Skin Suction Blister Fluid Research Articles

Effects of Prednisolone on Serum and Tissue Fluid IGF-I Receptor Activation and Post-Receptor Signaling in Humans.

Short-term glucocorticoid exposure increases serum insulinlike growth factor I (IGF-I) concentrations but antagonizes IGF-I tissue signaling. The underlying mechanisms remain unknown. To identify at which levels glucocorticoid inhibits IGF-I signaling. Nineteen healthy males received prednisolone (37.5 mg/d) and placebo for 5 days in a randomized, double-blinded, placebo-controlled crossover study. Serum was collected on days 1, 3, and 5, and abdominal skin suction blister fluid (SBF; ~interstitial fluid) was taken on day 5 (n = 9) together with muscle biopsy specimens (n = 19). The ability of serum and SBF to activate the IGF-I receptor (IGF-IR) (bioactive IGF) and its downstream signaling proteins was assessed using IGF-IR-transfected cells. Prednisolone increased IGF-I concentrations and bioactive IGF in serum (P ≤ 0.001) but not in SBF, which, compared with serum, contained less bioactive IGF (~28%) after prednisolone (P < 0.05). This observation was unexplained by SBF concentrations of IGFs and IGF-binding proteins (IGFBPs) 1 to 4. However, following prednisolone treatment, SBF contained less IGFBP-4 fragments (P < 0.05) generated by pregnancy-associated plasma protein A (PAPP-A). Concomitantly, prednisolone increased SBF levels of stanniocalcin 2 (STC2) (P = 0.02) compared with serum. STC2 blocks PAPP-A from cleaving IGFBP-4. Finally, prednisolone suppressed post-IGF-IR signaling pathways at the level of insulin receptor substrate 1 (P < 0.05) but did not change skeletal muscle IGF-IR, IGF-I, or STC2 messenger RNA. Prednisolone increased IGF-I concentrations and IGF bioactivity in serum but not in tissue fluid. The latter may relate to a STC2-mediated inhibition of PAPP-A in tissue fluids. Furthermore, prednisolone induced post-IGF-IR resistance. Thus, glucocorticoid may exert distinct, compartment-specific effects on IGF action.

A Comparative Proteomic Study of Human Skin Suction Blister Fluid from Healthy Individuals Using Immunodepletion and iTRAQ Labeling

Aberrations in skin morphology and functionality can cause acute and chronic skin-related diseases that are the focus of dermatological research. Mechanically induced skin suction blister fluid may serve as a potential, alternative human body fluid for quantitative mass spectrometry (MS)-based proteomics in order to assist in the understanding of the mechanisms and causes underlying skin-related diseases. The combination of abundant-protein removal with iTRAQ technology and multidimensional fractionation techniques improved the number of identified protein groups. A relative comparison of a cohort of 8 healthy volunteers was thus recruited in order to assess the net variability encountered in a healthy scenario. The technology enabled the identification, to date, of the highest number of reported protein groups (739) with concomitant relative quantitative data for over 90% of all proteins with high reproducibility and accuracy. The use of iTRAQ 8-plex resulted in a 66% decrease in protein identifications but, despite this, provided valuable insight into interindividual differences of the healthy control samples. The geometric mean ratio was close to 1 with 95% of all ratios ranging between 0.45 and 2.05 and a calculated mean coefficient of variation of 15.8%, indicating a lower biological variance than that reported for plasma or urine. By applying a multistep sample processing, the obtained sensitivity and accuracy of quantitative MS analysis demonstrates the prospective value of the approach in future research into skin diseases.

Matrix-metalloproteinase-2, -8 and -9 in serum and skin blister fluid in patients with severe sepsis

IntroductionMatrix metalloproteinases (MMPs) have various roles in inflammatory states. They seem to be able to modulate endothelial barriers and regulate the activity of chemokines and cytokines. The timely development of the levels during severe sepsis and thereafter have not been investigated. In addition it was of interest to study alterations of MMP-levels in intact skin, as the skin is the largest barrier against external pathogens and MMPs have not been studied at organ level in human sepsis. The aim of this study was to investigate the timely development of serum and skin MMP-2, -8 and -9 levels in human severe sepsis and their association with disease severity and mortality.MethodsForty-four patients with severe sepsis and fifteen healthy controls were included in this prospective longitudinal study. The amounts of MMP-2, -8 and -9 were analyzed from serum at days 1, 4, 6, 8, and 10, and from skin suction blister fluid at days 1 and 5 from the beginning of severe sepsis. Additionally, samples from the survivors were obtained after three and six months.ResultsThe levels of MMP-2 and -8 were up-regulated in severe sepsis in comparison to healthy controls in skin blister fluid and serum. Compared to the controls MMP-9 levels were lower in sepsis from the fourth day on in serum and both the first and fifth day in skin blister fluid. Active forms of MMP-2 and -9 were present only in severe sepsis. The non-survivors had higher pro- and active MMP-2 levels than the survivors in skin blister fluid samples. Furthermore, MMP-2 levels were more pronounced in blister fluid and serum samples in patients with more severe organ failures. In the survivors at 3 and 6 month follow-up the MMP levels had returned to normal.ConclusionsMMP-2 and -8 are elevated in serum and blister fluid in severe sepsis, implying that they may play a significant role in the pathogenesis of severe sepsis and organ dysfunctions. Active forms of MMP-2 and 9 were only present in patients with severe sepsis, and higher MMP-2 levels in skin blister and serum were associated with more severe organ dysfunctions.

