Does Imiquimod Histologically Rejuvenate Ultraviolet Radiation–Damaged Skin?

BACKGROUND Imiquimod (IMI) 5% is believed by some to result in an improved cosmetic appearance of chronically ultraviolet radiation (UV)-damaged skin.
OBJECTIVE The objective was to determine what histologic and immunohistologic changes were present in actinically damaged skin after treatment with IMI.
METHODS AND MATERIALS Pre- and posttherapy biopsies of 12 patients with histories of actinic keratoses were evaluated with routine histology and immunohistochemical stains including p53, p63, proliferating cell nuclear antigen (PCNA), c-kit, and Factor XIIIa.
RESULTS After IMI therapy there was less compact hyperkeratosis, a more uniform rete ridge pattern with a more ordered proliferation of the epidermis, and a decrease in sun-damaged melanocytes. The papillary dermis showed a more uniform cellularity, and there was increased cellularity within the area of solar elastosis. After therapy, staining for p53, p63, and PCNA was decreased within the epidermis; staining for c-kit was decreased but more uniform in the basal cell; and Factor XIIIa expression was increased within the papillary dermis with a more ordered pattern of staining.
CONCLUSION These morphologic and immunohistochemical patterns may explain some of the improvement in overall skin appearance after IMI therapy and may be related to the spectrum of signaling pathways induced by the imidazoquinolines.     

Altered Pattern of Connexin40 Distribution in Persistent Atrial Fibrillation in the Goat

Cx40 Distribution in Goat Atrial Fibrillation. Introduction : Since altered expression of gap junction proteins (connexins) in diseased myocardial tissue may lead to abnormal electrical coupling between cardiomyocytes and hence contribute to arrhythmogenesis, the expression of connexin(Cx)40 and Cx43 was studied in atrial appendage from goats in sinus rhythm (SR) and persistent atrial fibrillation (AF).
Methods and Results : Biopsies were taken from the left and right atrial appendages from goats in SR or after pacing-induced persistent AF. Analyses of Cx40 and Cx43 mRNA and protein levels, using quantitative (competitive) polymerase chain reaction and western blotting, respectively, revealed no significant changes in the overall expression of Cx40 and Cx43 as a result of persistent AF. At the cellular level, immunohistochemistry and confocal laser canning microscopy showed a homogeneous distribution of either connexin in atrial sections taken during SR. After induction of AF, the distribution of Cx43 gap Junctions was unchanged whereas the Cx40 pattern showed marked inhomogeneities with small areas (0.15 to 0.6 mm in diameter, 25% of section surface area) of low-density Cx40 located between larger areas of normal (unchanged) Cx40 density. Activation mapping (244 electrodes, spatial resolution 2.25 mm) of the right atrial wall did not reveal changes in atrial conduction velocity.
Conclusion : Pacing-induced persistent AF in the goat gave rise to changes in the spatial organization of Cx40 gap junctions. Although the overall conduction velocity appeared not to have changed, microheterogeneities in conduction due to the local redistribution of Cx40 gap junctions might have contributed to the initiation and maintenance of AF.     

Photoageing: the role of UVB, solar-simulated UVB, visible and psoralen UVA radiation

We have studied the morphological and histological effects of chronic exposure of two strains of haired mice (albino Balb/c and pigmented C3H-) to various types of radiation. UVB (280-320 nm) radiation from unfiltered sunlamp bulbs for 20 and 30 weeks produced marked epidermal acanthosis and dyskeratosis which was reversible in mice exposed for 20 weeks followed by a 20-week rest. In the dermis the elastic fibres were altered and in the pigmented mice these changes had almost completely reversed 29 weeks after cessation of exposure. Cellulose acetate-filtered sunlamp bulbs (greater than 289 nm) produced similar but less marked changes. Chronic exposure to UVA (320-400 nm) radiation produced minimal alterations in the dermis while the epidermis was normal. Visible (greater than 400 nm) radiation in large doses produced no degenerative changes. Methoxsalen/UVA radiation produced epidermal acanthosis, dermal sclerosis, and alteration of elastic fibres, which was prominent in both strains at 40 weeks. These findings suggest that the UVB component of sunlight is largely responsible for photoageing of the skin. Furthermore, chronic exposure to methoxsalen/UVA therapy is likely to potentiate solar-induced photoageing.     

Family Support in Infant Death

There is a widespread need in obstetric and pediatric settings for follow-up support and counseling for the parents of infants who die. The implementation of a perinatal death and dying counseling group through an infant intensive care unit, with the emphasis on the parents' needs, and the role of the group co-leaders, is described below.     

A blinded comparison of clinical and echocardiographic evaluation of the preterm infant for patent ductus arteriosus

The accuracy of the characteristic physical signs of a patent ductus arteriosus (PDA), that is, a systolic murmur, increased volume of pulses and increased praecordial activity, in diagnosing a haemodynamically significant PDA in ventilated premature infants was prospectively evaluated. Fifty-five ventilated preterm infants (birthweight >1500g) had daily echocardiographic and clinical evaluation for a PDA for the first 7 days of life. The examiners were blinded to each other's findings. Probability analysis was performed for the accuracy of each clinical sign in detecting a haemodynamically significant PDA as defined by echocardiographic criteria. Clinical signs were poor at detecting a significant PDA in the first 4 days of life. On day 1, none of the 10 infants with a significant PDA had a murmur. By day 4, clinical signs were better at detecting a significant PDA, but specificity remained poor with many false positive signs. Six infants had murmurs with a closed duct. The development of echocardiographic haemodynamic significance preceded the development of physical signs by a mean of 1.8 days. Significant ductal shunts often occurred silently, but the development of a murmur often marked an increase in the velocity of the flow through the duct rather than an increase in the size of a shunt. This study confirms that echocardiography is required for the reliable early diagnosis of a PDA in ventilated preterm infants.     

The atopic syndrome: in vitro immunological characteristics of clinically defined subgroups of atopic subjects

Total IgE, selected specific IgE antibody levels, C2 and yeast opsonization were measured in four clinically defined subgroups of atopic patients who had previously been HLA-typed. Each group was characterized by a distinctive mean total IgE level and profile of specific IgE responses. All groups gave comparable levels of IgE antibodies to Timothy grass pollen but in patients initially presenting with infantile eczema and who subsequently developed asthma and/or hay fever, IgE antibodies to bovine milk proteins, egg ovalbumin and cat dander were frequently observed whereas in patients initially presenting with hay fever later in life these antibodies were usually absent. Computer assisted analysis failed to show any association between IgE antibody responses and (a) the HLA phenotypes A1,B8 and A3,B7 (b) C2 levels and (c) the yeast opsonization index.     

Sweet Syndrome in Infancy

Abstract: Sweet syndrome, or acute febrile neutrophilic dermatosis, is characterized by the presence of fever, peripheral leukocytosis, painful erythematous plaques and nodules, and a predominately neutrophilic dermal infiltrate. We report a case occurring in a 10‐week‐old male child, with preceding upper respiratory tract, and gastrointestinal infection symptoms. Sweet syndrome occurring in an infant should prompt a work‐up for immunodeficiency, as well as a review of the peripheral blood smear to rule out the rare case of malignancy.