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NEW TREPHINE FOR SUBUNGUAL HÆMATOMA
1223
transmissible agent could affect D.N.A. in human cell culture. Penrose8 has discussed the possibility of involvement of the male germ cell in such a process, but this can only An affected spermatozoon the large number of its be able to with might compete to fertilise the endeavours in their healthy counterparts the statistical probability of an ovum; and, in any event, involvement would be small. Our view is that the ovum is the vital unit. This conclusion is supported by the paucity of multiple cases, even after a mongoloid child has been born to an older mother-as distinct, of course, from those where a transmissible mongolism is shown to exist. Although most cases are simple trisomies, transmissibility occurs through the translocation type of defect; but, even with these, most translocations seem to be isolated events.10 Even with the transmissible type, one would still have to consider what caused the mutation in the first place; this could quite well have been due to the virus of infective hepatitis. The implications of a demonstrable association between infective hepatitis and Down’s syndrome could well extend to a wide spread of genetic abnormalities. The interaction between virus and ovum (especially the ageing ovum) needs closer study. be
a
very uncommon event. not
8. 9. 10.
Penrose, L. S. Lancet, 1962, i, 1101. Polani, P. E. Pediat. Clins N. Am. 1963, 10, 423. Polani, P. E., Hamerton, J. L., Gianelli, F., Carter, C. O.
Cytogenerics,
1965, 4, 193.
New Inventions
SUMMARY
Epidemiological investigations in the State of Victoria, over a period of 23 years have revealed regular peaks in the incidence of Down’s syndrome. The last peak for 1962-63 was predicted. The characteristic epidemiological findings, the peaking, the clustering of cases, and urban-rural differences suggest a viral cause of Down’s syndrome-the chromosomes of the ovum being affected by the virus before or at about the time of conception. Australia,
From 1952 to 1964 the annual incidences in Melbourne of all notifiable infectious diseases and of births of children with the syndrome 9 months later have shown a close association between infective hepatitis and Down’s
syndrome. This hypothesis could lead genetic investigation of disease
fruitful results in the
in
man.
We should like to thank the Mental Health Authority of Victoria for its continued support of this work; the staffs of the Royal Women’s Hospital, the Queen Victoria Memorial Hospital, and Margaret Coles House, all of Melbourne; Dr. J. Krupinski, of the statistical-epidemiological unit of the Mental Health Research Institute, Melbourne; and Dr. A. G. Baikie and Dr. S. Wiener. Requests for reprints should be addressed to A. S. Chief Clinical Officer, Mental Health Authority, Mental Health Research Institute,
Royal Park, N.2,
ALAN STOLLER
Poplar Street,
F.A.
Victoria, Australia Consulting Psychologist, Mental Health Research Institute, Victoria, Australia
may also be varied
50-100
SIMPLE STIMULATOR FOR USE IN STEREOTACTIC SURGERY MANY neurosurgeons now carry out stereotactic treatment for parkinsonism and other disorders of voluntary movement and for intractable pain. The effect of electrical stimulation applied at the tip of an electrode is frequently helpful in judging the best site for producing a permanentlesion. For this the neurosurgeon must have a simple and cheap instrument which is electrically safe and reliable. Experience has shown that a pulse repetition-rate of 50 per second provides effective stimulation. To avoid the possibility of cell damage by electrolysis the pulse duration should not exceed 3 milliseconds. The switching on and off of the stimulator must not be revealed to the conscious patient by any noise from the switch mechanism. The switch should be of the push-button type and silent in operation. It should control both the electrode and a light signal which indicates to the surgeon that stimulus is being applied. I have been using a new instrument which completely satisfies all these criteria. This is a simple transistor batteryoperated stimulator, contained in a small case measuring 13 x 11.5 x 12 cm. The circuit provides a single positive square wave output of 3 milliseconds’ duration and with a repetitionrate of 50 pulses per second. The intensity of stimulation is controlled by varying the output voltage by means of a panel control. The control is calibrated directly in output voltage to a maximum of 10 V. The output impedance is approximately 100 ohms, which ensures that the accuracy of the outputvoltage setting is unaffected by the stimulating current loading. The amber pilot lamp visibly indicates the correct functioning of the circuit, since it is energised from the square wave output. The instrument is powered by two mercury batteries (11-2 V). The unit may be used for unipolar or bipolar stimulation; suitable light sterilisable cables are supplied for both types of stimulation. For simplicity of operation the pulse duration is pre-set. An internal control, however, allows variation in the pulse duration from 1 to 6 milliseconds. The repetition-rate
to
pulses
by
per second
a
N.Z.C.P.,
D.P.M.
