Erythema toxicum neonatorum is a common rash of unknown etiology affecting healthy newborn infants. In this study, we postulated that the rash reflects a response to microbial colonization of the skin at birth, and that the hair follicle constitutes an "easily opened door" for microbes into the skin of the newborn. We collected microbial cultures from the skin of 69 healthy, 1-d-old infants with and without erythema toxicum to identify the colonizing flora and correlate culture results with clinical findings. We also analyzed biopsies from lesions of erythema toxicum with scanning and transmission electron microscopy in the search for microbes. Finally, each infant's body temperature was measured as a sign of acute phase response. We found that 84% of 1-d-old healthy infants, with and without erythema toxicum were colonized with coagulase-negative staphylococci. In all lesions of erythema toxicum, TEM identified cocci-like bacteria localized in the hair follicle epithelium and into recruited immune cells surrounding the hair follicle; morphology and dimension supported their identification as belonging to the genus Staphylococcus. SEM revealed 10 times more hair structures per skin surface unit in newborns compared with adults. Infants with erythema toxicum also had higher body temperature. In erythema toxicum, commensal microbes gain entry into the skin tissue, most probably through the hair canal. This triggers the local immune system and a systemic acute phase response, including an increase in body temperature. We speculate that early microbial exposure to the newborn may be important for the maturation of the immune system. (Pediatr Res 58: 613-616, 2005) Abbreviations CoNS, coagulase-negative Staphylococcus SEM, scanning electron microscopy TEM, transmission electron microscopy Erythema toxicum neonatorum is an acute, self-limiting skin manifestation that develops in 50 -70% of all healthy newborn infants, particularly those born at term (Fig. 1) (1). It starts soon after birth and disappears spontaneously within a few weeks without leaving sequelae. Infants with it have papulopustules on an intense erythematous base. The presence of the rash is often a matter of concern for parents with affected newborns and may be misinterpreted by healthcare professionals, leading to unnecessary investigations and inappropriate therapies. Its etiology has been attributed to hematological, toxic, and allergic factors but still remains to be determined (2-4). Histology shows a dense inflammatory infiltrate around hair follicles, composed mostly of eosinophils, but also containing neutrophils, macrophages, and dendritic cells, as well as an up-regulation of various inflammatory mediators such as IL-1, IL-8, eotaxin, psoriasin, and nitric oxide synthases 1-3 (5-8). The rash has been suggested to reflect a response to the presence, for the first time, of microbes on the skin of the newborn infant (8).In this study, we postulated that the skin appendages, especially the hair follicles, might act as an entry port for microbes,...
The effect of motion on two-dimensional Fourier transformation magnetic resonance (MR) images was investigated using phantoms, animals, and normal volunteers. All images were obtained with a 0.30-Tesla superconducting magnet using spin echo pulse sequences. Respiratory motion was simulated while imaging the phantoms. In addition to image blurring, motion produced ghost images, or image harmonics. These ghost images were copies of the static image that was produced at periodic intervals. Canine images, which were obtained during respiration and after the administration of curare, showed significant improvement after respiratory motion was eliminated. Images of normal volunteers were improved with respiratory and cardiac gating, but data acquisition time was significantly increased. These results indicate that MR image quality could be improved with a system that acquires all necessary data within a single breathhold .
A total of 305 magnetic resonance (MR) examinations were performed in 236 patients with metallic implants. Most examinations were performed at 0.3 T. The metallic implants included central nervous system shunting devices, tantalum mesh, surgical wire, skin staples, surgical clips, metallic orthopedic devices, and a few miscellaneous metallic objects. Patients with cardiac pacemakers, electrical implants, prosthetic cardiac valves, and aneurysm clips were excluded from MR examinations. The images were reviewed for evidence of metallic artifact. The conspicuity of artifact was related to the composition, mass, orientation, and position of the metallic object in the body. In most instances, the metallic artifact did not interfere with the interpretation of the image. The patients' records were also reviewed for adverse effects noted by each patient during the MR examination. Only two patients reported discomfort that could possibly have been related to their metallic implants, but in both cases it seemed unlikely that the symptoms were actually related to the imaging process. There were no apparent short-term adverse effects demonstrated in these patients.
Coagulase-negative staphylococci and its subtype Staphylococcus epidermidis are major indigenous Gram-positive inhabitants of the human skin. Colonization occurs in direct connection with birth and terrestrial adaptation. This study focuses on factors that may influence skin colonization of the newborn infant that relates to the immune status of both the bacteria and the host. Skin is an effective barrier against bacteria, and this function is partly mediated by the presence of antimicrobial peptides including human cathelicidin peptide LL37. Gram-positive bacteria have been described to have adhesive pili on their surface that mediates specific attachment to the host. Here, we identify, by negative staining transmission electron microscopy (EM), two different types of piluslike structures commonly expressed on S. epidermidis isolated from newborn infants. We also show that the cathelicidin antimicrobial peptide LL37, constitutively expressed in the skin barrier of the newborn, significantly inhibited growth of S. epidermidis indicating its importance for the ecological stability of the skin microbiota. Further studies are required to elucidate molecular mechanisms of host-microbe interactions, both for the maintenance of a mutually beneficial homeostatic relationship and for the protection of self when it results in overt disease. (Pediatr Res 66: 174-178, 2009) C oagulase-negative staphylococci (CoNS) are major skin commensals in humans (1). Within the first few hours of life colonization occurs (2), and by 1 d of age 84% of all healthy neonates have their skin colonized (3). Among the CoNS, particular attention has been focused on Staphylococcus epidermidis because it is the most common species responsible for infection causing significant morbidity, mortality, and incurring healthcare costs worldwide (4). In neonates, CoNS have emerged as prevalent and important pathogens, responsible for approximately 50% of all episodes of lateonset (Ͼ72 h) sepsis in very low birth weight infants (5). Recent evidence also links these bacteria to the pathogenesis of the immunologic skin reaction erythema toxicum, frequently seen in healthy newborns (3).Ecological stability of the commensal microflora is partly maintained by interactions with its human host. Our knowledge of how commensal bacteria interact with their host or how they communicate with each other is limited. We know that at birth commensals have to face the antimicrobial defense mechanisms of the skin and the vernix caseosa, a cream-like coating on newborns secreted by the fetal sebaceous glands. Human antimicrobial cathelicidin peptide LL37 is present in both vernix caseosa and the skin already at the time of birth, and the peptide is also up-regulated in the erythema toxicum lesions of the newborn infant (6). The presence of LL37 offers increased protection against bacterial infections in mice and humans (7,8). Thus, we hypothesized that LL37 is of importance for the microbial milieu of the skin, and we tested if it could influence growth of S. epi...
Magnetic resonance (MR) images of a variety of cardiac malformations in 19 patients aged 1 week to 33 years were obtained using pulse plethysmographic- or ECG-gated spin echo pulse sequences. Coronal, axial, and sagittal images displaying intracardiac structures with excellent spatial and contrast resolution were acquired during systole or diastole. It is concluded that MR will be a valuable noninvasive method of diagnosing congenital heart disease.
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