In vitro test of nicotine's permeability through human skin. Risk evaluation and safety aspects

Permeability tests with Franz' diffusion cells and an in vitro test model were made to evaluate the importance of dermal absorption of nicotine as a pathway for intoxication. Studies were carried out to ensure that safety procedures, when spilling nicotine on skin, are sufficient to prevent poisoning. Pure nicotine and nicotine in various concentrations in water or ethanol were applied on human skin or gloves in Franz' cells. Washing was simulated by removing nicotine from skin after 3 or 5 min. Permeation rate (flux) and lag time were calculated and estimated for human skin. Different glove materials were tested for their nicotine breakthrough time. Flux depended on concentration in a non-linear way when nicotine-water solutions were tested. Highest flux was found in 50% w/w nicotine dissolved in water. Solutions with low concentration of nicotine (1% w/w) dissolved in water had a similar permeation rate to 100% nicotine. Flux was found to be low when using ethanol as a vehicle; flux was also pH-dependent. The nicotine-water solution containing acetic acid had the lowest flux. The tests where nicotine was washed away revealed that skin served as a possible nicotine depot, because nicotine concentration in the receptor compartment continued to increase after removing the nicotine from the surface. The length of contact time affected the amount of substance passing the skin, resulting in great difference between 3 and 5 min contact time, 5 min giving higher nicotine concentration and 3 min lower. This emphasizes the importance of washing away nicotine spilled on skin rapidly. Two glove types were tested and they were found to be appropriate in their use with nicotine if changed regularly.

Oral terbinafine in toenail dermatophytosis. A double-blind, placebo-controlled multicenter study with 12 months' follow-up

The treatment of onychomycosis has previously often been protracted and unsuccessful. Terbinafine has been shown to be effective in short-term regimens. In this double-blind, placebo-controlled study, 148 patients with toenail dermatophytosis were randomized to treatment with either 250 mg terbinafine daily or placebo for 3 months. An additional treatment was given for 3 months to patients whose infection had not responded. The patients were followed clinically and mycologically through 12 months. After 3 months 82% of the terbinafine-treated group, versus 5% of the placebo group, showed significant improvement, i.e. negative culture and growth of unaffected nail more than 2 mm (p = < 0.0001). After 12 months clinical and mycological cure was seen in 40% of the patients treated with terbinafine for 3 or 6 months, while 67-81% were clinically cured, but with positive microscopy. Side-effects occurred in 13.5% of the terbinafine group, versus 5.4% of the placebo group, and were mild. 250 mg terbinafine daily for 3 months was significantly more effective than placebo. The efficacy did not appear to improve with additional treatment for 3 months.

Oxazolidonylethyl adducts to hemoglobin and DNA following nornitrogen mustard exposure

Formation of adducts to hemoglobin (Hb) and DNA of nornitrogen mustard (NNM) was studied with the aim of developing a method for monitoring exposure to NNM. Adducts to N-terminal valines in Hb were studied by the N-alkyl Edman method using pentafluorophenyl isothiocyanate (PFPITC) as the derivatizing reagent. In preliminary studies five major Hb adducts were shown to be formed in reaction of NNM with red cell hemolysate in vitro. Following treatment with PFPITC three of these were found to be pentafluorophenylthiohydantoins (PFPTHs) of N-alkylated valines and the fourth probably originates from NNM esters in which PFPITC had reacted with the nitrogen of N-chloroethylaminoethyl. A PFPTH was found to originate from N-2-(3-oxazolidonyl)ethylvaline, Val-OZ. Val-OZ is formed in reaction, with ring closure to oxazolidone, of CO2 with the 2-chloroethylamino group in the primary valine-N adduct. Besides a few other adducts, Val-OZ was also observed in mouse Hb following injection of NNM, and also after injection of cyclophosphamide. Following reaction in vitro of NNM with DNA, three major adducts to guanine-N-7 were observed; one of them, 7-(N'-(2-chloroethyl)-2-aminoethyl]-guanine (NNMCl), was converted by carbonate to 7-(2-3-oxazolidonyl)ethyl]guanine (Gua-OZ). In mice treated with NNM, Gua-Oz was the only DNA adduct observed. Val-Oz is a chemically stable Hb adduct, potentially useful for monitoring exposures to NNM and cyclophosphamide.

