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Microbial Colonization (microbial + colonization)

Distribution by Scientific Domains

Medical Sciences	68%
Life Sciences	27%

Distribution within Medical Sciences

Dermatology	19%

Selected Abstracts

Microbial colonization induces oligoclonal expansions of intraepithelial CD8 T cells in the gut

EUROPEAN JOURNAL OF IMMUNOLOGY, Issue 12 2004
Lars Helgeland
Abstract Two populations of CD8+ IEL generally express restricted, but apparently random and non-overlapping TCR repertoires. Previous studies in mice suggested that this could be explained by a dual origin of CD8+ IEL, i.e. that CD8,,+ IEL derive from a few peripheral CD8+ T cell lymphoblasts stimulated by microbial antigens in gut-associated lymphoid tissue, whereas CD8,,+ IEL descend from an inefficient intestinal maturation pathway. We show here that the gut mucosa, instead, becomes seeded with surprisingly broad and generally non-overlapping CD8 IEL repertoires and that oligoclonality is induced locally after microbial colonization. In germ-free (GF) rats, both CD8,,+ and CD8,,+ IEL displayed surprisingly diverse TCR V, repertoires, although ,-chain diversity tended to be somewhat restricted in the CD8,,+ subset. CDR3 length displays in individual V,-C, and V,-J, combinations generally revealed polyclonal distributions over 6,11 different lengths, similar to CD8+ lymph node T cells, and CDR3, sequencing provided further documentation of repertoire diversity. By contrast, in ex-GF rats colonized with normal commensal microflora, both CD8,,+ and CD8,,+ IEL displayed oligoclonal CDR3 length distributions for most of the V, genes analyzed. Our data suggest that microbial colonization induces apparently random clonal expansions of CD8,,+ and CD8,,+ IEL locally in the gut. [source]

Microbial colonization patterns predict the outcomes of surgical treatment of intrabony defects

JOURNAL OF CLINICAL PERIODONTOLOGY, Issue 1 2006
Lisa Heitz-Mayfield
Abstract Aim: To explore the impact of bacterial load and microbial colonization patterns on the clinical outcomes of periodontal surgery at deep intrabony defects. Materials and Methods: One hundred and twenty-two patients with advanced chronic periodontitis and at least one intrabony defect of >3 mm were recruited in 10 centres. Before recruitment, the infection control phase of periodontal therapy was completed. After surgical access and debridement, the regenerative material was applied in the test subjects, and omitted in the controls. At baseline and 1 year following the interventions, clinical attachment levels (CAL), pocket probing depths (PPD), recession (REC), full-mouth plaque scores and full-mouth bleeding scores were assessed. Microbial colonization of the defect-associated pocket was assessed using a DNA,DNA checkerboard analysis. Results: Total bacterial load and counts of red complex bacteria were negatively associated with CAL gains 1 year following treatment. The probability of achieving above median CAL gains (>3 mm) was significantly decreased by higher total bacterial counts, higher red complex and T. forsythensis counts immediately before surgery. Conclusions: Presence of high bacterial load and specific periodontal pathogen complexes in deep periodontal pockets associated with intrabony defects had a significant negative impact on the 1 year outcome of surgical/regenerative treatment. [source]

ETFAD/EADV eczema task force 2009 position paper on diagnosis and treatment of atopic dermatitis

