A national epidemiological study of Myasthenia Gravis in Australia.

BACKGROUND AND PURPOSE: Existing epidemiological studies of Myasthenia Gravis have generally examined small populations. Few national studies have been conducted, and published incidence and prevalence rates vary widely. We report one of the largest national studies of Myasthenia Gravis, and the first incidence and prevalence rates for Australia. METHODS: Prescriptions for Pyridostigmine Bromide in 2009 were utilized from a national prescribing database to estimate incidence and the prevalence of symptomatic and treated disease. Crude rates were age-standardized to the WHO world population. We compared standardized rates to recent national studies from Norway and Taiwan. RESULTS: In 2009, there were 2574 prevalent cases of symptomatic and treated Myasthenia Gravis, corresponding to an annual crude prevalence rate of 117.1 per 1 million residents. There were 545 incident cases, yielding a crude incidence rate of 24.9 per 1 million residents. The crude incidence in women and men was estimated to be 27.9 and 21.9 per 1 million, respectively. Prevalence and incidence rates were higher in women than men between the ages of 15 and 64 years, and were higher in men than women in those older than 65 years. Rates peaked between the ages of 74 and 84 years, declining thereafter. Standardized incidence was higher in Australia than Norway, but similar to Taiwan (P-values = 0.007 and 1.00, respectively). CONCLUSIONS: This first Australian epidemiological study of symptomatic Myasthenia Gravis is one of the largest population-based studies ever reported and supports higher incidence rates for Myasthenia Gravis. Myasthenia Gravis disproportionately affected younger females and older males.

Low positive predictive value of the ABCD2 score in emergency department transient ischaemic attack diagnoses: the South Western Sydney transient ischaemic attack study.

BACKGROUND: The ABCD(2) stroke risk score is recommended in national guidelines for stratifying care in transient ischaemic attack (TIA) patients, based on its prediction of early stroke risk. We had become concerned about the score accuracy and its clinical value in modern TIA cohorts. METHODS: We identified emergency department-diagnosed TIA at two hospitals over 3 years (2004-2006). Cases were followed for stroke occurrence and ABCD(2) scores were determined from expert record review. Sensitivity, specificity and positive predictive values (PPV) of moderate-high ABCD(2) scores were determined. RESULTS: There were 827 indexed TIA diagnoses and record review was possible in 95.4%. Admitted patients had lower 30-day stroke risk (n = 0) than discharged patients (n = 7; 3.1%) (P < 0.0001). There was no significant difference in proportion of strokes between those with a low or moderate-high ABCD(2) score at 30 (1.2 vs 0.8%), 90 (2.0 vs 1.9%) and 365 days (2.4 vs 2.4%) respectively. At 30 days the sensitivity, specificity and PPV of a moderate-high score were 57% (95% confidence interval (CI) 25.0-84.2), 32.2% (95% CI 29.1-35.6) and 0.75% (95% CI 0.29-1.91) respectively. CONCLUSIONS: Early stroke risk was low after an emergency diagnosis of TIA and significantly lower in admitted patients. Moderate-high ABCD(2) scores did not predict early stroke risk. We suggest local validation of ABCD(2) before its clinical use and a review of its place in national guidelines.

Efficacy of portable filtration units in reducing aerosolized particles in the size range of Mycobacterium tuberculosis.

OBJECTIVE: To evaluate engineering control measures to prevent nosocomial transmission of diseases such as tuberculosis, we studied four portable high-efficiency air filtration units, including three high-efficiency particulate air (HEPA) filtration units, for their ability to remove aerosolized particles. DESIGN: Studies were conducted in either a nonventilated aerosol chamber or in a hospital isolation room that met CDC guidelines for TB control (negative pressure, > or = 6 air changes per hour, air exhausted directly to the outside). The rooms were challenged with aerosolized mineral oil in the size range of 0.3 to 5.0 microns at levels 10 to 20 times the normal airborne particle load in the room at baseline. Airborne particles were counted with a laser counter capable of simultaneously measuring sizes > or = 0.3, > or = 0.5, > or = 1.0, and > or = 5.0 microns. Experimental runs were conducted with the filtration units in the center or corner of the chamber or room, and the particle counter in the center of the room or at the exhaust vent. RESULTS: Portable filtration units were effective in accelerating the removal of aerosolized submicron particles. In the nonventilated room, time required by the various portable filtration units for removal of 90% of aerosolized particles (> or = 0.3 microns) ranged from a low of 5 to 6 minutes to a high of 18 to 31 minutes, compared to the control (no filtration unit), > 171 minutes. In the hospital room, individual filtration units removed 90% of aerosolized particles (> or = 0.3 microns) in times ranging from 5 to 8 minutes to 9 to 12 minutes, compared to the control (no filtration unit), 12 to 16 minutes. The location of the portable filtration unit (center versus corner) did not affect the clearance rate of airborne particles. CONCLUSION: Our data indicate that portable filtration units can rapidly reduce levels of airborne particles similar in size to infectious droplet nuclei and, therefore, may aid in reducing the risk of tuberculosis exposure.

