Skin Of Healthy Individuals Research Articles

Role of IL-10 and TGF-β in melanoma.

IL-10 and TGF-β are immunosuppressive cytokines expressed in tumors including melanoma and, therefore, deemed major cause for failing antitumor immune responses. Re-evaluating their role, we compared their expression by quantitative RT-PCR in melanoma and skin of healthy individuals, tested their induction in dendritic cells and T cells co-cultured with tumor cells, and their effects on the immune cells. Both cytokines as well as their receptors were expressed in melanoma at significantly lower levels than in healthy skin. Consequently, the expressions of IL-10-responsive SOCS-3 and TGF-β-responsive Smad-7 were low in tumors but high in healthy skin. T cells co-cultured with tumor cells developed an anergic state without increased IL-10 or TGF-β expression. In vitro tumor-induced immature dendritic cells produced high IL-10 levels and less efficiently induced T-cell proliferation. Nonetheless, they could be induced to mature, and blocking IL-10 did not alter the capacity of the resulting mature dendritic cells to stimulate T cells. Mature dendritic cells co-cultured with tumor cells produced increased IL-10 but decreased TGF-β and more efficiently induced T-cell proliferation. The lack of correlation of IL-10 and TGF-β with immune deficits in situ and in vitro suggests re-evaluating their roles in cancer.

Green areas around homes reduce atopic sensitization in children.

BackgroundWestern lifestyle is associated with high prevalence of allergy, asthma and other chronic inflammatory disorders. To explain this association, we tested the ‘biodiversity hypothesis’, which posits that reduced contact of children with environmental biodiversity, including environmental microbiota in natural habitats, has adverse consequences on the assembly of human commensal microbiota and its contribution to immune tolerance.MethodsWe analysed four study cohorts from Finland and Estonia (n = 1044) comprising children and adolescents aged 0.5–20 years. The prevalence of atopic sensitization was assessed by measuring serum IgE specific to inhalant allergens. We calculated the proportion of five land-use types – forest, agricultural land, built areas, wetlands and water bodies – in the landscape around the homes using the CORINE2006 classification.ResultsThe cover of forest and agricultural land within 2–5 km from the home was inversely and significantly associated with atopic sensitization. This relationship was observed for children 6 years of age and older. Land-use pattern explained 20% of the variation in the relative abundance of Proteobacteria on the skin of healthy individuals, supporting the hypothesis of a strong environmental effect on the commensal microbiota.ConclusionsThe amount of green environment (forest and agricultural land) around homes was inversely associated with the risk of atopic sensitization in children. The results indicate that early-life exposure to green environments is especially important. The environmental effect may be mediated via the effect of environmental microbiota on the commensal microbiota influencing immunotolerance.

Can bioinformed design promote healthy indoor ecosystems?

Can bioinformed design promote healthy indoor ecosystems?

Prevalence of biofilm-producing Staphylococcus epidermidis in the healthy skin of individuals in Tamil Nadu, India

Purpose:Staphylococcus epidermidis is a major commensal bacteria. Various strains of S. epidermidis are capable of forming biofilms by attaching to several surfaces. Biofilm-forming ability of this organism is found to be associated with many hospital-acquired infections and can even impair wound healing. S. epidermidis strains producing polysaccharide-biofilms possess the intercellular adhesion (ica) operon while strains forming the protein adhesion-mediated biofilms possess the accumulation associated protein (aap) gene. We screened for biofilm-forming S. epidermidis in the skin of healthy individuals in Tamil Nadu in order to determine the risk of acquiring S. epidermidis infections in hospital settings. Materials and Methods: Skin swabs were taken from seventy two subjects residing in Chennai with healthy skin who showed no visible signs of skin lesions or allergies. S. epidermidis was isolated from 58 samples out of the 72 collected. The presence of ica operon in S. epidermidis isolates was determined by PCR and biofilm production was examined using quantitative tissue culture plate assay. Results: Majority of the samples (47/72; 65.3%) showed pure S. epidermidis growth, (14/72; 19.4%) showed pure Staphylococcus aureus growth and the remainder (11/72; 15.3%) showed mixed growth. Biofilm-forming S. epidermidis were found in the majority of samples (53/58; 91.4%) and ica operon was detected in 19 samples out of 58 (32.8%) which is a significantly higher percentage when compared to other studies conducted at different parts of the globe (P = 0.0003). Conclusion: We inferred that ica operon and biofilm-forming S. epidermidis are common in the healthy skin of individuals in Tamil Nadu. Measures have to be taken to reduce the risk of hospital-acquired S. epidermidis infections.

