Penetration depth of a dye marker into dentine using a novel hydrodynamic system (RinsEndo).

AIM: To investigate the efficiency of a hydrodynamic irrigation system compared with conventional cleansing techniques in root canals. METHODOLOGY: Forty-five freshly extracted single-rooted teeth were de-coronated and their root canals were enlarged to size 30 at the apex. The teeth were randomly divided into three groups (n = 15) for the final rinsing sequence using 2% NaOCl plus acid fuchsin: group I: static application of irrigant, 3 min; group II: flushing with a syringe; 5-mL NaOCl, 1 min; group III: RinsEndo-system; 5-mL NaOCl, 50 s. Apical extrusion was documented photographically. The roots were sectioned at 2, 4, 6 and 8 mm from their apices and the penetration depths of dye into dentine measured, using a stereomicroscope. Wilcoxon's test and Pearson's chi-squared test were employed to prove statistic relevance. RESULTS: Greater dye penetration depth into the dentinal tubules was achieved when employing hydrodynamic rinsing procedures. Using this technique, 23% of the specimens were penetrated for more than 50% of their dentine thickness, whereas the results for flushing with a syringe were 12% (static application, 7%). No penetration of dentine occurred in 63% of specimens with static application, 39% flushing with a syringe and 15% using the hydrodynamic system (P < 0.05 Pearson's chi-squared test). Apical extrusion occurred more frequently after hydrodynamic rinsing (extruded specimens: RinsEndo = 80%; static application/flushing with a syringe = 13%; P < 0.05 Pearson's chi-squared test). CONCLUSIONS: Hydrodynamic rinsing demonstrated an improvement over conventional methods in terms of dentine penetration of a dye marker. A higher risk of apical extrusion with the RinsEndo-system was evident.

Syndactyly/brachyphalangy and nail dysplasias as marker lesions for sclerosteosis.

Sclerosteosis describes an autosomal recessive form of hyperostosis corticalis generalisata (MIM 239100). Sclerosteosis is primarily a disorder of osteoblast hyperactivity and metabolic abnormalities are not present. Besides generalized bone changes the presence of asymmetric cutaneous syndactyly of the index and middle fingers is characteristic. In many cases this syndactyly is associated with nail dysplasia and therefore dermatologists should recognize this clinical finding as a possible marker of this entity. We report on a 36-year-old female of Greek origin who had had finger and nail dysplasias and facial asymmetry since birth. The patient was hospitalized on the Neurology ward because of increasing spastic and ataxic gait disturbances. Physical examination revealed numerous neurological problems resulting from bony compression of nerves. Furthermore the patient had remarkably deformed fingers with hypoplasia of the second finger on both sides. The nails were dysplastic, especially on both index fingers. All laboratory results concerning metabolic diseases were normal. It has been shown that sclerosteosis is clinically and radiographically very similar to van Buchem disease. Through a genome-wide search with a highly polymorphic microsatellite the gene responsible for van Buchem disease has been mapped to 17q12-q21, and Balemans et al. (1999) assigned the locus for sclerosteosis to the same region providing genetic support for the hypothesis of allelism. Dermatologists should be able to interpret such syndactyly associated with nail deformities as a possible hint for the diagnosis of sclerosteosis in patients with hyperostotic features.

[Cerebrotendinous xanthomatosis]. / Die zerebrotendinöse Xanthomatose.

Cerebrotendinous xanthomatosis (CTX) is a rare lipid storage disorder due to an autosomal-recessive inherited defect of the hepatic mitochondrial steroid 26-hydroxylase. The resultant reduced biosynthesis of cholic and especially chenodeoxycholic acid and the increased production and accumulation of cholestanol and cholesterol in most tissues is described and pathogenetic aspects as well as typical pathological findings are discussed. In the light of three personal observations the clinical symptoms and the results of auxiliary investigations are discussed and compared with the literature. The suspected diagnosis of CTX may be confirmed by demonstration of a pathologically elevated concentration of cholestanol or biliary alcohols in serum and urine respectively. The chronically progressive neurologic deficit can be halted or is in some cases partially reversible by treatment with chenodeoxycholic acid. Therefore, early diagnosis is mandatory and CTX should be considered in every patient presenting with intellectual impairment, spastic-ataxic signs, juvenile cataracts and tendon xanthomas.

Effects of LSD on classical conditioning as a function of CS-UCS interval: relationship to reflex facilitation.