Advancing from flexible sigmoidoscopy to colonoscopy in rural family practice.

This paper describes the background, experience, training, and preceptorship of a rural family physician that culminated in provision of diagnostic and therapeutic colonoscopy to his patients. Initial training took place in a two-day continuing medical education course. Subsequent training consisted of one-on-one training in 11 colonoscopies and five polypectomies, correspondence, recommended readings, a one-on-one preceptorship, and telephone consultation. Training was provided by University of Tennessee faculty who were experts in the area of colonoscopy and polypectomy procedures. The outcomes of 250 consecutive colonoscopies performed by the rural family physician are documented here. Training requirements vary widely by professional organization and subspecialty. Some subspecialists have recommended as many as 100 supervised colonoscopies and 25 polypectomies as a minimum training requirement for hospital privileges. It is our contention that unnecessarily high training requirements add to educational costs and may restrict qualified rural physicians from providing these services.

Cecal and fecal bacterial flora of the Mongolian gerbil and the chinchilla.

The Mongolian gerbil is being increasingly used as a laboratory animal and as a pet. Both chinchillas and gerbils are used as animal models for otitis media and other otic research. Previously, only incomplete information was available regarding the indigenous bacterial flora of the lower intestinal tracts of these coprophagic animals. Using the strict anaerobic methodology of the Virginia Polytechnic Institute Anaerobe Laboratory, we studied the predominant bacterial flora of the cecum and fecal pellets of the gerbil and the chinchilla and the bacterial flora of digesta pellets in the proximal colon. We found species of the following anaerobic genera in high dilutions of gerbil fecal pellets: Bifidobacterium, Clostridium, Propionibacterium, Lactobacillus, and Bacteroides. Only lactobacilli were found in high dilutions of digesta from the upper colon, although the cecum yielded Peptostreptococcus, Bifidobacterium, Clostridium, Lactobacillus, Propionibacterium, and Bacteroides species from high dilutions of cecal contents. The facultatively anaerobic and aerobic flora isolated consisted of species of Bacillus, Streptococcus, Staphylococcus, Acinetobacter, Alcaligenes, Escherichia, Pasteurella, and Pseudomonas plus several unidentifiable organisms. Species of Bifidobacterium, Bacteroides, Eubacterium, and anaerobic Lactobacillus were isolated from chinchillas.

Superoxide dismutase in ruminal bacteria.

Of 13 species of anaerobic ruminal bacteria examined, 11 were found to contain measurable levels of superoxide dismutase activity. Four of five other strict anaerobic species studied for comparison were found to contain superoxide dismutase activity.

Butyl rubber stoppers increase the shelf life of prereduced, anaerobically sterilized media.

Butyl rubber stoppers as compared with neoprene or black rubber stoppers significantly increased the shelf life of prereduced, anaerobically sterilized media for growth of obligately anaerobic bacteria.

Using tissue adhesive for wound repair: a practical guide to dermabond.

Dermabond is a cyanoacrylate tissue adhesive that forms a strong bond across apposed wound edges, allowing normal healing to occur below. It is marketed to replace sutures that are 5-0 or smaller in diameter for incisional or laceration repair. This adhesive has been shown to save time during wound repair, to provide a flexible water-resistant protective coating and to eliminate the need for suture removal. The long-term cosmetic outcome with Dermabond is comparable to that of traditional methods of repair. Best suited for small, superficial lacerations, it may also be used with confidence on larger wounds where subcutaneous sutures are needed. This adhesive is relatively easy to use following appropriate wound preparation. Patients, especially children, readily accept the idea of being "glued" over traditional methods of repair.

Indigenous nasopharyngeal, auditory canal, and middle ear bacterial flora of gerbils: animal model for otitis media.

The indigenous microbial flora of the middle ear cavity of Mongolian gerbils, Meriones unguiculatus, was isolated, characterized, and identified, showing it to be sparse and transitory. Organisms, when found in the middle ear cavity, were most likely to be Staphylococcus epidermidis-like organisms. Cerumen from the external auditory canal of these animals yielded mostly staphylococci, coryneforms, and other gram-positive rods, including some anaerobic species. The nasopharynx supported a flora consisting mainly of staphylococci, lactobacilli, and coryneforms, with a smaller incidence and numbers of many other species. No mycoplasmas were cultured or seen in scanning electron microscope studies. None of the major pathogens of human otitis media were found; therefore, Mongolian gerbils are microbiologically acceptable candidates as a model for induced otitis media, using organisms isolated from human otitic infections.