The effect of autoclaving on torsional moment of two nickel-titanium endodontic files.

AIM: To evaluate the effects of repeated autoclaving on torsional strength of two nickel-titanium (NiTi) rotary endodontic files: Twisted Files (SybronEndo, Orange, CA, USA) and GT Series X files (Dentsply Tulsa Dental Specialties, Tulsa, OK, USA). METHODOLOGY: Four groups of 20 GT Series X (size 20, .06 taper) and four groups of 20 Twisted Files (size 25, .06 taper) were subjected to 0, 1, 3 or 7 autoclave cycles. The nonautoclaved files served as controls. Failure in torsion was recorded using a torsiometer according to ANSI/ADA 58 and ISO 3630-1 standards. Mean results were analysed using analysis of variance (anova) at a 95% confidence level. Dunnett's procedure was used for post hoc analysis. RESULTS: There was no significant difference in torsional moment between the number of autoclave cycles for Twisted Files. However, the mean torque at failure was significantly lower for GT Series X files after three (P<0.001) and seven (P<0.001) autoclave cycles. For Twisted Files, there was a significant increase (P<0.001) in mean number of degrees of rotation to failure with more autoclave cycles compared to nonautoclaved files. For GT Series X files, there was no significant association (P=0.527) between the number of autoclave cycles and the degrees of rotation to failure. CONCLUSIONS: Repeat autoclaving of unused GT Series X files between three and seven times resulted in a significant reduction in torsional strength, whilst there was no effect observed for Twisted Files.

Increased Functional Connectivity After Listening to Favored Music in Adults With Alzheimer Dementia.

BACKGROUND: Personalized music programs have been proposed as an adjunct therapy for patients with Alzheimer disease related dementia, and multicenter trials have now demonstrated improvements in agitation, anxiety, and behavioral symptoms. Underlying neurophysiological mechanisms for these effects remain unclear. METHODS: We examined 17 individuals with a clinical diagnosis of Alzheimer disease related dementia using functional MRI following a training period in a personalized music listening program. RESULTS: We find that participants listening to preferred music show specific activation of the supplementary motor area, a region that has been associated with memory for familiar music that is typically spared in early Alzheimer disease. We also find widespread increases in functional connectivity in corticocortical and corticocerebellar networks following presentation of preferred musical stimuli, suggesting a transient effect on brain function. CONCLUSIONS: Findings support a mechanism whereby attentional network activation in the brain's salience network may lead to improvements in brain network synchronization.

Incidence and risk factors for hypoadrenocorticism in dogs treated with trilostane.

The aim of this study was to describe the incidence and permanence of hypoadrenocorticism associated with trilostane treatment and to assess potential risk factors for hypoadrenocorticism. A retrospective cohort study was conducted using case records for 156 dogs treated with trilostane after a diagnosis of hyperadrenocorticism. Occurrences of hypoadrenocorticism were categorised as either transient or permanent. After initiation of treatment with trilostane, the estimated cumulative incidence of hypoadrenocorticism was 15% by 2 years and 26% by 4.3 years, respectively. Occurrences of hypoadrenocorticism were transient in 14/19 (74%) affected study dogs. The risk of hypoadrenocorticism was not significantly associated with trilostane dose rate and other potential risk factors assessed were not significantly associated with subhazard of hypoadrenocorticism, but effect estimates for most were imprecise. In conclusion, approximately 15% of dogs being treated with trilostane developed hypoadrenocorticism within the first 2 years of treatment and about one quarter became affected by 4 years. However, first occurrences of hypoadrenocorticism were mostly transient. Over the range of dose rates studied, each 1mg/kg/day increase in trilostane dose rate resulted in, at most, only a small increase in the risk of developing hypoadrenocorticism.

Proximal tubular nephropathy in two dogs diagnosed with lead toxicity.

CASE REPORT: Lead toxicity was diagnosed in two dogs presenting with vague clinical symptoms. Complete blood count, biochemical testing and imaging changes showed a metarubricytosis in dog 1, but were largely normal in dog 2. Both dogs had glucosuria and proteinuria on urinalysis consistent with damage to the proximal renal tubules. Both animals returned elevated blood lead levels. A history of ingestion of lead was reported by the owner in one dog and elucidated from the second owner once the animal had recorded elevated blood lead levels. CONCLUSION: Lead toxicity is rarely reported in the human literature as a cause of proximal tubular dysfunction. To the author's knowledge this is the first case report specifically examining this in the dog. The clinical awareness that lead is a potential cause of proximal renal tubular dysfunction offers another tool to assist the clinician in the diagnostic process. This is particularly important given that the clinical signs and minimum database findings in animals with lead toxicosis are highly variable. Evidence of proximal tubular dysfunction should trigger the clinician to closely examine the history for a potential source of lead exposure and consider submitting samples to test blood lead levels.

An assessment of antiseptic bladder washout solutions using a physical model of the catheterized bladder.

