Quantitative Fourier transform infrared diagnostics of the gas-phase composition using the HITRAN database and the equivalent width of the spectral features.

This paper presents a strategy for quantification of medium resolution Fourier transform infrared (FT-IR) spectra. The approach is based on a comparison of the values of the equivalent width of spectral features determined from the measured FT-IR spectra with those calculated from corresponding molecular spectra simulated using spectroscopic parameters tabulated in the HITRAN database. Although the equivalent-width method is routinely applied in many high-resolution experiments, its potential is often ignored when the spectral resolution of the measurements is bigger than the width of the studied molecular transitions. Here with an eye on application of the method to the study of the biomass thermal decomposition products, we demonstrate the capability of the method for analysis of FT-IR spectra with moderate resolution. The method is validated for a number of molecules (NH3, CO, CH4, C2H2, C2H4, and NO) that are important products of biomass thermal decomposition. Namely, known amounts of gases were placed in a sample cell and their concentrations were determined using the method for different FT-IR settings. The agreement between the concentration values determined using the present method and those found in the sample cell was generally better than 10%. The paper also shows examples of application of the developed methodology for the analysis of FT-IR spectra from biomass pyrolysis.

A cloudy bag and genital ulcers.

A 30-year-old patient treated with CCPD presented with genital ulcers and a culture-negative peritonitis. Herpes simplex virus type 2 (HSV-2) was cultured from the effluent and the genital lesions. Primary HSV-2 infection was diagnosed by serology. This is the first documented case of PD peritonitis caused by HSV-2. We speculate that cases of culture-negative PD peritonitis may be due to recurrences of genital herpes.

Cushing's syndrome caused by topical steroid therapy for psoriasis.

A 72-year-old woman developed manifestations of Cushing's syndrome after long-term topical steroid therapy for psoriasis. Shortly after tapering the dose of topical steroids she developed signs of adrenal insufficiency (provoked by a urinary tract infection) requiring intravenous administration of a stress dose of hydrocortisone. There have only been a few reports of systemic side effects of topically applied corticosteroids in adults. Considering their serious consequences physicians should be alert to signs of Cushing's syndrome in patients on long-term topical steroid therapy. Furthermore, clobetasol propionate ointment doses exceeding 50 g a week should not be prescribed and use of occlusive dressings should be avoided.

[Recognition of malignant skin tumors of the head and neck]. / Herkenning van maligne huidtumoren in het hoofd-halsgebied.

Skin cancer is the most common malignancy in man. The sun-exposed surfaces of the head and neck are the areas most frequently involved. Since skin cancers in most instances are easily recognized, they may be diagnosed at an early stage. The dentist may play a role in the early detection of skin cancers of the head and neck.

[Ascending phlebothrombosis]. / Ascenderende flebotrombose.

Ascending phlebothrombosis of the lower extremities can have serious consequences if not identified at an early stage. In the Academic Hospital of the Free University, Amsterdam, 18 patients with this disease were seen in the period 1980-1991. Treatment should be aimed at preventing progression of the disease to the deep venous system. This may necessitate ligation and dissection of the V. saphena magna in the groin. Usually conservative treatment will do, provided regular follow-up is performed to see whether progression has taken place to the hiatus saphenus or the popliteal fossa. As the disease has usually progressed further than the clinical signs indicate, duplex scanning should be used in case of doubt. Progression to the deep system should immediately be treated surgically.

Retroperitoneal sarcomas: pre-operative assessment and surgical therapy.

The clinical and pathological records of 22 patients treated for retroperitoneal sarcomas were retrospectively studied. The initial symptoms were pain and swelling of the abdomen in 11 patients. All tumours had a diameter of more than 10 cm. The pathological diagnosis was in 16 cases liposarcoma or leiomyosarcoma. Fourteen tumours were graded as high and eight as low. Sixteen of the 22 operated patients had complete resection of the tumour. Eleven patients had recurrence after five to 42 months, nine of them local recurrence and two distant metastases. Eleven patients needed repeated radical or palliative resections. Additional therapy (pre- or post-operative radiation or chemotherapy) was given to 11 patients. Radical resection of primary and recurrent tumours seems to give the best results in patients with retroperitoneal sarcomas but debulking of the tumour improves the quality of life in selected patients.

Effect of mineral oil and linoleic-acid-containing emulsions on the skin vapour loss of sodium-lauryl-sulphate-induced irritant skin reactions.

This study evaluates the influence of mineral oil and linoleic-acid-containing emulsions on the skin vapour loss (SVL) of detergent-induced irritant skin reactions. During a period of 2 weeks, 2 x 45 min applications of a sodium lauryl sulphate solution of low molarity were performed on the forearm of 9 volunteers. In the same period, a standard amount of each emulsion was applied on the induced irritant skin reactions, 3 times each day. The effect of the emulsions on the barrier function of the skin was evaluated by means of SVL measurements. The emulsion based on mineral greases significantly reduced SVL values during both weeks, possibly because of an occlusive effect. The emulsion with 15% of linoleic acid significantly reduced SVL values during the 1st week but not during the 2nd week. The emulsion with 38% of linoleic acid did not reduce SVL values at all.

Pemphigus-like eruption induced by d-penicillamine and captopril, in the same patient.

A patient suffering from rheumatoid arthritis and hypertension is described who developed pemphigus foliaceus during simultaneous treatment with d-penicillamine and captopril. Discontinuation of the d-penicillamine afforded some improvement, but skin symptoms still persisted after 3 months. When the captopril was discontinued as well, all lesions healed within 2 weeks. Our findings suggest that both these chemically related drugs might have been responsible for the pemphigus-like eruption in this patient.