Role of CD11c-positive dendrite cells in the psoriasis pathogenesis

The immune response, developing with psoriasis relapse, starts from the concentration of activated myeloid dendrite cells, being the main source of the necrosis factor of α -tumor in the area of originating papula. Target: studies of the number of sub-populations of dendrite cells in skin of patients, suffering from psoriasis in different periods of the disease. Маterial and methods. Skin biopsy samples of 43 patients, suffering from psoriasis vulgaris and skin biopsy samples of 16 healthy people have been studied. The skin immunohistochemistry with use of anti-CD11c, CD83 and CD3 аntibodies was performed. Results. The number of CD11c+ and CD83+ dendrite cells in the skin of patients, suffering from psoriasis in the progressing period was 11,2 and 7,8 times more than in the skin of healthy individuals and 3,0 and 2,4 times more than at patients, suffering from psoriasis during remission accordingly. Opinions. In the skin of patients, suffering from psoriasis, during remission at the place of the delivered psoriatic papule the number of CD83+, CD11c+ dendrite cells and CD3+ lymphocytes exceeds its number in the healthy skin, and the ratio of these cells and its localization in the lesion focuses differ from the skin of healthy people.

β-catenin is a central mediator of pro-fibrotic Wnt signaling in systemic sclerosis

ObjectivesPathologic fibroblast activation drives fibrosis of the skin and internal organs in patients with systemic sclerosis (SSc). β-catenin is an integral part of adherens junctions and a central component of...

Pulmonary Cryptococcosis Secondary to Bronchial Asthma Presenting as Type I Respiratory Failure- A Case Report with Review of Literature

Cryptococcus spp, was first isolated and described in 1894 by Sanfelice F in Italy from peach juice and named it as Saccharomyces neoformans, is an yeast like fungus, first isolated from a clinical specimen by Busse in the same year from Germany. Cryptococci are a saprophytic fungi present in soil contaminated with bird droppings mainly of pigeons, roosting sites and decaying vegetables. Previous reports have also showed the presence of Cryptococcus spp colonized in the nasopharynx and on skin of healthy individuals. Belonging to Basidiomyctes group of fungi Cryptococcus spp primarily infects central nervous system causing meningoencephalitis mostly in immunocompromised individuals. Classical and molecular genetic studies have revealed that Cryptococcus spp are closely related to ascomycetes group (Saccharomyces cerevisiae, Schizosaccharomyces pombe) and basidiomycetes pathogens and mushrooms (Ustilago maydis,Coprinus cinereus, Schizophyllum commune)

Detection of Merkel cell polyomavirus on environmental surfaces

The Merkel cell polyomavirus (MCPyV) is a human virus identified recently which is associated with the Merkel cell carcinoma. This virus is also detected frequently in the skin of healthy individuals. The presence of MCPyV has been investigated on environmental surfaces in contact with human skin. Various surfaces in four laboratories, public places, and individual homes were swabbed. Human DNA and MCPyV DNA were detected in swabs by real-time PCR. MCPyV DNA levels were measured before and after DNase treatment in a set of 12 MCPyV DNA-positive samples. A total of 60 environmental surface samples were collected. Fifty-one (85.0%) were positive for human DNA detection and 45 (75.0%) were positive for MCPyV DNA detection. All samples positive for MCPyV DNA were positive for human DNA detection. After DNase treatment, a 1.3 log decrease in MCPyV DNA level was observed indicating that about 5% of viral DNA is protected from DNase degradation and might be associated with infectious virus. These results indicate that MCPyV DNA may be detected on environmental surfaces in contact with human skin. Detection of viral DNA might reflect the presence of infectious viral particles and transmission from environmental source to humans cannot be ruled out.

