bluuebunny/crossref_metadata_2025 huggingface dataset:
Vascular consequences of dietary salt intake
Authors: Sanders Paul W.
Published: April 2009

Animal and human studies support an untoward effect of excess dietary NaCl (salt) intake on cardiovascular and renal function and life span. Recent work has promoted the concept that the endothelium, in particular, reacts to changes in dietary salt intake through a complex series of events that are independent of blood pressure and the renin-angiotensin-aldosterone axis. The cellular signaling events culminate in the intravascular production of transforming growth factor-β (TGF-β) and nitric oxide in response to increased salt intake. Plasticity of the endothelium is integral in the vascular remodeling consequences associated with excess salt intake, because nitric oxide serves as a negative regulator of TGF-β production. Impairment of nitric oxide production, such as occurs with endothelial dysfunction in a variety of disease states, results in unopposed excess vascular TGF-β production, which promotes reduced vascular compliance and augmented peripheral arterial constriction and hypertension. Persistent alterations in vascular function promote the increase in cardiovascular events and reductions in renal function that reduce life span during increased salt intake.
Fetal Leydig Cell Origin and Development
Authors: Griswold S.L. , Behringer R.R.
Published: April 2009

Male sexual differentiation is a complex process requiring the hormone-producing function of somatic cells in the gonad, including Sertoli cells and fetal Leydig cells (FLCs). FLCs are essential for virilization of the male embryo, but despite their crucial function, relatively little is known about their origins or development. Adult Leydig cells (ALCs), which arise at puberty, have been studied extensively and much of what has been learned about this cell population has been extrapolated to FLCs. This approach is problematic in that prevailing dogma in the field asserts that these 2 populations are distinct in origin. As such, it is imprudent to assume that FLCs arise and develop in a similar manner to ALCs. This review provides a critical assessment of studies performed on FLC populations, rather than those extrapolated from ALC studies to assemble a model for FLC origins and development. Furthermore, we underscore the need for conclusive identification of the source population of fetal Leydig cells.
Sox100B, a Drosophila Group E Sox-domain Gene, Is Required for Somatic Testis Differentiation
Authors: Nanda S. , DeFalco T.J. , Hui Yong Loh S. , Phochanukul N. , Camara N. , Van Doren M. , Russell S.
Published: April 2009

Sex determination mechanisms are thought to evolve rapidly and show little conservation among different animal species. For example, the critical gene on the Y chromosome, SRY, that determines sex in most mammals, is not found in other animals. However, a related Sox domain transcription factor, SOX9, is also required for testis development in mammals and exhibits male-specific gonad expression in other vertebrate species. Previously, we found that the Drosophila orthologue of SOX9, Sox100B, is expressed male-specifically during gonad development. We now investigate the function of Sox100B and find, strikingly, that Sox100B is essential for testis development in Drosophila. In Sox100B mutants, the adult testis is severely reduced and fails to interact with other parts of the reproductive tract, which are themselves unaffected. While a testis initially forms in Sox100B mutants, it fails to undergo proper morphogenesis during pupal stages, likely due to defects in the pigment cells. In contrast, no substantive defects are observed in ovary development in Sox100B mutant females. Thus, as is observed in mammals, a Sox9 homolog is essential for sex-specific gonad development in Drosophila, suggesting that the molecular mechanisms regulating sexually dimorphic gonad development may be more conserved than previously suspected.
Sex Chromosome Rearrangements in Polyphaga Beetles
Authors: Dutrillaux A.M. , Dutrillaux B.
Published: April 2009

The presence of a parachute sex chromosome bivalent (Xyp) at metaphase I of male meiosis is a well-known characteristic of Coleoptera, present in almost all families of this order and assumed to represent their ancestral sex chromosome formula. Sex chromosomes appear to be manifold more frequently involved in inter-chromosomal rearrangements than the average of the nine autosomal pairs usually forming their karyotype. This leads to various formulae such as neo-sex, multiple sex and perhaps unique sex chromosomes. These rearrangements alter the intimate association between sex chromosomes and nucleolar proteins, which are usual components of the Xyp. Different situations, selected in a series of 125 mitotic and meiotic cytogenetic studies of Polyphaga beetle species, are reported and discussed, with the aim to improve our knowledge on the mechanisms of sex chromosome rearrangements, the relationships with nucleoli and the consequences on dosage compensation and chromosome segregation.
Endothelial Dysfunction, Vascular Disease and Stroke: The ARTICO Study
Authors: Roquer J. , Segura T. , Serena J. , Castillo J.
Published: April 2009

Endothelial dysfunction is a fundamental step in the atherosclerotic disease process. Its presence is a risk factor for the development of clinical events, and may represent a marker of atherothrombotic burden. Also, endothelial dysfunction contributes to enhanced plaque vulnerability, may trigger plaque rupture, and favors thrombus formation. The assessment of endothelial vasomotion is a useful marker of atherosclerotic vascular disease. There are different methods to assess endothelial function: endothelium-dependent vasodilatation brachial flow-mediated dilation, cerebrovascular reactivity to L-arginine, and the determination of some biomarkers such as microalbuminuria, platelet function, and C-reactive protein. Endothelial dysfunction has been observed in stroke patients and has been related to stroke physiopathology, stroke subtypes, clinical severity and outcome. Resting ankle-brachial index (ABI) is also considered an indicator of generalized atherosclerosis, and a low ABI is associated with an increase in stroke incidence in the elderly. Despite all these data, there are no studies analyzing the predictive value of ABI for new cardiovascular events in patients after suffering an acute ischemic stroke. ARTICO is an ongoing prospective, observational, multicenter study being performed in 50 Spanish hospitals. The aim of the ARTICO study is to evaluate the prognostic value of a pathological ABI (≤0.9) in the presence of a major cardiovascular event during a 1-year follow-up after first-ever ischemic stroke. Secondary objectives include the evaluation of the predictive value for major cardiovascular events of the carotid intima-media thickness, carotid duplex findings, and certain biomarkers. Data from the ARTICO study will increase the knowledge of patient outcome after ischemic stroke and may help to improve our ability to detect patients at high risk of stroke recurrence or major cardiovascular events.
Underlying Pathology of Stroke of Unknown Cause (Cryptogenic Stroke)
Authors: Amarenco Pierre
Published: April 2009

