Monika Gniadecka

Removal of dermal edema with class I and II compression stockings in patients with lipodermatosclerosis

BACKGROUND Lipodermatosclerosis is a sequela of deep venous insufficiency and a risk factor for the occurrence of venous leg ulceration. Medical compression stockings facilitate leg ulcer healing and prevent occurrence of ulcers resulting from removal of edema. Although the exact level of compression necessary for removal of dermal edema in patients with deep venous insufficiency has not been established, garments providing high compressive values of 30 to 40 mm Hg have been recommended. Dermal edema can be visualized by high-frequency ultrasonography. OBJECTIVE We used ultrasound imaging to study whether a lower level of compression (class I 18 to 26 mm Hg vs class II 26 to 36 mm Hg) is effective in removal of dermal edema. This question is important because the use of hosiery with a lower compression class would enhance compliance and enable treatment of patients with mixed arteriovenous disease. METHODS In 11 patients skin images were obtained with 20 MHz ultrasound from the malleolar region in lipodermatosclerotic skin and corresponding normal skin of the contralateral leg. The ratio of low echogenic pixel number to total pixel number (LEP/TP), which correlates with dermal water, was measured before and after 5 days of applied compression in two treatment courses where classes of compression were switched randomly. Ankle circumference was also measured. RESULTS We found that LEP/TP was 33% higher in lipodermatosclerotic skin than in the matched normal skin indicating presence of skin edema. Application of class I and II compressive hosiery resulted in LEP/TP decrease by 17% (95% confidence interval, 0.07 to 0.26) and 14% (95% confidence interval, 0.04 to 0.21), respectively, suggestive of dermal edema reduction. No statistically significant difference in efficacy of dermal edema removal between class I and II was found. No changes in ankle circumference after application of both classes of compression was observed. CONCLUSION Application of light and moderate compression results in a partial edema removal from the dermis in lipodermatosclerosis in the absence of measurable reduction in leg circumference. Class I compression is as effective as class II for elimination of dermal edema. These data indicate that light compression may be a useful modality for patients with deep venous insufficiency and lipodermatosclerosis who are not eligible for treatment with garments having higher compressive forces.

NEAR-INFRARED FOURIER TRANSFORM RAMAN SPECTROSCOPY OF THE MUMMIFIED SKIN OF THE ALPINE ICEMAN, QILAKITSOQ GREENLAND MUMMIES AND CHIRIBAYA MUMMIES FROM PERU

Near-infrared Fourier transform (NIR-FT) Raman spectroscopy was employed to compare archaeological skin samples of a late Neolithic man (5200 BP) preserved in a glacial field in the Alps (the Iceman), skin of fifteenth century mummies preserved at low temperature and dry air in stone graves in Qilakitsoq, Greenland, and skin samples from mummified bodies from the Chiribaya culture from the Southern Peruvian desert (1000 BP). In all the spectra of mummified skin, a progressive loss of protein amide I (1640–1680 cm−1) and amide III (1220–1290 cm−1) band intensities was found, indicating either loss of protein or changes in the secondary protein structure. Thus, the observed changes or degradation in protein structure in the samples of the 500-year-old skin of the Qilakitsoq mummy and the 1000-year-old skin of Chiribaya mummies have been observed to be broadly similar to those found in the 5200-year-old Iceman. This implies that most changes in the molecular structure of the skin take place in a relatively short time interval during the natural mummification process. The spectra of lightly pigmented Peruvian mummies showed a relatively strong peak near 1300 cm−1 and an increased intensity of the ν(CH) peak at 2850 cm−1. The band near 1300 cm−1 is characteristic of twisting and wagging CH2 vibrations in lipids and the 2850 cm−1 band represents lipid CH stretching vibrations. These spectral changes suggest an increased lipid content in lightly pigmented Peruvian mummy skin compared with contemporary skin and the skin of the mummies preserved in ice. We ascribe this increased lipid intensity in the skin of the Peruvian mummies to embalming, by which means a better preservation is achieved. In conclusion, NIR-FT-Raman spectroscopy has potential use for the non-destructive chemical analysis of archaeological biomaterial. By using this technique it is possible to assess the degree of protein degradation and also to provide an analysis of embalming materials employed for the mummification processes. Copyright

Fourier Transform Raman Spectroscopy of 15th Century Mummies from Qilakitsoq, Greenland

To investigate molecular changes in mummified skin, near-infrared Raman spectroscopy was applied to the skin obtained from four mummies found in Qilakitsoq in Greenland. The mummies date from AD 1475 (±50 years) and are the oldest preserved bodies in the Arctic region. The spectra of the skin obtained from the different mummies were very similar, but they were distinctly different from those of fresh and freeze-dried contemporary skin. Especially in the spectra of the ancient skin the amide I (1640–1680 cm-1) and amide III (1220–1300 cm-1) bands had very low intensity, indicating loss of protein and/or changes in the secondary protein structure. Similar spectral changes have previously been found in the 5200-year-old skin of the Iceman. This may suggest that most changes in molecular structure take place in a relatively short time after mummification.

Potential for high-frequency ultrasonography, nuclear magnetic resonance, and Raman spectroscopy for skin studies.

N THE PAST 20 years non-invasive measurements of I skin have been expanding. More and more methods are available and it is nowadays quite difficult to have an overview of all of them. This paper is an attempt to discuss the potential of just a few methods with which the author has most experience: skin ultrasonography, nuclear magnetic resonance (NMR), and Raman spectroscopy. These methods are complementary to each other and offer a unique possibility of studying specific phenomena in intact skin (Table 1).