Radiation-induced changes in skin type I and III collagen synthesis during and after conventionally fractionated radiotherapy

Background and purpose To measure local changes of collagen metabolism in irradiated breast skin and systemic changes in serum during and after radiotherapy and correlate these changes with skin thickness, erythema and palpable subcutaneous induration. Patients and methods Aminoterminal propeptides of type I and type III procollagens (PINP and PIIINP, respectively) were measured from skin suction blister fluid (SBF) in 21 breast cancer patients with breast conserving surgery and conventionally fractionated radiotherapy (RT) to a total dose of 50 Gy. Suction blisters were induced in the operated and contralateral breast skin before RT, at 2.5 weeks, at the end of RT, and at 1, 4, 7, 12 and 24 months post-treatment. Blood samples for serum were taken simultaneously with SBF induction. Skin thickness of the suction blister sites was measured with a high-frequency ultrasound device. The investigated sites were scored for erythema at the end of RT and palpable subcutaneous induration at 1 and 2 years post-treatment. Results In SBF the mean levels of PINP and PIIINP of the operated breast before RT were about 3–4 times higher than those in the contralateral breast due to the operation-related wound healing. The synthesis of PINP in irradiated breast after RT increased 7.7-fold ( P<0.001) 4 months post-irradiation. The PIIINP synthesis was at maximum at 1 month post-irradiation ( P<0.001). Both synthesis stayed elevated until 2 years. The level of PINP correlated significantly with the palpable skin induration at 1 and 2 years ( P=0.038 and P=0.003, respectively). The skin thickness of the irradiated breast was highest at 4 months post-treatment and significantly elevated until 1 year. The skin thickness correlated with the PINP level until 7 months and with PIIINP between 4 and 18 months. The PINP/PIIINP ratio reached the maximum at 4 months and stayed elevated until 2 years. No change in mean serum level of PINP was found during or after RT. Conclusions We demonstrated a maximum and elevated levels for PINP and PIIINP skin collagen metabolism determined from SBF during the 2 years' follow-up. Elevated levels of PINP and PIIINP correlated with the thickening of the skin and subcutaneous induration but not with erythema.

Levels of mast-cell growth factors in plasma and in suction skin blister fluid in adults with mastocytosis: Correlation with dermal mast-cell numbers and mast-cell tryptase

Background: Mast-cell accumulation has been observed in the skin and other organs of patients with systemic indolent mastocytosis (SM). The basis for this pathologic increase is not fully understood. Objective: We sought to determine levels of mast-cell growth factors in the skin and plasma of patients with SM, patients with atopic dermatitis (AD), and healthy individuals and to correlate these levels to dermal mast-cell numbers and levels of mast-cell tryptase. Methods: Skin suction blister fluid and plasma levels of stem-cell factor, IL-3, IL-4, IL-6, vascular endothelial growth factor, and total mast-cell tryptase were analyzed by means of ELISA. The number of mast cells was determined in a biopsy section taken from adjacent skin. Results: Mast-cell numbers in the dermis were higher in patients with SM compared with numbers in patients with AD (P < .001) or in healthy control subjects (P < .0001) and correlated with tryptase levels in both skin blister fluid (P < .0001) and plasma (P < .0001). Stem-cell factor and vascular endothelial growth factor levels in the skin blister fluid and plasma of patients with SM were not significantly different from those in patients with AD or healthy control subjects. IL-3 and IL-4 levels were below the limit of detection. IL-6 levels were significantly increased in the plasma of patients with SM compared with in plasma of patients with AD (P < .002) and healthy control subjects (P < .0001) and correlated with plasma tryptase levels (P < .05) and dermal mast-cell numbers (P < .02). Conclusion: Because elevated levels of IL-6 could contribute to the fever, fatigue, and osteoporosis observed in patients with SM and because IL-6 is antiapoptotic for mast cells, IL-6 could potentiate the biologic consequences of this disease. (J Allergy Clin Immunol 2002;109:82-8.)