Effect of age on the biomechanical and microcirculatory properties of the skin in healthy individuals and during venous ulceration.

Background:With aging there is alteration of elastic properties of the skin and skin-blood flow.Aim:The purpose of this study was to compare age-related changes in selected biomechanical parameters of the skin (skin hardness, skin extensibility, relaxation time constant, τ) and subcutaneous microcirculatory quality (SMQ) in individuals with and without venous diseases.Materials and Methods:Two groups were studied: the first group was of asymptomatic healthy individuals and the second group included patients with chronic venous insufficiency (CVI) and venous ulceration, without edema. Both groups were subdivided to three age categories (21-40, 41-60 and 61-90 years old). Skin hardness was measured by durometer, extensibility and τ were measured using extensometer and SQM was assessed via postural vasoconstrictive response (LDF).Results:Results showed that skin hardness, extensibility, and τ-values were increased, whereas LDF was decreased in the older groups as compared with younger groups. These changes are attributed to alterations in the skin structure and reduced capillaries density networks. Similar behavior was found in the biomechanical and microcirculatory changes in patients with venous ulceration and CVI, but these changes were more increased further in older patients with venous ulceration as compared with older patients with CVI and that can be attribute to more intense response against tissue injury.Conclusions:Since aging elevated skin hardness and extensibility, but lowered vasoconstrictive response in individuals, with and without, venous diseases, we conclude that aging process is likely to cause an accumulation of damaged skin tissues and that could induce an apparent antigen-driven response that altered skin structure and the subsequent biomechanical properties obtained in this study.

Evaluation of toxicity and Stat3 activation induced by hydrogen peroxide exposure to the skin in healthy individuals

[1] MacDonald Hull SP, WoodML, Hutchinson PE, SladdenM,Messenger AG. Guidelines for the management of alopecia areata. Br J Dermatol 2003;149:692–9. [2] OgawaH, Imai R, Nishiyama S, NakajimaH, Ikezawa Z, Tokuda Y, et al. The effect of an anti-allergic drug on the disease activity of alopecia areata. Skin Res 1994;36:60–8 [in Japanese]. [3] Yoshizawa Y, Kawana S. Efficacy of ebasitne in the treatment of alopecia areata. Jpn J Dermatol 2005;115:1473–80 [in Japanese]. [4] Inui S, Nakajima T, Toda N, Itami S. Fexofenadine hydrochloride enhances the efficacy of contact immunotherapy for extensive alopecia areata: retrospective analysis of 121 cases. J Dermatol 2009;36:323–7. [5] Nori M, Iwata S, Munakata Y, Kobayashi H, Kobayashi S, Umezawa Y, et al. Ebastine inhibits T cell migration, production of Th2-type cytokines and proinflammatory cytokines. Clin Exp Allergy 2003;33:1544–54. [6] Gilhar A, Paus R, Kalish RS. Lymphocytes, neuropeptides, and genes involved in alopecia areata. J Clin Invest 2007;117:2019–27. [7] Sundberg JP, Cordy WR, King Jr LE. Alopecia areata in aging C3H/HeJ mice. J Invest Dermatol 1994;102:847–56.

Chimerism Analysis of Langerhans Cells Early after T Cell Depleted Allogeneic Hematopoietic Stem Cell Transplantation.

