1
740 The similarity between our findings for inorganic elements, and those of Bergstrom,2 is of interest, for in the Swedish study values are given for fat-free dry weight. We did not try to solvent-extract fat from the tissue, and this suggests that in our series con- tamination with fat was not a problem. If it is assumed that the sample sodium (table ill) is all extracellular and at a concentration of 140 mM, it can be estimated that the sodium space of the fresh muscle constitutes 27% of the total volume. The chloride space, similarly calculated, is 24%. There is debate as to the significance of the various electrolyte spaces in muscle; however, the value of 27% of the total volume may be taken as the uppermost limit for contamination of the muscle sample with extracellular fluid in normal circumstances. In this case plasma- proteins might contribute 7% of the dry weight of the muscle powder, while plasma potassium and phos- phorus would contribute less than 1 % to their respec- tive total muscle contents. Blood contamination was found by Bergstrom 2 to be very small, 10-6 ml. per kg. wet muscle (i.e., only 1%). In our experience serious blood contamination is unusual even when samples are taken from hyperaemic muscles during exercise. In a normally active person the major part of the total energy expenditure occurs as the result of skeletal muscle activity. It is tempting, therefore, to suppose that decreased reserves of muscle A.T.P. or phosphoryl- creatine, or inadequate processes resynthesising A.T.P., might be the explanation of the symptoms of weak- ness and fatigue common in a wide variety of com- plaints. In many cases, the weakness can be accounted for by the loss of cross-sectional area of functional fibres due either to a reduction in the total number of fibres and/or atrophy of existing fibres with replacement of muscle bulk by fat and connective tissue. There may, however, be conditions where the symptoms of weakness are the direct result of metabolite changes, as has been suggested for fatigue in isolated muscle preparations,2a,2g and to identify these correctly, it is important not to be misled by altered muscle structure. Support from the Wellcome Trust and Muscular Dystrophy Group of Great Britain is gratefully acknowledged. Requests for reprints should be addressed to R. H. T. E. REFERENCES 1. Duchenne, G. B. Archs gén. Méd. 1868, 11, 179. 2. Bergström, J. Scand. J. clin. Lab. Invest. 1962, 14, suppl. 68. 3. Hultman, E. ibid. 1967, 19, suppl. 94. 4. Karlsson, J. Acta physiol. scand. 1971, suppl. 358. 5. Pernow, B., Saltin, B. (editors) Muscle Metabolism during Exercise. New York, 1971. 6. Edwards, R. H. T., Harris, R. C., Hultman, E., Kaijser, L., Koh, D., Nordesjö, L.-O. J. Physiol., Lond. 1972, 220, 335. 7. Ahlborg, B., Bergström, J., Ekelund, L.-G., Guarnieri, G., Harris, R. C., Hultman, E., Nordesjö, L.-O. J. appl. Physiol. 1972, 33, 224. 8. Gollnick, P. D., Piehl, K., Saltin, B. J. Physiol., Lond. 1974, 241, 45. 9. Edwards, R. H. T. Lancet, 1971, ii, 593. 10. Edwards, R. H. T., Maunder, C. M., Lewis, P. D., Pearse, A. G. E. ibid. 1973, ii, 1070. 11. Roch-Norlund, A. E., Bergström, J., Castenfors, H., Hultman, E. Acta med. scand. 1970, 187, 445. 12. Roch-Norlund, A. E. Scand. J. clin. Lab. Invest. 1972, 29, 237. 13. Roch-Norlund, A. E., Bergström, J., Hultman, E. ibid. 1972, 30, 77. 14. Bergström, J., Hultman, E. Clin. Nephrol. 1974, 2, 24. 15. Hultman, E. J. Physiol., Lond. 1973, 231, 56p. 16. Lundin, S., Hagenfeldt, L., Saltin, B., Wahren, J. Clin. Sci. mol. Med. 1974. 47. 493. 17. Nordemar, R., Lövgren, O., Fürst, P., Harris, R. C., Hultman, E. Scand. J. clin. Lab. Invest. 1974, 34, 185. 18. Flear, C. T. G., Carpenter, R. G., Florence, I. J. clin. Path. 1965, 18, 74. 19. Flear, C. T. G., Florence, I., Williams, J. A. ibid. 1968, 21, 555. 20. Harris, R. C., Hultman, E., Nordesjö, L.-O. Scand. J. clin. Lab. Invest. 1974, 33, 109. 21. Newbold, R. P., Scopes, R. K. Biochem. J. 1967, 105, 127. 22. Batra, G. J., Bewley, D. K. J. Radioanalyt. Chem. 1973, 16, 275. 23. Karlsson, J., Nordesjö, L.-O., Jordfeldt, L., Saltin, B. J. appl. Physiol. 1972, 33, 199. 24. Grimby, G., Björntorp, P., Fahlén, M., Hoskins, T. H., Höök, O., Oxhöj, H., Saltin, B. Scand. J. clin. Lab. Invest. 1973, 31, 301. 25. Gollnick, P. D., Sjödin, B., Karlsson, J., Jansson, E., Saltin, B. Pflügers Arch. 1974, 348, 247. 26. Satoyoshi, E., Kinoshita, M. in Muscle Diseases (edited by J. N. Walton, N. Canal, and G. Scarlat); p. 455. Amsterdam, 1970. 27. Wilkie, D. R. J. Physiol., Lond. 1968, 195, 157. 28. Spande, J. I., Schottelius, B. A. Am. J. Physiol. 1970, 219, 535. 29. Murphy, R. A. ibid. 1966, 211, 1082. Round the World United States ENTICING PRACTITIONERS TO THE RURAL AREAS In rich and poor countries alike, the reluctance of physi- cians to settle in rural areas is a major Government head- ache. It is most convenient to make the medical schools the culprits, charging that their high-powered, gadget- oriented teaching renders their students reluctant or unable to practise in rural areas. Other people lay the blame on that favourite subject for criticism, " modern institution- alised medicine "-whatever that may be. Practical people feel that the main objections to rural practice are the lack of professional contacts for the practitioner, the restricted social contacts for the wife, and the limited educational opportunities for the children. The hope has been put forward that if more medical students were recruited from rural areas there would be more doctors willing to return there and settle down. This is similar to the oft-expressed belief that if more students were admitted from the urban ghettos, more physicians would return there-a hope which does not appear to be being realised. Now, Dr W. M. O’Brien of the University of Virginia Medical School at Charlottesville (Virginia has been much concerned with the decline in rural prac- titioners) has carried out a survey of 1375 Virginia Medical School graduates for the years 1943 to 1964, and he has dis- covered that, of those who came from rural areas, 27-4% returned to rural areas to practise, while only 2-5% of those from urban areas chose to practise in rural areas. So the answer would seem to be to increase the students from rural areas. The trouble is that candidates from the rural areas, even those with much potential ability, are not applying for medical-school places. It was not that students had not considered a career in the medical field-in fact, a very high percentage had considered such an application, but they had not gone forward with it. The reasons were varied; many students, especially in the Black population, had very limited educational aspirations, many had not been at schools with science courses, others were put early into vocational streams, others were inadequately coun- selled. Over 20% thought that medical:-school education was too expensive or too long, but only 3% thought it too difficult; 16% said they lacked encouragement. Dr O’Brien’s valuable survey has indicated where improve- ments are needed, and, if attended to, Virginia may be able to find all the rural practitioners it needs.

