Tooth movement and cytokines in gingival crevicular fluid and whole blood in growing and adult subjects.

INTRODUCTION: Tooth movement has been studied largely with respect to the force required for tipping when pressure distribution varies along the length of the periodontal ligament. But important factors for effective canine translation include the nature and magnitude of applied stress and the patient's cell biology. The purpose of this research was to test 3 hypotheses: (1) the velocity of tooth translation (v(t)) is related to applied stress and growth status, (2) a threshold of stress accounts for the lag phase, and (3) v(t) is correlated with the ratio (AI) of 2 cytokines (IL-1beta, IL-1RA) measured in gingival crevicular fluid (GCF) and stimulated whole blood (SWB). METHODS: Continuous maxillary canine retraction stresses of 13 kPa and 4, 26, or 52 kPa were applied bilaterally in 6 growing and 4 adult subjects for 84 days. Dental models and GCF samples were collected at 1- to 14-day intervals. Cytokines were measured in GCF and SWB cell cultures. RESULTS: V(t) was positively related to stress and was higher in growing subjects (P = .001). It was also related to AI(GCF) in growers (R2= 0.56) and nongrowers (R2= 0.72). Canines moved with 52 kPa showed a lag phase, and postlag phase AI(GCF) was twice that of lag phase AI(GCF). Mean v(t) and associated AI(GCF) during the postlag phase were nearly double the values for canines moved with 13 and 26 kPa. SWB production of cytokines was dose-dependent. For growing subjects, SWB IL-1RA was correlated with v(t) (R = 0.70-0.72), and AI(SWB) and IL-1beta concentrations were correlated with AI(GCF) (R = 0.73-0.78). CONCLUSIONS: V(t) varied with growth status and stresses < or = 52 kPa; stresses of < 52 kPa showed no lag phase; and equivalent stresses yielded subject-dependent differences in v(t), which correlated with cytokines in GCF and SWB.     

Intubating conditions after vecuronium and atracurium given in divided doses (the priming technique)

Intubating conditions have been assessed at 60 s following administration of vecuronium 0.1 mg kg-1 or atracurium 0.5 mg kg-1 given either as a single dose after induction of anaesthesia with thiopentone or in divided doses; vecuronium 0.015 mg kg-1 followed 4 or 6 min later by 0.085 mg kg-1, or atracurium 0.075 mg kg-1 followed 4 or 6 min later by 0.425 mg kg-1. In the divided dose groups the smaller initial (priming) dose was given prior to induction of anaesthesia. Onset and duration of clinical relaxation were assessed using a peripheral nerve stimulator. The intubating conditions at 60 s improved significantly, with the use of relaxants in divided doses being acceptable in 80 and 70% of patients, respectively, with vecuronium and atracurium, but the conditions are not as good as those commonly found using suxamethonium. Priming at 6 min has no advantage over priming at 4 min. The onset of complete block was accelerated with priming, but the difference was not significant. The duration of clinical relaxation of vecuronium was significantly prolonged by giving it in divided doses. Unpleasant awareness of muscle weakness was observed in 15 patients, requiring early induction of anaesthesia in five of them.     

Ocular motor and manual tracking in Parkinson''s disease and the effect of treatment.

A quantitative analysis of unpredictable saccadic and smooth pursuit ocular motor and manual tracking was performed in 15 mildly affected, previously untreated subjects suffering from Parkinson's disease and in age-matched normal controls. The patients' ocular saccades were characterised by an increased variability of their latencies and reduced accuracy, with normal velocity profiles apart from saccadic duration. Their smooth pursuit had a decreased velocity gain. Similar abnormalities were found with manual tracking. Clinical improvement with dopaminergic drugs was associated with an improvement of saccadic accuracy and smooth pursuit gain. It is postulated that the ocular motor changes seen in Parkinson's disease are contingent upon functional dopamine levels in the basal ganglia.     

An assessment of the characteristics of n-type diodes for use in electron beam radiotherapy.

Diodes are now commercially available for use in electron beams. This paper aims to assess their response and limitations under different clinical conditions. Parameters considered were applicator factors, focus skin distance (FSD), angle of incidence, and temperature dependence. The beam perturbation was also measured. The beam energies used varied from 5 to 17 MeV. Applicator factors, measured at the surface of a phantom, differed by up to 7% compared with ion chamber measurements at Dmax. Similarly, large differences were found in FSD dependence. The temperature dependence was found to be approximately double the manufacturer's specification at 0.7% per degree Centigrade and the angular dependence was within the specification of +/- 2% for angles of +/- 30 degrees. The beam perturbation was measured as a maximum of 25% for 5-MeV electrons. The measurements were compared to other published data but this is highly dependent on the methodology employed. It was concluded that the diodes could be used in some circumstances, but only if used with extreme caution. An extensive set of commissioning measurements would be required before introducing the diodes into use clinically.     

Medical imaging of fetal ventriculomegaly

Five cases of fetal ventriculomegaly are described in detail. Following ultrasonography, either computerized tomography or magnetic resonance imaging was used in an attempt to clarify the structural pathology of the ventriculomegaly. In two patients, a precise diagnosis was achieved while a probable diagnosis was established in a third patient. The diverse etiology of fetal ventriculomegaly in these five cases demonstrates that ancillary medical imaging may be necessary to achieve diagnostic precision prior to therapeutic intervention.     

Neuroblastoma of the Anterior Mediastinum in an 80-Year-Old Woman

A 7-cm anterior mediastinal tumor in an 80-year-old woman was found by light and electron microscopy to be a neuroblastoma. Immunoreactivity for neuron-specific enolase, synaptophysin, and chromogranin supported the diagnosis. Neuroblastoma is an uncommon tumor in adults and we are not aware of a previous report of such a tumor in a patient of this age.