Non-invasive methods for determination of oedema and water behaviour in the skin.

Background/Aim: In an accompanying review, Mani and coworkers discuss methods for measurement of global oedema of the limb. Here, we have concentrated on methodology enabling investigation of oedema and water compartment selectively in the skin and its layers. Results of the studies with magnetic resonance and ultrasound based methods are reviewed.

Water structure and water/protein interactions in biological materials characterized by Raman spectroscopy

The R(v)-representation of the low-frequency Raman spectrum was used to investigate the low-frequency Raman spectrum of water. The advantages of using reduced representations in low-frequency Raman studies to display water structure are discussed. Tetrahedrically hydrogen bonded water molecules showed a characteristic low-frequency band with a peak maximum around 180 cm-1. O-18 and O-17 isotopic substitution revealed that the corresponding vibrational mode mainly involves displacements of the oxygen atoms, but no significant hydrogen motion. This mode can be used to monitor the existence of water with a bulk-like structure in biological macromolecular materials. To test its applicability NIR-FT-Raman spectroscopy was used in studies of biopolymers in order to avoid fluorescence.

CaF2:Dy and CaF2 crystal‐based UV dosimeters

Background/aims: Monitoring of ultraviolet (UV) exposure in humans is important, since UV has been implicated in the pathogenesis of skin cancer, skin ageing and immunosuppression. Biological and physical dosimeters are being developed to measure occupational and environmental UV radiation exposure. We studied the UV‐dependent thermoluminescence in CaF2:Dy and CaF2 crystals and report on the development of a small personal UV dosimeter based on the thermoluminescent phenomenon.

Electronic UV dosimeters

Background/aims: The pathogenic role of ultraviolet (UV) in the development of skin cancer, skin ageing and immunosuppression makes it important to monitor human exposure to UV radiation. In a previous study we constructed UVB and UVC dosimeters based on a thermoluminescent phenomenon induced by UV in CaF2:Dy and CaF2 crystals. However, these dosimeters were insensitive to UVA radiation and readout was time‐consuming. In the present study we aimed to develop an electronic dosimeter suitable for UVA, UVB and UVC. The principle of this dosimeter is a measure of accumulated electric current induced by UV on a photodetector.

Studies of Water Structure by Low-Frequency Raman Spectroscopy

In a recent minireview with the title “Water: now you see it, now you don’t” Levitt and Park [1] ask four general questions about water molecules interacting with proteins. Where are they? How long do they stay there? How strongly do they interact with the protein? How do they affect protein structure and stability? They mention also the three key techniques of modern structural research: crystallography, NMR spectroscopy, and computer methods. These methods are certainly important, but also other methods like IR and Raman spectroscopy, inelastic neutron scattering and time domain experiments by femtosecond laser pulses can contribute to structural studies of the biological solvent water and its interaction with biomolecules. Water absorbs very strongly in the IR spectrum, making the study of aqueous solutions difficult. Raman spectroscopy is more suited because the Raman signals from water are rather weak. The present investigation deals with the low-frequency Raman spectrum below 400 cm−1 of water in lysozyme, and water in human skin samples.

Low-wavenumber NIR-FT-Raman studies of water structure in human and animal skin: biomedical aspects

This contribution reports on experimental studies of water in human and animal skin by low-wavenumber Raman scattering. The water structure is related to human skin diseases. A comparison is performed between the water structure in human normal skin and animal skin used as a model for human skin in biomedical applications. Water is a major constituent of all living systems. Human skin contains around 70% of water. In healthy skin most of the water molecules are bound to biological macromolecules and a water structure like the one in pure liquid water is not present. It is not easy to distinguish between a liquid like water structure and water bound to biomolecules, because individual water molecules take part in a dynamical exchange of hydrogen atoms from one molecule to another and water molecules are exchanged between different sites. This problem has been excellently stated in the mini review by Lewitt and Park [1] “Water: now you see it, now you don’t”. They ask four general questions about water molecules interacting with proteins: (1) where are they? (2) How long do they stay there? (3) How strongly do they interact with the protein? (4) How do they affect protein structure and stability? Lewitt and Park [1] mention that three key techniques of modern structural research are: crystallography, NMR-spectroscopy and computer modeling. Advantages by these methods are that structural information is directly obtained. However, none of these methods can easily be applied to structural studies of water in skin samples. Raman spectroscopy with cw-laser excitation reflects the dynamics on a pico-second time scale and faster. Thus Raman spectroscopy gives a snapshot of the interacting water/biomolecule system. The water stretching and bending vibrations are only slightly perturbed by differences in water hydrogen bonding. The low-wavenumber region is much more sensitive, because this part of the spectrum depends directly on the intermolecular hydrogen bonds. However, Rayleigh scattering yields a very intense band extending to Raman shifts of several hundred wavenumbers (cm). This band tends to hide weaker bands from intermolecular water vibrations. By use of the so-called R( ν )-representation the band due to Rayleigh scattering is converted to a plateau, and weak vibrational features of water below 400 cm are more easily seen [2-5]. H-, Oand Oisotopic substitution in water showed that a band with a maximum around 180 cm in the R( ν )representation was caused solely by oxygen displacements [2,4]. The hydrogen atoms in water are not involved in the vibrational mode for this band. Fig.1 illustrates potential energy curves for two different oxygen displacements. A water molecule with four neighbours (shown to the left in Fig.1) exhibits a vibrational motion. The corresponding band is observed at 180 cm in the R( ν )representation. With only three neighbours the potential changes as shown in the right part of Fig.