Codeine-induced histamine release in intact human skin monitored by skin microdialysis technique: comparison ofintradermal injections with an atraumatic intraprobe drug delivery system

Background The skin microdiallysis technique makes it possible to measure histamine release in intact human skin in vivo directly. In this study we have used the microdialysis technique to characterize histamine release by codeine after intracutaneous injectioin and following skin challenge by a novel atraumatic delivery technique. Objective The purpose of the study was to compare histamine release in human skin by codeine. delivered by an intraprobe drug delivery system (IPD) and intracutaneous injections (ICT), with respect to dose-response relations, kinetics of histamine appearance and decay, corelations between histamine release and skin respones, and reproducibility. Methods Hollow dialysis fibres were inserted intradermally in 12 healthy subjects. Twelve fibres were inserted in each subjects, six fibres in each arm. Each fibre was perfused at a rate of 3 μL/min, and samples were collected in 2 min fractions. By the IPD technique, codeine was administrered to the skin by adding codeine to the perfusion medium. Sequential IPD challenges were performed in one arm. and ICTs were done on the other arm. Results Sixfold serial dilutions of codeine (0.01-3 mg/mL) caused a significant doserelated histamine release by ICT and IPD. Peak histamine release was found within the first 4 min after skin challenge by ICT and IPD, followed by a fast decline with a dialysate histamine half life of approximately 2-3 min. Peak hisamine release was linearly correlates with cumulative release of the 20 min sampling period, and histamine release correlated with weal soze. The coefficient of variation on peak histamine releae was 18.9% and 4.8% for codeine ICT and IPD, respectively. Conclusioin We have described in detail codeine-induced histamine release in intact human skin in vivo by the microdialysis technique. It was possible to administer codeine atraumaticallyl to the skin by intraprobe delivery. The skin microdialysis codeine atraumaticallly to the skin by intraprobe delivery. The skin microdialysis technique opens up possibilities for measurement of infllammatory mediators release in normal and diseases skin, and it will be possible to deliver immunopharmacologically active drugsto the skin by intraprobe delivery.     

Hereditary angio-oedema: new clinical observations and autoimmune screening, complement and kallikrein-kinin analyses

Objectives. To study clinical and laboratory manifestations of hereditary angio-oedema (HAE).
Subjects. Thirty-three affected members of a kindred of 63.
Results. Oedematous attacks in the skin, mucous membranes and gastrointestinal tract with fluid displacement were elicited by mental and physical stress, minor traumas, dental and surgical procedures, eruption of teeth, tonsillitis, pregnancies, and use of oestrogen-containing pills including menopausal substitution. Every adult woman with symptomatic HAE ( n =11) showed symptoms of urinary tract infections in conjunction with the attacks ( P = 0.010), and also experienced more spontaneous abortions or premature labours ( P =0.037) than healthy relatives. Patients with HAE of both sexes more frequently reported heartburn or peptic ulcers ( P =0.002). Rheumatic complaints were reported by 53% of HAE patients and 12% of their unaffected relatives ( P =0.013), but biochemical screening for 18 autoantibodies and quantitation of immunoglobulins did not reveal statistically significant differences between the two groups. C3, prekallikrein, total kininogen, high molecular weight kininogen (HK), alpha-2-macroglobulin and factor XII were not significantly different in HAE patients. In contrast, levels of C1-INH and C4 were depressed and cleaved HK increased in patients compared to unaffected relatives.
Conclusions. HAE manifests in a variety of ways, and may influence risk of spontaneous abortions and premature labour.     

Activation of the Complement, Coagulation, Fibrinolytic and Kallikrein–Kinin Systems During Attacks of Hereditary Angioedema

Five patients with hereditary angioedema (HAE) were studied during attacks and remission as were healthy controls. The high levels of C1/C1-INH complexes, low C4 and high ratio C4 activation products (C4bc)/C4 also differed significantly during remission compared to controls.During attacks C4bc/C4 increased (922–2007; P =0.022, remission versus attacks, median values throughout), C2 and CH50 dropped (111–31%; P =0.043 and 110–36%; P =0.016, respectively), TCC (C5b-9) increased (0.88–1.23 AU/ml; P =0.028). Cleavage of HK increased to be almost complete during attacks (20–90%; P =0.009). While factor XIa/serpin-complexes did not increase, a more than twofold rise in thrombin/antithrombin-complexes (0.20–0.50 μg/l; P =0.009) and in plasmin/alpha-2-antiplasmin-complexes (7.3–17 nmol/l; P =0.028) was observed. For the first time cascade activation in HAE was studied simultaneously, and corroborates that attacks lead to activation of the kallikrein-kinin system, fibrinolysis and early part of the classical complement pathway. In addition, the authors present novel data of terminal complement and coagulation activation, the latter apparently not via FXIa.     