JOURNAL OF THE EUROPEAN ACADEMY OF DERMATOLOGY & VENEREOLOGY, Issue 3 2010
U Darsow
Abstract Background, The diagnosis of atopic dermatitis (AD) is made using evaluated clinical criteria. Management of AD must consider the symptomatic variability of the disease. Methods, EADV eczema task force developed its guideline for atopic dermatitis diagnosis and treatment based on literature review and repeated consenting group discussions. Results and Discussion, Basic therapy relies on hydrating topical treatment and avoidance of specific and unspecific provocation factors. Anti-inflammatory treatment based on topical glucocorticosteroids and topical calcineurin antagonists is used for exacerbation management and more recently for proactive therapy in selected cases. Topical corticosteroids remain the mainstay of therapy, but the topical calcineurin inhibitors, tacrolimus and pimecrolimus are preferred in certain locations. Systemic anti-inflammatory treatment is an option for severe refractory cases. Microbial colonization and superinfection may induce disease exacerbation and can justify additional antimicrobial/antiseptic treatment. Systemic antihistamines (H1) can relieve pruritus, but do not have sufficient effect on eczema. Adjuvant therapy includes UV irradiation preferably of UVA1 wavelength or UVB 311 nm. Dietary recommendations should be specific and given only in diagnosed individual food allergy. Allergen-specific immunotherapy to aeroallergens may be useful in selected cases. Stress-induced exacerbations may make psychosomatic counselling recommendable. ,Eczema school' educational programmes have been proven to be helpful. [source]

Position paper on diagnosis and treatment of atopic dermatitis

JOURNAL OF THE EUROPEAN ACADEMY OF DERMATOLOGY & VENEREOLOGY, Issue 3 2005
U Darsow
ABSTRACT The diagnosis of atopic dermatitis (AD) is made using evaluated clinical criteria. Management of AD must consider the symptomatic variability of the disease. It is based on hydrating topical treatment, and avoidance of specific and unspecific provocation factors. Anti-inflammatory treatment is used for exacerbation management. Topical corticosteroids remain the first choice. Systemic anti-inflammatory treatment should be kept to a minimum, but may be necessary in rare refractory cases. The new topical calcineurin inhibitors (tacrolimus and pimecrolimus) expand the available choices of topical anti-inflammatory treatment. Microbial colonization and superinfection (e.g. with Staphylococcus aureus, Malassezia furfur) can have a role in disease exacerbation and can justify the use of antimicrobials in addition to the anti-inflammatory treatment. Evidence for the efficacy of systemic antihistamines in relieving pruritus is still insufficient, but some patients seem to benefit. Adjuvant therapy includes ultraviolet (UV) irradiation preferably of UVA wavelength; UVB 311 nm has also been used successfully. Dietary recommendations should be specific and only given in diagnosed individual food allergy. Stress-induced exacerbations may make psychosomatic counselling recommendable. ,Eczema school' educational programmes have proved to be helpful. [source]

Microbial colonization of nebulizers used by asthmatic children

PEDIATRICS INTERNATIONAL, Issue 5 2006
HERMAN A COHEN
Abstract Background: The aim of the present study was to determine the microbial colonization of nebulizers used at home by asthmatic children, and to investigate their parents' cleaning and maintenance routines. Methods: The nebulizer equipment used at home by 39 asthmatic children was examined. Swabs taken from the inner surface of the reservoir cups, face masks and filters were cultured. Results were recorded as mean number of colony-forming units per cultured surface. Parents were interviewed regarding their cleaning and disinfection routines. Results: Twenty-six reservoir cups (66.7%), 24 face masks (61.5%), and 18 filters (78.3%) were found to be contaminated. Pseudomonas aeruginosa was isolated from 17 reservoir cups (43.6%) and 12 face masks (30.8%), and Staphylococcus aureus from two face masks (5.1%). None of the parents knew that the nebulizer has a filter and that it requires periodic cleaning or changing; only eight of the parents (20.5%) received maintenance instructions from the medical staff, and only 19 (48.7%) cleaned the nebulizer equipment after use. Conclusion: Home nebulizers are frequently colonized with microorganisms. As recommended, nebulizers should be washed after each use and air-blown dry. Nebulizer maintenance should be emphasized in educational programs for managing asthma. [source]

Microbial colonization induces oligoclonal expansions of intraepithelial CD8 T cells in the gut

