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Biomedical subjects

T Karlsmark

Publications and source records attributed to T Karlsmark.

At least 55 records · Page 3Linked to original sources
PubMed1986

Immediate dermal changes in pig skin after exposure to moderate amounts of heat and electrical energy.

Pig skin was exposed to approximately 80 joules of heat and electrical energy [50 Hz alternating current (a.c.) and direct current (d.c.)], respectively, under controlled conditions in order to find methods to document electrical torture. Biopsies were obtained immediately after exposure, and the morphology of the electrical lesions was compared with that of heat lesions and unexposed skin by using normal and polarized light microscopy. In areas exposed to 50 Hz a.c. and in cathode areas after d.c., where calcified collagen fibers have been found 2 days after injury, the collagen fibers showed a regular, densely spaced, cross-striation. This type of cross-striation was not found in heat or anode lesions. It was possible to blindly group all biopsies correctly with regard to influence of heat, 50 a.c. and d.c.

Animals↗
PubMed1986

New parameters for evaluation of blood flow in patients with leg ulcers.

Three new parameters have been introduced to provide data for quantitative evaluation of peripheral cutaneous blood flow in patients with leg ulcers. Reactive hyperemia was induced by occlusion of the blood flow for four minutes at the thigh-level. Blood flow was subsequently measured by laser-Doppler velocimetry in an unselected group of 14 patients with leg ulcers and a matched control group. The parameters used for evaluation was: 1) "peak flow" f(p), 2) divided by time to "peak flow" t(p), rendering a rate constant k (k = f(p)/t(p)) expressing the ability to increase blood flow abruptly in case of need. These parameters were all significantly reduced in the patients with leg ulcers, indicating that this simple and atraumatic technique was useful for discriminating blood flow values that may be relevant for healing time and with a sensitivity comparable to the measurements of distal systolic blood pressure. Distal systolic blood pressure measurements can still be considered to be of value when screening for arterial insufficiency in patients with leg ulcers. The values obtained were significantly lower in 36 patients with leg ulcers compared with 9 age-matched control persons.

Adult↗
PubMed1984

Tracing the use of electrical torture.

With the aim of being able to trace skin sequelae to electrical torture, an interdisciplinary group of scientists (the "electrical group" of Anti-Torture Research, ATR) has performed controlled morphological studies on skin biopsies from experiments with fully anesthetized pigs. "Vesicular nuclei" in epidermis and a characteristic pattern of collagen calcification in dermis were found to be typical of electrical damage. These alterations were produced by alternating current as well as by direct current.

Calcinosis↗
PubMed1983

Tracing the use of torture: electrically induced calcification of collagen in pig skin.

Reports of the use of electrical torture are usually denied, so that there is an urgent need of diagnostic methods to distinguish the consequences of electrical torture from other superficial injuries. The 'electrical group' of Anti-Torture Research (ATR) has accordingly studied the possibility of distinguishing between the sequelae of electrical and heat injury. Among the reported differences of the two types of injuries is the occurrence in epidermis, vessel walls and sweat glands of vesicular nuclei exclusively in electrically injured skin. On the basis of experiments with anaesthetized pigs, we now report that the late sequelae of electrical injury appear to include the deposition of calcium salts beneath the area of an electrical cathode.

Aggression↗
PubMed1983

The effect of direct current, sodium hydroxide and hydrochloric acid on pig epidermis. A light microscopic and electron microscopic study.

Lesions in pig skin were induced by direct current, hydrochloric acid and sodium hydroxide, and the morphology of the lesions was compared in order to establish the influence of electrolysis in the electrical lesions. Both light microscopically and electron microscopically a pronounced similarity was found between cathode lesions and base-induced lesions including the presence of vesicular nuclei in both kinds of lesions. Some features were also common to anode lesions and acid induced lesions, but dissimilarities were present as well. From the results it is concluded that electrolysis in the tissue with the subsequent shift of pH, especially towards the alkaline side, is responsible for the formation of the vesicular nuclei which we repeatedly have found to be characteristic of electrical skin lesions. The shift of pH also induces the cytoplasmic feature called "white necrosis" which therefore is found more regularly in electrical lesions than in heat lesions.

Animals↗
PubMed1983

Epidermal changes in heat and electrically injured pig skin. A light microscopic study of the influence of heat energy intensity and electrical current frequency.

Pigs were exposed to heat of low and high temperature and electricity of various frequences. Comparable amounts of energy were transferred in all experiments. In lesions induced by heat of low temperature granularity and/or fibrillarity of the cytoplasm were present in the epidermal cells. Lesions induced by heat of high temperature had a similar appearance, but occasionally "white necrosis", defects in the epithelium and light yellow material in stratum corneum were present. Lesions induced by 100.000 hz alternating current were segmental but otherwise microscopically often indistinguishable from lesions produced via transfer of heat of low temperature. Lesions induced by 8000 hz and 59 hz alternating current were segmental. Vesicular nuclei, "white necrosis" and yellow, clumped keratin were present in most lesions. Anode areas in direct current induced lesions showed a shrunken epidermis. The cytoplasm of the epidermal cells were often eosinophilic and homogeneous, and the nuclei were small with condensed chromatin. Occasionally, "empty" nuclei were noted. Yellow, clumped keratin was presented in all lesions. In cathode areas epidermis was of varying thickness and "white necrosis" and vesicular nuclei were present. The pathogenesis of the individual morphological features is discussed based upon theoretical concepts and the difference in morphology of the various lesions encountered in the present study as well as in other studies in this series of experiments. It is concluded that except for lesions produced via transfer of high frequency alternating current the morphology of electrical lesions is specific. Further, an alleged torture instrument was able to produce lesions similar to those observed in the experimental studies.