Cefodizime in Skin Suction Blister Fluid and Serum Following a Single Intravenous or Intramuscular Dose in Adult Patients

Cefodizime is a third generation cephalosporin for parenteral use. The phar-macokinetics of this cephem antibiotic were determined in serum and skin suction blister fluid (SBF) after intravenous (i.v.) or intramuscular (i.m.) administration of a single 1 g dose in 8 adult patients with normal renal and hepatic function who volunteered for the study. The concentration versus time curve showed a slower elimination rate from the extravascular compartment: the half-lives were 4.4±0.5 and 5.4±0.4 hours after i.v. and i.m. route respectively. The relatively long elimination half-life in SBF with a mean residence time of about 8 hours allows the use of cefodizime once-a-day for the treatment of infections due to sensitive pathogens.

Pharmacokinetics of the 8-methoxyquinolone, moxifloxacin: tissue distribution in male rats.

BAY 12-8039 (moxifloxacin-HCl) and 14C-labelled BAY 12-8039 were administered to male rats as single i.v. and oral doses of 4.6 and 5.0 mg/kg bodyweight respectively. The distribution of substance-associated radioactivity in the body was investigated by whole-body autoradiography. The concentrations of the unchanged compound in plasma, skin suction blister fluid and lung tissue were determined by HPLC. Whole-body autoradiography revealed distinctly higher concentrations of radioactivity in the gastrointestinal tract, urinary bladder and in most organs and tissues (e.g. kidneys, liver, spleen, lungs, various glands, cartilaginous tissues and in melanin-containing structures located in the eye, meninges and hair follicles of pigmented skin) than in blood. Radioactivity crossed the blood-brain barrier only to a small extent. The results show a high tissue affinity and a rapid and homogeneous distribution of radioactivity from blood to organs or tissues. No relevant difference in the distribution of radioactivity was found following i.v. and oral administration. After i.v. and oral dosing similar concentrations of the unchanged compound were determined in skin suction blister fluid and plasma. The concentrations of the unchanged compound in lung tissue were about three times higher than those in plasma following both i.v. and oral administration. The concentration-time courses for moxifloxacin in plasma and lung tissue were parallel.

Plasma and skin suction-blister-fluid pharmacokinetics and time course of the effects of oral mizolastine.

To investigate plasma and skin suction-blister-fluid pharmacokinetics of oral mizolastine in order to determine whether the drug concentration in the fluid of suction-induced skin blisters could better predict the antihistamine activity than the plasma concentration. Department of Internal Medicine, Université Paris 6. Ten healthy male volunteers. The volunteers (mean age 26.8 years, mean weight 75.8 kg) received a single 10-mg oral dose of mizolastine at 1000 hours. The pharmacokinetic study included 11 plasma and 9 blister fluid samples and blister epidermal-roof specimens. Mizolastine was assayed by high-performance liquid chromatography (HPLC). Each volunteer also received nine intradermal injections of 5 micrograms histamine. Antihistamine activity was assessed as the post-treatment percentages of changes in the histamine-induced relative wheal and flare areas versus baseline. Mizolastine mean Cmax (SD) and median tmax were, respectively, 380 ng.ml-1 and 0.8 h in plasma, and 21.8 ng.ml-1 and 10 h in blister fluid. Mizolastine could not be quantified in the epidermis. The maximal histamine-induced relative flare inhibition was 72.5% and was attained at the median time of 3 h post-dosing and therefore was delayed by 2.2 h with respect to the plasma tmax. Mean relative wheal inhibition, although lower, showed the same time profile. A direct relationship could not be found between drug concentrations in blister fluid and antihistamine activity. Simulated concentrations in the peripheral compartment better explain the maximum inhibition effect on flare, observed 3 h post-dosing, with a flatter hysteresis loop obtained when plotting relative flare inhibition versus plasma or blister-fluid drug concentrations. The mizolastine concentrations in the skin suction-blister fluid were not predictive of the antihistamine activity.

Chloroquine phosphate: a long/term follow/up of drug concentrations in skin suction blister fluid and plasma.

Chloroquine is known to bind strongly to melanin and is accumulated in the skin. In dermatology, the drug is mainly used to treat photosensitivity disorders, but it has also been reported to cause sun sensitivity, especially in patients with rheumatoid arthritis. In the present study the concentrations of chloroquine phosphate in plasma and skin suction blister fluid (interstitial fluid in the skin) from 16 patients were studied by HPLC at steady-state (after 2 months' ingestion of 250 mg of the drug daily) and 2, 4 and 6-7 months after cessation of therapy. At steady-state the concentrations were similar in the two compartments, whereas after discontinuation the drug remained much longer in the skin than in the plasma. In tests using cow's eye melanin in vitro, UV irradiation failed to interact with the binding of chloroquine to melanin. It is speculated that the prolonged storage of the drug in the skin could be of importance for its therapeutic as well as adverse effects.

