Quantitative X-ray microanalysis of skin. Particle probe evaluation of the skin barrier function.
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Animals↗
Biomedical subjects
B Forslind
Publications and source records attributed to B Forslind.
Assessment of qualitative and quantitative data from pathological hairs--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.
Adolescent↗
Particle probe analysis in the study of skin physiology.
The basic function of the epidermis is to provide a barrier which 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 fulfil 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.(ABSTRACT TRUNCATED AT 250 WORDS)
Cell Differentiation↗
Elemental content of anagen hairs in a normal Caucasian population studies with proton induced X-ray emission (PIXE).
The elemental content of anagen hair fibers in a Caucasian population of healthy females and males in the age range 10-69 years was performed to constitute a baseline for further studies of pathological conditions. Proton induced X-ray emission (PIXE) analyses were performed on single hair fibers in triplicate from 103 individuals in order to determine sulfur, zinc, calcium, and chlorine content. The hair fibers were all anagen hairs collected from a site little influenced by genetic and hormonal influences 1.5 cm above the right ear of the probands. An area 5-8 mm from the follicle bottom was chosen for the analysis in all cases to minimize effect of hair-do contamination. The average sulfur content was 0.049 g/g and the average zinc content 170 micrograms/g. These results were not significantly influenced by chloroform/ethanol rinsing before analysis. The calcium and chlorine contents were 330 micrograms/g and 0.0033 g/g respectively. The latter data are expected to be more seriously influenced by external factors (e.g., contamination) than sulfur and zinc. No correlation between elemental concentration and sex was found for sulfur and zinc in the present material. PIXE analysis of single hair fibers yields valuable information on the elemental composition of hair fibers and can be rapidly and efficiently performed after simple mounting procedures.
Adolescent↗
[The hair and hair growth--what is normal and what is pathological?].
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Alopecia↗
Elemental analysis of hair fibres using PIXE--a population study of sulphur and zinc content.
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Electron Probe Microanalysis↗
Quantitative correlative proton and electron microprobe analysis of biological specimens.
To investigate the possibility of quantitative correlative proton microprobe (PMP) and electron microprobe (EMP) analysis of biological soft tissue, model specimens were analyzed by both techniques. The specimens consisted of freeze-dried sections of gelatin containing known concentrations of nickel chloride. Both for PMP and for EMP, the signal was expressed as the ratio of the characteristic intensity and the continuum intensity in a peak-free region of the spectrum. With both techniques, calibration curves (signal versus known concentration) obtained, showed a deviation from linearity at high nickel concentrations. However, a linear relation (correlation coefficient 0.996) was obtained in a plot of EMP signal versus PMP signal. This indicates that quantitative correlative PMP and EMP analysis can be carried out by using the same standard for both analytical techniques.
Animals↗
X-ray microanalysis of psoriatic skin.
Electron probe x-ray microanalysis was used to study elemental distribution in uninvolved and involved skin from patients with psoriasis, and in skin from healthy controls. Significant differences were found between the involved and uninvolved psoriatic skin. In the involved skin, the concentrations of Mg, P, and K were higher in the stratum germinativum, spinosum, and granulosum, compared to the corresponding strata in uninvolved skin. Neither involved nor uninvolved psoriatic stratum germinativum differed markedly from nonpsoriatic control stratum germinativum. In uninvolved psoriatic skin only a lower level of K was noted. In comparison to uninvolved psoriatic skin, the elemental composition of the various strata of involved psoriatic skin shows a pattern typical for highly proliferative, nonneoplastic cells.
Adult↗
Spun glass hair: two cases investigated with SEM and TEM.
Two cases of spun glass hair have been investigated with SEM and TEM. The SEM studies confirm previous findings by other authors. The TEM investigations reveal a completely normal cross section appearance. These findings stress the need for investigation of the time sequence of the keratinization process of the different layers of the inner root sheath.
Child, Preschool↗
Ultrastructural studies on experimental hair infections in vitro caused by Trichophyton mentagrophytes and Trichophyton rubrum.
Experimental infections with Trichophyton mentagrophytes and Trichophyton rubrum were performed on human hair in vitro and studied by conventional light microscopy, scanning (SEM) and transmission (TEM) electron microscopy. The penetrations visible by light microscopy in hair infected with T. mentagrophytes appeared at SEM as disrupted surface areas with perforating holes. T. rubrum-infected hair displayed minute perforations and less conspicuous cuticular damages seen at SEM and TEM. In both organisms multiple tiny perforating holes were observed at SEM previously unnoticed in experimental hair infections. From a morphological point of view the differences between the fungi investigated in this experimental system seem to be more of a quantitative nature than involving different mechanisms of action.
Child, Preschool↗
Recent advances in X-ray microanalysis in dermatology.
Electron microprobe and proton microprobe X-ray analysis can be used in several areas of dermatological research. With a proton probe, the distribution of trace elements in human hair can be determined. In contrast to sulfur, which is homogeneously distributed, calcium, iron, and zinc appear to be non-homogeneously distributed over the hair cross-section. Electron microprobe analysis on freeze-dried cryosections of guinea-pig and human epidermis shows a marked gradient of Na, P and K over the stratum granulosum. In sections of freeze-substituted human skin this gradient is less steep. This difference is likely to be due to a decrease in water content of the epidermis towards the stratum corneum. Electron microprobe analysis of the epidermis can, for analysis of trace elements, be complemented by the proton microprobe. Quantitative agreement between the two techniques can be obtained by the use of a standard. Proton microprobe analysis was used to determine the distribution of Ni or Cr in human epidermis exposed to nickel or chromate ions. Possible differences in water content between the stratum corneum of patients with atopic eczema and normal stratum corneum was investigated in skin freeze-substituted with Br-doped resin. No significant differences were observed. Proliferative reactions in the epidermis appear to be associated with increased levels of the elements P and K. Such changes were found in guinea-pig skin after exposure to sodium lauryl sulfate, and in plaques of skin from patients with psoriasis.
