635 research outputs found
Clinical Applications of Scanning Electron Microscopy and Energy Dispersive X-Ray Analysis in Dermatology - An Up-Date
Dermatological papers comprising scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) analysis data published 1983 through 1986 in international journals are reviewed, as an update to our 1984 paper on Clinical applications of scanning electron microscopy and X-ray microanalysis in dermatology. The present paper not only deals with a review of recent publications in this area but also presents the application of microincineration to hair and cryosectioned freeze-dried skin specimens. Examples of the increased contrast obtained in hair cross sections are presented and a discussion on the feasibility of microincineration at analysis of hair and skin cross sections is given.
Particle probe analysis (EDX: energy dispersive X-ray analysis and PMP: proton microprobe analysis) as applied to hair and skin samples are presented with stress put on the proton probe analysis. The complementarity of EDX and PMP is demonstrated and future applications are suggested
The Use of Scanning Electron Microscopy in the Analysis of Pathological Hairs
The potentials of the scanning electron microscope (SEM) have only to a certain degree been exploited in the study of pathological hair fibers. In this review brief viewpoints on aspects of preparation and interpretation are discussed. It is shown that SEM will reveal important facts on the morphology of pathological hairs is appropriate experiment are performed, such as forming a knot on the fiber. Such a simple experiment will provide information on the fiber cross section, and on the tensile strength of the cuticle and the fiber. Complementary methods for qualitative and quantitative analysis of pathological hair fibers are suggested
Particle Probe Analysis in the Study of Skin Physiology
The basic function of provide a barrier which the epidermis is will separate the body compartment from the environment thus protecting the organism from excessive loss of water and to hinder the entrance of noxious agents. A continuous renewal of the actual barrier makes it possible to fulfill these requirements. Using particle probe analysis, electron microprobe (EMP) and proton microprobe (PMP) analysis we have demonstrated the feasibility of these techniques in the study of skin physiology. The results reported here have been obtained on quench frozen skin specimens inertly prepared by cryotechniques to produce freeze-dried sections presenting cross sections of the skin. The distribution of Na and K is compatible with the idea that the Na/K pump of the cell membranes is dysfunctional above the basal cell layer. The phosphorus distribution over the epidermal cross section coincides with a previously shown phospholipid distribution. S and mass distributions correspond to the results of the keratin synthesis of the epidermis. Calcium displays a profile over the epidermis which is compatible with recent data obtained on the calcium dependence of the differentiation of epidermal cells in culture. Also this distribution corresponds to recent data obtained by histochemical methods at transmission electron microscope resolution. Zn and Fe have been shown to reside mainly in the basal cell layer of the normal epidermis but are found in high amounts in the outer cell layers of the epidermis in hyperproliferative paralesional psoriasis. The penetration of Ni and Cr (Cr2O72-) through human epidermis was studied in vitro and it was found necessary to employ the PMP for the analysis of these substances due to the low amounts present ( \u3c 100 ppm). It appears that chromate penetrates more readily than nickel at neutral pH
Quantitative and Computer Assisted Electron Microscopic and Microprobe Studies in Dermatology
Electron microscopes are not yet routine instruments in modern dermatological pathology even though they have provided detailed data about pathological changes in the skin for more than three decades. At present, dermatopathology is still dominated by light microscopy and especially so since the introduction of immunological techniques such as the use of monoclonal antibodies. These tools applied at electron microscopic resolution, however, may provide the ultimate identification of cells and subcellular components. In addition, electron microscopes have no peers in areas of quantitative investigation at subcellular levels, e.g. morphometry.
The electron microprobe provides a unique tool in elemental analysis and may be used for the analysis of conventonally prepared specimens when foreign matter, not soluble in water, is deposited in the tissue. On the other hand, with water soluble substances the technique is most effective when freeze sections are utilized.