Skin is the most frequently affected organ in acute graft versus host disease (GVHD). Data from murine studies support the hypothesis that the interaction of residing host Langerhans cells of the epidermis (LC) and donor T cells is crucial for the initiation of acute GVHD. Donor T cells are also necessary to induce the switch of LC from host to donor origin after allogeneic stem cell transplantation (SCT). In an ongoing clinical protocol applying alemtuzumab-based T cell depleted (TCD) allogeneic SCT (Meyer, Blood 2007; 109:374), we observed acute skin GVHD occurring early after transplantation. We therefore intended to analyse the LC chimerism in patients undergoing this protocol. So far, LC-chimerism analysis in humans has been performed by the detection of the Y-chromosome restricting it to sex-mismatched donor/recipient pairs. Here we introduce a new method to isolate LC from small skin samples at high purity for a sensitive STR-based chimerism analysis of general applicability. Epidermal skin layers were obtained from 6 mm punch biopsies by dispase I digestion. A small slice of epidermis was used for immunofluorescent staining. The remaining sample was digested by trypsin, and CD1a/MHC-class II-positive LC were sorted by flow cytometry. This approach resulted in a mean purity of > 96% with skin of healthy individuals. However, the density of LC early after SCT following non-TCD myeloablative regimens had previously been shown to be much lower compared to healthy individuals. By CD1a-staining, we were able to show that this is also the case after TCD reduced intensity SCT. Nevertheless, LC could be purified in all of 8 analyzed patients. The isolated LC numbers ranged from 10 to more than 1000. In 4 patients we performed a re-analysis of the isolated cells by flow cytometry and confirmed a purity exceeding 97%. We obtained reliable results for LC chimerism in 6 of 8 patients. After the RNA-isolation protocol was further improved, we were able to detect signals even with 35 isolated LC in patient MZ-47. In two patients, the majority of isolated LC were of donor origin whereas the other 4 patients had predominantly host LC (patients' characteristics and chimerism results are summarized in Table 1). None of the patients developed spontaneous acute GVHD so far. For patients MZ-37 and MZ-43 LC-chimerism was also performed after day +50 post HSCT and showed a switch to >97% donor chimerism at that time. In summary, we have established a sensitive method that enables the chimerism analysis on highly purified LC independent of sex-mismatched donor/recipient pairs. Our results on a few patients' samples can not yet be related to clinical events. This assay, however, allows the comprehensive investigation of the chimerism of LC and potentially of other tissue-resident antigen presenting cells to study their impact on GVHD in humans.Table 1patientdonortypesex (patient/donor)LC (n)purity (%)donor chimerism (%)37MSDF/M112797,7<339MMUDF/M75098,6>9740MMUDM/M180098,31343MMUDM/M10n.a.n.a.44MSDM/M157n.a.n.a.45MSDM/F325> 983646MMUDM/M355n.a.4847MSDM/M35n.a.>90MSD, matched sibling donor; MMUD, mismatched unrelated donor; n.a., not applicable; M, male; F, female

Betapapillomaviruses frequently persist in the skin of healthy individuals

Infections with human papillomaviruses (HPVs) belonging to the genus Betapapillomavirus have been linked to the development of non-melanoma skin cancer. Although persistence is expected, systematic investigation of this aspect of betapapillomavirus (beta-PV) infection has not been conducted. This study investigated the prevalence and persistence of 25 known beta-PV types in the skin of immunocompetent individuals. Over a 2 year period, eight consecutive plucked eyebrow hair samples taken from 23 healthy individuals were analysed for the presence of beta-PV DNA. Using a recently published general beta-PV PCR and genotyping method, 61% of the individuals were beta-PV DNA positive for one or more types at intake, whereas during follow-up this percentage rose to 96%. HPV23 was the most frequently detected beta-PV type. Type-specific beta-PV DNA was detected over 6 months or longer in 74% of the individuals. In 57% of the individuals, DNA from multiple beta-PV types was detected simultaneously for 6 months or longer. When the detection intervals of all beta-PV type-specific infections in the study population were considered, a substantial proportion, 48%, lasted at least half a year. The consistent beta-PV patterns found over time in most individuals strongly suggested that beta-PV DNA detection in plucked eyebrow hairs reveals true beta-PV infection. If the minimum interval of detection was set at 6 months, persistent beta-PV infections were found in the majority of the study population (74%).