After-work emollient creams: effects on irritant skin reactions.

In this study, the influence of 4 after-work emollients on the healing of irritant skin reactions of varying intensity was assessed. To this end 5 patch tests with sodium lauryl sulphate (SLS) 2.5 g/v% were performed on the volar side of the forearm of 30 healthy Caucasian volunteers. Patch tests were removed after 12 h (group A, n = 10), 24 h (group B, n = 10) or 48 h (group C, n = 10). Then standard amounts of the emollients were applicated to the induced skin reactions, twice daily for a period of 5 days. One skin site served as a control. Skin sites were evaluated before, during and after the test period using laser Doppler flow measurements, skin vapor loss measurements and a visual scoring system. In all groups, data obtained from the skin sites treated with the emollients did not differ significantly from the data obtained from the control site. Thus, skin regeneration of the irritant skin reactions was not really enhanced by the application of these preparations. Further investigations on after-work emollient creams with physiologically better adapted constituents are necessary.

Protective effect of barrier creams and spray coatings against epoxy resins.

This study evaluates the protective capacity of 4 barrier creams and 2 methacrylate spray coatings against skin contact with epoxy resins. The effect of these materials on the strength and on the surface area of patch test reactions caused by epoxy resin was assessed in 11 volunteers with a known allergy to epoxy resins. Standard amounts of barrier cream and spray coating were applied on the skin. Then patch tests were carried out with epoxy resin on the pretreated sites. After 24 h patches were removed, 48 h thereafter the strength and surface area of the reactions were scored. Results were compared with the score of a control test. The use of 2 barrier creams resulted in a significant reduction of the surface area of the patch test reactions. Spray coatings significantly reduced both the strength and the surface area of the reactions. Our results suggest that methacrylate spray coatings and barrier creams may provide protection against epoxy resins during a test period of 24 h. However, the development of new formulations, adapted more specifically to this purpose, is necessary.

Epidermodysplasia verruciformis: Langerhans cells, immunologic effect of retinoid treatment and cytogenetics.

A case study is presented of a 44-year-old negroid male with epidermodysplasia verruciformis (EV), cutaneous carcinomas, and impaired cell-mediated immunity (CMI), infected with human papillomavirus type 8 and 17. Analysis was made of (a) T6+ and HLA-DR+ Langerhans cells (LCs) by immunoperoxidase staining in lesional and clinically normal skin before and during retinoid treatment, (b) the effect of retinoid treatment on CMI in vivo and in vitro, and (c) cytogenetic aspects related to chromosomal instability. The results showed the virtual absence of T6+ and HLA-DR+ LCs in koilocytic areas of epidermis involved with EV. Light-exposed, clinically normal skin also demonstrated microscopic EV lesions largely devoid of T6+ and HLA-DR+ LCs. Retinoid treatment with etretinate (Ro 10-9359) appeared both to increase the CMI response in vitro to T-cell mitogens and to influence the in situ pattern of T6+ and HLA-DR+ LCs. The cytogenetic study did not show evidence of spontaneous or UV-induced chromosomal instability.

Defined in situ enumeration of T6 and HLA-DR expressing epidermal Langerhans cells: morphologic and methodologic aspects.

An essential prerequisite for the in situ enumeration of epidermal Langerhans cells (LCs) is the unequivocal identification of the desired cell type. We have examined over 250 cryostat sections of normal human skin to analyze morphologic and methodologic problems underlying the quantification of epidermal LCs, defined by anti-T6 (OKT6) and anti-HLA-DR (OKIal) immunoperoxidase staining. Our findings show that OKT6 reactivity of dendritic processes in cross-sectioned epidermis yields microscopic images which are not easy to analyze objectively. The morphology that we find leads us to categorize dendritic cells into 3 arbitrary types of T6+ LC profiles. In addition we describe criteria for the assessment of OKT6 staining patterns relating to the dendritic state of epidermal LCs. Preliminary quantitative data on this issue are discussed in relation to: epidermal thickness; the thickness of skin tissue sections; and the discrepancy between the number of T6+ and HLA-DR+ LCs. We hope that the principles outlined in this report may serve to overcome potential methodologic problems with quantitation of T6+ epidermal LCs in skin sections.

Laser-Doppler flowmetry in the investigation of irritant compounds on human skin.

The value of laser-Doppler flowmetry was assessed in the evaluation of increased microvascular blood flow caused by the application of low concentrations of irritant compounds on the skin. Laser-Doppler flow values were compared with a visual scoring system for erythema and with skin vapour loss measurements. To this end patch tests were performed on the volar side of the forearm of 24 healthy Caucasian volunteers. The test substances were sodium lauryl sulphate 0.5 g/v%, 1 g/v%, 2 g/v% and phenol 5.0 g/v% in aqua dest. Distilled water served as a control. Laser-Doppler flow and skin vapour loss measurements were performed before and after an application time of 24 h. Data obtained with skin vapour loss measurements and with the visual scoring system demonstrated a statistically significant contribution of substance- as well as subject-related factors to the obtained scoring patterns. The results of laser-Doppler flow measurements were less consistent and could only partly be explained in this way, indicating that other factors also influence the microvascular blood flow in the skin. In this investigation laser-Doppler flowmetry and the visual scoring system were equally sensitive. The results of all three methods make it clear that (analogous to experience in daily life) barrier function impairment and inflammatory response caused by irritant compounds vary in different subjects. For the elucidation of the pathogenesis of irritant contact dermatitis further (longitudinal) investigations on the possible predictive value of skin blood flow measurements will be necessary.