Biomedical subjects
D Lubach
Publications and source records attributed to D Lubach.
Livedo racemosa generalisata: an evaluation of thirty-four cases.
The results of investigations in 34 patients (28 women, 6 men) with livedo racemosa generalisata are presented. Neurologic or psychiatric symptoms were present in 28 patients. Nineteen patients had had one or more cerebral infarctions, and epilepsy (Sneddon's syndrome) developed in six. In most cases livedo preceded the neurologic disorder. In addition, many patients with livedo racemosa generalisata had Raynaud's phenomenon, cardiac abnormalities, or vascular changes in the ocular fundus.
The extension technique: a new method of demonstrating initial lymph vessels in excised human skin.
The initial lymph vessels, the lymph capillaries and precollectors, are difficult to detect in normal skin using routine histological methods. A method is described in which specimens of the skin are fixed in an expanded condition. In 1.05 microns thick plastic-embedded sections the dilated lymph vessels of the skin can be demonstrated. The dermal lymph vessel network can be seen following the subepidermal injection of a coloured solution. The endothelial cells and subendothelial fibrous network can be examined using electron microscopy.
Influence of ciclosporin on epidermal proliferation after mechanical skin irritation.
In mice (NMRI and hr/hr), ciclosporin, subcutaneously administered once daily over 7-10 days, influenced epidermal hyperproliferation induced by abrasion of superficial epidermal layers. While in vehicle-treated control animals the mechanical irritation of skin caused an increase in 3H-thymidine triphosphate incorporation rate into DNA and also in epidermal thickness of tail and flank skin, the hyperproliferative response was diminished in ciclosporin-treated animals. Thus, only a slight increase of the 3H-thymidine triphosphate incorporation rate and of epidermal thickness was measured after pretreatment with ciclosporin, the effect being dose-dependent. The strongest inhibitory activity was found after application of 30 mg/kg BW. These findings indicate that the immunosuppressive peptide ciclosporin inhibits the epidermal proliferation in vivo.
The mouse epidermis as a model in skin pharmacology: influence of age and sex on epidermal metabolic reactions and their circadian rhythms.
The influence of age and sex on epidermal metabolism and histology was studied in mice (NMRI). Within a few weeks postpartum, thymidine triphosphate incorporation into DNA and amino acid incorporation into epidermal protein decreased. Differences between tail epidermis and other skin regions (back, abdomen, ear) were found. Sex dependent differences could not be demonstrated. A circadian rhythm of the studied epidermal metabolic processes was shown (artificial 12L:12D light/dark cycle). Maximum incorporation of thymidine triphosphate and of amino acids was found at the end of the light period at 1800 h, while a minimum incorporation was demonstrated at the end of the dark period. Considering described biological variations, the mouse tail assay seems to be suited to study influences of drugs in epidermal metabolism and histology.
[Steroid-induced damage of the facial skin following use of prednicarbate].
Prednicarbate is known to be a potent topical corticosteroid with few side-effects. On the basis of 5 case reports, however, it is shown that topical application of prednicarbate can have serious side effects on the facial skin. For this reason, prednicarbate should be used only in exceptional cases and for short periods in the facial region.
Sneddon's syndrome: clinical course and outcome.
Fifteen patients with Sneddon's syndrome presenting since 1979 were re-examined. After a neurological examination, an orienting test of mental ability as well as an electroencephalogram were performed in all patients. In 10 of the 15 patients computed tomography of the brain was performed, too. Preceding reports and the results of the present study have been used to discuss the characteristics and prognosis of Sneddon's syndrome.
Vacuum injection--a new indirect fixing method for the demonstration of initial lymphatics in biopsy specimens of human organs.
With the indirect vacuum injection method (IVIM) at a negative pressure of 30 kPa, it is possible to demonstrate the initial lymphatics (IL) by scanning electron microscopy even in biopsy specimens of various organs (minimum size 0.5 X 0.5 cm2). IL can also be dilated and fixed using the indirect perfusor injection method (IPIM), but only in larger specimens (minimum size 2.0 X 2.0 cm2). Only dilated IL can be examined by scanning electron microscopy, and only the IL of the ampulla of the Fallopian tube can be reliably dilated during immersion fixation. The quality of fixation on use of the vacuum technique conforms to the standard achieved with other methods. No one has yet succeeded in demonstrating the IL in biopsy specimens smaller than mentioned above using any of the methods described.
Investigations on the development and regression of corticosteroid-induced thinning of the skin in various parts of the human body during and after topical application of amcinonide.
In 15 subjects 6 different parts of the body were treated with the potent topical corticosteroid (CS) amcinonide once a day for 21 days. The skin thickness of the treated areas was measured sonographically at intervals of 2 days. After completion of the CS application the regression of the CS-induced reduction in skin thickness was measured for a further 14 days. A clear thinning of the skin could be measured after only 4 days and continued up to the 21st day of treatment. This thinning regressed completely in all areas after 10-12 days. The thinning and regression curves were very similar for all body areas. Differences in intensity of thinning were evident. No tachyphylaxis was detected.
[The extension technic--a new method for in vitro imaging of the initial lymphatic system of the skin in the human].
A technique for detecting initial lymphatics in excised human skin is reported. Excidates are carefully stretched. By subepidermal injection of a Berlin blue solution, dermal lymphatic networks can be imaged. The initial lymphatics can be clearly detected by light microscopy in semi-thin sections.
Steroid-induced dermal atrophy. Investigations on discontinuous application.