Microbial biofilms associated with biliary stent clogging

FEMS IMMUNOLOGY & MEDICAL MICROBIOLOGY, Issue 3 2010
Emilio Guaglianone
Abstract Endoscopic stenting is a palliative approach for the treatment of diseases involving biliary obstruction. Its major limitation is represented by stent occlusion, followed by life-threatening cholangitis, often requiring stent removal and replacement. Although it has been suggested that microbial colonization of biliary stents could play a role in the clogging process, the so far available data, particularly on the role of anaerobic bacteria, are not enough for a comprehensive description of this phenomenon. Our study was focused on the analysis of 28 explanted biliary stents by culturing, denaturing gradient gel electrophoresis and scanning electron microscopy to identify all the aerobic/anaerobic bacteria and fungi involved in the colonization of devices and to verify the ability of isolated anaerobic bacterial strains to form a biofilm in order to better understand the mechanisms of stent clogging. [source]

Effects of drying regime on microbial colonization and shredder preference in seasonal woodland wetlands

FRESHWATER BIOLOGY, Issue 3 2008
MARTYN D. INKLEY
Summary 1. Energy budgets of wetlands in temperate deciduous forests are dominated by terrestrially derived leaf litter that decays under different drying conditions depending on autumn precipitation. We compared decay rates and microbial colonization of maple leaves under different inundation schedules in a field experiment, and then conducted a laboratory study on shredder preference. In the field, litter bags either remained submerged (permanent), were moved to a dried part of the basin once and then returned (semi-permanent), or were alternated between wet and dry conditions for 8 weeks (temporary). 2. There was no difference in decay rates among treatments, but leaves incubated under permanent and semi-permanent conditions had higher fungal and bacterial biomass, and lower C : N ratios than those incubated under alternating drying and wetting conditions. 3. To determine the effects of these differences in litter nutritional quality on shredder preference, we conducted a laboratory preference test with larvae of leaf-shredding caddisflies that inhabit the wetland. Caddisflies spent twice as much time foraging on permanent and semi-permanent litter than on litter incubated under temporary conditions. 4. There is considerable variation among previous studies in how basin drying affects litter breakdown in wetlands, and no previous information on shredder preference. We found that frequent drying in a shallow wetland reduces the nutritional quality of leaf litter (lower microbial biomass and nitrogen content), and therefore preference by invertebrate shredders. These results suggest that inter-annual shifts in drying regime should alter detritus processing rates, and hence the mobilization of the energy and nutrients in leaf litter to the wetland food web. [source]

Unravelling the microbial role in ooid formation , results of an in situ experiment in modern freshwater Lake Geneva in Switzerland

GEOBIOLOGY, Issue 4 2008
K. PLEE
ABSTRACT The microbial role in the formation of the cortex of low-Mg calcite freshwater ooids in western part of Lake Geneva in Switzerland has been suggested previously, but not demonstrated conclusively. Early work mostly concentrated in hypersaline milieus, and hence little is known about their genesis in freshwater environments. We designed an in situ experiment to mimic the natural process of low-Mg calcite precipitation. A special device was placed in the ooid-rich bank of the lake. It contained frosted glass (SiO2) slides, while quartz (SiO2) is the most abundant mineral composition of ooid nuclei that acted as artificial substrates to favour microbial colonization. Microscopic inspection of the slides revealed a clear seasonal pattern of carbonate precipitates, which were always closely associated with biofilms that developed on the surface of the frosted slides containing extracellular polymeric substance, coccoid and filamentous cyanobacteria, diatoms and heterotrophic bacteria. Carbonate precipitation peaks during early spring and late summer, and low-Mg calcite crystals mostly occur in close association with filamentous and coccoid cyanobacteria (e.g. Tolypothrix, Oscillatoria and Synechococcus, Anacystis, respectively). Further scanning electron microscope inspection of the samples revealed low-Mg calcite with crystal forms varying from anhedral to euhedral rhombohedra, depending on the seasons. Liquid cultures corroborate the in situ observations and demonstrate that under the same physicochemical conditions the absence of biofilms prevents the precipitation of low-Mg calcite crystals. These results illustrate that biofilms play a substantial role in low-Mg calcite ooid cortex formation. It further demonstrates the involvement of microbes in the early stages of ooid development. Combined with ongoing microbial cultures under laboratory-controlled conditions, the outcome of our investigation favoured the hypothesis of external microbial precipitation of low-Mg calcite as the main mechanism involved in the early stage of ooid formation in freshwater Lake Geneva. [source]

