Reduced sensory stimulation alters the molecular make-up of glutamatergic hair cell synapses in the developing cochlea

Neural activity during early development is known to alter innervation pathways in the central and peripheral nervous systems. We sought to examine how reduced sound-induced sensory activity in the cochlea affected the consolidation of glutamatergic synapses between inner hair cells (IHC) and the primary auditory neurons as these synapses play a primary role in transmitting sound information to the brain. A unilateral conductive hearing loss was induced prior to the onset of sound-mediated stimulation of the sensory hair cells, by rupturing the tympanic membrane and dislocating the auditory ossicles in the left ear of P11 mice. Auditory brainstem responses at P15 and P21 showed a 40-50-dB increase in thresholds for frequencies 8-32kHz in the dislocated ear relative to the control ear. Immunohistochemistry and confocal microscopy were subsequently used to examine the effect of this attenuation of sound stimulation on the expression of RIBEYE, which comprises the presynaptic ribbons, Shank-1, a postsynaptic scaffolding protein, and the GluA2/3 and 4 subunits of postsynaptic AMPA receptors. Our results show that dislocation did not alter the number of pre- or postsynaptic protein puncta. However, dislocation did increase the size of RIBEYE, GluA4, GluA2/3 and Shank-1 puncta, with postsynaptic changes preceding presynaptic changes. Our data suggest that a reduction in sound stimulation during auditory development induces plasticity in the molecular make-up of IHC glutamatergic synapses, but does not affect the number of these synapses. Up-regulation of synaptic proteins with sound attenuation may facilitate a compensatory increase in synaptic transmission due to the reduced sensory stimulation of the IHC.

Protocol for the ProCare Trial: a phase II randomised controlled trial of shared care for follow-up of men with prostate cancer

INTRODUCTION

Men with prostate cancer require long-term follow-up to monitor disease progression and manage common adverse physical and psychosocial consequences of treatment. There is growing recognition of the potential role of primary care in cancer follow-up. This paper describes the protocol for a phase II multisite randomised controlled trial of a novel model of shared care for the follow-up of men after completing treatment for low-moderate risk prostate cancer.

METHODS AND ANALYSIS

The intervention is a shared care model of follow-up visits in the first 12 months after completing treatment for prostate cancer with the following specific components: a survivorship care plan, general practitioner (GP) management guidelines, register and recall systems, screening for distress and unmet needs and patient information resources. Eligible men will have completed surgery and/or radiotherapy for low-moderate risk prostate cancer within the previous 8 weeks and have a GP who consents to participate. Ninety men will be randomised to the intervention or current hospital follow-up care. Study outcome measures will be collected at baseline, 3, 6 and 12 months and include anxiety, depression, unmet needs, prostate cancer-specific quality of life and satisfaction with care. Clinical processes and healthcare resource usage will also be measured. The principal emphasis of the analysis will be on obtaining estimates of the treatment effect size and assessing feasibility in order to inform the design of a subsequent phase III trial.

ETHICS AND DISSEMINATION

Ethics approval has been granted by the University of Western Australia and from all hospital recruitment sites in Western Australia and Victoria.

RESULTS

of this phase II trial will be reported in peer-reviewed publications and in conference presentations.

TRIAL REGISTRATION

Australian New Zealand Clinical Trial Registry ACTRN12610000938000.

Observations on Seals at Montague Island, New South Wales

Australian fur-seals Arctocephalus pusillus doriferus and New Zealand fur-seals A. forsteri haul-out (come ashore) at the north end of Montague Island. They were counted from study boats on 82 occasions during nine trips to the island, each of about one week, between November 1997 and November 1998, and in July 1999 and April 2000. Highest numbers were recorded between August and October 1998, and more animals were ashore during 1997 and 1998 than Irvine et al. (1997) observed in 1993 and 1994. The maximum number of A. p. doriferus recorded ashore in this study was 540 in October 1998, compared with a little over 300 observed in September 1993. There are reports of a few fur-seal pups on Montague Island. An A. forsteri pup born there in the 1999/2000 summer survived for at least 4 months. Nevertheless, the island should be considered as supporting haul-out sites rather than breeding sites. A Subantarctic fur-seal A. tropicalis and an Australian sea-lion Neophoca cinerea were also recorded during the study. Seven juvenile A. p. doriferus were observed ashore with manmade debris (straps or portions of a trawl net) around their necks. Fur-seals at Montague Island generate interest because of tourism and interactions with local fisheries. Trends in their abundance should be monitored annually in March, for which there is a long-term data set, and in October, when they are most abundant.

Whole body movements in altered G environments

Davies and Rennie determined that the instantaneous peak and mean power transferred to the center-of-mass of a subject during jumping could be calculated from analyzing the ground reaction force. Since Davies and Rennie's report, vertical jumping has been used to measure the peak and mean power transferred to the center-of-mass and to assess human performance. It has also been suggested that the external load a subject experiences effects the power production. However, it is difficult to determine if the difference in power production as defined in these studies is due to the external loading, or is an effect of changing the dynamics of the movement. In this paper, we describe a study which allows us to more clearly define the power developed during jumping under different weights, and the relationship between the power developed and jump height.

Thermal comparison of aircrew clothing aboard OV-10 aircraft

Thermal evaluation of aircrew clothing in the field usually involves conditions which make it difficult to distinguish clothing effects from other, confounding factors. This paper reports a field study designed to solve this problem. The question concerned possible heat stress effects caused by adding an oxygen mask, an anti-g suit, or both to the usual clothing worn by pilots of OV-10 (twin turboprop) aircraft during 20 hot-weather flights (actual experimental temperatures of Tdb = 28-38 degrees C, rh = 18-20%). The four test ensembles were flown simultaneously, allowing side-by-side comparison to compensate for variations in flight profile and weather. Subjects (n = 10) encountered noticeable heat stress in flight, with rectal temperature = 37.4-37.6 degrees C, skin temperature = 35.0-35.5 degrees C, and weight losses = 2.1-2.4 kg. There were no measurable differences among the four clothing outfits, indicating that the anti-g suit does not present a heat stress problem. The mask and anti-g suit did contribute to aircrew discomfort as their impermeable materials prevented evaporation of sweat and caused 100% skin wetting in covered areas. Under these dry, desert conditions, the body was apparently able to compensate for the loss of evaporative surface area.

Liver packing for uncontrolled hemorrhage: a reappraisal

The efficacy of liver packing for uncontrolled hemorrhage was assessed in 345 patients with hepatic injuries divided into two groups: Group I (1977-1980; n = 177), when packing was not used and Group II (1981-1985; n = 168) when the technique was employed. Despite similar clinical details, mortality from bleeding was unchanged (19.2% and 19.4% overall, and 63.7% and 61.7% for Grade IV, V, VI liver injuries). Packing was used in 14 patients who were in clinical coagulopathy after debridement-resection of the injured liver: eight patients (57%) expired from continued bleeding; five of the six survivors (83.3%) developed intra-abdominal abscesses despite early removal of the pack. The incidence of sepsis was significantly (p less than 0.002) increased as compared to that of 15 similar patients who had debridement-resection without packing. Liver packing, in our experience, has not altered the mortality from major hepatic trauma and appeared to increase the incidence of abdominal sepsis.

Mandates for a changing practice: PSRO and P.L. 94-142

Federal legislation in the fields of education and health care now requires the development of systems of professional accountability. This accountability to the sponsoring system and to the client is making profound changes in practice. Implications of these changes are reviewed with a challenge to social workers to assume leadership in translating these changes into effective practice models.