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740

The similarity between our findings for inorganicelements, and those of Bergstrom,2 is of interest, forin the Swedish study values are given for fat-free dryweight. We did not try to solvent-extract fat fromthe tissue, and this suggests that in our series con-tamination with fat was not a problem.

If it is assumed that the sample sodium (table ill)is all extracellular and at a concentration of 140 mM,it can be estimated that the sodium space of the freshmuscle constitutes 27% of the total volume. Thechloride space, similarly calculated, is 24%. There isdebate as to the significance of the various electrolytespaces in muscle; however, the value of 27% of thetotal volume may be taken as the uppermost limit forcontamination of the muscle sample with extracellularfluid in normal circumstances. In this case plasma-proteins might contribute 7% of the dry weight ofthe muscle powder, while plasma potassium and phos-phorus would contribute less than 1 % to their respec-tive total muscle contents. Blood contamination wasfound by Bergstrom 2 to be very small, 10-6 ml. perkg. wet muscle (i.e., only 1%). In our experienceserious blood contamination is unusual even when

samples are taken from hyperaemic muscles duringexercise.

In a normally active person the major part of thetotal energy expenditure occurs as the result of skeletalmuscle activity. It is tempting, therefore, to supposethat decreased reserves of muscle A.T.P. or phosphoryl-creatine, or inadequate processes resynthesising A.T.P.,might be the explanation of the symptoms of weak-ness and fatigue common in a wide variety of com-plaints. In many cases, the weakness can beaccounted for by the loss of cross-sectional area offunctional fibres due either to a reduction in the totalnumber of fibres and/or atrophy of existing fibres withreplacement of muscle bulk by fat and connectivetissue. There may, however, be conditions where thesymptoms of weakness are the direct result of metabolitechanges, as has been suggested for fatigue in isolatedmuscle preparations,2a,2g and to identify these correctly,it is important not to be misled by altered musclestructure.

Support from the Wellcome Trust and Muscular DystrophyGroup of Great Britain is gratefully acknowledged.

Requests for reprints should be addressed to R. H. T. E.

REFERENCES

1. Duchenne, G. B. Archs gén. Méd. 1868, 11, 179.2. Bergström, J. Scand. J. clin. Lab. Invest. 1962, 14, suppl. 68.3. Hultman, E. ibid. 1967, 19, suppl. 94.4. Karlsson, J. Acta physiol. scand. 1971, suppl. 358.5. Pernow, B., Saltin, B. (editors) Muscle Metabolism during Exercise.