Leaf Quality of Some Tropical and Temperate Tree Species as Food Resource for Stream Shredders

INTERNATIONAL REVIEW OF HYDROBIOLOGY, Issue 1 2010
Manuel A. S. Graça
Abstract We tested the hypotheses that (1) plant defenses against consumers increase in the tropics, and that these differences in quality are perceived by detritivores; and (2) microbial conditioning of leaf litter is important for the feeding ecology of shredders from both geographical regions. We compared quality parameters of 8 tree species from Portugal and 8 from Venezuela. The tropical leaves were tougher, but did not differ from temperate leaves in terms of N, C: N, and polyphenols. In multiple-choice experiments, shredders from Portugal (Sericostoma vittatum and Chaetopteryx lusitanica) and from Venezuela (Nectopsyche argentata and Phylloicus priapulus) discriminated among conditioned leaves, preferentially consuming softer leaves. In another set of experiments, all shredders preferentially fed on conditioned rather than unconditioned leaves, grew faster when fed conditioned than unconditioned leaves and fed more on temperate than tropical leaves. We conclude that leaf litter from the tropics is a low-quality resource compared to leaves in temperate systems, because of differences in toughness, and that tropical shredders benefit from microbial colonization, as previously demonstrated for temperate systems. We suggest that leaf toughness could be one explanation for the reported paucity of shredders in some tropical streams. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Influence of anode pretreatment on its microbial colonization

JOURNAL OF APPLIED MICROBIOLOGY, Issue 1 2007
J.L. Liu
Abstract Aims:, To assess the influence of chemical treatment of the anode of a marine sediment biofuel cell (MSBFC) on the microbial diversity of the anode biofilm. Methods and Results:, A MSBFC was equipped with two graphite plate anodes, one pretreated by electrochemical oxidation in sulfuric acid and the other untreated. After 6 weeks of operation, 16S rRNA clone libraries were constructed from each anode biofilm. The pretreated anode exhibited a fourfold depletion in , -proteobacteria, a fourfold enrichment in , -proteobacteria, a sixfold increase in sulfate reducers, a fivefold enrichment in unclassified micro-organisms, and 6% of the colonies were sulfur oxidizers while none were detected on the untreated anode. Conclusion:, Anode pretreatment significantly affects the anode-colonized microbial communities of MSBFCs. Significance and Impact of the Study:, The MSBFC is one of a new class of microbial fuel cells in which the anode is spontaneously colonized by a subset of micro-organisms indigenous to a complex anaerobic mixture (such as sewage and food processing effluents). These micro-organisms utilize the anode as an oxidant, catalysing power generation by oxidizing fuel in the mixture and reducing the anode. This study reveals that pretreatment of the anode can greatly affect the composition of the microbial colony of such fuel cells. [source]

