however, limited because of ethical considerations of using invasive methods and therefore until recently data has been scarce. Technical innovations and the availability of non-invasive in vivo techniques, such as evaporimetry, electrical impedance measurement, in vivo video and confocal microscopy, and in vivo fibre-optic based spectroscopy, opened up the field of in vivo infant skin physiology research. Studies incorporating such methods have demonstrated that compared to adult, infant skin continues to develop during the first years of life. Specifica...

Research paper thumbnail of Optical non-invasive approaches to diagnosis of skin diseases

The journal of investigative dermatology. Symposium proceedings / the Society for Investigative Dermatology, Inc. [and] European Society for Dermatological Research, 2002

A number of noninvasive approaches have been developed over the years to provide objective evalua... more A number of noninvasive approaches have been developed over the years to provide objective evaluation of the skin both in health and in disease. The advent of computers, as well as of lasers and photonics, has made it possible to develop additional techniques that were impossible a few years ago. These approaches provide the dermatologist with sensitive tools to measure the skin's condition in terms of physiologic parameters (e.g., color, erythema and pigmentation, induration, sebaceous and stratum corneum lipids, barrier function, etc.). Yet, a typical dermatologic diagnosis relies primarily on the trained eyes of the physician and to a lesser extent on information from other senses, such as touch and smell. The trained senses of the dermatologist backed by his/her brain form a powerful set of tools for evaluating the skin. The golden rule in diagnosis remains the histologic examination of a skin biopsy, a rather invasive method. These tools have served the profession well. The...

Research paper thumbnail of The Infant Skin Barrier: Can We Preserve, Protect, and Enhance the Barrier?

Dermatology Research and Practice, 2012

Infant skin is different from adult in structure, function, and composition. Despite these differ... more Infant skin is different from adult in structure, function, and composition. Despite these differences, the skin barrier is competent at birth in healthy, full-term neonates. The primary focus of this paper is on the developing skin barrier in healthy, full-term neonates and infants. Additionally, a brief discussion of the properties of the skin barrier in premature neonates and infants with abnormal skin conditions (i.e., atopic dermatitis and eczema) is included. As infant skin continues to mature through the first years of life, it is important that skin care products (e.g., cleansers and emollients) are formulated appropriately. Ideally, products that are used on infants should not interfere with skin surface pH or perturb the skin barrier. For cleansers, this can be achieved by choosing the right type of surfactant, by blending surfactants, or by blending hydrophobically-modified polymers (HMPs) with surfactants to increase product mildness. Similarly, choosing the right type of oil for emollients is important. Unlike some vegetable oils, mineral oil is more stable and is not subject to oxidation and hydrolysis. Although emollients can improve the skin barrier, more studies are needed to determine the potential long-term benefits of using emollients on healthy, full-term neonates and infants.