In this study several schedules of discontinuous application (DA) were tested, using various weak and strong topical corticosteroids (CS). The purpose of this study was to measure the influence of corticosteroids on skin thickness by means of a mechanical method. In a first experiment, betamethasone 17,21-dipropionate (Bet) and fluprednidene 21-acetate (Flu) were applied to the skin of the volar side of the forearm at a rhythm of 1:1 (1 day CS, 1-day interval) and 1:2 under occlusive dressing. The investigation period was 8 weeks. For comparison, Bet and Flu were applied continuously (CA) for 3 weeks. Flu thinned the skin to a lesser extent than Bet. With DA the skin was thinned to the same extent as with CA. In a second experiment, hydrocortisone 17-butyrate, betamethasone 17-valerate, desoxymethasone and hydrocortisone were tested. Here the treatment regimen was 5:9. The CS preparations were tested for 3 months on the volar side of the forearms under occlusive dressing. Skin thinning occurred during the 5 days of CS action and, in the beginning, receded again in the CS-free interval. However, this regressive process became weaker each time. At the end of the experiment the skin thinning persisted. With the exception of hydrocortisone, all CS tested produced statistically significant skin thinning after DA. The results of the investigation presented here show that thinning of the skin must also be expected with discontinuous application of topical CS.
Comparative investigation of the antiproliferative efficacy of alclometasone.
In this study, the antiproliferative activity of a 0.05% alclometasone ointment (Alc, Delonal) on the epidermis of the mouse tail was investigated. We have found that Alc thins the epidermis to approximately the same extent as hydrocortisone acetate (1%), but has an extremely slighter epidermal thinning effect than betamethasone (betametasone-17,21-dipropionate, 0.064%, Diprosis). The incorporation rate of 3H-thymidine triphosphate into the DNA was inhibited to almost the same extent. In conclusion the small antiproliferative effect of Alc shows no correlating effects compared with its high vasoconstrictory efficacy.
[Brown hair and nail discoloration by water containing iron].
A 24-year-old patient who was otherwise in good health noticed an increasing brown discoloration of all her nails and her previously fair hair 7 weeks before consultation. On investigation it could be found that the patient used water with a high iron content for washing. A high iron content was detected in the discolored parts of the hair.
Investigation of the skin thinning effect of prednicarbate and other corticoids in mouse skin.
In this investigation skin fold thinning was determined after topical application of several potent corticosteroids in hairless mice using a simple mechanical measuring device. The skin thinning effect of prednicarbate was compared with other corticosteroids (amcinonide, beta-methasone-17-valerate, clobetasol-17-propionate, diflorasone-17,21-diacetate, hydrocortisone-21-acetate). Prednicarbate produced a clear thinning of skin. Like other tested dermatocorticoids prednicarbate caused a significant atrophy of the mouse tail epidermis. By prednicarbate the 3H-thymidine triphosphate incorporation into epidermal DNA was inhibited.
Effects of treatment with dithranol, etretinate and a combination of dithranol and etretinate on epidermal metabolism and histology. Mouse tail assay.
The mouse tail assay is useful for studying dermatological therapeutics that influence epidermal differentiation. The effect of dithranol (0.1% w/v in acetone, topically; DI), etretinate (2 mg/kg body weight/d, orally; ET) and of the simultaneous administration of both preparations (DI/ET) on the epidermis of the mouse tail was examined. The thickness of the epidermis, the number of nuclei per defined epidermal section, and the development of a granular layer in the interfollicular areas were determined. The incorporation of 3H-thymidine-triphosphate onto the DNA and global protein synthesis were also determined in vitro. The incorporation rates of leucine and histidine into protein in vitro were measured separately. DI caused retention acanthosis and at the same time orthokeratotic differentiation of the interfollicular areas of the epidermis. Light microscopy of the tail epidermis after application of ET showed no significant changes. Administration of ET/DI yielded the same effects as treatment with DI alone. DI partially reduced the biochemical parameters. ET increased DNA-polymerase activity, global protein synthesis, and the incorporation rate of histidine. The biochemical results after treatment with DI/ET were very similar to those obtained after DI administration. From the histological and biochemical results it is therefore concluded that the simultaneous administration of DI and ET produces the same effects as DI treatment alone.
[Examining the initial lymph vessels of the guinea pig ear using an extension technic].
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[The effect of benzoyl peroxide in a model study of the mouse epidermis].
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Effects of etretinate in epidermal metabolism and histology after abrasio of superficial layers. Mouse tail assay.
The mouse tail assay is suitable for the histological detection of altered differentiation of the epidermis. In the present study, the stratum corneum of the tail epidermis of female mice (NMRI) was removed by means of fine sandpaper. One group of mice was treated with 2 mg of ethyl (all-trans)-9-(4-methoxy-2,3,6-trimethylphenyl)-3,7-dimethyl- 2,4,6,8-nonatetraenoate (etretinate)/kg body weight daily. The untreated group served as control. After removal of the stratum corneum epidermal hyperplasia and formation of a stratum granulosum was found in the controls (peak on the third day). The alterations declined from the fourth day onwards. The histidine incorporation into protein was increased from days 4 to 6. A similar reaction sequence was observed in the animals treated with etretinate. In addition to the hyperplasia, there was an enlargement of the cells (hypertrophy). The control group showed a significant elevation of leucine incorporation and a reduction of histidine incorporation into protein on the first day after removal of the stratum corneum. The incorporation rate of thymidine triphosphate into DNA peaked on the second day. The rise of leucine incorporation into protein and the increase of thymidine triphosphate incorporation into DNA on the second day after removal of the stratum corneum could not be detected in the animals treated with etretinate. In these animals histidine metabolism could not be influenced by etretinate. In conclusion, etretinate greatly influences the alteration of basal metabolism caused by the removal of the stratum corneum.(ABSTRACT TRUNCATED AT 250 WORDS)