Biofilms in the Edentulous Oral Cavity

JOURNAL OF PROSTHODONTICS, Issue 5 2008
Amit Sachdeo BDS, DMSc
Abstract Purpose: The oral cavity presents numerous surfaces for microbial colonization. These surfaces produce biofilms of differing complexities unique to each individual. Several studies have looked at biofilms in dentate patients. There has been limited research regarding biofilms on dentures or soft tissues of edentulous patients. The purpose of the present investigation was to provide meaningful data describing microbial ecological relationships in the oral cavity of edentulous patients and to evaluate the microbiota on hard and soft tissue surfaces and saliva in edentulous patients wearing complete dentures. Materials and Methods: Sixty-one edentulous subjects with complete maxillary and mandibular dentures were recruited. "Supragingival" biofilm samples were taken from 28 denture teeth for each subject. Biofilm samples were also taken from the dorsal, lateral, and ventral surfaces of the tongue, floor of mouth, buccal mucosa, hard palate, vestibule/lip, "attached gingiva," and saliva. Samples were individually analyzed for their content of 41 bacterial species using checkerboard DNA,DNA hybridization. Levels and proportions of each species were determined for every sample location. Results: Periodontal pathogens such as Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis were clearly present in the samples from the edentulous subjects. Microbial profiles in samples from the soft tissue surfaces differed among site locations. Samples from the dorsum of the tongue exhibited the highest bacterial counts followed by the "attached gingiva" and the lateral surfaces of the tongue, while the lowest mean counts were found in samples from the buccal mucosa and labial vestibules. Using cluster analysis of the proportions of the test species, three clusters were formed. The first cluster comprised saliva, supragingival plaque, and the lateral and dorsal surfaces of the tongue. The second cluster comprised the other six soft tissue surfaces. Species on the denture palate formed a third cluster. Conclusions: One of the major findings in this study was the detection of periodontal pathogens, A. actinomycetemcomitans and P. gingivalis, in the edentulous subjects, as these species were thought to disappear after removal of all natural teeth. This finding has implications regarding future dental treatment and the general health of individuals. Distinct patterns of microbial colonization were seen on the different soft tissue surfaces. Thus, this investigation provided the first step in defining the organisms that are associated with edentulous patients on both soft (mucosa) and hard surfaces (denture). The study also provided meaningful data that described microbial ecological relationships in the oral cavity of edentulous subjects. The authors believe that this study is the first comprehensive assessment of the microbiota in the complete denture-wearing subject. [source]

Candida albicans colonization of surface-sealed interim soft liners

JOURNAL OF PROSTHODONTICS, Issue 4 2000
Luciano Olan-Rodriguez DDS
Purpose This in-vivo investigation evaluated the effect of 2 denture sealer agents on the microbial colonization of a newly placed soft interim denture liner during a period of 14 days. Materials and Methods An interim soft denture liner (Coe-Soft; GC America, Alsip, IL) was coated with 2 different denture surface sealants (Palaseal [Heraeus Kulzer, Irvine, CA] and Mono-Poly [Plastodent, New York, NY]). Three rectangular wells of 1 cm wide × 2 cm long × 2 mm deep were placed in the intaglio of 10 maxillary complete dentures and filled with the soft liner material. The soft liner surface was treated with Palaseal (first well) and Mono-Poly (second well), and the unsealed (third well) was used as a control. These were exposed to the oral cavity for 14 days. The effect the sealant had in the prevention of Candidal colonization in vivo of the soft liner material was evaluated. Microbiological specimens were recovered from all samples and cultivated. Microbiological data from the control and 2-test samples in each denture were tabulated, and statistical analyses were performed. Results This investigation showed clear differences (p < .001) between the sealed and unsealed soft liners. The sealed material showed significantly less colonization by yeast and bacteria. Intercomparison of the surface denture sealers, Palaseal versus Mono-Poly, showed no statistically significant differences (p < .005) in total yeast or bacterial colonization. Conclusion Coating of Coe-Soft denture liner with either Palaseal or Mono-Poly significantly decreased yeast and bacterial colonization. [source]

Influence of copper-alloying of austenitic stainless steel on multi-species biofilm development

LETTERS IN APPLIED MICROBIOLOGY, Issue 2 2001
J. Kielemoes
Aims: To investigate the bactericidal influence of copper-alloying of stainless steel on microbial colonization. Methods and Results: Inhibition of bacterial adherence was investigated by monitoring (192 h) the development of a multi-species biofilm on Cu-alloyed (3·72 wt%) stainless steel in a natural surface water. During the first 120 h of exposure, lower numbers of viable bacteria in the water in contact with copper-containing steel relative to ordinary stainless steel were observed. Moreover, during the first 48 h of exposure, lower colony counts were found in the biofilm adhering to the Cu-alloyed steel. No lower colony or viable counts were found throughout the remainder of the experimental period. Conclusions: The presence of Cu in the steel matrix impedes the adhesion of micro-organisms during an initial period (48 h), while this bactericidal effect disappears after longer incubation periods. Significance and Impact of the Study: The application of Cu-alloyed stainless steels for bactericidal purposes should be restricted to regularly-cleaned surfaces. [source]