CD4+CD25+ regulatory T cells: I. Phenotype and physiology

The immune system protects us against foreign pathogens. However, if fine discrimination between self and non-self is not carried out properly, immunological attacks against self may be launched leading to autoimmune diseases, estimated to afflict up to 5% of the population. During the last decade it has become increasingly clear that regulatory CD4⁺CD25⁺ T cells (T_reg cells) play an important role in the maintenance of immunological self-tolerance, and that this cell subset exerts its function by suppressing the proliferation or function of autoreactive T cells. Based on human and murine observations, this review presents a characterization of the phenotype and functions of the Treg cells in vitro and in vivo . An overview of the surface molecules associated with and the cytokines produced by the Treg cells is given and the origin, activation requirements and mode of action of the Treg cells are discussed. Finally, we address the possibility that Treg cells may play a central role in immune homeostasis, regulating not only autoimmune responses, but also immune responses toward foreign antigens.     

Catheter-Assisted Vein Sclerotherapy: A New Approach for Sclerotherapy of the Greater Saphenous Vein with a Double-Lumen Balloon Catheter

OBJECTIVE: We sought to optimize sclerotherapy of the greater saphenous vein (GSV) by targeted application of foamed sclerosant by using a catheter. METHODS: We designed a new double-lumen catheter that is inserted into the GSV. Via one lumen, a balloon at the tip of the catheter can be inflated to stop the blood flow. Via the second lumen, the sclerosing agent can be injected and aspirated. This method enabled us to perform a targeted application of the sclerosing agent [catheter-assisted vein sclerotherapy (KAVS)]. In an open study, outpatients suffering from varicosis of the GSV received a foam sclerotherapy under ultrasound guidance, using the newly developed KAVS catheter. RESULTS: Thirty patients with an insufficiency (reflux) of the GSV were treated with the newly developed KAVS method using foamed polidocanol. The intervention was well tolerated in all patients without the occurrence of serious side effects. In 27 of the 30 treated patients (90%), we found a closure of the GSV at control visits 6 weeks, 3 months, and 6 months after treatment. CONCLUSIONS: The KAVS method represents a feasible approach for sclerotherapy of the GSV. The efficiency and treatment modalities need to be explored in further studies.     

Reproducibility of responsiveness to a standardized bronchial allergen provocation—Rt compared to FEV1 as measurement of response to provocation

Standardized bronchial allergen provocation was performed twice in nineteen extrinsic, well defined, stable asthmatic patients, with an interval of median 15 days (range 14–19) to study the reproducibility of the bronchial response. Smoking and medications were withheld prior to the provocation after a rigid scheme. Ten-fold increasing concentrations of allergen solution 0.9 ml were inhaled by tidal volume breathing for 5 min with intervals of 10 min. The bronchial response to inhaled allergen was determined by forced expiratory volume in the first sec (FEV₁) and by total resistance to breathing (R_t) determined by an opening interrupter method. The provocation was continued until an allergen concentration causing at least 20% decrease of the postsaline FEV₁ or a 40% increase in R_t was reached. A PC₂₀-FEV₁ and a PC₄₀-R_t was calculated by interpolation on the log-dose-response curve. The reproducibility of PC₂₀-FEV₁ allergen was high with a 95% confidence interval (CI) for a single determination being the observed value ±0.83, ten-fold concentration difference, the intraclass correlation (IC) was 0.99 and the coefficient of variation 8.46%. Concerning PC₄₀-R_t a 95% CI for a single determination was calculated being the observed value ±0.58, ten-fold concentration difference, IC was 0.99 and the coefficient of variation was 5.79%. No significant correlation was found between differences in pre-challenge FEV₁ and R_t values and the corresponding PC₂₀-FEV₁ and PC₄₀-R_t values. Least square regression between PC₂₀-FEV₁ and PC₄₀-R₁ was performed for the first and the second provocation (P < 0.05). We conclude that bronchial allergen challenge performed in stable asthmatics is highly reproducible and as such a valuable test in the diagnosis of allergic asthma when connected with anamnesis, skin-prick test and the level of specific immunoglobulin E in peripheral blood.     