Animals↗
PubMed1982

Epidermal changes in heat and electrically injured pig skin: a light microscopic study of the sequences in morphology.

Biopsies were obtained from heat and electrically exposed pig skin at different at different times after exposure, in order to describe the morphological sequences in heat and electrically injured skin. The work is part of a series of studies in which it is investigated whether morphological methods can be used in disclosing electrical torture. Epidermal changes in heat lesions differed from those of electrical lesions in all experiments. Heat lesions typically showed a detached epidermis with fibrillar or granular cytoplasm. In older lesions the epidermis appeared concrete. Electrical lesions showed an attached epidermis with small defects, a white, homogeneous cytoplasm, vesicular nuclei and curled, clumped keratin. The electrical lesions were rejected at day 4 or 5. The number of characteristic morphological changes in epidermis decreased with the age of the lesions. It is concluded that epidermal electrical lesions differ in morphology from heat lesions and that it is possible to evaluate the age of the lesions.

Animals↗
PubMed1980

Palmoplantar hyperhidrosis. Treatment with alcohol solution of aluminium chloride hexahydrate: a simple method of transpiration measurement.

16 patients with palmar and/or plantar hyperhidrosis were treated with topically applied aluminium chloride hexahydrate in a 25% solution in absolute ethyl alcohol. Compared to treatment of axillary hyperhidrosis this formulation seems to be less effective, but a controlled study is needed. A simple method for transpiration measurement is described. It may be useful in daily practice to control the effect of the treatment.

Adolescent↗
PubMedDate not supplied

Topical therapy for peristomal pyoderma gangrenosum.

BACKGROUND: Pyoderma gangrenosum (PG) is an uncommon condition. Literature on the management of peristomal PG (PPG) is sparse. In the absence of randomized controlled trials the reporting of case series is potentially helpful to the management of this uncommon disease. OBJECTIVE: In this study we report our experience with topical corticosteroid therapy for 14 consecutive cases of PPG. METHODS: A clinical diagnosis PPG was made by a trained dermatologist using the appropriate investigations where necessary. RESULTS: The majority of the cases presented were managed with simple topical corticosteroids, occasionally in combination with a change of dressing. In 8/14 (57%) cases ulcer resolution was achieved within 3 months with topical treatment alone or topical treatment plus a change of dressing to a silicone-based product applied directly to the wound under the normal base plate of the stoma bag. CONCLUSION: Our experience suggests that a significant proportion of PPG can be managed by topical treatment alone. The simple topical treatment allows the patient to continue use of stoma care products while minimizing the potential for side effects.

Adult↗
PubMedDate not supplied

Electrical and thermal injuries in pig skin--evaluated and compared by light microscopy.

The morphology of pig skin after electrical (el) and thermal exposure was studied in order to find methods applicable for disclosing electrical torture. Biopsies from pig skin exposed 24 hours earlier to either heat or electrical current under general anesthesia were studied by light microscopy. The amount of energy used of either type ranged from about 6 to about 100 joule deposited on two circular areas of the skin measuring 12 mm in diameter. In sections stained with hematoxylin and eosin alterations were found in heat-influenced specimens following the administration of moderate and large doses of energy. Changes were observed in el-influenced specimens also after the administration of low amounts of energy, which did not lead to macroscopical changes in the skin. The two types of energy induced different patterns of alterations inside the epidermis. The most characteristic change following heat exposure was the presence of a granular or fibrillar eosinophilic cytoplasm and subepidermal clefts, while el-expoure often produced white homogeneous cytoplasm and shadowy nuclei ("white necrosis") in the attached epidermis. The individual changes could be produced by both types of injury, but to a highly different degree. However, the alteration classified as "vesicular nuclei" was only observed observed in el-damaged skin. The dermis from the more severely injured skin of both groups showed a homogeneous appearance ("necrosis"). While the changes of epidermis and dermis in response to heat were diffusely distributed, the changes created by electrical injury were often present in segments. By electrical damage homogeneous areas with loss of stainability and shadowy nuclei were occasionally observed in sweat glands, hair sheaths and in vessel walls, structures which are suggested to serve as conductors for the electrical current. "Vesicular nuclei" were observed in similar structures. Some of the findings may be associated with differences in intensity of energy during exposure to heat and electricity. Furthermore, the existence of different biological patterns following the two types of exposure should be considered. The studies are being continued to elucidate these basic questions, and to study further the medical diagnostic potential of examining skin biopsies from tortured individuals.

Animals↗
PubMedDate not supplied

Early epidermal changes in heat- and electrically injured pig skin. I. A light microscopic study.