Underlying pathologies of stroke of unknown cause include atherosclerosis in brain arteries, either intracranial (e.g. moderate middle cerebral artery stenosis), extracranial (e.g. vertebral artery origin stenosis) or proximal (e.g. thick plaques in the aortic arch), thought to be unrelated to the stroke; cardiac findings of undetermined causal link (e.g. patent foramen ovale); incomplete or late workup responsible for true, undiagnosed cause (e.g. arterial dissection, mobile intracardiac/luminal thrombus disappeared at the time of examination). In the next years, new diagnostic tools may hopefully determine which of these pathologies are or are not causally related to stroke.
Antiplatelet Drugs for Ischemic Stroke Prevention
Authors: Leys Didier , Balucani Clotilde , Cordonnier Charlotte
Published: April 2009

In primary prevention trials conducted in low-risk subjects, aspirin is associated with a small reduction in ischemic strokes in women. It also reduces the incidence of stroke in patients with nonvalvular atrial fibrillation (NVAF), but warfarin is more effective in patients with high blood pressure, or left ventricular dysfunction, especially those aged >75 years. According to secondary prevention trials in patients after noncardioembolic ischemic stroke or transient ischemic attacks, aspirin at any dose between 50 and 1,300 mg per day reduces the risk of new events, but doses >150 mg per day are associated with a worse gastrointestinal tolerance. Clopidogrel and a combination of aspirin plus extended-release dipyridamole are both slightly more effective than aspirin, but the combination of aspirin and clopidogrel does not reduce the risk of new vascular events and increases life-threatening bleedings. Aspirin cannot be recommended for secondary prevention in NVAF, except in the case of absolute contraindications to warfarin. The available data show that at the acute stage of ischemic stroke, aspirin is safe and slightly more effective than placebo or heparin, even in NVAF, but other antiplatelet agents have not been evaluated.
Lipid-Lowering Drugs in Ischemic Stroke Prevention and Their Influence on Acute Stroke Outcome
Authors: Fuentes Blanca , Martínez-Sánchez Patricia , Díez-Tejedor Exuperio
Published: April 2009

Introduction: Dyslipidemia is a recognized risk factor for coronary arterial disease, but its role as risk factor for stroke has been controversial for a long time. In the last years, much attention has been paid to lipid-lowering therapies as a key preventive measure to reduce stroke risk. Methods: We conducted a nonsystematic review of published studies analyzing the association between serum lipids and stroke risk, with special attention to the findings of clinical trials with lipid-modifying therapies (LDL-lowering drugs such as statins, HDL-increasing drugs such as torcetrapib) and to the effect of prior statin therapies on acute stroke severity. Results: Data from large cohort prospective studies, case-control studies and clinical trials confirm the association between serum lipids and stroke risk. In secondary stroke prevention, atorvastatin 80 mg is effective in patients with prior transient ischemic attack and noncardioembolic ischemic stroke. Pretreatment with statins in stroke patients is associated with better outcomes. This protective effect is more evident in atherothrombotic and lacunar infarctions. Statin withdrawal during acute stroke is associated with loss of the protective effect, and statin discontinuation after an acute ischemic stroke is also associated with higher mortality at 1 year of follow-up. Conclusions: Dyslipidemia is a modifiable stroke risk factor. Long treatment with atorvastatin 80 mg has been associated with reduced risk of stroke recurrences and other cardiovascular events in patients with noncardioembolic transient ischemic attack or ischemic stroke. Prior statin treatment is associated with lower stroke severity and better outcomes in acute ischemic stroke patients. Statin treatment should never be discontinued in these patients.
Endoscopic Argon Plasma Coagulation for the Treatment of Gastric Antral Vascular Ectasia-Related Bleeding in Patients with Liver Cirrhosis
Authors: Fuccio L. , Zagari R.M. , Serrani M. , Eusebi L.H. , Grilli D. , Cennamo V. , Laterza L. , Asioli S. , Ceroni L. , Bazzoli F.
Published: April 2009

Background and Aim: Gastric antral vascular ectasia (GAVE) is a cause of bleeding in patients with liver cirrhosis. Argon plasma coagulation (APC) is the most used endoscopic treatment for GAVE-related bleeding. Treatment failures have been described in patients with haemorrhagic diathesis; post-procedure complications include haemorrhages and septicaemia. The aim of the study was to evaluate efficacy and safety of APC treatment of GAVE-related bleeding in patients with liver cirrhosis. Methods: Patients included were suffering from GAVE-related bleeding and liver cirrhosis. APC treatment was performed until eradication. Resolution of transfusion-dependent anaemia and evaluation of complications were the primary outcomes. Results: 20 patients (16 Child C and 4 Child B) were enrolled and prospectively followed for a mean period of 28 months. GAVE eradication was achieved in all patients after a median of 3 sessions (range 1–10). Resolution of anaemia was achieved in 18 patients. Six patients had relapse of GAVE after a mean of 7.7 months, successfully retreated by APC. Hyperplastic polyps developed in 3 patients causing active bleeding in 2 cases. Five patients had liver transplants and 1 had a relapse of GAVE after transplantation. Conclusion: APC is an effective and safe endoscopic treatment for GAVE in patients with liver cirrhosis.
Intralymphatic Injections as a New Administration Route for Allergen-Specific Immunotherapy
Authors: Martínez-Gómez Julia M. , Johansen Pål , Erdmann Iris , Senti Gabriela , Crameri Reto , Kündig Thomas M.
Published: April 2009