R. D. COLLMANN B.A., B.SC., M.ED.,
PH.D.
similar control within the range
(10-20 milliseconds).
The unit is manufactured by Messrs. Matburn Research 20-24, Emerald Street, London, W.C.l.
Department of Neurosurgery, University College Hospital, Gower Street, London, W.C.1
Ltd.,
KENNETH TILL M.A.,
M.B.
Cantab.,
F.R.C.S.
NEW TREPHINE FOR SUBUNGUAL HÆMATOMA SUBUNGUAL hsematoma may cause considerable pain and discomfort. Release of the hasmatoma by means of drills, files, needles, or red-hot wire results in immediate relief. The trephine (see accompanying figure) has been developed with the unskilled trephinist in mind. It consists of a metal cylindrical drill holder, with a small twist drill held in place by
The drill-bit when fully inserted into the holder, 0-035 in., which will just allow it to penetrate through the hasmatoma. When not in use, the drill-bit is kept in an
a set screw.
projects to
antiseptic’fluid. The trephine is held vertically in one hand and twisted with a watch-winding or rotary action while it is guided with the other hand. A number of turns are usually needed after the first appearance of the blood, since the drilling action causes the nail to burr out in front of the drill, with a resulting valve-like effect. I have found that drilling through to the proximal end of a subungual splinter prevents the development of negative suction pressure when the splinter is withdrawn; as a result, removal is easier and mutilation
to
the nail is less.
thank Mr. Norman Cutler, of Alpha Bearings Ltd., who helped to improve the design, and Mr. A. Patterson who made the first prototype. This trephine is manufactured by L. J. Taylor Precision Engineering Ltd., West Bromwich, Staffs. I wish
to
West Bromwich, Smethwick and District Manufacturers’ Occupational Health Service Ltd., 82, High Street, West Bromwich
HILARY LORING WEBB M.B. N.U.I.,
D.P.H.,
D.I.H.
transmissible agent could affect D.N.A. in human cell culture. Penrose8 has discussed the possibility of involvement of the male germ cell in such a process, but this can only An affected spermatozoon the large number of its be able to with might compete to fertilise the endeavours in their healthy counterparts the statistical probability of an ovum; and, in any event, involvement would be small. Our view is that the ovum is the vital unit. This conclusion is supported by the paucity of multiple cases, even after a mongoloid child has been born to an older mother-as distinct, of course, from those where a transmissible mongolism is shown to exist. Although most cases are simple trisomies, transmissibility occurs through the translocation type of defect; but, even with these, most translocations seem to be isolated events.10 Even with the transmissible type, one would still have to consider what caused the mutation in the first place; this could quite well have been due to the virus of infective hepatitis. The implications of a demonstrable association between infective hepatitis and Down’s syndrome could well extend to a wide spread of genetic abnormalities. The interaction between virus and ovum (especially the ageing ovum) needs closer study. be
a
very uncommon event. not
8. 9. 10.
Penrose, L. S. Lancet, 1962, i, 1101. Polani, P. E. Pediat. Clins N. Am. 1963, 10, 423. Polani, P. E., Hamerton, J. L., Gianelli, F., Carter, C. O.
Cytogenerics,
1965, 4, 193.
New Inventions
SUMMARY
Epidemiological investigations in the State of Victoria, over a period of 23 years have revealed regular peaks in the incidence of Down’s syndrome. The last peak for 1962-63 was predicted. The characteristic epidemiological findings, the peaking, the clustering of cases, and urban-rural differences suggest a viral cause of Down’s syndrome-the chromosomes of the ovum being affected by the virus before or at about the time of conception. Australia,
From 1952 to 1964 the annual incidences in Melbourne of all notifiable infectious diseases and of births of children with the syndrome 9 months later have shown a close association between infective hepatitis and Down’s
syndrome. This hypothesis could lead genetic investigation of disease
fruitful results in the
in
man.