Hyphal Invasion of Candida albicans Inhibits the Expression of Human β-Defensins in Experimental Oral Candidiasis

Oral epithelium reacts to microbial challenges by eliciting a defensive response that includes the production of antimicrobial peptides. This study investigated the expression of human beta-defensins-1, 2, and 3 in reconstituted human oral epithelia during experimental oral infections with six different Candida species, and a wild-type C. albicans isolate and five of its mutants. The expression of defensins was induced after 12 hours infection with the wild-type C. albicans, but this response was not seen for the noninvasive hyphal mutants nor the secreted aspartyl proteinase mutants. Furthermore, defensin expression was not detected after 48 hours in epithelia infected with either C. albicans wild-type isolate or its invasive hyphal and proteinase mutants. Most of the non-albicans Candida were capable of inducing the expression of defensins in epithelia after 24 or 48 hours of infection. These Candida-host interaction patterns suggest that the oral epithelia possess mechanisms for sensing the early invasion of C. albicans through recognition of the presence of hyphae and proteinases of Candida and respond to the insult by producing antimicrobial peptides. This hyphal-invasion-dependent inhibition of defensin expression in oral epithelium that undermines the host surveillance system represents a hitherto undescribed novel pathogenic mechanism of C. albicans.

Study of the distribution of Malassezia species in patients with pityriasis versicolor and healthy individuals in Tehran, Iran.

BackgroundPityriasis versicolor is a superficial infection of the stratum corneum which caused by a group of yeasts formerly named pityrosporium. The taxonomy of these lipophilic yeasts has recently been modified and includes seven species referred as Malassezia. The aim of this study is to compare the distribution of Malassezia species isolated from pityriasis versicolor lesions and those isolated from healthy skins.MethodsDifferentiation of all malassezia species performed using morphological features and physiological test including catalase reaction, Tween assimilation test and splitting of esculin.ResultsIn pityriasis versicolor lesions, the most frequently isolated species was M. globosa (53.3%), followed by M. furfur (25.3%), M. sympodialis(9.3%), M. obtusa (8.1%) and M. slooffiae (4.0%). The most frequently isolated species in the skin of healthy individuals were M. globosa, M. sympodialis, M. furfur, M. sloofiae and M. restricta which respectively made up 41.7%, 25.0%, 23.3%, 6.7% and 3.3% of the isolated species.ConclusionsAccording to our data, M. globosa was the most prevalent species in the skin of healthy individuals which recovered only in the yeast form. However, the Mycelial form of M. globosa was isolated as the dominant species from pityriasis versicolor lesions. Therefore, the role of predisposing factors in the conversion of this yeast to mycelium and its subsequent involvement in pityriasis versicolor pathogenicity should be considered.

Differential expression of cytokines in UV-B-exposed skin of patients with polymorphous light eruption: correlation with Langerhans cell migration and immunosuppression.

Disturbances in UV-induced Langerhans cell migration and T helper (T(H)) 2 cell responses could be early steps in the pathogenesis of PLE. To establish whether UV-B exposure induces aberrant cytokine expression in the uninvolved skin of patients with polymorphous light eruption (PLE). Immunohistochemical staining and comparison of microscopic sections of skin irradiated with 6 times the minimal dose of UV-B causing erythema and the unirradiated skin of patients with PLE and of healthy individuals. University Medical Center (Dutch National Center for Photodermatoses). Patients Patients with PLE (n = 6) with clinically proven pathological responses to UV-B exposure and normal erythemal sensitivity. Healthy volunteers (n = 5) were recruited among students and hospital staff. Expression of cytokines related to Langerhans cell migration (interleukin [IL] 1, IL-18,and tumor necrosis factor [TNF] alpha); T(H)2 responses (IL-4 and IL-10); and T(H)1 responses (IL-6, IL-12, and interferon gamma). Double staining was performed for elastase (neutrophils), tryptase (mast cells), and CD36 (macrophages). The number of cells expressing IL-1beta and TNF-alpha was reduced in the UV-B-exposed skin of patients with PLE compared with the skin of healthy individuals (P<.05 for TNF-alpha). No differences were observed in the expression of T(H)1-related cytokines but fewer cells expressing IL-4 infiltrated the epidermis of patients with PLE 24 hours after irradiation (P =.03). After UV exposure TNF-alpha, IL-4, and, to a lesser extent, IL-10 were predominantly expressed by neutrophils. The reduced expression of TNF-alpha, IL-4, and IL-10 in the UV-B-irradiated skin of patients with PLE appears largely attributable to a lack of neutrophils, and is indicative of reduced Langerhans cell migration and reduced T(H)2 skewing. An impairment of these mechanisms underlying UV-B-induced immunosuppression may be important in the pathogenesis of PLE.

