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XIPHILINUS, JOANNES
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See also:XIPHILINUS, JOANNES , epitomator of Dio See also:Cassius, lived at See also:Constantinople during the latter See also:half of the Irth See also:century A.D. He was a See also: X-See also:RAY TREATMENT. The X rays (see See also:RONTGEN RAYS) are now used extensively in medical work for purposes of treatment. They have been found to be valuable in many forms of skin disease, more particularly in those of a chronic See also:character: They have a favourable See also:influence upon glandular tumours, as for example in enlargements of the lymphatic glands, of the See also:spleen and of the See also:thyroid gland. They give useful palliative effects in certain forms of See also:malignant disease, although it is not yet certain that any permanent See also:cures of cancerous conditions have been obtained by their use. In the disease known as rodent See also:ulcer, which is a See also:process of destructive ulceration, and to that extent presents features allied to See also:cancer, there is no doubt of the efficacy of X-ray treatment for bringing about a See also:complete cure in the See also:majority of cases, provided that the disease has not advanced too deeply into the tissues. See G. B. See also:Grundy, See also:Great See also:Persian See also:War (1901), and in See also:criticism W. \V. See also:Tarn, " The See also:Fleet of See also:Xerxes," in Amami of Hellenic Studies (T9o8), 202-34; also Macan's notes on I-Ierod. iv .-vi. (1895), and authorities See also:fur See also:PLATAEA, See also:SALAMIS. The See also:idea of using X rays in the treatment of disease arose from the recognition of the injurious effects which followed the prolonged application of the rays for diagnostic purposes. It See also:fell to the See also:lot of many early workers with X rays to See also:notice the See also:production of an inflammation of the skin, or a falling out of the See also:hair over parts which had been subjected to X rays, and See also:Leopold See also:Freund, of See also:Vienna, has stated that his first attempts to utilize X rays in treatment were made in 1896 to cure a hairy See also:mole and were prompted by what he had read of such occurrences. A definite See also:action of the rays upon the skin having been observed, their employment in the treatment of skin diseases followed as a natural corollary. Amongst the earliest investigators of the possible therapeutic effects of X rays the names of Schiff, Freund, Kienbock, Holtzknecht, Sjogren and Stenbeck may be mentioned. In Great See also:Britain See also:Sir See also:Malcolm See also:Morris, E. See also:Dore and J. H. See also:Sequeira were amongst the earliest investigators. For operating successfully with an See also:agent capable of producing decidedly harmful effects when given in large doses it is necessary to have some method of measurement, and the need for this quickly became apparent when X rays were used for treatment. The results of X-ray See also:photography had already shown that the tubes employed were capable of emitting radiations of very varying See also:powers of penetration, and that the tubes were by no means See also:constant in this respect; and the question whether highly penetrating rays or rays of feeble penetration were to be preferred for therapeutic use became the subject of much discussion. It is now recognized that the rays which See also:act upon the tissues are those which are absorbed by the tissues, and consequently the softer or less penetrating rays are now regarded as those to be used in treatment. So too the problem of measuring the quantity of rays emitted by a See also:tube during a given See also:time began to See also:call for a See also:solution, if that were in any way possible. In See also:loot Benoist designed an apparatus by which the quality of the rays emitted by a tube at any moment could be accurately determined, and in 1902 Holtzknecht brought out the first quantitative See also:device. It was called a chromoradiometer, and it enabled the dose administered to a patient to be observed, and recorded for future guidance. Holtzknecht also See also:drew up a See also:scale of See also:units by means of which the indications of his apparatus could be interpreted. The units of Holtzknecht are still used to See also:express the dosage of X rays, though his apparatus has been superseded. Holtzknecht's method of measurement consisted in observing the See also:change of See also:colour in certain pastilles when exposed to X rays, and his apparatus consisted of a scale of tints, and a number of pastilles of a yellow tint which acquired a See also:green colour during exposure. The See also:composition of these was kept a See also:secret, but See also:analysis revealed in them the presence of See also:potassium sulphate combined with celluloid or gelatine. The pastilles were laid upon the See also:surface under treatment, and their change of colour was compared at intervals with the scale of See also:standard tints.
It was next thought that under suitable conditions the measurement of the current passing through the X-ray tube might serve as a See also:guide to the quantity of X rays emitted by the tube, but, although this is the See also:case to a certain extent, the method of quantity measurement which is now employed almost universally in X-ray treatment is that devised by Sabouraud and Noire, and used with See also:signal success by them in an enormous number of cases of See also:ringworm, in which disease measurement of dose is of the most See also:critical importance, for the following See also:reason. The cure of ringworm by X rays requires that all the hair of the affected region shall be caused to fall out, but, nevertheless, it is necessary for obvious reasons that the hair should grow again after the disease has disappeared. Now if the dose of X rays be insufficient the hair does not come out and no cure results, while if the dose be too great the hair comes out but does not grow again; and the margin of safety is quite a narrow one. The method of Sabouraud and Noire which has proved itself reliable for such critical measurements of dosage as are required for ringworm treatment,has to-See also:day the universal See also:acceptance of all X-ray workers for other formsof X-ray treatment, although the use of their pastilles has certain disadvantages.
