The oral health and treatment needs of community‐dwelling older people in a rural town in Western Australia

Objectives: The aim of this study was to assess, in a sample of older rural community‐dwelling Australians, their: oral health status, dental treatment needs, perceived barriers to access dental services and the prevalence and severity of dental anxiety. Methods: A cross‐sectional study of elderly rural Australians. Results: Eighty participants (mean age of 71.7 years) had a mean number of 0.69 (SD 1.6) decayed teeth, 15.72 (SD 13.3) missing teeth and 3.9 (SD 5.4) filled teeth. Forty‐one per cent were edentulous. Xerostomia was reported by 53% of the edentulous and 43% of the dentate. The average Corah Dental Anxiety Scale score was 8.72 (SD 3.8). Prevalence of dental anxiety was 15.6%. Two‐thirds needed dental treatment. Conclusions: Caries experience was lower than that reported in other studies. Reported barriers to use of dental services were long waiting times, lack of perceived dental need and costs.     

Speed of repolarization and morphology of glygerol-treated frog muscle fibres

1. Single muscle fibres from frog semitendinosus were subjected to sudden changes in [K](o), while recording membrane potential.2. In agreement with Hodgkin & Horowicz (1960), a sudden increase in [K](o) in normal fibres produced a rapid depolarization (half-time 0.3 sec), whereas a sudden decrease in [K](o) produced a slower repolarization (half-time 2-3 sec).3. Fibres were subjected to ;glycerol-treatment', a procedure which was supposed to produce a functional disconnexion of the T-system from the surface. In these glycerol-treated fibres both depolarization and repolarization induced by changes of [K](o) took place rapidly.4. The results suggest that the slowness of the repolarization in normal fibres is due to a retention of K ions inside the T-tubules.5. Electron microscopical observation of single fibres or bundles of fibres, which have been soaked in a Ringer containing ferritin, revealed that normal fibres contained ferritin particles in the T-system, while glycerol-treated fibres showed no ferritin. Except for the presence of some large vacuoles and some swelling of the T-system, glycerol-treated fibres appeared morphologically normal.6. Prolonged soaking in a high potassium solution produced electrical effects suggesting that K ions can enter the tubules of treated fibres very slowly, in spite of their inaccessibility to ferritin.7. The main effect of glycerol-treatment does not seem to be a total disconnexion of the T-system from the fibre surface, but rather constriction of the T-tubules near their openings to the exterior.     

The distribution of the T-system along the sarcomeres of frog and toad sartorius muscles

1. Frog and toad sartorius muscles were soaked in ferritin suspensions and then fixed and prepared for electron microscopy. Ferritin particles were counted in micrographs of regions where fibril striations were in good register, and the number of particles plotted according to position along the sarcomeres.2. The distribution of ferritin particles in both frog and toad muscle sarcomeres could be accounted for by a single peak centred at the Z-line, with a total width of about 0.4 mu.3. The peak in toad fibres was slightly broader than that in frog fibres, and this was due to more frequent branching of the T-system in the toad. In both frog and toad sartorius muscles branching increases the total quantity of T-system by around 30%.4. No peak was found in the ferritin distribution which could account for the peak of albumin distribution observed near the A-I boundary of toad sartorius muscles by Hill (1964).     

Mouse b-wave mutants

The b-wave is a major component of the electroretinogram that reflects the activity of depolarizing bipolar cells (DBCs). The b-wave is used diagnostically to identify patients with defects in DBC signaling or in transmission from photoreceptors to DBCs. In mouse models, an abnormal b-wave has been used to demonstrate a critical role of a particular protein in the release of glutamate from photoreceptor terminals, in establishing the structure of the photoreceptor-to-DBC synapse, in DBC signal transduction, and also in DBC development, survival, or metabolic support. The purpose of this review is to summarize these models and how they have advanced our understanding of outer retinal function.     

Effects of light adaptation on the response characteristics of human oscillatory potentials.

We have examined the response characteristics of the oscillatory potentials (OPs) of the human electroretinogram (ERG) obtained to ganzfeld flash stimuli presented against adapting fields. First, we determined the extent to which the OPs obtained to high luminance flashes change during the course of light adaptation to a cone-isolating adapting field. Regardless of the number of OP wavelets, the last OP wavelet increased in amplitude and decreased in implicit time to a greater extent than did the earlier wavelet(s). In addition, we examined the role of both flash and adapting field luminance in determining the wave form of the OPs. For each adapting field luminance that was tested, the number of OP wavelets increased as flash luminance increased, primarily resulting from the splitting of the last OP into 2 distinct wavelets. While the number of OP wavelets generally decreased as adapting field luminance increased, the amplitude of the last OP became larger. These functional distinctions between the last and the earlier wavelets are consistent with their representing the activity of different retinal generators.     

Smith-Lemli-Opitz综合征的啮齿动物模型中的视网膜退行性病变 电生理、生物化学和形态学方面的特性

目的：评估Smith-Lemli—Opitz综合征（SLOS）动物模型的电生理、组织学和生物化学方面的特性。     

Progesterone-induced erythema multiforme.

This paper presents the 1st reported case of progesterone-induced cyclical erythema multiforme. The patient, 33 years of age, suffered from recurrent pruritic annular and target lesions on the hands, feet, and trunk and oral laceration from 1977-83. She had taken oral contraceptives in 1972 without adverse effects. The eruptions began in the 2nd half of the menstrual cycle, worsened through the luteal phase, and were at their most florid on days 2-4 of menstrution. There was no relationship to estrogen levels; however, the postovulatory progesterone peak, as indicated by serial serum progesterone levels, corresponded to the initiation of eruptions. Erythema multiforme was induced within 48 hours by intramuscular injection of 10 mg progesterone or 10 mg medroxyprogesterone; this further evoked a rise in circulating immune complexes for 48 hours. There was no indication that the erythema multiforme was associated with menstrual-linked herpes simplex or the use of analgesics during menstruation. Autoimmune progesterone dermatitis is often associated with prior exposure to synthetic progesterones, as in this case. It has been suggested that the synthetic progesterone acts as a stimulus for antibodies which cross-react with natural progesterone. The antiestrogen tamoxifern was used successfully in this case and is a valuable alternative to treatment with oophorectomy.