Short and middle latency vestibular evoked responses to acceleration in man.

We have succeeded in recording short and middle latency vestibular evoked responses in human subjects. The head was held rigidly in a special, patented head holder, constructed individually for each subject, which gripped the teeth of the upper jaw. The stimulus consisted of 2/sec steps of angular acceleration impulses produced by a special motor with intensities of about 10,000 degrees/sec 2 and with a rise time of 1-2 msec. The electrical activity was recorded as the potential difference between special forehead and mastoid electrodes having a large, secure contact area with the skin. The activity was digitally filtered and averaged in 2 separate channels by means of a Microshev 2000 evoked response system. The short latency responses, with peaks at about 3.5 msec (forehead positive), 6.0 msec (forehead negative) and 8.4 msec (forehead positive; bandpass: 200-2000 Hz; average of 1024 trials), had amplitudes of about 0.5 microV. The middle latency responses had peaks at about 8.8 msec (forehead positive), 18.8 msec (forehead negative) and 26.8 msec (forehead positive; 30-300 Hz; N = 128 trials), with larger amplitudes (about 15 microV). These responses were consistently recorded in the same subject at different times and were similar in different normal subjects. Strenuous control experiments were conducted in order to ensure that these responses are not artefacts due to the movement of conducting media (head, electrodes and leads) in the electromagnetic field of the motor and are elicited by activation of normal labyrinths.(ABSTRACT TRUNCATED AT 250 WORDS)     

Ultrastructural changes in the blood-brain barrier after nimodipine treatment and induced hypertension

Fourty-four narcotized rats were split into two equal groups, one being treated with nimodipine and the other with a placebo. By use of norfenefrine the blood pressure was raised to values of 150 and 180 mm Hg within the limits of the autoregulation of brain perfusion and under continuous measurement. Fifteen minutes after application of the standard tracer, horseradish peroxidase, the animals were exsanguinated using a saline perfusion and then perfusion-fixed with Karnovsky's solution. After development of the peroxidase staining the brain sections were evaluated and then allocated to their respective groups. In brain tissues from the experimental group significantly more frequent perivascular accumulations of horseradish peroxidase reaction product were found (P less than 0.001). In electron micrographs it could be seen that the tight junctions were intact and that there was a neuroendothelial transport, with horseradish peroxidase-filled vesicles, in the endothelium, muscle cells, and brain parenchyma. These vesicles represent a medium of transport for all proteins of high molecular weight and can therefore result in brain edema. It is concluded that nimodipine damages the blood-brain barrier by disturbance of the autoregulation of the cerebral blood flow.     

Non-endemic Burkitt's lymphoma

Burkitt's lymphoma, characterized by jaw and abdominal tumors, is the most common early childhood malignancy in Central Africa and well-known in the United States, with only sporadic reports coming from other countries. Considered to be the fastest growing tumor in man, it is thought to be of viral etiology with warm, humid climate and malaria regarded as co-factors. This is the first case of Burkitt's lymphoma reported from Greece.     

Modification of a hand splint to permit playing of the guitar

Modification of a hand splint for a musician who had suffered an incomplete disruption of the left ring finger extensor tendon is described. This modification enabled the patient to receive the benefit of conservative treatment of this disruption while continuing his employment. The modification can be performed easily with the standard stack splint; the success of this method is described.     

Der Einsatz des Prophy-Jet®-Gerätes zur Schmelzpolitur nach der Bracketentfernung

Zusammenfassung In einer In-vitro-Studie wurde die Einsatzfähigkeit des Prophy-Jet-^®-Gerätes für die Schmelzpolitur nach Bracketentfernung untersucht. In die Studie wurden drei verschieden stark gefüllte orthodontische Kleber einbezogen: Concise^®, Genie^® und Mono Lok^®. Alle Proben wurden rasterelektronenoptisch untersucht und fotografisch dokumentiert in Vergrößerungen zwischen 20- und 10 000fach. Die Oberflächenanalyse ergab, daß das Prophy-Jet^®-Gerät allein zur Schmelzpolitur nach Bracketentfernung nicht ausreicht, um unter klinisch vertretbarem Zeitaufwand (1 Minute/Zahn) eine kunststofffreie Schmelzoberfläche zu erzielen. Nach konventioneller makroskopischer Vorreinigung mit Scalern oder rotierenden Hartmetallfinierern zeigten sich nach fünfsekündiger Prophy-Jet^®-Bestrahlung noch geringe Kleberreste. Nach zehnsekündiger Expositionsdauer waren beim Mono Lok^®-Adhäsiv keine Kleberreste mehr nachweisbar, beim Concise^®-bzw. Genie^®-Adhäsiv fanden sich noch vereinzelte geringe Kleberinseln. Das Prophy-Jet^®-Gerät erscheint zur Unterstützung der Schmelzpolitur nach Bracketentfernung sinnvoll; eine sorgfältige Vorreinigung mit Hand- oder rotierenden Instrumenten ist jedoch erforderlich, um eine weitgehende Adhäsivreduktion zu erreichen. Die konventionelle Gummi- und Bimssteinpolitur kann nach 20sekündiger Prophy-Jet^®-Bestrahlung entfallen.