Background: IgE-mediated allergy can be treated by subcutaneous allergen-specific immunotherapy (SIT). However, the percentage of allergic patients undergoing SIT is low, mainly due to the long duration of the therapy and the risk of severe systemic allergic reactions associated with the allergen administration. To improve the safety and attractiveness of SIT for patients, alternative routes of allergen administration are being explored, such as sub-lingual or oral administration. Methods: The present study evaluated direct intralymphatic allergen administration as a means to enhance SIT with bee venom and cat fur allergens in mice. Allergen-specific antibody and T-cell responses were analysed by ELISA and flow cytometry. The therapeutic potential of intralymphatic immunisation in sensitised mice was analysed using an anaphylaxis model. Results: Direct injection of the major bee venom allergen phospholipase A2 or the major cat fur allergen Fel d 1 into inguinal lymph nodes enhanced allergen-specific IgG and T-cell responses when compared with subcutaneous injections. Moreover, only intralymphatic immunisation stimulated the production of the Th1-dependent subclass IgG2a, which is associated with improved protection against allergen-induced anaphylaxis. Biodistribution studies showed that injection into the lymph node delivered antigen more efficiently to subcutaneous lymph nodes than subcutaneous injection. Conclusions: As intralymphatic immunisation induced more than 10-fold higher IgG2a responses with 100-fold lower allergen doses than subcutaneous immunisation, this approach should allow to reduce both the number of allergen injections as well as the allergen dose, improving both efficacy and safety of SIT.
Dietary Conjugated Linoleic Acid Induces Tissue-Specific Lipoprotein Lipase mRNA Modulation in High-Sucrose-Fed Mice
Authors: Castellanos-Tapia Lyssia , Yepiz-Plasencia Gloria , Moya-Camarenaa Silvia Y.
Published: April 2009

Background/Aims: To delineate the hypotriglyceridemic effect of conjugated linoleic acid (CLA) in mice, the effect of this fatty acid on lipoprotein lipase (LPL) and apolipoprotein C-III (ApoCIII) mRNA accumulation in muscle, adipose and liver tissue was studied. Methods: CD-1 mice were housed in groups of 6 and randomized to one of three experimental diets for 3 weeks: SUC: 65% sucrose by weight; CLA: 1% CLA oil (34.4% c9,t11; 35.1% t10,c12 and 4.1% other conjugated isomers) and 65% sucrose, and DEX: 65% dextrose, as a control. Results: LPL mRNA levels in muscle tissue were increased in the DEX group and in the CLA group (240% increase) compared with the SUC group. In contrast, LPL mRNA levels were 81% lower in epididymal adipose tissue from the CLA group compared with the SUC group. There was no effect of dietary treatments on ApoCIII mRNA accumulation in the liver. Conclusions: These data suggest that dietary CLA may induce partitioning of circulating triglycerides to muscle tissue, preventing their accumulation in adipocytes.
Long-Term Low-Dose Spironolactone Therapy Is Safe in Oligoanuric Hemodialysis Patients
Authors: Matsumoto Yoshihiro , Kageyama Shinji , Yakushigawa Toru , Arihara Kazuo , Sugiyama Toshikazu , Mori Yasuo , Sugiyama Hatsumi , Ohmura Hiromichi , Shio Nobuo
Published: April 2009

The Randomized Aldactone Evaluation Study showed that low-dose spironolactone treatment dramatically reduced mortality in patients with heart failure. However, the clinical use of this drug may be limited due to its tendency to cause life-threatening hyperkalemia in hemodialysis (HD) patients. We assessed whether low-dose spironolactone could be safely administered to HD patients for a long period. The study design comprised 2-month baseline and 6-month treatment periods. Sixty-one oligoanuric HD patients were administered a spironolactone dose of 25 mg/day. Serum potassium levels at baseline were compared with those during the treatment. Eleven patients discontinued the treatment because of adverse events other than hyperkalemia or for other reasons. The remaining 50 patients completed the trial, and none of them showed a potassium level of >6.8 mEq/l or required additional ion exchange resin therapy throughout the study period. The mean potassium levels during the treatment were higher than those at baseline; the differences were statistically significant, but only marginally. The safety of spironolactone should be examined in larger trials. However, from this study, we conclude that long-term low-dose spironolactone treatment is clinically safe for many HD patients. A more extensive treatment may help in determining whether spironolactone can reduce cardiovascular mortality in HD patients.
A Retrospective Analysis of Thirty-One Cases of Plasma Cell Leukemia from a Single Center in China
Authors: Peijing Qi , Yan Xu , Yafei Wang , Dehui Zou , Zengjun Li , Junyuan Qi , Yaozhong Zhao , Lugui Qiu
Published: April 2009