The antibacterial activity of six antiseptic solutions formulated for use in bladder washout procedures has been examined in a simple model of the catheterized bladder. The experiments were carried out under conditions which examined the efficacy of the formulations against organisms that had recently contaminated the bladder urine. At cell densities of 10(4) cfu ml-1 all the solutions tested proved effective in eliminating bacteria from the bladder urine. Under conditions simulating heavy contamination (10(7)-10(8) cfu ml-1) however, only mandelic acid (1% w/v) eliminated the range of bacterial species commonly responsible for catheter-associated urinary tract infection.

Effects of physical activity on some components of the skeletal system.

Sporting activities impose on the skeletal system forces of a high intensity and frequency. Ligaments, bone and tendons behave in a time-dependent load-extension fashion, and it is important for both scientists and clinicians to consider, for example, the alterations in failure properties shown by ligaments, tendons and bone at different rates of deformation. Whether the ability of the skeletal system to withstand stress can be improved with appropriate training is still controversial. The effects of physical exercise depend on the modality, intensity and duration with which the exercise itself is performed. Moreover, genetic factors, also influencing growth and hormonal status, may exert a significant influence on the response of a given tissue to an external load. Overloading may cause a lesion, and this may decrease or annihilate performance capability. The skeletal system may not be resistant enough, and so it may prove limiting to intensive physical activity. In vitro studies on resistance of a single tissue have not taken into consideration the specific resistance of that structure in vivo, and the results so obtained cannot be readily extrapolated to sporting activities, as in vivo muscles, joints, tendons, ligaments and cartilage act as one. This article reviews some of the possible beneficial and detrimental effects of intense exercise on various components of the skeletal system, focusing on its ability to withstand and adapt to stresses and allow maximal performance.

The impact of patients perceptions of high blood pressure on attendance at screening, An extension of the Health Belief Model.

This study is concerned with a neglected area: the synthesis of two approaches relevant to health-related behaviour-the Health Belief Model and Attribution Theory. A prospective design was used to test the combination of health beliefs and causal attributions that predispose patients to attend a screening for raised blood pressure. It was proposed that causal attributions concerning high blood pressure (HBP) would (i) affect other health beliefs, (iii) would act in conjunction with health beliefs in relation to actual behaviour and (iii) might show, in some cases, a more direct influence on behaviour and behavioural intention. One hundred and three adults responded to the questionnaire. Multivariate analyses were used to discriminate between the characteristics of attenders and non-attenders. The general prediction was confirmed: overall, eight factors comparing both HBM and attributional items produced a highly significant discrimination. A correlational analysis revealed a variety of linear relationships between HBM-items and causal attributions. Much of the variance in attendance was accounted for by the intention variable, and multiple regression analysis was performed to examine the determinants or intention, as a significant intervening factor between beliefs and behaviour. Participation bias limits the generalisability of these findings. The potential significance of causal attribution as predictors of both health beliefs and behaviour is nevertheless apparent. The implications of such a synthesis of approaches are discussed in terms of psychological theory and health education.

Isolated ganglions of the anterior cruciate ligament.

We report three athletes with symptomatic isolated ganglion of the anterior cruciate ligament. The symptoms consisted of anteromedial knee pain, worse when changing direction while running, and on squatting. All gave a history of repeated minor knee trauma without a single episode of serious injury. At day-case arthroscopy, a unilobulated cystic mass arising from a clinically and arthroscopically intact anterior cruciate ligament was noted and removed in each case. No further intra- or extra-articular knee lesion was seen. Histology revealed a cystic ganglion in each case. With early physiotherapy, the patients could start gentle training 3 wk after arthroscopy, and, at 6-month review, were fully asymptomatic. A review of the literature shows that an isolated ganglion arising from the anterior cruciate ligament is exceedingly rare, with only three such ganglia having been previously reported.

A prospective, double-blind trial of electrical capacitive coupling in the treatment of non-union of long bones.

Twenty-three patients who had an established non-union of a long bone were entered into a prospective, double-blind trial in which electrical capacitive coupling was used for treatment. Twenty-one patients completed the study: ten who were actively managed and eleven who were managed with a placebo unit. The non-union healed in six of the ten patients who had been managed actively but in none of the patients who had been managed with the placebo unit. This difference in the rates of healing between the actively managed and the placebo groups is highly significant (p = 0.004).

Blockage of urethral catheters by bacterial biofilms.

We report the case of a 63-year-old woman whose indwelling urethral catheter became blocked regularly at 4-5 day intervals over a period of 10 weeks. 'Worm-like' structures 25-30 cm in length were found either in the catheter, completely occluding the lumen, or in the drainage tube thereby blocking the valve of the drainage bag. Electron microscopy showed that these structures were composed of bacteria, while culture revealed them to be mixed communities of Pseudomonas aeruginosa, Escherichia coli, Enterococcus faecalis and Proteus mirabilis. Following treatment with ciprofloxacin, catheter drainage continued freely for a further period of 10 weeks.

The Stryker knee arthrometer in clinical practice.