This paper gives a selected review of the present day status of quantitative skin research as analysed with electron microscopy and the related technique of electron microprobe analysis
REPLICATION TECHNIQUES FOR DRY AND WET BIOLOGICAL SURFACES
Abstract This overview of replication techniques for light and electron microscopic applications gives a generalized background to past and current approaches. The silicone mould replication techniques, which have the great advantage of being applicable to dry as well as wet surfaces, have proven to be the most successful so far. They are discussed in some detail and a number of practical hints for a successful procedure are given. These techniques have a potential of use in material, biological and even in archaeological sciences, although so far such applications have not attracted much attention
Proton Induced X-Ray Emission Analysis of Biological Specimens - Past and Future
Proton induced X-ray emission (PIXE) analysis is a comparatively new member of the family of spectrographic methods. In the last decade PIXE techniques have been applied to biological problems with great success. This review gives a condensed presentation of recent developments in biological (medical, zoological, and botanical) applications of PIXE analysis with special focus on factors which commonly influence the results, such as calibration, contamination, and preparation. The great advantage of PIXE analysis in studying physiologically important trace elements such as Zn, Mg, Fe, and Cu is underlined. Elemental mapping not only allows quantitative elemental analysis, but can also demonstrate the important differences in the morphological distributions of elements by comparing normal and pathological tissue
Hereditary Hair Changes Revealed by Analysis of Single Hair Fibres by Scanning Electron Microscopy
In many disorders with a genetic background the sparsity of scalp hairs may deter the clinician from trying to extract information from single hair fibres. Presenting a number of diverse conditions, we propose to show that simple measures can be taken in the doctor\u27s office which makes single fibre analysis a useful tool for assessment of factors involved in genetic disorders including the integument and its appendages. The paper is focussed on the utilization of the scanning electron microscope with the goal of demonstrating that pertinent information can be gained where information from transmission electron microscopy and other techniques are not immediately available
Disturbance of resting behaviour of broilers under different environmental conditions
Resting behaviours make up a large part of the daily time budget of broilers. However, in intensive broiler production systems disruptions of resting behaviours occur, where resting individuals get disturbed by active individuals. Such interruptions of resting behaviour may negatively affect the welfare of the birds but also disturb important functions of sleep related for instance to restoration and growth. This study investigated if a lower stocking density or the provision of separate resting places in the form of elevated platforms would result in less disruption of resting patterns of fast-growing broilers. Three different treatments were used, one with an elevated platform, one with lowered stocking density and a control setting. A randomized block design was used, consisting of six blocks, giving six to eight replicates of each treatment. Depending on treatment, 422-497 broilers (Ross 308) were kept per pen. Data on duration of resting bouts, occurrence of disturbances and position in pen during resting were collected on days 20 and 34 of age. An overall effect of treatment x position was found on duration of resting bouts both during day (P < 0.01) and night (P < 0.001). When resting on platforms the duration of resting bouts during daytime was longer compared to when birds were resting in open areas in the control groups (P = 0.04). During night the duration of resting bouts on platforms was longer compared to duration of resting bouts at all other locations in all treatments. In addition, resting position also had an overall effect on proportion of disturbances during day (P = 0.0018) and night (P = 0.0225). Resting on platforms reduced the number of physical disturbances of resting chickens compared to open areas in the control group both during day (P adj < 0.001) and night (P adj = 0.01). Generally, the level of disturbances was high in all treatments, suggesting that birds experience disrupted rest. As rest and sleep are vital needs, it is a welfare concern that chickens negatively affect other individuals' resting behaviour. A separate resting place appears to reduce disturbances to some extent and thus potentially increases the welfare of broiler chickens. However, provision of platforms is not enough to prevent frequent disturbances of resting and it is concluded that additional changes in housing conditions of broiler chickens are needed to improve their rest and sleep
Interaction behaviours of warthogs (Phacochoerus africanus) with humans in Kenya
VÄrtsvin (Phacochoerus africanus) har en komplex beteenderepertoar. De vuxna individerna lever naturligt i matriarkala grupper och populationens dynamik pÄverkas av mÀnskliga aktiviteter. VÄrtsvin kommer i kontakt med mÀnniskor eftersom de föredrar mark som har blivit pÄverkad av mÀnniskor, exempelvis grÀsmattor eller rancher.