Background/Aims: The study was undertaken to understand the characteristic of plasma cell leukemia (PCL) in China. Methods: We reviewed and compared medical data of 22 primary PCL, 9 secondary PCL and 461 multiple myeloma (MM) diagnosed at our institute from January 2000 to January 2008. Results: The median onset ages of primary and secondary PCL patients were 49.5 and 56 years, respectively. PCL patients presented with a low peripheral blood plasmacytosis, extensive involvement of visceral organs and poor residual bone marrow function, without severe renal insufficiency. Seventeen of twenty-one PCL patients had abnormal karyotypes, mostly complex and hypodiploid or pseudodiploid. The deletion of 13q was frequent in primary and secondary PCL (57.1 and 42.9%, respectively). There was a significant difference in survival among primary PCL, secondary PCL and MM (median 14, 2 and 37 months, respectively, p = 0.0000). Conclusion: Overall, primary and secondary PCL are different disorders with distinct natural histories and survival.
Biological Effects of Electrolyzed Water in Hemodialysis
Authors: Nakayama Masaaki , Kabayama Shigeru , Nakano Hirofumi , Zhu Wan-Jun , Terawaki Hiroyuki , Nakayama Keisuke , Katoh Kiyoshi , Satoh Toshinobu , Ito Sadayoshi
Published: April 2009

Background/Aims: The application of electrolyzed water (EW) at the cathode side to manufacture reverse osmosis (RO) water and hemodialysis (HD) solution can actually lead to less oxidative capacity in chemical terms. The present study examined the biological actions of this water on human polymorphonuclear leukocytes (PMNs), and the clinical feasibility of applying this technology to HD treatment. Methods: RO water using EW (e-RO) exhibited less chemiluminescence in luminol-hydrogen peroxide and higher dissolved hydrogen levels (–99.0 ppb) compared with control RO water. The effects of e-RO on PMN viability were tested. HD using e-RO was performed for 12 consecutive sessions in 8 patients for the feasibility test. Results: Basal cellular viability and function to generate superoxide radicals of PMNs were better preserved by e-RO application. In the clinical trial, reductions of blood pressure were noted, but no adverse events were observed. There were no changes in the blood dialysis parameters, although methylguanidine levels were significantly decreased at the end of study. Conclusion: The present study demonstrated the capacity of e-RO to preserve the viability of PMNs, and the clinical feasibility of applying this water for HD treatment. The clinical application of this technology may improve the bio-compatibility of HD treatment.
Predictors of Oliguric Acute Kidney Injury in Leptospirosis
Authors: Daher Elizabeth F. , Silva, Jr. Geraldo B. , Karbage Nahme N.N. , Carvalho, Jr. Paulo C. , Kataoka Raquel S. , Silva Eveline C. , Magalhães Max M. , Mota Rosa M.S. , Araújo Sônia M.H.A. , Gutiérrez-Adrianzén Oswaldo A. , Libório Alexandre B.
Published: April 2009

Background: Acute kidney injury (AKI) occurs in 10 to 60% of patients with leptospirosis. The aim of this study is to investigate markers for oliguric AKI in leptospirosis. Methods: A retrospective study was performed with 196 consecutive patients with leptospirosis-associated AKI. These patients were categorized into either oliguric or non-oliguric according to their urine output. Clinical and laboratory characteristics were compared between the two groups. Results: Among these patients, 64 (32.6%) were oliguric and 132 (67.4%) nonoliguric. Markers for oliguria were age higher than 40 years (OR = 1.02, p = 0.04), hyponatremia (OR = 0.94, p = 0.03), elevated serum creatinine (OR = 1.11, p = 0.04), low arterial pH (OR = 1.0002, p = 0.01), high levels of AST (OR = 1.005, p = 0.01), crackles (OR = 3.83, p < 0.001) and direct bilirubin (OR = 1.03, p = 0.03). Elevated activated prothrombin time (OR = 0.97, p = 0.03) was a factor associated with nonoliguric AKI. Independent markers for oliguria were crackles (OR = 5.17, p = 0.0016) and direct bilirubin levels (OR = 1.051, p = 0.04). Mortality was significantly higher in oliguric than nonoliguric (27 vs. 8%, p < 0.001). Renal function at discharge was similar in oliguric and nonoliguric patients. Conclusion: Age higher than 40 years, hyponatremia, elevated serum creatinine, low arterial pH, high levels of AST, crackles and direct bilirubin levels would be useful to early identify patients with oliguric AKI in leptospirosis.
Evaluation of a New Method of Assessing Pruritus and Antipruritic Drugs
Authors: Wahlgren Carl-Fredrik , Hägermark Östen , Bergström Reinhold , Hedin Björn
Published: April 2009

A new method (Pain-Track®) for recording subjective symptoms was evaluated for its capacity to quantify clinical itch. The Pain-Track system includes portable data loggers carried by the patients, a personal computer with a software package for storage and analysis of the data and a terminal unit to connect the loggers and computer. Every 60 min a signal from the logger commands the patient to mark his presence and rate the itch intensity. During night time the hourly buzz can be turned off but the intensity rate can be adjusted whenever wanted. The antipruritic effect of betamethasone dipropionate and its cream base was studied according to a double-blind, crossover protocol in 30 adult outpatients with atopic dermatitis, 26 of whom completed the study. Analysis with parametric and nonparametric methods showed that the itch intensity was significantly lower during active treatment than with placebo. Onset of the antipruritic action was rapid. Examination of the ‘itch profile’ revealed that atopies have more intense itch both in the mornings and evenings than during the day. It is concluded that by using a drug with known antipruritic effect we have shown that Pain-Track is a useful tool for assessing clinical pruritus and the antipruritic effects of drugs. The main advantages are possibilities for frequent recordings, surveillance of compliance improving authenticity, and storage and analysis of a large amount of data.
Leukotriene B4 Receptors on Neutrophils in Patients with Psoriasis and Atopic Eczema
Authors: Meier Friedegund , Gross Eva , Klotz Karl-Norbert , Ruzicka Thomas
Published: April 2009