Occupational exposure to nor-nitrogen mustard: chemical and biological monitoring

Nor-nitrogen mustard is an alkylating agent used in kilogram quantities in the production of various cytostatics. It has been shown to be mutagenic in vitro, and therefore must be regarded as a health hazard. We have studied the environment and blood of a small group of individuals working with nor-nitrogen mustard. New chemical methods for measuring surface contamination were used to make comparisons with ambient air levels of nor-nitrogen mustard. Surprisingly high levels of surface contamination were found even after decontamination, which has led to new decontamination routines and the establishment of wipe test limits of 0.5 microgram nor-nitrogen mustard/dm2. The wipe test has proved effective in following the day-to-day routine handling of nor-nitrogen mustard. Blood samples were taken before, during, and after production runs and analyzed for the frequency of chromosome aberrations (CAs), sister chromatid exchanges (SCEs), and somatic (HPRT) mutations. No significant differences in chromosome aberrations, SCEs, or somatic mutations were found in the peripheral blood from production workers before, during, or after handling of nor-nitrogen mustard. Nor was any difference found between the production workers and a local control group. However, the local controls' chromosome and HPRT frequencies appeared to be somewhat high, demonstrating the problems involved in these types of studies, in which the group sizes are small.

Leukocyte adherence in atopic dermatitis: diminished responses to histamine and isoproterenol

Leukocyte adherence was examined in atopic and normal subjects and the influence of histamine and the beta-adrenergic agonist, isoproterenol, evaluated. Atopics included patients with mild to severe atopic dermatitis and patients with asthma and hayfever. No inter-group differences in leukocyte adherence of untreated leukocytes could be demonstrated, but there was a significantly smaller histamine and isoproterenol effect on the adherence of cells from patients with atopic dermatitis and hayfever. The induced inhibition of leukocyte adherence by histamine could be blocked by the H-2 histamine receptor antagonist, metiamide, suggesting that this effect may be mediated via cAMP. Our findings support the hypothesis that atopic dermatitis patients may have a defect or blockade of their cellular response to histamine.

Skin sensitivity to denture base materials in the burning mouth syndrome

The significance of sensitizing compounds in the denture base for the etiology of the burning mouth syndrome (BMS) has been studied in 53 denture-wearing persons, seven males and 46 females. Epicutaneous patch tests were performed with standard concentrations of benzoyl peroxide, dibutylphthalate, dimethyl-p-toluidine, formaldehyde, hydroquinone, methylmethacrylate, p-phenylendiamine and with cadmium sulfate, potassium dichromate, cobalt chloride and nickel sulfate. Furthermore, patch testing was performed with filings from the denture mixed with the patient's own saliva. In cases with an inflamed oral mucosa, the presence of hyphae of Candida albicans was assessed by a smear technique. Positive skin reactions were observed in 15 persons to dimethyl-p-toluidine, hydroquinone, formaldehyde, methylmethacrylate, p-phenylendiamine, potassium dichromate, cobalt chloride and nickel sulfate, including three cases with reactions to filings from their dentures, and one patient who after subsequent testing showed skin sensitivity to balsam of Peru. In 12 cases an etiological connection could be traced between the oral symptoms and the denture base, indicating that contact sensitivity to base materials or to allergens and microbial antigens on the denture plate plays a greater role in the pathogenesis of BMS in edentulous persons than previously suggested.

Long-term transfer factor treatment in severe atopic dermatitis

Transfer factor therapy was applied in three patients with severe atopic dermatitis and given at regular intervals for 1 1/2 years. Clinically, slight improvements were seen, attacks of impetigo ceased and admissions to hospital were not necessary. However, IgE concentrations in serum remained constantly high in all cases and the absolute number of T and B lymphocytes was continuously subnormal despite treatment. The in vitro cellular reactivity to PPD as assayed by a leucocyte migration test was not significantly altered in the patients, although a slight increase was found early on in the therapy. Finally, a serum factor inhibiting leucocyte migration and appearing simultaneously with attacks of impetigo disappeared during treatment. In conclusion, no convincing effect of transfer factor therapy was encountered in immune parameters and no major alterations were found in the status of the patients' atopic dermatitis.

