MASKING OF ANTIGENS ON TROPHOBLAST

MASKING OF ANTIGENS ON TROPHOBLAST

1055 stimulating and may be of some practical use, there is much to be learned and accomplished by cross-cultural studies closer to home. Research ...

166KB Sizes 0 Downloads 14 Views

1055

stimulating and may be of some practical use, there is much to be learned and accomplished by cross-cultural studies closer to

home. Research

Unit,

Division of Epidemiology, School of Public Health and Administrative Medicine, Columbia University, New York 32.

LAWRENCE BERGNER.

SELF-MEDICATION IN A PSYCHIATRIC HOSPITAL scheme for self-administration of oral medication SIR,-A in was introduced this in January, selected patients hospital by 1967. The system was evolved initially for long-term patients, under consideration for discharge, as a test of their willingness and capacity to continue taking drugs without regular supervision. Soon to be included in the programme was another group of patients-those known to mishandle or refuse medication during previous periods on discharge or leave from

hospital. The first four months of operation have shown several advantages which have warranted an extension of the practice generally throughout all units in the hospital with the exception of the geriatric wards. The patients appreciate the trust shown in them and become less dependent on the nursing staff, and in turn the staff recognise and encourage the patients’ potential for responsibility. There is a saving of nursing time, not only in routine drug administration, but in the considerable amount of time involved in making up prescriptions at ward level for patients going on pass, leave, and days out. From the patients’ point of view time is saved by no longer having to wait for drug rounds, and it is no longer necessary for patients to return to wards from places of employment and recreation in other parts of the hospital. The drugs mainly used in this programme have been phenothiazines and antiparkinsonian and anticonvulsant drugs. To begin with, a four-day supply was given; but this has now been increased to a seven-day supply. A prerequisite for self-medication has been that each patient selected to participate must have an individual locker or wardrobe which could be locked and the key retained in the patient’s own safekeeping. Normal pharmacy pill-boxes and bottles are used with dosage and times clearly written on the labels. Urine samples are taken at irregular times from patients on phenothiazines and are tested for phenothiazine compounds by a specific reagent. Occasionally, if a patient is suspected of not following directions, a spot check is made by counting the remaining medication to determine whether there is a surplus or

shortage.

Our brief experience to date has shown that patients and staff alike favour the scheme, and the latter especially consider that the advantages of such a programme far outweigh any disadvantages. Indeed, it has been suggested that such a procedure could be effective in hospitals other than psychiatric

hospitals. Bilbohall Hospital, Elgin, Scotland.

JOHN

H. HENDERSON.

MASKING OF ANTIGENS ON TROPHOBLAST SiR,ŁThe hypothesis proposed by Dr. Currie and Dr.

Bagshawe (April 1, p. 708) to explain the immunologically favoured position of the trophoblast is of great interest. We have tried to ascertain the presence or absence of transplantation

antigens in human trophoblast. Bain,l Bach,2 and others have cultured homologous leukocytes from unrelated individuals and observed blastogenic transformation of the lymphocytes. The degree of stimulation was related to the degree of histocompatibility between them. We have used essentially the 1. 2.

Bain, B., Vas, M., Lowenstein, L. Blood, 1964, 23, 108. Bach, F. H., Hirschhorn, K. Science, N. Y. 1964, 143, 815.

same technique, and challenged the lymphocytes of the mother and unrelated persons with the trophoblast cells of the newborn infant. The trophoblastic cells were harvested by a technique, devised by one of US,3 based on repeated superficial trypsinisation of intact villi. In three sets of parallel experiments trophoblastic cells were added to leucocyte cultures as intact living cells, after freezing and thawing (6 or 7 times) and after sonication: in no instance did trophoblast cells stimulate blastogenesis of homologous lymphocytes. Since the cytotoxic effect of lymphocytes in tissue-cultures has been shown to be dependent on the degree of stimulation, recorded as transformation into blast cells, and since this effect is independent of the stimulating factor,4 we find it hard to accept that cytolysis of trophoblast cells in tissue cultures is due to the presence in them of histocompatibility antigens. Department of Pediatrics and Obstetrics-Gynecology, S. M. FIKRIG State University, C. VALENTI Downstate Medical Center, T. KEHATY. Brooklyn, New York, U.S.A.

WARNING SYSTEM FOR APNŒA Sin,ŁI was interested to see the description by Dr. Wick and Mr. Schmitt (April 22, p. 880) of a simple warning device for apnoea in premature infants. Although I have no personal experience of such a device, it seems to have much wider potential application, so that a simpler arrangement that would achieve the same result might be of value-i.e., by using a belt switch instead of the transducer they describe, because only a very simple non-electronic circuit is then required. A suitable switch5 was developed for and used by the 1961 Himalayan expedition for respiration counting. It operates on a movement of only 0-75 mm. and yet is capable of switching several amperes, so that at least stages 2 and 3 of Dr. Wick and Mr. Schmitt’s warning system could be eliminated, and the rest of the circuit would require only a resistance-capacity network and a battery and relay to operate the alarm. National Institute for Medical Research, Mill Hill, London N.W.7.

B. M. WRIGHT.

ANÆSTHESIA FOR DENTAL SURGERY SIR,-Despite the stern warnings of danger voiced in the report from the joint subcommittee on dental anaesthesia of the Central Health Services Council, and echoed in your annotation last week (p. 991), we should not lose sight of the fact that the mortality from dental anaesthesia has come tumbling down in recent years. In 1952, there were 22 deaths 6; and, according to the joint subcommittee’s report, in the five years 1952-56 there were 87 deaths. But in the five years 1961-65 (also according to the report) there were only 31 deaths, though the number of patients at risk had not fallen greatly. Furthermore, we learn from appendix B and other data in the report that in the four years 1962-65 deaths occurring in dentists’ surgeries, as distinct from those occurring in dental patients anaesthetised in hospitals, were averaging 2 per year, or roughly 1 per million administrations of general anxsthesia, despite the fact that only 20% of the administrations were given by practitioners with special training in anaestheticsŁi.e., fewer than were given by dentists who were performing the operation. It should be borne in mind, also, that local anxsthesia is not, as the report assumes it to be, completely without mortality in dental

patients. Last year7gave my reasons for thinking sional tragedies of dental ansesthesia had little

that these occado with what anxsthetic was used or who gave it; and it is noteworthy that in the last 3 deaths reported, the ansesthetists were specialists. I suggested that the trouble was usually due to the traditional, to

3. Valenti, C. Unpublished. 4. Holm, G., Perlmann, P. J. exp. Med. 1967, 125, 721. 5. Wright, B. M. J. scient. Instrum. 1962, 39, 37. 6. Br. med. J. 1967, i, 447. 7. Bourne, J. G. Lancet, 1966, i, 879.