Polymorphonuclear leukocyte (PMNL) infiltration is an important characteristic in psoriatic lesions. Elevated concentrations of the chemoattractant eicosanoid leukotriene B4 (LTB4) are present in psoriatic skin. Its chemotactic activity is mediated via high affinity receptors on PMNL. The goal of our work was to ascertain whether PMNL infiltration in psoriasis can be accounted for by functional abnormalities of the circulating PMNL due to alterations in the LTB4 receptor density or affinity (or both). No significant difference was found between patients with psoriasis, healthy controls and patients with another inflammatory dermatosis (atopic eczema) with regard to the binding parameters of LTB4 receptors on PMNL. Our findings suggest that PMNL accumulation in psoriatic skin may be the result of an excess of cutaneous chemoattractant rather than the increased readiness of psoriatic PMNL to migrate towards LTB4 due to altered LTB4 receptor density or affinity.
Use of a New Argon Laser Technique to Evaluate Changes in Sensory and Pain Thresholds in Human Skin following Topical Capsaicin Treatment
Authors: Bjerring Peter , Arendt-Nielsen Lars
Published: April 2009

A new argon laser technique was introduced to evaluate the excitability of the free nerve endings in the skin following topical application of capsaicin. Short argon laser pulses can be perceived as distinct, painful pin pricks and the pain threshold can be determined. This gives the possibility to follow changes in sensory and pain thresholds after topical application of various substances. In the present study the long-term effect of topically applied capsaicin on the pain threshold was monitored. Capsaicin was applied to human skin once daily for 21 days, and the pain threshold was significantly increased after 10 days of application, and after 21 days the increase was found to be 260%. After termination of capsaicin treatment the thresholds were monitored for 21 days, and normalization occurred after 7 days. Argon laser stimulation is a reliable method to evaluate sensory and pain thresholds in human skin.
Vasoactive Pharmacologic Responses of Human Skin Xenografts in Ciclosporin-Treated Rats
Authors: Salm Martin , McCullough Jerry L. , Weinstein Gerald D.
Published: April 2009

Human skin xenografts in ciclosporin-treated rats have been reported to preserve many of the characteristics of normal human skin. This model was used to study the cutaneous responses of human skin xenografts and host rat skin to intradermal injections of vasoactive agents. The xenograft responses to corticosteroids (blanching), nicotinic acid (erythema), histamine HC1 (urticaria), and privine (blanching) all paralleled those of the host rat skin. However, when quantitatively compared to the responses reported for human skin in vivo, the xenografts were less sensitive to these compounds. The large variability seen in the xenograft responses may be due to variable graft revascularization and to structural irregularities in the dermis from the recent grafting procedure. It is concluded that the lower sensitivity and variable responsiveness of the xenografts limit the potential usefulness of this pharmacologic model for evaluating vasoactive agents.
Pseudoepidermis, Constructed in vitro, for Use in Toxicological and Pharmacological Studies
Authors: Scavarelli-Karantsavelos Rosa Maria , Zaman Saroya Shahanara , Vaughan Frizell L. , Bernstein Isadore A.
Published: April 2009

The purpose of this study was to establish the validity of the stratified, cornified keratinocyte culture as a model for investigating cutaneous toxicities. This pseudoepidermis, grown on a nylon membrane at the air-liquid interface, responded to topical application of a known vesicant similarly to the response of the tissue in vivo. Alterations in the morphology of the in vitro model also resembled pathological changes seen in in vivo models after exposure to this agent. The effects of the skin irritants benzoate and salicylate on protein and DNA synthesis in the culture were also similar to those observed in vivo.
Effect of Tiacrilast, a Mast Cell Mediator-Release Inhibitor, on Murine Experimental Contact Dermatitis
Authors: Csatò M. , Judák Rita , Bozóky B. , Czarnetzki B.M.
Published: April 2009

The effect of tiacrilast, a mast cell mediator-release inhibitor, was studied in dinitrofluorobenzene-induced allergic and croton oil- or dimethyl sulfoxide-induced irritant murine contact dermatitis. At 1 % concentration, the compound significantly reduced the ear swelling in both allergic and irritant dermatitis and preserved the mast cell architecture on histopathology. These findings suggest that mast cells participate in the elicitation of murine contact dermatitis.
Differentiation of F9 Embryonal Carcinoma Cells by Synthetic Retinoids: Amplitude of Plasminogen Activator Production Does Not Depend on Retinoid Potency or Affinity for F9 Nuclear Retinoic Acid Receptors
Authors: Bailly J. , Delescluse C. , Bernardon J.M. , Charpentier B. , Martin B. , Pilgrim W.R. , Shroot B. , Darmon M.
Published: April 2009