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Summary The purpose of this in vitro investigation was to ascertain the effects of the Prophy-Jet^® air-powder abrasive system for enamel polishing after debonding. Three adhesives differing in filler content were included in this study: Concise^®, Genie^®, and Mono Lok^®. All specimens were examined by scanning electron microscopy and documented photographically at magnifications from 20 to 10 000. Surface analysis showed that using the Prophy-Jet^® exclusively is not sufficient to produce a clean and smooth enamel surface without residual adhesive after debonding and after one minute of exposure time, as might be justifiable in a clinical situation. After macroscopic conventional clean-up with scalers or rotary finishing instruments and five seconds of exposure time to the Prophy-Jet^® some occasional adhesive remnants could be located. After ten seconds of Prophy-Jet^® treatment all Mono Lok^®-adhesive was removed from the enamel surface; in the Concise^® and Genie^®-group few isolated adhesive remnants could be detected. The Prophy-Jet^® air-powder abrasive system was found to be efficient in supporting enamel polishing after debonding; but an accurate pretreatment with scalers or rotary finishing instruments is essential to achieve an extensive reduction of adhesive. Final polishing of the enamel surface with rubber wheels or prophy cup and pumice can be omitted after treatment with the Prophy-Jet^® for 20 seconds.

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Résumé Le but de ce travail était d'éxaminer à l'aide d'une étude in vitro, l'emploi du Prophy Jet^® pour le polissage de l'émail après l'arrachage des brackets. Dans l'étude on a analysé trois substances adhésives différentes: Concise^®, Genie^® et Mono Lok^®. Après avoir examiné les spécimens par le microscope électronique à balayage, on les a documentés à l'aide de photos d'un grossissement de 20 à 10 000. L'analyse de la surface montre que la seule application du Prophy Jet^® (après l'arrachage des brackets) ne suffit pas pour obtenir une surface d'émail sans substance adhésive en un temps clinique d'une minute par dent. Après prétraitement macroscopique selon la méthode conventionnelle (scaler ou instruments montés sur tour) il demeurait encore de petits restes de la substance adhésive après l'application du Prophy Jet^® pendant cinq secondes. Après une durée d'application de dix secondes, on ne pouvait pas déceler de restes de Mono Lok^®, tandis qu'il y avait sporadiquement des restes de Concise^® et Genie^®. Ces résultats indiquent, que le Prophy Jet^® est efficace pour le polissage de l'émail après l'arrachage des brackets, mais on a tout de même besoin d'un nettoyage précédent minutieux avec des instruments convenables (scaler ou instruments montés sur le tour) pour obtenir une réduction considérable de la substance adhésive. On peut renoncer au polissage conventionnel à l'aide de caoutchouc ou de la pierre ponce après l'application du Prophy Jet^® pendant 20 secondes.

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Vortrag auf der wissenschaftlichen Jahrestagung der Deutschen Gesellschaft für Kieferorthopädie 1985.     

Necrosis of the femoral head following fracture of the femoral neck

One hundred and thirty fractures of the femoral neck treated with sliding screw-plate or sliding nail-plate were followed for up to 65 months postoperatively. Throughout the observation period the yearly incidence of necrosis of the femoral head was between 5 and 10 per cent, as estimated by the life table method, and after 5 years 37 per cent of the patients with united fractures had developed necrosis of the femoral head. The cases of necrosis were all characterized radiographically by one or more areas of subchondral cortical depression, generalized subchondral fragmentation or isolated patches of sclerosis. It is concluded that estimation of the frequency of femoral head necrosis after fracture of the femoral neck requires long-term follow-up and reliable, reproducible radiographical criteria for necrosis of the head. Because of the high mortality of patients sustaining these fractures, statistical methods employing censored data should be used.     

Oxybutynin versus propantheline in patients with multiple sclerosis and detrusor hyperreflexia

Hyperreflexia is the most common urological finding in patients with multiple sclerosis. A prospective randomized study was done to compare the effectiveness of 2 commonly used drugs, oxybutynin and propantheline. Of the 34 patients entered into the trial 19 were treated with oxybutynin and 15 with propantheline. The urological symptoms (frequency, nocturia, hesitancy, urgency and urge incontinence) were graded according to severity from 0 to 3. Patients with urinary infection were excluded. Urodynamic examination, consisting of cystometrography and electromyography, was performed in all patients before treatment. Both groups of patients had comparable neurological, urological and urodynamic status before treatment. In 4 patients (21 per cent) treated with oxybutynin and in 4 (27 per cent) treated with propantheline side effects were so severe that the treatment had to be discontinued. Symptomatic response to oxybutynin was good in 10 patients (67 per cent), fair in 2 (13 per cent) and poor in 3 (20 per cent). Propantheline produced good symptomatic results in 4 patients (36 per cent), fair in 1 (9 per cent) and poor in 6 (55 per cent). The mean increase in maximum cystometric capacity on cystometrography was significantly larger in the oxybutynin group than in the propantheline group (144 +/- 115 versus 35 +/- 101). Our results indicate that oxybutynin is more effective than propantheline in the treatment of detrusor hyperreflexia in patients with multiple sclerosis.