Transmission electron microscopy of early microbial colonization of human enamel and root surfaces in vivo

Abstract – This study describes the early microbial colomization of teeth by the use of light-and transmission electron microscopy. Six dental students carried a total of 60 test pieces of unerupted enamel and root surface in intraoral acrylic appliances for 4, 8, 12, 24 and 48 h, during which periods oral hygiene was abandoned. Pronounced variations were recorded in structure and thickness of the pellicle across the individual surfaces of both dental tissues. Bacterial single-cell colonization increased the electron density of the adjoining pellicle. Micro-colonies of bacteria were observed in relation to enamel surface irregularities such as perikymata, while the distribution on root surfaces appeared incidental. Root surfaces were generally colonized by thicker deposits than homologous enamel surfaces although the structural composition of the microbiota was similar. Gram-positive bacteria with thick cell walls appeared in coccoid or rod-shaped configurations depending on the age of the bacterial deposit. These bacteria were further characterized by selective invasion between collagen fibers. After 48 h the complexity of the microbiota was increased by the establishment of new bacterial species in the superficial layer. It is concluded that the pattern and composition of the early microbiota on teeth is more complex and variable than hitherto assumed.     

Dependency of renal potassium excretion on Na,K-ATPase transport rate

Potassium secretion may depend on the transport rate of Na, K-ATPase in basolateral cell membranes of distal tubular cells. To examine this hypothesis experiments were performed in anaesthetized dogs during inhibition of proximal potassium reabsorption by acetazolamide or mannitol (fractional potassium excretion 1.2-1.4) or additional stimulation of potassium secretion by ethacrynic acid (fractional potassium excretion 2.1). Ouabain in a dose which inhibits 70–80% of the Na, K-ATPase activity reduced fractional potassium excretion to 0.8-0.9 by an effect on distal tubular secretion since potassium transport in the proximal tubules was not affected. Ouabain-sensitive potassium excretion varied in proportion to ouabain-sensitive sodium reabsorption during variation in glomerular nitration rate, even at urinary sodium concentrations exceeding 80 mmol 1^-1. In experiments without ouabain, saline infusion raised potassium excretion and sodium reabsorption until maximal Na, K-ATPase transport rate was reached, as judged from heat production measurements, but not during further increments in urine flow. After inhibition of Na, K-ATPase activity by hypokalaemia, potassium excretion and cortical heat production remained constant over a wide range of urine flow and sodium excretion. We conclude that potassium secretion is dependent on intact Na, K-ATPase activity and is stimulated by sodium delivery to the distal nephron until maximal transport rate of the enzyme is reached.     

Effects of dynamic leg exercise on subcutaneous blood flow rate in the lower limb of man

Subcutaneous blood flow (SBF) was studied simultaneously in the upper arm at heart level and in the lower limb during positional changes and during leg exercise in seven healthy males. SBF was estimated by local clearance of ‘“Xenon registered by portable cadmium telluride detectors. Venous pressure was recorded directly on dorsum on the foot. Changinr the position from supine to head-up tilt, SBF decreased by 43 % (P < 0.01) at the arm level, 40% at the thigh (P < 0.01), 47% at the calf (P < 0.01) and decreased by 51 % at the ankle level (P < 0.01). Performing 20 heel-raisings per min in nearly erect posture, SBF increased by 96% at the thigh (P < 0.01), 25% at the calf (P > 0.1) and increased by 18% at the ankle level (P > 0.1). At 40 heel-raisings per min SBF increased by 99% at the thigh (P < 0.0 1), 121 % at the calf (P < 0.0 1), but only 44% at the ankle level (P > 0.1). During leg exercise subcutaneous vascular resistance was significantly increased at arm and ankle levels. In contrast, a vasodilatory response was noticed at the thigh and calf levels and seemed associated with a decrease in local venous pressure to below the trigger level of the sympathetic veno-arteriolar reflex mechanism. In conclusion, SBF in the lower limb of man was increased during exercise. The increase in SBF could only partly be ascribed to the concomitant increase in perfusion pressure. The local blood flow response seemed modified by changes in sympathetic nervous activity and metabolic rate.