Orbitopalpebral repair after 835 excisions of malignant tumours

Repair of any defect in the eyelid depends on its size and position and the state of the surrounding tissues. Basal cell carcinoma (BCC) is the most common malignant tumour of the eyelids, and squamous cell carcinoma (SCC), mixed carcinomas or basosquamous cell carcinomas (BSC), and cutaneous melanomas (CM), also invade the eyelids and periocular zones. Reconstruction of the eyelids and associated orbital structures after resection requires a complete understanding of the anatomy. The adequacy of the reconstruction is judged by the quality of functional restoration and the aesthetic appearance. The purpose of this study was to document various, simple or complex reconstructive procedures that may be used after excision of malignant tumours of the eyelids and to assess the outcome of surgical treatment.     

Vertical trapezius musculocutaneous flap: A retrospective study

From 1986 to 2001, 17 patients (aged 26–77 years) were treated using the vertical trapezius musculocutaneous flap. A two-stage procedure was used in 7 and a single-stage island flap in 10. The donor site was closed directly in all patients. Mean length of hospital stay was 16 days (range 12–25). There was no operative mortality. Complications were one partial flap necrosis and two seromas of the donor site, complicated by infection. With a minimum follow-up of more than two years, our study confirms the usefulness of the vertical trapezius musculocutaneous flap in head and neck reconstructive surgery. It is a reliable, thin flap of uniform thickness, which carries hairless skin. The length and thickness of its pedicle allows excellent mobility. The main disadvantage of the flap is the complete sacrifice of the muscle necessary for total mobilisation of the flap, and the intraoperative repositioning of the patient.     

Unilateral optic nerve crush induces bilateral retinal glial cell proliferation

The post-injury responses of retinal ganglion cells elicit a number of glial reactions which have not been completely understood. The bilateral pattern of non-neuronal retinal cell proliferation was examined in association with the differential fates of unilaterally injured adult retinal ganglion cells by means of bromodeoxyuridine (BrdU) immunocytochemistry. Lateralization of the glioproliferative events was studied by analysing both the experimental and the uninjured contralateral as well as matched retinas of sham-operated animals. Control adult rat retina included very few BrdU-positive cells within the nerve fibre and ganglion cell layers; however, experimental retinas of degenerating groups exhibited statistically significantly higher densities of newborn cells in most layers. Clusters of labelled cells were found in the inner plexiform layer related to OX-42 staining, indicating their microglial nature. Indeed, double-labelling experiments, after short-term unilateral optic nerve crushing, identified proliferating retinal glial cells in vivo. Both types of glia, astroglial and microglial cells, exhibited BrdU-positive labelling in injured as well as uninjured experimental rat retinas. Moreover, microglial proliferating cells were also identified in explanted retinal pieces after 2 days in culture. Affected and contralateral retinas responded similarly to the unilateral experimental manipulations applied with respect to BrdU labelling. The acute glial responses observed suggest that bilateral glial proliferation might represent a common response related to degeneration events in both retinas, i.e. ipsi- and contralateral to the experimental injury.     

Multiple sclerosis, cannabinoids, and cognition

There is increasing interest in the therapeutic potential of cannabis-based medicinal extracts in multiple sclerosis. Cognitive deficits that have been attributed to long-term heavy recreational use of cannabis are not necessarily extended to controlled pharmaceutical use of cannabis-based medicinal extracts. Available data indicate that after relatively short-term administration of cannabis-based medicinal extracts no significant cognitive decline occurs. Due to the absence of large scale long-term systematic clinical trials of cannabis-based medicinal extracts in multiple sclerosis therapeutics, however, many issues remain unresolved, including the possible adverse effects of cannabis-based medicinal extracts on cognition. This article critically reviews the current literature and considers the potential for cognitive adverse effects of long-term cannabinoid use in multiple sclerosis therapeutics.     

Role of alpha7 nicotinic receptors in nicotine dependence and implications for psychiatric illness

It has previously been shown that the reinforcing and dependence-producing properties of nicotine depend to a great extent on activation of nicotinic receptors within the ventral tegmental area (VTA), i.e. the site of origin of the mesolimbocortical dopaminergic projection. Based on the data reviewed in the present study, it is suggested that nicotine by stimulating presynaptic alpha7 nicotinic receptors within the VTA, that are probably localized on glutamatergic afferents from the medial prefrontal cortex, produces sequentially an increase in glutamate concentrations, stimulation of NMDA receptors found on dopamine (DA)-containing neurons in the VTA, enhanced firing activity of VTA-DA neurons, augmented DA release in the nerve terminal regions, and enhanced c-fos expression in the dopaminergic projection areas through activation of D1-DA receptors. In addition, it appears that alpha7 nicotinic receptors within the VTA are directly involved in nicotine-related reward and withdrawal responses. These data may be instrumental in understanding how nicotine interacts with the mesolimbocortical dopaminergic system, which is perhaps the most important component of the neural mechanisms underlying nicotine dependence. These results may also contribute to unraveling the cellular basis of nicotine's association with neuropsychiatric disorders, thereby offering the prospect of new therapeutic advances for their treatment.