New York, 1971.6. Edwards, R. H. T., Harris, R. C., Hultman, E., Kaijser, L., Koh, D.,

Nordesjö, L.-O. J. Physiol., Lond. 1972, 220, 335.7. Ahlborg, B., Bergström, J., Ekelund, L.-G., Guarnieri, G., Harris,

R. C., Hultman, E., Nordesjö, L.-O. J. appl. Physiol. 1972, 33, 224.8. Gollnick, P. D., Piehl, K., Saltin, B. J. Physiol., Lond. 1974, 241, 45.9. Edwards, R. H. T. Lancet, 1971, ii, 593.

10. Edwards, R. H. T., Maunder, C. M., Lewis, P. D., Pearse, A. G. E.ibid. 1973, ii, 1070.

11. Roch-Norlund, A. E., Bergström, J., Castenfors, H., Hultman, E.Acta med. scand. 1970, 187, 445.

12. Roch-Norlund, A. E. Scand. J. clin. Lab. Invest. 1972, 29, 237.13. Roch-Norlund, A. E., Bergström, J., Hultman, E. ibid. 1972, 30, 77.14. Bergström, J., Hultman, E. Clin. Nephrol. 1974, 2, 24.15. Hultman, E. J. Physiol., Lond. 1973, 231, 56p.16. Lundin, S., Hagenfeldt, L., Saltin, B., Wahren, J. Clin. Sci. mol.

Med. 1974. 47. 493.

17. Nordemar, R., Lövgren, O., Fürst, P., Harris, R. C., Hultman, E.Scand. J. clin. Lab. Invest. 1974, 34, 185.

18. Flear, C. T. G., Carpenter, R. G., Florence, I. J. clin. Path. 1965,18, 74.

19. Flear, C. T. G., Florence, I., Williams, J. A. ibid. 1968, 21, 555.20. Harris, R. C., Hultman, E., Nordesjö, L.-O. Scand. J. clin. Lab.

Invest. 1974, 33, 109.21. Newbold, R. P., Scopes, R. K. Biochem. J. 1967, 105, 127.22. Batra, G. J., Bewley, D. K. J. Radioanalyt. Chem. 1973, 16, 275.23. Karlsson, J., Nordesjö, L.-O., Jordfeldt, L., Saltin, B. J. appl.

Physiol. 1972, 33, 199.24. Grimby, G., Björntorp, P., Fahlén, M., Hoskins, T. H., Höök, O.,

Oxhöj, H., Saltin, B. Scand. J. clin. Lab. Invest. 1973, 31, 301.25. Gollnick, P. D., Sjödin, B., Karlsson, J., Jansson, E., Saltin, B.

Pflügers Arch. 1974, 348, 247.26. Satoyoshi, E., Kinoshita, M. in Muscle Diseases (edited by J. N.

Walton, N. Canal, and G. Scarlat); p. 455. Amsterdam, 1970.27. Wilkie, D. R. J. Physiol., Lond. 1968, 195, 157.28. Spande, J. I., Schottelius, B. A. Am. J. Physiol. 1970, 219, 535.29. Murphy, R. A. ibid. 1966, 211, 1082.

Round the World

United States

ENTICING PRACTITIONERS TO THE

RURAL AREAS

In rich and poor countries alike, the reluctance of physi-cians to settle in rural areas is a major Government head-ache. It is most convenient to make the medical schoolsthe culprits, charging that their high-powered, gadget-oriented teaching renders their students reluctant or unableto practise in rural areas. Other people lay the blame onthat favourite subject for criticism, " modern institution-alised medicine "-whatever that may be. Practical peoplefeel that the main objections to rural practice are the lackof professional contacts for the practitioner, the restrictedsocial contacts for the wife, and the limited educationalopportunities for the children. The hope has been putforward that if more medical students were recruited fromrural areas there would be more doctors willing to returnthere and settle down. This is similar to the oft-expressedbelief that if more students were admitted from the urbanghettos, more physicians would return there-a hope whichdoes not appear to be being realised.

Now, Dr W. M. O’Brien of the University ofVirginia Medical School at Charlottesville (Virginia hasbeen much concerned with the decline in rural prac-titioners) has carried out a survey of 1375 Virginia MedicalSchool graduates for the years 1943 to 1964, and he has dis-covered that, of those who came from rural areas, 27-4%returned to rural areas to practise, while only 2-5% ofthose from urban areas chose to practise in rural areas. Sothe answer would seem to be to increase the students fromrural areas. The trouble is that candidates from the ruralareas, even those with much potential ability, are not

applying for medical-school places. It was not that studentshad not considered a career in the medical field-in fact, avery high percentage had considered such an application,but they had not gone forward with it. The reasons werevaried; many students, especially in the Black population,had very limited educational aspirations, many had notbeen at schools with science courses, others were put earlyinto vocational streams, others were inadequately coun-selled. Over 20% thought that medical:-school educationwas too expensive or too long, but only 3% thought it toodifficult; 16% said they lacked encouragement. DrO’Brien’s valuable survey has indicated where improve-ments are needed, and, if attended to, Virginia may beable to find all the rural practitioners it needs.