Transcutaneous lower blepharoplasty

Transcutaneous lower blepharoplasty as a standard procedure for cosmetic lower blepharoplasty is being replaced by transconjunctival blepharoplasty and laser resurfacing techniques. Nevertheless, there remain specific indications for the transcutaneous approach and its modifications. The accomplished facial plastic surgeon will be able to choose the appropriate technique based on the patient's concerns, the eyelid pathology, and his or her clinical experience.     

Preoperative functional magnetic resonance imaging (fMRI) of the motor system in patients with tumours in the parietal lobe

Intracranial lesions may compromise structures critical for motor performance, and mapping of the cortex, especially of the motor hand area, is important to reduce postoperative morbidity. We investigated nine patients with parietal lobe tumours and used functional MRI sensitized to changes in blood oxygenation to define the different motor areas, especially the primary sensorimotor cortex, in relation to the localization of the tumour. Activation was determined by pixel-by-pixel correlation of the signal intensity time course with a reference waveform equivalent to the stimulus protocol. All subjects showed significant activation of the primary sensorimotor cortex while performing a finger opposition task with the affected and unaffected side. In five patients the finger opposition task additionally activated the ipsilateral sensorimotor cortex and the supplementary motor area (SMA). Extension and flexion of the foot, additionally performed in two patients, also activated the sensorimotor cortex, in one case within the perifocal oedema of the tumour. Tumour localization near the central sulcus induced displacement of the sensorimotor cortex as compared to the unaffected side in all patients with a relevant mass effect. The results of our study demonstrate that functional MRI at 1.5 T with a clinically used tomograph can reproducibly localize critical brain regions in patients with intracranial lesions.     

Graphbots: cooperative motion planning in discrete spaces

Most previous theoretical work on motion planning for a group of robots has addressed the problem of path planning for the individual robots sequentially, in geometrically simple regions of Euclidean space (e.g. a planar region containing polygonal obstacles). In this paper, we define a version of the motion-planning problem in which the robots move simultaneously. We establish conditions under which a team of robots having a particular configuration can move from any start location to any goal destination in a graph-structured space. We show that, for a group of robots that maintain a fixed formation, we can find the “shortest” path in polynomial time, and we give faster algorithms for special kinds of environments     

A quantitative method for LDH, MDH and albumin levels in tears with ocular surface toxicity scored by Draize criteria in rabbit eyes

We have established a quantitative method for evaluation of ocular surface lesions on the basis of lactate dehydrogenase (LDH) activity, malate dehydrogenase (MDH) activity, and albumin levels in rabbit tears. Lesions were produced with solutions of 0.005-0.02% benzalkonium chloride (BAK), 0.01-0.03% chlorhexidine digluconate (CHX), and 0.01-0.03% polyhexamethylene biguanide hydrochloride (PHMB), all of which are widely used in topical ophthalmic preparations. Two drops of test solution were instilled 15 times into rabbit eyes at 5 minute intervals. Sixty minutes after 0.02% BAK instillation, tear LDH activity increased from 1,840 U/L (without instillation) to 26,100 U/L, and concomitantly tear albumin levels rose from 0.11 mg/mL (without instillation) to 9.48 mg/mL. Instillation of 0.03% CHX and 0.03% PHMB caused smaller increases in LDH and MDH activity and albumin tear levels. LDH activity and albumin levels in tears were significantly correlated with the degree of total ocular surface lesions in both cornea and conjunctiva as observed by slit lamp biomicroscopy quantified using a modified Draize score. Based on the results of this study, we believe that LDH activity and albumin level in tears can be used as objective indicators for the quantitative evaluation of ocular surface lesions on both cornea and conjunctiva following application of topical ophthalmic preparations containing cytotoxic preservatives in animals and man.     

Cartilage-sparing otoplasty: a review with long-term results

Prominent ears are the most frequent congenital deformity in the head and neck region. Anatomy of normal and prominent ears as well as the psychological aspects of prominent ears are reviewed. Two types of surgical technique are described with emphasis on the cartilage-sparing technique. A sound pre-operative analysis, focusing on all parts of the deformity, and surgical techniques which are gradually applied to these deformities should result in pleasing, permanent changes for the vast majority of patients. In our opinion, a combination of cartilage-sparing techniques augmented with cartilage-weakening procedures give predictable long-term results with a natural appearing ear and concomitant few, easily treated complications.     

Substantial narrowing of the Niemann-Pick C candidate interval by yeast artificial chromosome complementation

Niemann-Pick disease type C (NP-C) is an autosomal recessive lipidosis linked to chromosome 18q11-12, characterized by lysosomal accumulation of unesterified cholesterol and delayed induction of cholesterol-mediated homeostatic responses. This cellular phenotype is identifiable cytologically by filipin staining and biochemically by measurement of low-density lipoprotein-derived cholesterol esterification. The mutant Chinese hamster ovary cell line (CT60), which displays the NP-C cellular phenotype, was used as the recipient for a complementation assay after somatic cell fusions with normal and NP-C murine cells suggested that this Chinese hamster ovary cell line carries an alteration(s) in the hamster homolog(s) of NP-C. To narrow rapidly the candidate interval for NP-C, three overlapping yeast artificial chromosomes (YACs) spanning the 1 centimorgan human NP-C interval were introduced stably into CT60 cells and analyzed for correction of the cellular phenotype. Only YAC 911D5 complemented the NP-C phenotype, as evidenced by cytological and biochemical analyses, whereas no complementation was obtained from the other two YACs within the interval or from a YAC derived from chromosome 7. Fluorescent in situ hybridization indicated that YAC 911D5 was integrated at a single site per CT60 genome. These data substantially narrow the NP-C critical interval and should greatly simplify the identification of the gene responsible in mouse and man. This is the first demonstration of YAC complementation as a valuable adjunct strategy for positional cloning of a human gene.