Fibre type-specific expression of p94, a skeletal muscle-specific calpain.

Members of the calpain proteinase family are present in all mammalian cells, although a novel calpain 94 kDa isoform is found almost exclusively in skeletal muscle. p94 is difficult to purify from muscle and recombinant p94 autolyses rapidly when expressed in COS cells. However, in vivo the enzyme may be stabilised by interaction with titin, which has two well-characterised binding sites for p94 at the N2- and M-lines. Both these titin subdomains are subject to muscle-specific alternative splicing, which could be related to p94 expression level or stability in muscles of different fibre type. In this study, porcine longissimus dorsi (LD), trapezius (TZ) and adductor longus (AL) were characterised as fast, intermediate and slow using commercially available specific anti-human fast- and slow-myosin heavy chain mAbs and also by conventional histochemistry. p94 was quantified both in whole muscle preparations and single fibres by western blotting using an anti-p94 antiserum generated by expressing a recombinant p94 sequence as a GST fusion protein antigen. SDS PAGE and immunoblotting revealed a single band of approximately 94 kDa with identical mobility in all muscle and fibre preparations. The intensity of the 94 kDa band was greater in LD (22 +/- 1.7 densitometric units mean +/- SEM, n = 3) than TZ and AL (10 +/- 2.3 and 6 +/- 0.9 units, respectively). Expressed as a ratio relative to actin immunoreactivity, p94 is present in all types of single fibres isolated from TZ, but at a significantly lower level (P < 0.01) in slow type I (0.08 +/- 0.01, n = 9), compared to fast IIA/IIB fibres (0.22 +/- 0.02, n = 26). No evidence was seen for rapid or variable rate of p94 degradation in either type of fibre. These data suggest a positive correlation between p94 expression level and fast glycolytic characteristics in porcine muscle.

Relationship between skeletal muscle-specific calpain and tenderness of conditioned porcine longissimus muscle.

Tenderization of skeletal muscle in meat animals has been closely linked to the postmortem activity of the calpain proteolytic enzyme system, which includes the specific inhibitor calpastatin. Increased understanding of the skeletal muscle-specific calpain isoform p94 has prompted suggestions as to whether it too could have a role in the tenderization process. In this study, two groups of pigs were identified in which shear force measurements after 8 d of conditioning indicated a large variation in the tenderness of longissimus muscle. The quantity of p94 in the muscle was monitored by immunoblotting, using a porcine-specific polyclonal antibody raised against a recombinant peptide fragment generated as a fusion protein. The antiserum recognized a 94-kDa protein associated with myofibrils in skeletal but not cardiac muscle, as expected for this calpain isoform, although it could not be tested with the native protein because of the extreme instability of p94. In the first experiment, the mean shear force for the tough group was 6.71 +/- .28 kg (n = 12, SEM) and that of the tender group was 3.87 +/- .12 kg (n = 12), but there was no difference in the normalized absorbance of the immunopositive 94 kDa band on Western blots from samples collected at approximately 40 min postmortem. In the second experiment, the stability of p94 in chilled carcasses was investigated over 24 h, using a further two groups of 10 tough and 10 tender pigs of mean shear force values 5.36 +/- .14 kg and 2.81 +/- .15 kg, respectively. In tough and tender animals, there was a decline (P < .05) in the 94-kDa immunostaining material of mean half-lives of 13.8 and 12.9 h, respectively, although there was considerable variability. Despite this variability in half lives and shear force values, no correlation was seen between these factors. Thus, in porcine longissimus muscle, the variability in tenderness after 8 d of conditioning cannot be attributed to an underlying variability in p94.

Job satisfaction and stress in staff working in a specialist psychiatric unit for the elderly following relocation from a traditional psychiatric hospital setting.

AIM: This study examines self-reported stress and job satisfaction of staff working in a specialist psychiatric unit for the elderly (n = 79) following relocation from a traditional psychiatric hospital setting (n = 66). The levels of reported stress were examined in relation to the two staff groups before and after the relocation, and in relation to data available for similar occupational groups. METHODS: Stress and job satisfaction levels were surveyed using the Occupational Stress Indicator. The analysis of data included t-test for independent groups. FINDINGS: The results suggested that that there were no significant changes in the patterns of the staff groups' experience of stress at the traditional psychiatric hospital and later at the new purpose-built unit. However, it was felt that there may have been different factors contributing to staff stress at the two time-points. The staff groups in this survey reported similar, and in some areas more positive levels of occupational stress than both community and other health authority samples. However, it was felt that, due to the limited response rate of staff at both times (63 and 59%), the results may be an underestimate of stress levels. In the absence of a measure of general health and symptomatology it was not possible to assess the impact of stress levels on the psychological well-being of staff. CONCLUSIONS: Routine audit of staff stress would be beneficial to identify potential for staff training, and individual professional development plans. This is particularly important in view of the current difficulties both locally and nationally in the recruitment and retention of qualified staff in this speciality.

Survey of carer satisfaction with the quality of care delivered to in-patients suffering from dementia.

Quality assurance in British National Health Service provision stresses the importance of taking account of the consumer's viewpoint. Elderly patients with dementia are not always able to contribute usefully to satisfaction surveys. Therefore, their careers' views were sought in order to assess the quality of services offered to this client group. Forty-one careers of patients discharged from the eight wards for the elderly mentally ill in Leicestershire, England, were randomly selected. Individual focused interviews were conducted in careers' own homes. Both quantitative and qualitative data were obtained by use of a questionnaire designed to tap the patients'/careers' experiences from pre-admission, through hospital stay to post-discharge. Interviews were asked to describe their favorable/unfavorable impressions of, and reactions to, all aspects of hospital care. These interviews were tape-recorded. Analysis of the data included quantitative measurements of scale ratings. Grounded theory was used to analyse qualitative data. A wealth of information was uncovered using this research technique. Much that was positive about the service was elicited. However, careers highlighted areas where they felt the quality of care could be improved within all the foci discussed. Twenty-two recommendations for quality improvements in service provision were made in the report as a result of this survey.