In order to find methods applicable for disclosing electrical torture, pig skin was exposed to heat and electricity under controlled circumstances. Biopsies were obtained immediately after exposure and the morphology of the heat lesions was compared to that of electrical lesions. The cytoplasm of epidermal cells in heat lesions appeared granular or fibrillar, while the nuclei were rather unaffected. In electrical lesions the cytoplasm appeared homogeneous often with a peculiar white colour in hematoxylin-eosin stained sections. The nuclei were either dark and shadowy or enlarged and vesicular. The keratin in electrical lesions often showed a bright yellow colour. Small defects in the epidermis were seen in some electrical lesions. Thus the morphology of electrical lesions differed markedly from that of heat lesions. Although some of these differences may be due to differences in distribution and intensity of energy, it is probable that pH shifts in the cells due to electrolysis is the main cause of the specific morphology of electrical lesions.

Animals↗
PubMedDate not supplied

Early epidermal changes in heat- and electrically injured pig skin. II. An electron microscopic study.

In order to find methods applicable for disclosing electrical torture, pig skin was exposed to heat and electricity under controlled circumstances. Biopsies for electron microscopy were obtained immediately after exposure. In heat lesions the nuclei were slightly distorted, sometimes with broken nuclear membranes. The tonofilaments were clumped, intracellular oedema was present and cell membranes were ruptured between desmosomes. In electrical lesions the nuclei were usually enlarged with strongly condensed chromatin. Some nuclei were composed of fine, evenly dispersed granular material. The cytoplasm appeared homogeneous, in large magnification finely granular. Cell borders could sometimes be identified located in situ. In the stratum corneum, which appeared normal in heat lesions, single or several cells or large areas had an electron-dense appearance. The difference in ultrastructure of heat and electrical lesions makes it probable that electricity has a specific action on epidermal cells.

Animals↗
PubMedDate not supplied

The wound healing process in surgical patients evaluated by the expanded polytetrafluoroethylene and the polyvinyl alcohol sponge: a comparison with special reference to intrapatient variability.

The aim of this study was to compare two wound healing models in surgical patients with special reference to the intrapatient variability. Two pieces of expanded polytetrafluoroethylene tubing and one perforated silicone tube containing two polyvinyl alcohol sponges were subcutaneously inserted into 28 patients and were removed after 10 (9 to 11) days. The amount of hydroxy-l-proline in two segments of the same piece of expanded polytetrafluoroethylene tubing correlated significantly with each other. Similar results were found for proline. Proline content in each polyvinyl alcohol sponge correlated weakly with each other, whereas no correlation was found between hydroxy-l-proline content in the two polyvinyl alcohol sponges from the same patient. In addition, no correlation was found between leucine in the two adjacent polyvinyl alcohol sponges or between the hydroxy-l-proline/leucine ratio in these same sponges. No concordance could be detected between the averages of hydroxy-l-proline content in the two segments of expanded polytetrafluoroethylene tubing and the hydroxy-l-proline content in the two polyvinyl alcohol sponges from the same person, although an association between the averages of proline in the two pieces of expanded polytetrafluoroethylene tubing and proline content in the two polyvinyl alcohol sponges from the same individual was observed. The measurement error was greater for the polyvinyl alcohol sponges than for the expanded polytetrafluoroethylene tubing implants during the first 10 days after wounding. The expanded polytetrafluoroethylene tubing accumulated 2.5 times more hydroxy-l-proline per length unit than the polyvinyl alcohol sponge. We concluded that the expanded polytetrafluoroethylene implant rather than the polyvinyl alcohol implant is preferred for quantitation of subcutaneous collagen deposition in surgical patients because it accumulates more new tissue and has a lower variability.

Journal Article↗
PubMedDate not supplied

Ultrasound therapy in chronic leg ulceration: a meta-analysis.

We reviewed all articles on ultrasound therapy published since 1950 to assess the evidence for an effect of this therapy in the treatment of chronic leg ulcers. Fourteen studies concerning ultrasound therapy, chronic leg ulcers, and wound healing were found. The six studies that fulfilled inclusion criteria for a randomized controlled trial were generally found lacking with respect to description of ulcer etiology-treated area, ultrasound head area, control of ultrasound apparatus, sham ultrasound apparatus, and follow-up evaluations. However, all six studies presented their data in a way that made pooling possible with respect to a decrease in ulcer area as a percent of the starting area. A standardized effect size was applied and gave evidence for a significant effect of ultrasound, showing a 16.9% (CI95: 6.3% to 27.5%, p = 0.011) mean difference in healing after 4 weeks of treatment and a 14.5% (CI95: 6.6% to 22.3%, p = 0.005) mean difference after 8 weeks of treatment compared with control treatment. In three studies, the number of healed ulcers was assessed, and pooling showed a nonsignificant (p = 0.06) therapeutic gain of 15% (CI95: 1% to 30%). This analysis would suggest that ultrasound has the best effect being delivered in low doses around the edge of the ulcer, but further studies are required to confirm this possible effect and to evaluate a possible dose-response relationship.

Aged↗