Periodontal condition of the mandibular anterior dentition in patients with conventional and self-ligating brackets

ORTHODONTICS & CRANIOFACIAL RESEARCH, Issue 4 2008
N Pandis
Structured Abstract Authors,,, Pandis N, Vlachopoulos K, Polychronopoulou A, Madianos P, Eliades T Objectives,,, To explore whether the use of self-ligating brackets is associated with better values for periodontal indices because of the lack of elastomeric modules and concomitantly, reduced availability of retentive sites for microbial colonization and plaque accumulation. Setting and Sample Population,,, Private practice of the first author. Patients were selected using the following inclusion criteria: age range 12,17 years, fixed appliances on both arches, aligned mandibular arch, and absence of oral habits and anterior crossbites. Materials and Methods,,, Prospective cohort investigation. Participants were grouped for bracket type, thus 50 patients formed the conventional bracket cohort and 50 patients the self-ligating bracket cohort. Both cohorts were followed with the purpose to examine periodontal status. Average length of follow-up was 18 months. This time period was considered adequate for a proportion of study participants to experience the outcome of interest. Outcome variables were plaque index, gingival index, calculus index, and probing depth for the two bracket cohorts. Results,,, No difference was found in the indices recorded between the two bracket cohorts studied. Conclusion,,, Under the conditions as applied in this study, the self-ligating brackets do not have an advantage over conventional brackets with respect to the periodontal status of the mandibular anterior teeth. [source]

Microbial colonization of nebulizers used by asthmatic children

The effect of incorporating straw or manure into the soil on the natural microflora of winter wheat

PLANT PATHOLOGY, Issue 5 2001
B. S. Rodgers-Gray
Over 3 years, five crops of winter wheat with different fertilization or pesticide treatments were grown in replicated plots in which straw, cattle manure or nothing was incorporated into the soil. It was previously shown that severities of several foliar diseases were reduced by the treatment with straw. Treatments with straw slightly increased leaf microbial numbers at growth stage (GS) 10, and significantly but slightly decreased numbers at GS 60 and 70, when averaged over all crops. There was no evidence of differences in potential for biological control between plots, because no differences were demonstrated between treatments in the proportion of phylloplane residents able to produce chitinase, siderophores or antibiotics. There was no link between soil and leaf nitrogen and microbial populations or soil amendment. The two youngest leaves of straw-treated plants remained green longer than leaves from untreated or manure-treated plants. Microbial numbers differed between crops, but within crops were more stable on leaves and ears than in soil. Soil populations were larger before the crops were sown. Bacteria predominated over fungi in all habitats throughout the growing season. The ratio of Gram-negative to Gram-positive bacteria recovered was similar on leaves and in soil, but not on ears. Soil and leaf microbes utilized similar carbon sources. More leaf epiphytes than soil microbes produced siderophores. The majority of identified organisms belonged to only a few species. Chromogenic organisms were more abundant on aerial surfaces. A fungicide, chlorothalonil, was applied in one crop; it reduced the microbial population but did not alter its composition (without affecting the reduction in disease due to straw). It is postulated that straw acts in the field by altering plant physiology and thus altering both microbial colonization and disease. [source]

Bacterial vaginosis Transmission, role in genital tract infection and pregnancy outcome: an enigma,

