Pathology of malignant skin tumours

The skin gives rise to a diverse spectrum of malignant tumours derived from the varied constituents of the epidermis and dermis. It is possible to discuss only a few of these in this article; the more common lesions derived from the epidermal keratinoctyes (basal and squamous cell carcinomas) together with melanomas (derived mainly from epidermal melanocytes) are presented. Some rarer but biologically aggressive tumours such as Merkel cell carcinoma and angiosarcoma are also discussed. Our understanding of the molecular biology of cutaneous tumours continues to evolve rapidly particularly for melanomas and in the coming years genetic profiling of individual tumours with targeted therapy is likely to play an important role in management.     

Long-term Vaginal Sequelae Secondary to Pediatric Pelvic Fracture

BackgroundPediatric pelvic fractures often appear radiographically benign despite significant injury to viscera. Vaginal injuries are rare, and therefore require a high index of suspicion.CaseA 26-year-old female patient who sustained a pelvic fracture in a motorcycle accident at the age of 10 presented with vaginal stenosis precluding sexual intercourse. Patient menstruated through a fistula in the distal vaginal vault. Radiographic and dye studies showed almost complete vaginal obstruction with heterotopic ossification. An extensive 30-year review of the literature was conducted looking for documented cases of vaginal injuries secondary to pelvic injury.Summary and ConclusionThis is the only recorded case of a long-term vaginal complication with subsequent heterotopic ossification secondary to pelvic fracture. Preventing debilitating long-term sequelae from vaginal injuries requires close patient follow-up and age-appropriate assessments.     

A phase synchrony measure for quantifying dynamic functional integration in the brain

The temporal coordination of neural activity within structural networks of the brain has been posited as a basis for cognition. Changes in the frequency and similarity of oscillating electrical potentials emitted by neuronal populations may reflect the means by which networks of the brain carry out functions critical for adaptive behavior. A computation of the phase relationship between signals recorded from separable brain regions is a method for characterizing the temporal interactions of neuronal populations. Recently, different phase estimation methods for quantifying the time‐varying and frequency‐dependent nature of neural synchronization have been proposed. The most common method for measuring the synchronization of signals through phase computations uses complex wavelet transforms of neural signals to estimate their instantaneous phase difference and locking. In this article, we extend this idea by introducing a new time‐varying phase synchrony measure based on Cohen's class of time–frequency distributions. This index offers improvements over existing synchrony measures by characterizing the similarity of signals from separable brain regions with uniformly high resolution across time and frequency. The proposed measure is applied to both synthesized signals and electroencephalography data to test its effectiveness in estimating phase changes and quantifying neural synchrony in the brain. Hum Brain Mapp, 2010. © 2010 Wiley‐Liss, Inc.     

Foetal Hypothalamic and Pituitary Expression of Gonadotrophin‐Releasing Hormone and Galanin Systems is Disturbed by Exposure to Sewage Sludge Chemicals via Maternal Ingestion

Animals and humans are chronically exposed to endocrine disrupting chemicals (EDCs) that are ubiquitous in the environment. There are strong circumstantial links between environmental EDC exposure and both declining human/wildlife reproductive health and the increasing incidence of reproductive system abnormalities. The verification of such links, however, is difficult and requires animal models exposed to ‘real life’, environmentally relevant concentrations/mixtures of environmental contaminants (ECs), particularly in utero, when sensitivity to EC exposure is high. The present study aimed to determine whether the foetal sheep reproductive neuroendocrine axis, particularly gondotrophin‐releasing hormone (GnRH) and galaninergic systems, were affected by maternal exposure to a complex mixture of chemicals, applied to pasture, in the form of sewage sludge. Sewage sludge contains high concentrations of a spectrum of EDCs and other pollutants, relative to environmental concentrations, but is frequently recycled to land as a fertiliser. We found that foetuses exposed to the EDC mixture in utero through their mothers had lower GnRH mRNA expression in the hypothalamus and lower GnRH receptor (GnRHR) and galanin receptor (GALR) mRNA expression in the hypothalamus and pituitary gland. Strikingly, this, treatment had no significant effect on maternal GnRH or GnRHR mRNA expression, although GALR mRNA expression within the maternal hypothalamus and pituitary gland was reduced. The present study clearly demonstrates that the developing foetal neuroendocrine axis is sensitive to real‐world mixtures of environmental chemicals. Given the important role of GnRH and GnRHR in the regulation of reproductive function, its known role programming role in utero, and the role of galanin in the regulation of many physiological/neuroendocrine systems, in utero changes in the activity of these systems are likely to have long‐term consequences in adulthood and represent a novel pathway through which EC mixtures could perturb normal reproductive function.