Animals↗
Electron microscopic observations of Langerhans' cells in human epidermis irradiated with grenz rays.
The effect of grenz rays on Langerhans' cells and epidermal morphology was studied at electron microscopic resolution in humans. Biopsies were obtained before and after grenz ray therapy (3 Gy X 3, 1 week interval) from 6 subjects. There was a pronounced reduction of the number of Langerhans' cells 24 hours after the final treatment. There appeared to be no consistent differences in keratinocyte morphology or changes of the intercellular space.
Adult↗
Fibrin gels as biological filters and interfaces.
We present data which show that fibrin gels are ordered network structures, the porosity of which is determined by the amount of thrombin being present during the activation step preceding gelation. On activation of fibrinogen, fibrinopeptides are released and simultaneously polymers are formed, obeying apparent first order kinetics. The pore size of the network is inversely related to the rate of polymer formation. It is proposed that at the time of gelation the polymers form an ordered lattice structure, which in the organism may serve as a biological interface.
Chromatography, Gel↗
Elemental analysis on freeze-dried sections of human skin: studies by electron microprobe and particle induced X-ray emission analysis.
The possibility of using the proton microprobe (PMP) in the elemental analysis of dermatological material, under conditions where the spatial resolution can be restricted to a few micrometers, was demonstrated. Comparison with the electron microprobe (EMP) technique using duplicate sections from the same human skin biopsies revealed that the PMP and EMP techniques are complementary and yield closely corresponding elemental distributions for elements of dermatological interest. The concentrations of phosphorus and potassium were low in the dermis, high in the stratum basale and stratum spinosum, and decreased markedly in the stratum granulosum to a low level in the stratum corneum. The sulfur concentration was highest in the stratum corneum.
Electron Probe Microanalysis↗
Brittle hair in osteogenesis imperfecta: transmission and scanning electron microscopy and mycologic assay.
The brittle hair fibres from a case of osteogenesis imperfecta were studied by scanning and transmission electron microscopy. Normal hair fibres are extremely difficult to infect with T. mentagrophytes. As a tentative assay for biochemical defects of hair fibres, experimental dermatophytic infection of the hair with T. mentagrophytes was performed. The massive growth induced suggested that the experimental fungal infection may indeed indicate a biochemical defect in the hairs from our case of osteogenesis imperfecta.
Adult↗
Clinical applications of scanning electron microscopy and X-ray microanalysis in dermatology.
Scanning electron microscopy is frequently applied to dermatological problems, as is evident from a review of the recent literature. In this tutorial, preparation methods and new techniques allowing experimental studies on the integumentary system are emphasized. Quantitative analysis in the electron microscope by use of energy-dispersive X-ray microanalysis ( EDX ) has become an important accessory technique. EDX can, for instance, be used to study problems involving physiological changes induced in skin by agents causing contact reactions. Recently, it has been shown that treatment with DNCB, chromate and nickel causes changes in elemental distribution in guinea-pig skin. In addition, elemental uptake in the integumentary system and in pathological inclusions in skin can be analyzed.
Animals↗
Elemental changes at irritant reactions due to chromate and nickel in guinea-pig epidermis.
The present investigation was performed to examine the possibility of using energy dispersive X-ray microanalysis (EDX) to obtain information on epidermal reactions at irritant dermatitis. The elemental redistribution in the stratum germinativum and stratum spinosum of the guinea-pig epidermis after intradermal injection of a chromate and a nickel solution was studied in thick cryo-sections. The two solutions caused different changes in elemental content in both cell layers. Nickel sulfate caused a conspicuous decrease in K levels whereas Na and Cl were elevated in both cell layers. Potassium chromate caused an increase in Cl but lowered the P values. The result of this study show that it is possible to use EDX-analysis of thick skin sections to obtain information on physiologically relevant alterations in epidermis at irritant dermatitis.
Animals↗
Proton-induced X-ray emission analysis - a new tool in quantitative dermatology.
Proton-Induced X-ray Emission analysis (PIXE) constitutes a method for trace element analysis characterized by multielemental capability, detection limits in the low ppm-range and size resolution down towards a micrometre. In applications where the sensitivity of the Electron-Induced X-ray Emission (EIXE) analysis is not sufficient and where a spatial resolution not better than a few micrometres is required, the PIXE technique provides a powerful tool. In this paper properties of the PIXE method are demonstrated by quantitative results from three different samples of dermatological interest. Firstly, mercury results from a longitudinal scan of a single hair strand from a mercury poisoned person are shown. With a spatial resolution of one or a few millimetres very fast scans may be performed on hair strands giving information on time and magnitude of intoxication or other exposures, as well as deficiencies. Secondly, results are given from a radial scan with a beam width of 4 micron on hair from a person exposed to high amounts of iron. The calcium, iron and zinc distributions but not the sulphur and potassium distributions show narrow peaks of concentration (less than 4 micron) about 15 micron from the surface of the hair. Further investigations have to be performed in order to interpret these data. Thirdly, the depth profiles in skin of some elements were measured with a beam width of 10 micron. The results show significant increases in sulphur, calcium and zinc concentrations and significant decreases in phosphorous and potassium concentrations at the skin surface, i.e. in the stratum corneum.
Adult↗