Sabouraud's pastilles consist of small disks of platinocyanide of See also:barium. This chemical See also:compound has a See also:bright yellow-green colour when freshly prepared, and changes through gradations of yellow to a See also: The pastilles are supplied in a book with which a permanent tint of colour is supplied, to indicate the colour change in the pastille which corresponds with a quantity of X rays equal to the maximum dose which the healthy skin will stand with-out inflammatory consequences. This is often spoken of as a " pastille dose." As the amount of irradiation needed to produce the change of colour is considerable, the See also:salt is fixed, during the treatment, at a point half-way between the source of the rays and the skin surface under treatment. During an exposure the chemical salt, in the See also:form of a small disk of the material on cardboard, is adjusted in the required position by means of a pastille holder, and it is examined at intervals during the course of the exposure, until it has reached the required tint. When in the holder the pastille must be protected from See also:light, and should have a piece of See also:metal as a backing, if its indications are to be accurate. In X-ray treatment some See also:protection of the surrounding healthy parts is usually necessary. With this See also:object various methods of shielding have been devised, either by coverings of the patient by impermeable materials, or by enclosing the tube in an impermeable See also:box. Both methods are used, but tube-boxes are the most convenient, and most See also:instrument makers now See also:supply these boxes with suitable windows or openings of different sizes for the passage of the See also:pencil of rays which is to fall upon the See also:part under treatment. The effect of the rays on healthy tissues is in the See also:main a destructive one, but some of the cells of the tissues are more sensitive to the rays than are others; and this permits of a selective effect being obtained, with the destruction of some cells and not of the whole See also:tissue. See also:Young cells, and actively growing cells, are the most susceptible, and for this reason it is possible to influence the glands of the skin and the papillae of the hairs with a dose which will not destroy the skin itself. The See also:art of successful working with X rays is based upon a careful See also:adjustment of the dose so as to secure a selective destructioa of the morbid elements, and to avoid wholesale damage to the part treated. The effects of excessive doses of X rays is to See also:pro-duce an inflammation which may result in painful sores which obstinately refuse to heal for many See also:weeks or months. A quantity up to See also:double that of the usual maximum or pastille dose may be employed in urgent cases without See also:risk of any serious inflammation, but anything over this is to be avoided most carefully. In the treatment of ringworm the exact pastille dose must not be exceeded, for after a dose of about one and a half pastilles the fall of the hair is likely to be followed by permanent baldness. In X-ray treatment it is customary to make use of moderate currents, and to bring the X-ray tube in its tube-holder and box into position so that the pencil of rays may fall upon the part to be treated. The distance of the skin surface from the centre of the tube must be known, and the pastille arranged in See also:place accordingly. Fifteen centimetres is a usual distance, and at this distance a tube working with a current of a milliampere should give the full therapeutic dose or " pastille dose " in about 15 minutes. In See also:general X-ray treatment it is quite usual at the See also:present time to proceed by the method of full doses at rather See also:long intervals. From the experience obtained by Sabouraud in numerous cases of ringworm it has been found that a full dose must not be repeated until a See also:month has elapsed. So too in the treatment of rodent ulcer full doses at long intervals are now thought better than smaller doses repeated more often, and such doses are more easily measured by the Sabouraud pastille, which records large doses more simply than small ones, in which the slighter changes of tint are not easy to distinguish. A great amount of work has been done with X rays for the treatment of cancer, but it is now recognized that the X rays do not cure a cancer, although they are of value for the See also:relief of See also:pain and for the healing of cancerous ulcers. Diminution of See also:size in cancerous growths has frequently been observed, and in some instances sarcomatous tumours have completely disappeared under X-ray treatment. Sooner or later, however, the cancer or sarcoma returns either in the original site or elsewhere, and the patient See also:dies of the disease. It is probable that X-ray treatment is able to prolong life in a See also:fair number of cases, and by its agency in causing a healing of ulceration in cancer cases it is able to give valuable relief both to the See also:body and mind of the patient, and this relief may last for a See also:year or more. In rodent ulcer X rays are usually sufficient to provide a lasting cure, but there are some exceptions, as for instance when the rodent ulcer has been long neglected, and has spread deeply so as to invade bony structures. An important See also:factor in the successful treatment of rodent ulcer by X rays is to continue the applications at intervals for several months after apparent cure. If this precaution is omitted there is a very great likelihood of relapse taking place later on.
In the treatment of skin diseases by X rays the method finds a very suitable See also: In the massive glandular enlargements of lymphadenoma a great reduction of the tumours can be brought about by heavy doses of X rays, but the results are to give a symptomatic rather than a real cure, for fresh glandular growths take place internally, and the usual course of the disease is not fundamentally modified.
So too in leukemia, the symptom of excessive abundance of See also: Additional information and CommentsThere are no comments yet for this article.
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