PPD and mitogen responsiveness of lymphocytes from patients with atopic dermatitis

Lymphocytes from twenty-five patients with atopic dermatitis were investigated for their in vitro reactivity to stimulation with tuberculin (PPD), lipopolysaccharide (LPS), phytohaemagglutinin (PHA), concanavalin A (Con A) and pokeweed mitogen (PWM). The response to a low dose of Con A was increased, and the reactivity in unstimulated cultures tended to be lower than similar cultures from the control group. Addition of inactivated autologous plasma to the cultures had an inhibitory effect, when the plasma came from patients with high levels of IgE. The patients' in vitro reactivity to PPD in a leucocyte migration test was equal to that found in normal persons and no effect was observed after addition of autologous serum. The mean percentage of E rosette forming cells was significantly reduced in patients with high levels of IgE. The number of EAC rosette forming cells was within normal range. It is hypothesized that the observations could reflect the existence of suppressor mechanisms in patients where the immune system is strongly stimulated.

Absence of leukocyte-migration inhibitory factor in serum from patients with mycosis fungoides

Sera from 16 patients with mycosis fungoides at various stages of the disease were investigated for the presence of a leukocyte-migration inhibitory factor. The agarose gel techinque with human peripheral blood leukocytes as migrating indicator cells was used for the purpose. The migration inhibitory effect of patients sera, pooled AB-sera and sera from control persons was tested on peripheral blood leukocytes from patients and controls. Also upconcentrated sera were used. The presence of substances with migration inhibitory effect in serum from patients with mycosis fungoides could not be demonstrated. The significance of these findings is discussed.

Allergy tests against formaldehyde, cresol, and eugenol in children with formocresol pulpotomized primary teeth

One hundred and twenty-eight children in the age range 5-14 years with formocresol pulpotomized teeth were tested for sensitivity againist formaldehyde, eugenol, and cresol using the patch test. The number of treated teeth on each child varied from one to six and the time between the pulpotomy and patch test varied from 2 months to 8 years. None of the children showed positive results.

Reactivity of lymphocytes from patients with syphilis towards T. pallidum antigen in the leucocyte migration and lymphocyte transformation tests

The reactivity of lymphocytes to Treponema pallidum antigen was studied before and after treatment in nine patients with early syphilis using a leucocyte migration test and a lymphocyte transformation test. Lymphocyte reactivity was also investigated in six patients treated for syphilis within the last 4 years, and in five untreated patients with a positive result to the T. pallidum immobilization test, but negative results to other serum tests for syphilis antibodies and without any known exposure to risk of infection by syphilis. Ten seronegative patients with different dermatological disorders served as a control group. A significant increase in lymphocyte reactivity to T. pallidum antigen was recorded in both tests in vitro after treatment. There was no difference in lymphocyte reactivity to T. pallidum antigen between the other patients studied and the control group. In early syphilis the spontaneous migration was found to be inhibited before treatment. Tuberculin skin tests were also performed and found to be suppressed in patients with primary and secondary syphilis. No difference in phytohaemagglutinin response was found between any of the groups. Plasma from patients with primary and secondary syphilis was found to change the in vitro reactivity of normal lymphocytes when stimulated with different mitogens.

In vitro parameters of cell-mediated immune reactions in healthy individuals following immune-stimulation attempts with levamisole

In vitro parameters of cellular immune reactions were followed by 10 healthy individuals during administration of levamisole. Leucocyte migration tests, lymphocyte transformation tests and ATP-ase activity of peripheral blood lymphocytes were investigated. Levamisole did not influence resting human lymphocytes of the stimulation response of lymphocytes. The metabolic activity of lymphocytes expressed by their ATP-ase activity was not significantly changed after levamisole administration.

Immune response to primary immunization with brucella antigen in mycosis fungoides

The immune response to primary immunization with brucella antigen was studied in 8 patients with mycosis fungoides and 11 controls. The development of as well cellular as humoral hypersensitivity to brucella antigen was followed by in vitro techniques. Both, patients with mycosis fungoides and controls were studied for previously acquired delayed hypersensitivity to tuberculin by skin test. The distribution of B and T cells was encountered among the patients. Previously acquired cellular immunity was found equal in the two groups, however, induction of cellular hypersensitivity to brucella antigen was found depressed in mycosis fungoides patients compared with the controls. Also the humoral response to brucella antigen could seem depressed, only one of seven patients with mycosis fungoides had a positive titer, while seven of eleven controls had positive titres following vaccination; but the difference between the two groups was not significant.