The Stryker knee arthrometer was assessed in the environment of a nonspecialized National Health Service clinic by junior doctors in training. Forty percent of proven anterior cruciate deficient knees had a measured anterior excursion of 2 mm or less compared with the normal side under the same circumstances. Twenty percent of normal knees tested showed more than this variation between knees when different observers were compared and also when the same observers were compared at three week intervals. There is thus a question about the use of this machine in a general orthopaedic clinic with different observers.

Surgical decompression of chronic central core lesions of the Achilles tendon.

We report the outcome of 14 athletes with chronic recalcitrant achillodynia and central core degeneration of the Achilles tendon. The patients underwent surgery after an average time from onset of symptoms to surgery of 87 months. All patients had undergone conservative management, including physical therapy treatment, orthoses, nonsteroidal antiinflammatory drugs, and steroid injections. At an average follow-up of 35 months (range, 27 to 52), only 5 patients had an excellent or good result, despite reexploration in 6 of the 14 patients. In athletes with long-standing pain and central core degeneration of the Achilles tendon, prognosis is poor, and even reexploration is not successful. If the referral pattern allows, surgery should probably be undertaken earlier.

Some observations on the Kerr effect in suspensions of bentonite.

Apparatus is described which allows continuous electro-optic signals to be obtained from aqueous suspensions of bentonite. A radiofrequency-field generator and external electrodes are used to allow the suspension to be contained in an all-glass cell. The magnitude of the response is found to depend both on cation charge and on concentration. There appears to be little chemical selectivity save under circumstances which cause the ion population available to the suspension to be depleted.

The surgical treatment of equinovarus deformity in adults with spasticity.

Adults with deformities of the lower limb due to spasticity may be considerably improved by operation, but thorough pre-operative assessment as an inpatient is essential in order to pinpoint the disability. The commonest deformity is equinovarus which often responds to simple operative procedures. The results of seventy-seven operative procedures in fifty patients are recorded. Correction once achieved is stable and the deformity does not recur.

Acute haemarthrosis of the knee in athletes. A prospective study of 106 cases.

We made a prospective arthroscopic study of 106 skeletally mature male sportsmen with an average age of 28.35 years (16.8 to 44) who presented with an acute haemarthrosis of the knee due to sporting activities. We excluded those with patellar dislocations, radiographic bone injuries, extra-articular ligamentous lesions or a previous injury to the same joint. The anterior cruciate ligament (ACL) was intact in 35 patients, partially disrupted in 28 and completely ruptured in 43. In the patients with an ACL lesion, associated injuries included meniscal tears (17 patients), cartilaginous loose bodies (6), and minimal osteochondral fractures of the patella (2), the tibial plateau (3) or the femoral condyle (9). We found no age-related trend in the pattern of ACL injuries. Isolated injuries included one small osteochondral fracture of the patella, and one partial and one total disruption of the posterior cruciate ligament. Three patients had cartilaginous loose bodies, and no injury was detected in five. Acute traumatic haemarthrosis indicates a serious ligament injury until proved otherwise, and arthroscopy is needed to complement careful history and clinical examination. All cases with a tense effusion developing within 12 hours of injury should have an aspiration. If haemarthrosis is confirmed, urgent admission and arthroscopy are indicated.

Lesions of the patellar ligament.

We report 18 cases of pain and tenderness in the mid-part of the patellar ligament in athletes. The condition may be disabling, but it responds to surgery. Ultrasound and CT scans were positive in all 17 confirmed cases, but ultrasound gave a better distinction between the cysts, granulation tissue, metaplasia, mucoid degeneration and congenital defects found at operation.

Accidental injection of white spirit into the hand in golfers.

We report two cases in which white spirit has been injected accidentally into the hand by golfers, while attempting to remove the grip of the golf-club handle in order to replace it. One of our patients has anecdotal evidence of this happening in at least two other cases, one of which resulted in amputation of the index finger, and the other in severe damage to the thumb.

Vocal matching of frequency modulation in synthesized vowels.

Nine male singers attempted to match rates and extents of synthesized vocal vibrato at low, middle, and high pitch levels. The results showed that on average, the singers were able to match rates of 3, 5, and 7 Hz within 13%. It was difficult for the singers, however, to match extents of 0.5, 1.0, and 1.5 semitones. Thus, the results indicated singers' reasonably good ability to match rates but, contrary to prevalent opinions, not extents of vocal vibrato.

Arthroscopy in sporting and sedentary children and adolescents.

We performed arthroscopic procedures on 97 knees in 91 patients younger than 16 years of age. Sixty arthroscopic procedures in 58 patients were for sports-related injuries or symptoms. The most common diagnosis was maltracking of the patella. In 78 cases, an operative procedure was performed at the time of diagnostic arthroscopy. No complications were experienced. The accuracy of diagnosis for suspected meniscal tears was poor. Further pathologies, especially meniscal tears, were commonly associated with anterior cruciate ligament tears. Arthroscopy of the knee in children is safe, has a high diagnostic accuracy, and, in a significant proportion of patients, it can have not only a diagnostic role but allows the management of a wide variety of intra-articular conditions.