Utanför Masai Maras National Reserve, pÄ det stÀngslade Kichwa Tembo Lodge, lever en population halvvilda vÄrtsvin. MÄlet med den hÀr studien var att observera vÄrtsvinens beteende under interaktioner mellan vÄrtsvin och mÀnniskor samt att analysera inverkan av samexistensen mellan vÄrtsvin och mÀnniskor. Observationerna varade i tio dagar och endast vuxna individer observerades. Fokaldjursobservationer, dÀr en individ observerades Ät gÄngen, med intervallstudie med momentan registrering, dÀr ett beteende registrerades per minut, anvÀndes. Under pÄgÄende intervallstudie genomfördes en kontinuerlig studie, dÀr varje beteende registrerades varje gÄng det förekom, med fokaldjursobservation som registrerade interaktionsbeteenden.
Attacker mot mÀnniskor med definitionen fysisk kontakt eller försök till stÄngning förekom inte och beteendet som förekom till störst andel var att vÄrtsvinen inte visade nÄgon reaktion alls pÄ mÀnniskor inom en radie pÄ tre meter. Inga statistiska analyser var möjliga att göra eftersom det var för fÄ observationer registrerade.
Studiens metod var inte anvÀndbar för att besvara studiens syfte att analysera interaktioner mellan vÄrtsvin och mÀnniskor för olika kategorier vÄrtsvin och mÀnniskor, men den leder till diskussion. Suggorna försvarar sina kultingar mot hot och dynamiken i populationen Àr instabil under parningssÀsongen, vilket kan pÄverka vÄrtsvinens beteende under den specfika sÀsongen. TillgÀngligheten pÄ föda och skydd mot predatorer samt trygghet för parning och ungvÄrd pÄverkar vÄrtsvinens val av habitat. MÀnskliga aktiviteter pÄverkar djurs beteendeutveckling vilket resulterar i konsekvenser för bevarandet av arter.
Slutsatsen Ă€r att mer forskning Ă€r nödvĂ€ndig för att analysera beteenden under interaktioner mellan vilda djur och mĂ€nniskor för att förstĂ„ möjligheterna till samexistens med fĂ€rre konflikter.Warthogs (Phacochoerus africanus) have a complex behaviour repertoire. The adult individuals naturally live in matriarchal groups and the dynamics of the population is affected by human activities. The warthogs get in close contact to humans since they prefer land that has been affected by humans. Outside Masai Mara National Reserve, at the fenced Kichwa Tembo Lodge, lives a semi-wild population of warthogs. The aim of this study was to observe the warthogâs behaviour during interactions between warthogs and humans and to analyze the impact of the coexistence between warthogs and humans. The observations went on for ten days and only adult individuals were recorded. Instantaneous sampling with focal sampling was used for the most common behaviours simultaneously with continuous sampling that were used for interaction behaviours. Attacks on humans were absent and the most frequent behaviour was that warthogs did not show any reaction to humans within a radius of tre meters. No statistical analyses were possible because there were too few observations recorded. The method used was not useful for answering the aim of the study, but it leads to a lot of discussion. According to other studies sows defend their piglets against threaths and the dynamics of the group is unstable during the mating season, which could affect the behaviour of the warthogs during this season. The availability of food and safety from predators as well ass saftety for mating and rearing of young affects the use of habitat. Human activities affect the behaviour development of animals which results in consequences for the conservation of species. To conclude more scientific studies are needed to analyze behaviours during interactions between wildlife and humans to understand the possibilities of coexistence with less conflicts
Assessment of Qualitative and Quantitative Data from Pathological Hairs â A Critical Evaluation of Scanning Electron Microscope and Proton Induced X-Ray Emission Analyses
Analysis of single hair fibres in genetic disorders is a desirable complement to the clinical diagnosis. The scanning electron microscope (SEM) allows detailed study of the surface morphology of hair fibres which may explain some mechanical characteristics of the pathological hair. Quantitative elemental data may indicate biochemical or metabolic abnormalities.
In this preliminary study we assess the feasibility of combining SEM and proton induced X-ray emission (PIXE) analysis on single hair fibres from 12 cases of genetic disease influencing the integument status. We conclude that SEM is a valuable tool in the analysis of hair pathology. The macro-PIXE technique involves some methodological and technical problems which in many cases are likely to be solved by using a proton microbeam. However, this means that routine methods have to be abandoned and careful selection of the material for analysis is an imperative necessity
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