Retinoic acid and analogues (retinoids) are able to induce the differentiation of F9 murine embryonal carcinoma stem cells into endoderm-like cells. The secretion of plasminogen activator (PA) which accompanies this differentiation is a good index of the biological response of F9 cells to retinoids. We have previously reported that the potency of a series of natural and synthetic retinoids, evaluated by the concentration which provokes half-maximal induction of PA, correlates well with the affinity of these compounds for the endogenous F9 nuclear retinoic acid receptors, but not for the cytosolic retinoic acid binding protein, CRABP. In this paper we show that various retinoids differ, not only in terms of potency, i.e. the dilution at which they are active, but also in terms of the amount of PA that they induce. This parameter, called amplitude, is used to quantify the extent of PA induction by a given retinoid relative to retinoic acid. The amplitude parameters of synthetic retinoids are found to vary over a wide range and are independent of both potency and binding affinity for F9 retinoic acid receptors. It is proposed that the amplitude of the biological response to a given retinoid is the resultant of three factors: (i) the total or partial agonist character of the retinoid; (ii) the binding spectrum of the retinoid for the various types of retinoic acid receptors; (iii) the chemical and metabolic stability of the retinoid in the test system.
Quantification of Epidermal Histological Changes Induced by Topical Retinoids and CD271 in the Rhino Mouse Model Using a Standardized Image Analysis Technique
Authors: Bouclier Marline , Chatelus Alain , Ferracin Joseph , Delain Chantal , Shroot Braham , Hensby Christopher N.
Published: April 2009

The rhino mouse has been used as an experimental model to screen topically active comedolytic agents. Adult rhino mice were treated on the back once daily for 5 consecutive days per week during 3 weeks. Skin histological preparations were analyzed by image analysis techniques to quantify the number of epidermal comedones, comedo profile and epidermal thickness. Using both a negative (treated with acetone) and a positive (treated with Aberel® gel 0.025%) control group of animals in all experiments conducted over a period of about 3 years, we defined the upper and lower limit of acceptability of the results. Topical treatment with an acetone solution of all-trans retinoic acid (0.01, 0.03, 0.1 %) and 13-cis-retinoic acid (0.1 %) induced comedolysis and a marked increase in epidermal thickness. Commercial preparations of all-trans retinoic acid (Aberel® lotion, gel and cream, Retin A® cream, Retacnyl cream) presented a similar comedolytic activity. However, the epidermal thickening was higher with Retin A and weaker with Retacnyl. CD271, a new modulator of cell differentiation, applied either in acetone solution (0.01, 0.1 %) or in lotion, gel or cream formulations (0.1 %) also demonstrated a marked activity (i.e. comedolysis and epidermal thickening). These data confirm that the rhino mouse model can be used to assay drugs applied either in solvent or in topical formulations. Activity in this model compares favorably with published clinical observations in the treatment of acne.
Automatic Scanner for Multi-Point Laser Doppler Flux Recordings on Human Skin
Authors: Fruhstorfer Heinrich , Selbmann Otto , Ziegenhagel Udo
Published: April 2009

A computer-driven device is described which moves the probes of a laser Doppler flowmeter linearly back and forth over the skin and stops precisely at preselected points to measure capillary perfusion. It offers extended possibilities to record the spatiotemporal flux changes in response to a local stimulus (e.g. injection of a vasoactive substance).
Presence of Vasoactive Intestinal Peptide Receptors in Nasal Mucosa
Authors: Agha-Mir-Salim S. , Baumgarten C. , Jahnke V. , Niedobitek G. , Kunkel G.
Published: April 2009

In recent years several tachykinins have been identified in the airway sensory nerves. Since the physiological and pathophysiological effects of neuropeptides depend on their functionally relevant concentrations and presence of specific receptors in the target tissue, specimens of enlarged turbinates and nasal polyps were removed in 11 patients and examined for the presence of vasoactive intestinal peptide (VIP) receptors. An intensive color reaction was observed in the cytoplasm of the tubular mucosa cells in polyps and turbinates as well as in the epithelium and submucosal glands. Since both these tissues reacted with VIP receptor antibody, noncross-reacting antibody against dendritic reticular cells (DRC 6-B7), nonspecific binding is possible, however it also must be speculated that the unspecific binding is overlaying specific binding. In addition a large number of cells located diffusely or in close association in the subepithelium and interstitial tissue stained only with VIP-specific antibody, indicating specific receptor binding. The color reaction is limited to the cell membrane and the cytoplasm of these cells was clearly eosinophilic. These cells were located in close proximity of the blood vessels, very indicative for active migration. Since VIP-positive nerves are also located near the blood vessels an activation process of these cells with subsequent release of enzymes and other active proteins is possible, thus influencing the inflammatory response.
Cutaneous NAD(P)H:Quinone Reductase: A Xenobiotica-Metabolizing Enzyme with Potential Cancer and Oxidation Stress-Protecting Properties
Authors: Merk Hans F. , Jugert Frank K.
Published: April 2009

The toxicity of quinones – including certain chemotherapeutic agents such as doxorubicin – have been related to the enzymatic or nonenzymatic formation of the corresponding semiquinones and their subsequent reaction with molecular oxygen yielding superoxide anion radicals by spontaneous regenerating of the quinones. This semiquinone redox cycling is prevented by the NAD(P)H:quinone reductase (NQR; EC 1.6.99.2) because it mediates a 2-electron reduction which results in the formation of hydroquinones instead of semiquinones. Interestingly, inducers of this enzyme such as butylated hydroxytoluene protect against the severe ulceration of accidental infiltration of doxorubicin into the area around the intravenous infusion. Recently, it has been shown that this highly protective enzyme has a very high basal activity in the epidermis which is in the same range as in the liver. The human gene of the NQR is localized on chromosome 16 and has been cloned recently as well as the gene of the murine liver NQR. We determined NQR in the cytoplasma of murine skin, liver, and human keratinocytes using 2,6-dichlorophenol-indophenol as substrate. In order to characterize this enzyme, induction by polycyclic hydrocarbones and inhibition with several known inhibitors of dihydrodiol dehydrogenase, aldo-keto and carbonyl reductase activities were determined. There was a similar pattern of inhibition of the basal and induced activity in all tissues so far investigated. Pyrazole, progesterone and phenobarbital did not inhibit; however, rutin and indomethacin inhibited dose-dependently. The most potent inhibitor was dicoumarol. These findings suggest that the same enzymatic form is present in liver and skin, and in murine skin and human keratinocytes.
A Quantitative Method for Measuring Antipsoriatic Activity of Drugs by the Mouse Tail Test
Authors: Bosman Brigitte , Matthiesen Theo , Hess Volker , Friderichs Elmar
Published: April 2009