The role of histamine in allergic disease: re-appraisal of its inflammatory potential.

Studiesofallergicdiseases,inparticularasthma,rhinitisand urticaria, have suggested that histamine, a biogenicamine synthesized and stored mainly in mast cells andbasophils, plays a prominent role in the pathophysiol-ogy of these diseases (1–3). Several immunologic andnonimmunologic stimuli, such as allergen, immunoglo-bulin (Ig)E, cytokines (interleukin (IL)-1, IL-3, IL-8,GM-CSF), substance P, complement C3a and C5a,platelet-activating factor (PAF), hyperosmolarity, phy-sical stimuli (vibration, heat, cold), etc., induce therelease of histamine from mast cells and basophils,following which it diffuses rapidly into the surroundingtissues and exerts its effects, before being metabolismand excreted in the urine (4).In experimental asthma induced by allergen orexercise challenge, it has been demonstrated that thelevels of histamine are increased in the circulation andimplicated in bronchoconstriction (5–7). Studies ofsymptomatic asthmatics have also demonstrated thathistamine levels are significantly increased in thebronchoalveolar lavage (BAL) of these individuals,compared with histamine levels in BAL of asympto-matic asthmatics (8,9). Similarly, allergen challenge inpatients with allergic rhinitis significantly increases thelevels of histamine in nasal secretions of theseindividuals (10–12), implicating a role for this mediatorin the pathophysiology of allergic rhinitis. Indeed, nasalchallenge with histamine has been shown to inducenasal blockage, sneezing and rhinorrhoea (13,14), likelyas a result of sensory nerve stimulation in the nasalmucosa (15). In patients with cold urticaria, challengewith ice-water leads to a rapid rise in plasma histamineconcentration within 2 min, which peaks at 5 min andreturns to baseline values by 15–30 min (16).Investigations of patients with chronic urticaria havealso indicated that histamine is a central mediator inthis allergic condition, with increased levels detectedboth in the lesions and normal skin of patients withurticaria, compared with skin of healthy individuals(17–19). Furthermore, the responsiveness of skin tohistamine is also increased in patients with urticaria(19).Apart from the classical activities of histamine, thereis an increasing body of evidence that histamine alsoelicits pro-inflammatory and immune-modulatoryeffects, whichmight be of pathophysiological relevance.The findings of histamine receptors expressed on avarietyof immuneandnonimmunecellssuggesta muchwider and more critical role of this mediator in allergicdisease, than is considered presently. Consequently, it islikely that antihistamines have a wider impact onallergic inflammation, and that effects on immune cellswhich have been linked to nonreceptor mediatedpathways so far, may actually be receptor-dependent.This review aims to give an overview on a currentlyemerging new understanding of the role of histamine inallergic disease.

Protease nexin-1 messenger RNA levels are not affected by serum or interferon beta in cultured systemic sclerosis fibroblasts.

The aim of the present study was to analyze the effect of serum and human recombinant beta interferon (rIFNbeta) treatment on PN-1 mRNA levels in cultured dermal fibroblasts obtained from the skin of healthy donors and from lesional skin of systemic sclerosis (SSc) patients with the limited (CREST syndrome) or the diffuse form of SSc. Total RNA was isolated from fibroblasts derived from the skin of healthy individuals and from lesional skin of patients with CREST syndrome and the diffuse form of SSc cultured under different conditions (1% or 10% serum-supplemented medium) and treated with 500 IU/ml of rIFNbeta. PN-1 gene expression was assessed by Northern blot analysis. We detected variable PN-1 mRNA levels in normal control fibroblasts as well as in SSc fibroblasts under the different culture conditions (1% or 10% serum-supplemented medium). Accumulated PN-1 mRNA levels found in normal cultured fibroblasts were similar to or even higher than in SSc fibroblasts. PN-1 messenger levels were not significantly altered by IFNbeta treatment in normal or SSc cultured fibroblasts despite the presence of an IFN-stimulated responsive element (ISRE) in the promoter of the PN-1 gene. Our findings suggest that PN-1 expression in SSc fibroblasts at the mRNA level requires further investigation in a large number of SSc patients to better characterize the role of this serpin in the pathogenesis of SSc. We conclude that the transcriptional regulation of PN-1 is not associated with IFNbeta, an antifibrotic cytokine naturally produced by fibroblasts.

