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J M Foley

Publications and source records attributed to J M Foley.

82 records · Page 5Linked to original sources

Energy cost of twitch and tetanic contractions of rat muscle estimated in situ by gated 31P NMR.

The phosphagen cost of maximal isometric twitch and tetanic contractions in rat gastrocnemius muscle was measured in situ by 31P NMR with acquisitions gated to precise time points after a brief (< 10 s) burst of contractions. Alteration of twitch stimulation frequency did not affect the energy cost per contraction. Pooled results of four twitch rates from 1 to 8 Hz produced an average cost of 0.257 +/- 0.012 mumol ATP/g/twitch. This value was compared with the initial twitch cost estimated from the time zero derivative of an exponential fit of averaged scan phosphocreatine (PCr) data from a previous study of 8 min of contraction in situ at 0.75 Hz. Agreement of the two estimates validates the use of the fitting/derivative method to assess energy cost and confirms the monoexponential character of the PCr time course. Evaluation of muscle pH changes demonstrated that all ATP use during the brief twitch contraction bouts could be accounted for by PCr hydrolysis. Results also showed a brief delay in onset of PCr recovery, consistent with the response time of oxidative systems. Tetanic contractions of 100 ms duration at 100 Hz required 2.17 +/- 0.07 mumol ATP/g muscle/contraction, in general agreement with estimates reported using a variety of other methods.

Adenosine Triphosphate↗

An integrated model of discharge planning for acutely-ill elderly patients.

Prior research has demonstrated that current discharge-related practices present resource-related and ethical problems for all those involved. The purpose of this 9-month qualitative study was to develop a more resource efficient and compassionate discharge planning model for acutely-ill, elderly patients. The focus group interviewing method was used to elicit 99 participants' perceptions of an ideal approach to discharge planning. Focus group participants included professionals from acute-care hospitals and community organizations. Telephone interviews were also completed with 25 patients and 6 family members. Themes identified in the analysis revealed that an ideal approach to discharge planning would incorporate seven elements. According to participants, the approach is ideal because it potentially addresses both resource utilization and ethical issues. Program evaluation of the model is underway in order to determine its effectiveness.

Acute Disease↗