Topical treatment of the mouse tail with antipsoriatic drugs enhances orthokeratotic cell differentiation in the epidermal scales. We developed a new evaluation system for this test which allows quantification of drug efficacy. Drugs were applied topically, once daily, 5 times a week, for 2 weeks. Two hours after the last treatment the animals were sacrificed, longitudinal sections of the tail skin were made and prepared for histological examination (hematoxylineosin staining). As indicator of orthokeratosis (OK), the length of the granular layer per scale was measured microscopically with a semiautomatic image evaluation unit and related to the total scale length(= % OK per scale). Drug activity was defined by the increase in the total length of orthokeratotic regions, 100% activity corresponds to a granular layer extending over the whole scale length. In this model dithranol and retinoic acid dose-dependently increased orthokeratosis up to 75 and 79%, respectively. Beech tar, in a concentration of 5 % induced a 19 % increase in orthokeratosis. Morphometric quantification by image analysis of the conversion of parakeratotic into orthokeratotic regions in mouse tail scales induced by topical drug treatment seems to be a suitable and reliable procedure to investigate new drugs from which antipsoriatic acitivity may be expected.
Reconstructed Human Epidermis: A Model to Study in vitro the Barrier Function of the Skin
Authors: Régnier M. , Caron D. , Reichert U. , Schaefer H.
Published: April 2009

In previous studies, we have shown that architecture and differentiation of human epidermis reconstructed by culturing dissociated keratinocytes on deepidermized dermis at the air-liquid interface resembles very much those of epidermis in vivo. The various types of epidermal layers are present with the appropriate differentiation markers, such as the bullous pemphigoid antigen, suprabasal keratins, involucrin, membrane-bound transglutaminase and filaggrin, positioned almost like in normal epidermis. At the ultrastructural level, heterogeneous keratohyalin granules and intra- and extracellular membrane-coating granules are observed. After 7 days of culture, a compact stratum corneum covers the reconstructed epidermis. In the present work, the barrier function of the reconstructed epidermis was evaluated by measuring fluxes of 3H-water. Our results show that under the various culture conditions tested, the presence of the reconstructed epidermis reduces dramatically the permeability of the deepidermized dermis although the skin equivalent exhibits a higher permeability than normal skin. Conditions that favor terminal differentiation of the keratinocytes such as maintaining the cultures in delipidized serum improve the barrier function. Reduction of the relative humidity has a similar effect, whereas the age of the culture is of no influence. Experiments are in progress to reconstruct human epidermis with a barrier function as efficient as in normal skin.
Effects of Calcipotriol (MC 903) and Calcitriol after Topical Application on the Skin of Hairless Rats
Authors: Bräutigam M. , Hübner H. , Rach P. , Thieroff-Ekerdt R.
Published: April 2009

Topical application of calcitriol or its analogs is a new approach for treating psoriasis, but may be limited by systemic calcitropic effects. Calcipotriol (MC 903) is a novel calcitriol analog with low calcitropic potency after systemic application. To compare the topical potency of calcitriol and calcipotriol we applied the two drugs on the right flanks of hairless rats for 10 days. In concentrations of 0.001-0.01 g/100 ml (ethanol) the two drugs are equally effective in inducing changes in the horny layer of the skin (increase in the amount of horny material that is able to be desquamated). This can be interpreted as a stimulation of terminal keratinocyte differentiation. However, only calcitriol caused a significant rise in the serum calcium concentration. In conclusion, calcitriol and calcipotriol seem to be equally effective after topical application on the skin of hairless rats, but calcipotriol has a much lower systemic calcium liability.
Absorption and Metabolism of Topically Applied Testosterone in an Organotypic Skin Culture
Authors: Ernesti Alexander M. , Swiderek Mark , Gay Roger
Published: April 2009

The Living Skin Equivalent (LSETM) is an organotypic coculture of human dermal fibroblasts in a collagen-containing matrix and a stratified epidermis composed of human epidermal keratinocytes. In order to establish the feasibility of using this in vitro system as a model for cutaneous biotransformation, the metabolic fate of topically applied testosterone (T) was monitored in the LSE. After a 24-hour exposure period (37 °C) to radiolabelled T, LSE extracts analyzed by high-performance thin-layer chromatography showed that approximately 50% of the applied T had been metabolized. Identified metabolites included bands which comigrated with polar metabolites and products of T 5Α-reductase. The general distribution of the observed metabolites was similar to that obtained usingbiopsied human skin. The rates of T penetration (32 °C) through the LSE were monitored after application of T in two vehicles (water and petrolatum) and yielded permeability constants (Kps) of 29 and 1.6 × 10-3 cm/h, respectively. These Kp values were 4- to 6-fold higher than those reported for human abdominal skin, and reflect the vehicle-related shift in penetration seen in human skin. The Kp values for two additional steroids, estradiol and hydrocortisone, and for T were also determined at 22 °C and compared to published Kp values. These Kp values in the LSE were, respectively, 63-, 187-and 35-fold higher than those reported for human skin. The data suggest that compared to human skin the LSE has only a partial barrier function to the passage of test chemicals. The magnitude of the difference in the rates of penetration between the LSE and human skin depends on the test chemical. For specific chemicals, such as T, the LSE simulates certain aspects of skin metabolism and percutaneous absorption.
The Possibility of Lidocaine Ion Pair Absorption Through Excised Hairless Mouse Skin
Authors: Nash Robert A. , Mehta Deepak B. , Matias Jonathan R. , Orentreich Norman
Published: April 2009