Diversity and Persistence of Staphylococcus epidermidis Strains that Colonize the Skin of Healthy Individuals

Diversity and Persistence of Staphylococcus epidermidis Strains that Colonize the Skin of Healthy Individuals

Influence of relative humidity and suspending menstrua on survival of Acinetobacter spp. on dry surfaces.

Acinetobacter spp. are being reported with increasing frequency as a cause of nosocomial infection and have been isolated from the skin of healthy individuals, patients, hospital staff, dry nonbiotic objects, and different pieces of medical equipment. Factors affecting the survival of Acinetobacter spp. under conditions closely similar to those found in the hospital environment were investigated in the present study to help us understand the epidemiology of nosocomial Acinetobacter infection. Bacterial cells were suspended in distilled water or bovine serum albumin and were dried onto glass coverslips and kept at different relative humidities. Cells washed from coverslips were used to determined viable counts. Freshly isolated strains of Acinetobacter spp. belonging to the clinically important Acinetobacter calcoaceticus-Acinetobacter baumannii complex were found to be more resistant to drying conditions (e.g., 30 days for A. baumannii 16/49) than American Type Culture Collection strains (e.g., 2 days for A. baumannii ATCC 9955). The majority of strains belonging to the Acb complex had survival times similar to those observed for the gram-positive organism Staphylococcus aureus tested in the experiment. Survival times were prolonged for almost all the strains tested when they were suspended in bovine serum albumin (e.g., 60 days for A. baumannii R 447) compared with those for strains suspended in distilled water (11 days for R 447). The survival times for strains at higher relative humidity (31 or 93%) were longer than those for strains of Acinetobacter kept at a relative humidity of 10% (11 days at 31% relative humidity and 4 days at 10% relative humidity for R447). These findings are consistent with the observed tendency of Acinetobacter spp. to survive on dry surfaces, and they can be transferred not only by moist vectors but also under dry conditions in a hospital environment during nosocomial infection outbreaks. The results obtained in the experiment support the previously suggested airborne spread of Acinetobacter spp. in hospital wards and repeated outbreaks after incomplete disinfection of contaminated dry surfaces.

Adhesion molecules in atopic dermatitis: VCAM-1 and ICAM-1 expression is increased in healthy-appearing skin

In the skin of normal and atopic individuals, the expression of E-selectin (ELAM-1), L-selectin (LECAM-1), P-selectin (CD62), CD31 (PECAM), vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), and cutaneous lymphocyte antigen (CLA) were compared by immunostaining of skin biopsies which were taken from normal individuals (n = 17), the healthy-appearing skin of patients with atopic dermatitis (n = 10), and their acute (n = 5) and chronic (n = 6) skin lesions. In contrast to ELAM-1, the expression of VCAM-1 and ICAM-1 was found to be significantly increased in nonlesional atopic skin in comparison to the skin of normal individuals. Moreover, in contrast to normal skin of healthy individuals, nonlesional atopic skin showed a further increase of VCAM-1, ICAM-1, and ELAM-1 when cultured with medium alone. This suggests that certain adhesion molecules are constitutively upregulated in healthy-appearing skin of patients with atopic dermatitis. In addition, atopic skin appears to respond to nonspecific stimuli (such as culture with medium alone) with upregulation of VCAM-1, ICAM-1, and ELAM-1. It is suggested that the observed upregulation of adhesion molecules is mediated by the release of cytokines such as interleukin-4 from cells which reside in atopic skin. The question of whether the inherent upregulation of adhesion molecules in atopic skin contributes to the development of Th2 cells, which have been found to predominate in atopic inflammation, has to be further investigated.