Skin tissue fluid levels of cefotiam in healthy man following oral cefotiam hexetil

Cefotiam hexetil is a pro-drug of cefotiam available for oral administration. To evaluate cefotiam concentrations at the active site in skin and soft-tissue infections, drug levels in skin suction blister fluid (SBF), cantharides blister fluid (CBF) and serum were determined. Six healthy subjects received oral cefotiam 400 mg as cefotiam hexetil. On an other day 200 mg was injected intravenously. Following the oral dose, the bioavailability of cefotiam was 45.5%, and the maximum concentration in serum of 2.6 mg.l-1 was obtained at 2.1 h. Peak concentrations in both types of blister fluid (0.9 mg.l-1) were significantly lower than after the iv dose (SBF 1.4 mg.l-1, CBF 1.5 mg.l-1), and the peak levels occurred later (3.3 versus 1.5 h in CBF). Despite the delay, the extent of penetration was about 100% following either mode of administration (SBF, iv dose 112%, oral dose 117%). The cefotiam level in skin blister fluids declined significantly more slowly than the serum level. Following the oral dose, the mean terminal half life was serum 0.8 h, SBF 2.6 h and CBF 4.6 h. Cefotiam concentrations in the blister fluids were close to the MIC90 of Staphylococcus aureus, S. epidermis and H. influenzae and exceeded the MIC90 of Streptococci, E. coli and Proteus mirabilis. Thus, the oral administration of cefotiam 400 mg t.i.d. should be curative in the majority of bacterial infections of the skin and soft-tissues.

Blood and tissue fluid levels of a new non-steroidal anti-inflammatory preparation of nabumetone.

The pharmacokinetic properties of a new non-steroidal anti-inflammatory preparation of nabumetone have been studied in both plasma and extravascular fluids. The skin suction blister technique was used on six healthy volunteers on two separate occasions and gave good, reproducible results. A single oral dose of 1 g nabumetone achieved significant blood and skin suction blister fluid concentrations. The partition index (area under the concentration curve for the skin suction blister/area under the concentration curve for blood) showed that the orally administered drug was well diffused within the body.

Cefodizime penetration into skin suction blister fluid following a single intravenous dose.

Cefodizime pharmacokinetics was investigated, evaluating drug concentrations in serum, skin suction blister fluid (SBF), saliva and urine in six healthy male subjects who were administered a 1-g dose intravenously. Serum levels in five subjects can be described according to a two-compartment open model; terminal half-life is 181 +/- 14 min. Volume of distribution (Vd beta) amounts to 15.3 +/- 1.61, serum clearance to 59 +/- 6 ml/min, renal clearance to 33 +/- 3 ml/min. Of the administered dose, 54% is renally excreted unchanged within 27 h. Unbound drug fraction in serum is 19.0% and in SBF 38.4%. Thus renal clearance of free cefodizime amounts to 172 ml/min, Vdss to 68.9 l (free drug). Whereas cefodizime has not been detected in saliva samples, SBF concentration 3-9 h post administration parallel serum levels, amounting to 40% of the respective serum concentration. At 9 h, unbound cefodizime concentrations in SBF amount to 1.4 +/- 0.4 micrograms/ml, this value being well above the MIC90% values of many clinically relevant bacteria.

Determination of 8-methoxypsoralen levels in plasma and skin suction blister fluid by a new sensitive fluorodensitometric method.

An improved fluorodensitometric assay for the determination of 8-methoxypsoralen (8-MOP) in plasma is described. Because of its low limit of detection (below 1 ng/spot) this method is suitable to determine the drug in skin suction blister fluid, too. The standard deviation of the procedure is 6.4% or less. Plasma and skin blister fluid levels of 8-MOP are determined 2 h following oral administration of 40-60 mg 8-MOP. They range from 0-239 ng/ml and 0-163 ng/ml, respectively. A rather close correlation (r = 0.91) between these two parameters could be observed. Thus, in cases with relatively high plasma levels sufficient skin levels can be predicted. If further investigations would prove, however, that a distinct concentration threshold required for therapeutic success exists--and recent experiments with fibroblast cultures imply that--skin blister fluid level determinations would seem highly desirable when plasma levels let us expect skin levels in the critical range. In general determination of 8-MOP skin blister fluid levels can be looked upon as a model for the evaluation of drug skin levels after systemic application in man.