The purpose of the present research was to test the ion pair absorption hypothesis with respect to the topical route of drug delivery. The experiment consisted of preparing various lido-cainen-alkanoate ion pairs, then characterizing them by proton magnetic resonance spectroscopy, elemental analysis and conductivity. Percutaneous absorption studies through excised hairless mouse skin were carried out using ethanolic solution of radiolabeled 14C-lidocaine-octanoate, 14C-lido-caine-decanoate and 14C-lidocaine-dodecanoate. Studies were conducted under steady-state conditions using Bronaugh’s flow-through apparatus and normal saline as the receptor fluid. Ethanolic solution of a lidocaine base served as a control. The apparent differences in flux between lidocaine and the various ion pairs were statistically significant (p < 0.05). The differences among the fluxes of the various ion pairs were not statistically significant (p > 0.05), nor were the differences in lag times (p > 0.05). The difference between the flux values of lidocaine- 1-14C-dodecanoate and 14C-lidocaine-dodecanoate infers that lidocaine-dodecanoate did not cross the excised, full-thickness, hairless mouse skin as an intact 1:1 ion pair. The formation of weakly associated ion pairs was suggested by the apparent low-association constants (Ka = 15-17 liters/mol) obtained at 25 °C in methanol by conductometric analysis.
Hair Cycle and Alopecia
Authors: Courtois Monique , Loussouarn Geneviève , Hourseau Colette , Grollier Jean François
Published: April 2009

Male pattern alopecia is the outcome of profound modifications in the duration, succession and frequency of hair cycles. These phenomena were studied by phototrichogram in 10 male subjects, with or without alopecia, over a period of 15 years. Almost 10,000 hair cycles were accounted for, yielding a detailed picture of the alopecia condition: (1) A decrease in the duration of anagen for a certain proportion of hairs, a proportion which increases in size, the more advanced the alopecia; the result of this premature transformation from anagen to telogen is an increase in the rate of hair loss. (2) A parallel decline in hair diameter. (3) Longer latency periods between the fall of a hair and the onset of regrowth, leading to a reduction in the number of hairs present on the scalp surface. The shorter finer hairs are absent more frequently and absent for longer periods and this contributes to the effect of alopecia.
Alpha-lnterferon Cream Restores Decreased Levels of Langerhans/indeterminate (CD1a+) Cells in Aged and PUVA-Treated Skin
Authors: Ghersetich Ilaria , Lotti Torello
Published: April 2009

Langerhans/indeterminate (CD1a+) cells are known for their role in stimulating T-lymphocyte-dependent immune reactions. They are normally present in the skin and are modified in a variety of different pathological and physiological events, including aging. Linear decrease of CD1a+ cells with aging (both true aging and photoaging) is considered the most important cause of reduced immunosurveillance in aged old skin of the elderly. Recently it has been suggested that alpha-interferon might have an effect on increasing levels of dendritic cells in aged and photoaged skin. We studied biopsies from the preauricular area in 15 subjects (5 subjects aged 18-21 years, 5 aged 57-75, and 5 aged 30-45 who underwent PUVA therapy, total irradiation 120 J/cm2) before and after the application of alpha-interferon cream. Our findings show that dendritic cells are significantly decreased in the 57- to 75-year-old group compared to the 8- to 21-year-old group. After PUVA therapy we also found a decrease in Langerhans cells. Our study shows that the application of alpha-interferon cream induces an increase in cutaneous CD1a+ cells and HLA-DR+ cells in both older subjects and subjects who have undergone PUVA therapy. On the basis of these results, one could hypothesize that alpha-interferon cream may have some beneficial effects on photoaging-reduced immunosurveillance.
High-Frequency Sonophoresis: Permeation Pathways and Structural Basis for Enhanced Permeability
Authors: Menon Gopinathan K. , Bommannan D.B. , Elias Peter M.
Published: April 2009

The mechanism of stratum corneum (SC) permeabilization by ultrasound (sonophoresis) is unknown. We studied here permeation pathways, and SC intercellular structural organization following applications of high-frequency sonophoresis to hairless mouse skin. Ruthenium tetroxide post-fixation and tracer solutions of LaNO3 and FITC-dextrans were employed to examine SC lamellar bilayers, lamellar body morphology and subcellular permeation pathways. Sonophoresis disrupted the compact organization of SC bilayers and LB-derived contents at the stratum granulosum (SG)-SC interface, leading to domain separation between 0 and 20 h, reverting by 48 h. Post-sonophoresis, tracers traversed the SC via lacunae within the lamellar bilayers, and via lamellae in sites that displayed domain separation. These studies provide insights about the penetration pathways, permeabilizing mechanisms, and kinetics of sonophoresis on the epidermis.