APMIS, Issue 4 2005
Review article III
Whether bacterial vaginosis (BV) is acquired from an endogenous or an exogenous source is subject to controversy. Despite findings of an association between sexual behaviour and BV, some data indicate that BV is not a sexually transmitted infection in the traditional sense, while other data indicate that BV is an exogenous infection. A third aspect of BV is its tendency to go unnoticed by affected women. All of this will have a strong impact on how physicians view the risks of asymptomatic BV. This review focuses on whether or not BV should be regarded as a sexually transmitted infection (STI), its role in postoperative infections and pelvic inflammatory disease (PID), and on whether or not treatment of BV during pregnancy to reduce preterm delivery should be recommended. The reviewed studies do not lend unequivocal support to an endogenous or exogenous transmission of the bacteria present in BV. For women undergoing gynaecological surgery such as therapeutic abortion, the relative risk of postoperative infection is clearly elevated (approx. 2.3,2.8). A weaker association exists between BV and pelvic inflammatory disease. Data on treatment of BV as a way of reducing preterm delivery are inconclusive and do not support recommendations for general treatment of BV during pregnancy. The discrepant associations between BV and preterm birth found in recent studies may be explained by variations in immunological response to BV. Genetic polymorphism in the cytokine response , both regarding the TNF alleles and in interleukin production , could make women more or less susceptible to BV, causing different risks of preterm birth. Thus, studies on the vaginal inflammatory response to microbial colonization should be given priority. [source]

Large Bore Catheters with Surface Treatments versus Untreated Catheters for Vascular Access in Hemodialysis

ARTIFICIAL ORGANS, Issue 7 2004
Rolf Bambauer
Abstract:, Infection, thrombosis, and stenosis are among the most frequent complications associated with blood-contacting catheters. Complications resulting from infection remain a major problem for hemodialysis catheters, with significant numbers of catheters being removed due to catheter-related sepsis. Numerous strategies have been employed to reduce the occurrence of infection and im-prove long-term outcomes, with varying degrees of success. The most important is the careful and sterile handling by the attending staff of the catheters during hemodialysis treatments to minimize or stop a microbial colonization of the skin and the catheter. Another approach is coating the external surface of the catheters with substances which are antibacterial like silver and/or substances with low thrombogenicity like silicone. This investigation reviews results of animal and clinical experiments conducted to assess the efficacy and biocompatibility of silver and silicone coated dialysis catheters. It is concluded that silver coatings can reduce bacterial colonization and occurrence of infection associated with these devices. The catheters employing ion implantation of silicone rubber showed low thrombogenicity. Results of the studies indicate that ion beam based processes can be used to improve thrombus and infection resistance of blood contacting catheters. A new development is the microdomain structured surface (PUR-SMA coated catheters). Preliminary results with these catheters are very encouraging. [source]

The mother's immune system is a balanced threat to the foetus, turning to protection of the neonate

ACTA PAEDIATRICA, Issue 2 2009
Lars Å Hanson
Immunological tolerance by the mother prevents rejection of the foetus, but aberrations may increase risk of abnormalities like spontaneous abortion, or foetal growth restriction. The neonate is normally colonized with mother's gut microflora, mainly composed of protective anaerobes. This least threatening form of microbial colonization of the neonate, is impaired by sectio delivery, but supported by breastfeeding. Mother's transplacental IgG, secretory IgA and other milk components help protect the neonate together with its own slowly expanding immune system. Conclusion: The mother's immune system tolerates her foetus via several mechanisms. Failure to do so may cause foetal growth retardation, or spontaneous abortion. The mother and the neonate cooperate in preventing infections in the offspring. [source]

Skin care for preterm and term neonates

CLINICAL & EXPERIMENTAL DERMATOLOGY, Issue 8 2009
F. S. Afsar
Summary Neonatal skin experiences a progressive adaptation to the extrauterine environment during which special care is needed. The immaturity of the epidermal barrier in the neonatal period may cause dry skin, vulnerability to trauma, rapid onset of microbial colonization and percutaneous drug toxicity. This article reviews the practical implications for hygiene, bathing practices, skin integrity, emollient use, infection control and exposure to percutaneous toxic agents in preterm and term infants. [source]