Classical conditioning of the rabbit nictitating membrane response was accomplished by presenting a 100-msec tone CS at intervals 0, 100, 200, 400 and 800 msec before the presentation of a 100-msec shock UCS. In addition, tone-alone trials were used to monitor CR acquisition and shock-alone trials to measure facilitation of the nictitating membrane reflex by the tone CS at the various CS-UCS intervals. LSD at a dose of 13 micrograms/kg (30 nmol/kg) increased the excitatory effects of the shock UCS as measured by a greater frequency and amplitude of UCRs elicited across a wide range of UCS intensities and by the ability of a low intensity shock to produce reflex facilitation. Consequently, LSD produced a higher amplitude of UCRs on UCS-alone trials and on paired trials across all CS-UCS intervals during measurement of tone-induced reflex facilitation. LSD also enhanced CR acquisition across all CS-UCS intervals. Because LSD produced larger amplitude reference UCRs on the UCS-alone trials as compared with controls, calculations of reflex facilitation as a percentage change from these reference amplitudes led to an artifactually smaller effect for the LSD group as compared with controls. Nevertheless, both reflex facilitation as measured prior to CR acquisition on the first day of conditioning and CR acquisition across 10 conditioning sessions were a function of CS-UCS intervals and these two measures were highly correlated in the LSD (+0.94) and vehicle control (+0.85) groups. It was concluded that LSD enhances CR acquisition by enhancing the excitatory effects of both the CS and UCS and thus increasing their ability to enter into associative learning.

Effect of warfarin on the activated partial thromboplastin time.

Outpatients followed in an anticoagulation clinic were studied retrospectively to determine the effect of warfarin on the activated partial thromboplastin time (APTT). Twenty-nine patients were studied in part 1 of the trial to determine whether their APTT values were elevated when their prothrombin time (PT) was within 1.5 to 2.5 times the control PT. Part 2 was carried out using the data of 32 patients to determine whether a correlation existed between the degree of elevation of the patients' PT values due to warfarin and the concurrent degree of elevation of their APTT results. Baseline PT and APTT values and a minimum of three concurrent PT and APTT values determined during anticoagulation therapy with warfarin were used. Data were collected by chart review and review of Hematology Department records. Results indicated that a statistically significant difference was evident between the baseline APTT (30.79 sec) and the mean APTT (55.10 sec) when the PT was within the therapeutic range of 1.5 to 2.5 times the control while on warfarin therapy. Good linear correlation was evident (r = 0.821) between the degree of elevation of the PT and the degree of elevation of the APTT for the group. In most cases, a good linear correlation was also evident for individual patients. Routine ordering of concurrent APTT and PT tests for patients receiving warfarin therapy is not needed since the PT alone can be monitored under most circumstances.

Relationship between heterosynaptic reflex facilitation and acquisition of the nictitating membrane response in control and scopolamine-injected rabbits.

Classical conditioning of the rabbit nictitating membrane response was accomplished by presenting a 100-msec tone conditioned stimulus at intervals of 0, 100, 200, 400, and 800 msec before the presentation of a 100-msec shock unconditioned stimulus. In addition, tone-alone and shock-alone trials were interspersed during conditioning. On the first day of conditioning, during which there was no evidence of acquisition of conditioned responses to the tone conditioned stimulus, the amplitudes of the nictitating membrane response evoked on paired tone-shock trials were compared with the amplitudes obtained on shock-alone trials to provide a measure of reflex facilitation. There was a significant correlation (+0.86) in control animals between the degree of reflex facilitation and the degree of learning demonstrated at the various tone-shock intervals. Both reflex facilitation and learning were absent at the 0-msec tone-shock interval, increased at the 100-msec interval, reached a maximum at the 200-msec interval, and then declined at the longer intervals. Scopolamine (0.4 mg/kg) did not affect the amplitude of the nictitating membrane response elicited on shock-alone trials but eliminated any evidence of reflex facilitation or learning at the 100- and 800-msec intervals and significantly reduced both reflex facilitation and learning at the 200- and 400-msec intervals. The comparable effects of scopolamine on both reflex facilitation and learning were reflected by a significant correlation (+0.95) between these two measures.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of scopolamine and methylscopolamine on classical conditioning of the rabbit nictitating membrane response.

Classical conditioning of the rabbit nictitating membrane response was accomplished by presenting tone- and light-conditioned stimuli for 800 msec before delivery of a 100-msec shock as the unconditioned stimulus. Scopolamine significantly retarded the rate of acquisition and final asymptotic performance of conditioned responses to the tone- and light-conditioned stimuli. Methylscopolamine was approximately 20 times less potent than scopolamine in retarding the rate of acquisition, and had no effect on the final asymptotic performance of conditioned responses. The retardation in acquisition of conditioned responses produced by scopolamine could still be detected 5 days after cessation of drug injections, indicating that the effects of scopolamine were on acquisition and not performance. In contrast, scopolamine and methylscopolamine had no affect on the development of long-term habituation produced by the unpaired presentations of tone, light and shock stimuli. Control experiments indicated that the acquisition of conditioned responses by animals injected with saline, scopolamine or methylscopolamine was not contaminated by the presence of changes in base-line responding, sensitization or pseudoconditioning. In addition, scopolamine and methylscopolamine did not affect the unconditioned nictitating membrane reflex. In previously trained animals, scopolamine produced a significant, approximately 25-db elevation in the intensity threshold of a tone-conditioned stimulus for elicitation of conditioned responses. It was concluded that scopolamine blocks the excitatory properties of tone stimuli and this accounts for its ability to retard the rate of acquisition of conditioned responses.