We should like to thank the Mental Health Authority of Victoria for its continued support of this work; the staffs of the Royal Women’s Hospital, the Queen Victoria Memorial Hospital, and Margaret Coles House, all of Melbourne; Dr. J. Krupinski, of the statistical-epidemiological unit of the Mental Health Research Institute, Melbourne; and Dr. A. G. Baikie and Dr. S. Wiener. Requests for reprints should be addressed to A. S. Chief Clinical Officer, Mental Health Authority, Mental Health Research Institute,
Royal Park, N.2,
ALAN STOLLER
Poplar Street,
F.A.
Victoria, Australia Consulting Psychologist, Mental Health Research Institute, Victoria, Australia
may also be varied
50-100
SIMPLE STIMULATOR FOR USE IN STEREOTACTIC SURGERY MANY neurosurgeons now carry out stereotactic treatment for parkinsonism and other disorders of voluntary movement and for intractable pain. The effect of electrical stimulation applied at the tip of an electrode is frequently helpful in judging the best site for producing a permanentlesion. For this the neurosurgeon must have a simple and cheap instrument which is electrically safe and reliable. Experience has shown that a pulse repetition-rate of 50 per second provides effective stimulation. To avoid the possibility of cell damage by electrolysis the pulse duration should not exceed 3 milliseconds. The switching on and off of the stimulator must not be revealed to the conscious patient by any noise from the switch mechanism. The switch should be of the push-button type and silent in operation. It should control both the electrode and a light signal which indicates to the surgeon that stimulus is being applied. I have been using a new instrument which completely satisfies all these criteria. This is a simple transistor batteryoperated stimulator, contained in a small case measuring 13 x 11.5 x 12 cm. The circuit provides a single positive square wave output of 3 milliseconds’ duration and with a repetitionrate of 50 pulses per second. The intensity of stimulation is controlled by varying the output voltage by means of a panel control. The control is calibrated directly in output voltage to a maximum of 10 V. The output impedance is approximately 100 ohms, which ensures that the accuracy of the outputvoltage setting is unaffected by the stimulating current loading. The amber pilot lamp visibly indicates the correct functioning of the circuit, since it is energised from the square wave output. The instrument is powered by two mercury batteries (11-2 V). The unit may be used for unipolar or bipolar stimulation; suitable light sterilisable cables are supplied for both types of stimulation. For simplicity of operation the pulse duration is pre-set. An internal control, however, allows variation in the pulse duration from 1 to 6 milliseconds. The repetition-rate
to
pulses
by
per second
a
N.Z.C.P.,
D.P.M.
R. D. COLLMANN B.A., B.SC., M.ED.,
PH.D.
similar control within the range
(10-20 milliseconds).
The unit is manufactured by Messrs. Matburn Research 20-24, Emerald Street, London, W.C.l.
Department of Neurosurgery, University College Hospital, Gower Street, London, W.C.1
Ltd.,
KENNETH TILL M.A.,
M.B.
Cantab.,
F.R.C.S.
NEW TREPHINE FOR SUBUNGUAL HÆMATOMA SUBUNGUAL hsematoma may cause considerable pain and discomfort. Release of the hasmatoma by means of drills, files, needles, or red-hot wire results in immediate relief. The trephine (see accompanying figure) has been developed with the unskilled trephinist in mind. It consists of a metal cylindrical drill holder, with a small twist drill held in place by
The drill-bit when fully inserted into the holder, 0-035 in., which will just allow it to penetrate through the hasmatoma. When not in use, the drill-bit is kept in an
a set screw.
projects to
antiseptic’fluid. The trephine is held vertically in one hand and twisted with a watch-winding or rotary action while it is guided with the other hand. A number of turns are usually needed after the first appearance of the blood, since the drilling action causes the nail to burr out in front of the drill, with a resulting valve-like effect. I have found that drilling through to the proximal end of a subungual splinter prevents the development of negative suction pressure when the splinter is withdrawn; as a result, removal is easier and mutilation
to
the nail is less.
thank Mr. Norman Cutler, of Alpha Bearings Ltd., who helped to improve the design, and Mr. A. Patterson who made the first prototype. This trephine is manufactured by L. J. Taylor Precision Engineering Ltd., West Bromwich, Staffs. I wish
to
West Bromwich, Smethwick and District Manufacturers’ Occupational Health Service Ltd., 82, High Street, West Bromwich
HILARY LORING WEBB M.B. N.U.I.,
D.P.H.,
D.I.H.