544

agents, to which hypersensitivity and bacterial resistance arerare and which have no systemic use are urgent priorities.Because gentamicin resistance in staphylococci has taken solong to emerge many of us have come to lean too readily ongentamicin. It is time we stopped leaning lest we have nothingto fall back on.

Department of Bacteriology,John Bonnett Clinical Laboratories,Addenbrooke’s Hospital,Cambridge CB2 2QQ

R. E. WARRENS. O. B. ROBERTS

PEAK-DOSE DYSPHONIA IN PARKINSONISM

SIR,-Professor Marsden and Dr Parkes (Feb. 7, p. 292) de-scribe the appearance of akinesia and dysphonia without rigi-dity or tremor at the peak of levodopa action as a very rarefeature, and are attracted by the theoretical issues raised. Iwould emphasise that such akinesia or dysphonia as separateand conflicting entities. I, too, have not encountered a convinc-ing example of peak-dose akinesia but have observed severalinstances of dysphonia and even aphonia.Most patients so afflicted exhibit a variety of dyskinetic dis-

turbances and one was subject to severe swallowing difficultiesnot presumed to be dyskinetic in origin. They would decide inadvance whether to be fully mobile or able to converse freely.One, wishing to walk round the block, would smoke a cigarettebeforehand but would avoid smoking if wishing to chat.The most convincing example of peak-dose dysphonia was in

a 52-year-old man, not otherwise subject to dyskinetic manifes-tations. He had been successfully maintained on levodopa 3 gdaily since 1970. But, in the summer of 1975, he had to reducethe dose to 2 g daily on account of dysphonia. Contrary tousual experience he preferred to take the daily dose in two lotsrather than four to lessen the effect. To be in a position toexplain his difficulty at his first attendance, he purposely leftoff his morning levodopa arriving rigid in a typical parkin-sonian state, barely able to totter into the room.

Departments of Neurosurgery and Neurology,Royal Infirmary,Preston PR1 6PS E. M. R. CRITCHLEY

DO &agr;-STEREOSPECIFIC GLUCORECEPTORSEXIST?

Sm,—Niki and Niki have suggested that diabetes mellituscorresponds to a generalised disorder of an a-stereospecific glu-coreceptor, leading to insufficient release of insulin, inappro-priate hyperglucagonsemia, and decreased ability to detect thesweet taste of glucose.’ This fascinating hypothesis is based onthe fact that «-D-glucose is better able than 3-D-glucose tostimulate insulin release, inhibit glucagon secretion, and evokethe sense of sweetness, and on the assumption that glucose-sensitive cells are equipped with a stereospecific glucoreceptor,presumably located at the level of the cell membrane. We havefound that the more striking insulinotropic action of a-D-glu-cose in rat pancreatic islets is attributable to the preferentialaffinity of the enzyme phosphoglucose isomerase towards a-D-glucose-6-phosphate, resulting in higher rates of glycolysisand, hence, insulin release.2 These findings cast doubt on theglucoreceptor hypothesis for the artiology of diabetes mellitus.

Laboratory of Experimental Medicine,Brussels Free University,Brussels, B-1000 Belgium

W. J. MALAISSEA. SENERM. KOSERA. HERCHUELZ

1. Niki, A., Niki, H. Lancet, 1975, ii, 658.2. Malaisse, W. J., Sener, A., Koser, M., Herchuelz, A. Diabetes (in the press).

E-ROSETTE-FORMING LYMPHOCYTES INMOTHER AND NEWBORN

StR,—Steel et al.’ reported a mean value of 53% for cord-blood lymphocytes forming spontaneous rosettes with sheeperythrocytes (T-cell marker). This figure is similar to thatrecorded by Campbell et al.,2 but differs from the 3S%reported by Diaz-Jouanen and Williams.3

Results in counting different types of lymphocytes are muchaffected by the procedures used, and figures for sheep-cetE-rosettes range from 35% to 80% for normal peripheral-bloodlymphocytes.4 Essentially following the method of Bentwich etal.,5 we determined the T-cell marker of spontaneous rosetteswith sheep erythrocytes in 19 normal-term deliveries (peri-pheral-blood lymphocytes of the mother and cord-blood lym-phocytes of the newborn). Blood was taken immediately afterdelivery. There was a constant inverse relationship betweenthe percentage of E-rosette-forming cells in the maternal andcord-blood lymphocytes: a high percentage of E-rosettes inmaternal lymphocytes was associated with a low percentage ofE-rosette-forming fetal lymphocytes and vice versa.On the basis of this observation, we divided the cases into

two groups: maternal lymphocytes which formed E-rosettes upto 50% and their corresponding cord-blood E-rosettes; andmothers in whom E-rosettes were formed by 50% or more ofthe lymphocytes and their newborns.The first group (10 cases) showed mean values of 43%

(31-50%) of E-rosettes for maternal lymphocytes and 37%(20-60%) for the newborns. In the second group (9 cases),maternal-lymphocyte E-rosettes averaged 58% (54-75%) andnewborn-lymphocyte E-rosettes 26% (6-46%). When the meanvalues were calculated for E-rosettes of maternal and newborn

lymphocytes in each group, they were nearly identical: 40% forthe first group and 42% for the second.The results suggest a balanced relationship between mater-

nal and fetal E-rosette-forming lymphocytes. The variation inthe values for E-rosette-forming cord-blood lymphocytes foundby different workers may be linked to this feto-maternal rela-tionship.Department of Obstetrics and Gynæcology,Research Institute of Human Reproductionand Fetal Development,Hasharon Hospital, Petah-Tikva, andTel-Aviv University Sackler Medical School,Israel

ISAAC HALBRECHTLUISE KOMLOS

IMPENDING HEART-ATTACKS

SiR,—Dr Nixon suggests (Jan. 3, p. 34) that the cardiac pa-tient’s "denial of diminution of powers" may be a useful dialnostic tool. It can also work as a powerful therapeutic force forchanging the life style.A 54-year-old male complained of angina pectoris at rest.

Symptoms appeared after meals and during excitement. Exer-cise E.c.G. showed ischtemic changes at a pulse-rate of 115 minAngiographs showed that all three coronary arteries were nar-rowed, by 99%, 95%, and 80%. He declined bypass surgeryand began a supervised programme of marathon training, 10months later he finished his second 42 km run in a time of 4h 52 min.

Clearly, this patient’s desire to run long distance fits Nixon’s"boast of virility". Such a plan does not fit the "natural history" of coronary disease. However, the patient’s goal to runin a marathon did motivate him to change his life style (avoidtobacco smoke, run about 15 km each day, and eat a modifiedvegetarian diet). If he considers himself a "marathon runner"

1. Steel, C. M., Evans, J., Smith, M. A. Lancet, 1975, i, 915.2. Campbell, A. C., Waller, C., Wood, J., Aynsley-Green, A., Yu, V. Clin. exp.

Immun. 1974, 18, 469.3. Diaz-Jouanen, E., Williams, R. C. Jr. Lancet, 1975, i, 688.4. Bentwich, Z., Kunkel, H. G. Transplant. Rev. 1973, 16, 29.5. Bentwich, Z., Douglas, S. D., Siegal, F. P., Kunkel, H. G. Clin. Immun. Im-

munopath. 1973,1, 511.