Israel Medical Association Journal

Background: Human chorionic gonadotropin, the pregnancy hormone, is synthesized by trophoblast cells which make up the placenta.

Objective: To determine whether antibody to hCG can be used to specifically detect living trophoblast in vitro by binding to the external membrane.

Methods: Trophoblast was isolated from fresh placentas of women undergoing termination of pregnancy in the first trimester and incubated with monoclonal antibody to hCG. Anti-mouse immunoglobulin G with a fluorescent marker was then added.

Results: Syncytiotrophoblast stained positive on the external surface of the cell, while controls of leukocytes, endometrial cells and hepatocytes were negative.

Conclusion: The hCG monoclonal antibody may be used to specifically detect hCG on the surface of living trophoblast in vitro.
 

Objective: To gain an insight into the forces behind these changes, we compared the trends in hospital utilization in Israel with those in 21 developed countries with available data.

Materials and Methods: Our data were derived from The "Hospitals and Day Care Units, 1995" report by the Health Information and Computer Services of the Israel Ministry of Health, and the Organization for Economic Cooperation and Development Health Data, 98. We examined the numbers of acute care hospital beds, of patients on dialysis and of doctors' consultations, health expenditures and age structure of the population in 1995 or closest year with available data, as well as changes in DRs, HDs and ALOS between 1976 and 1995.

Results: In Israel the DRs increased from 130 in 1976 to 177 in 1995 (36%), HDs declined from 992 to 818 (18%), and ALOS declined from 7.60 to 4.51 days (41%). Relative to other countries, in 1995 Israel had the lowest ALOS; low HDs similar to those in the UK, Portugal, Spain, the USA and Sweden; and intermediate DRs similar to those in Belgium, Germany, Sweden and Australia. The number of acute care beds per 1,000 population was directly related to HDs (r=0.954, P=0.000) and to DRs (r=0.419, P=0.052). Health expenditures (% of the gross national product) correlated with the number of patients on dialysis per 1,000,000 population (r=0.743, P=0.000). Between 1976 and 1995, HDs and ALOS declined in most countries, however the trends in DRs varied from an increase by 119% in the UK to a decline by 29% in Canada.

Conclusions and hypotheses: The increase in DRs in Israel from 1976 to 1995 was shared by many but not all countries. This variability may be related to differences in trends in local practice norms and in available hospital beds. If the number of patients on dialysis is a valid index for use of expensive treatment modalities, the correlation of health expenditures with the number of patients on dialysis suggests that the use of expensive technology is a more important determinant of health care costs than the age of the population or hospital utilization. Since the use of expensive technology is highest during the first few days in hospital, decisions about health care policy should consider the possibility that the savings incurred by a further decline in HDs and ALOS may be offset by a possible increase in per diem hospital costs and in health care expenditures after discharge from hospital.

Background: Most corneal damage induced by contact lenses is due to interference with corneal oxygenation.

Objective: To investigate the effect on the rabbit cornea of a rigid gas-permeable contact lens with a newly designed periphery.

Method: We fitted New Zealand white rabbits (n=12) with RGP[1] contact lenses that were identical in all respects except for the design of the periphery. In each animal, one contact lens had an innovative periphery consisting of a microscopic diffractive relief lathed on the back surface; the other contact lens was of a conventional design. The lenses were worn continuously for 7 days. During this experimental period and for 1 additional week we assessed the corneal damage by daily testing lactic dehydrogenase activity in the tears.

Results: On the last day of the experimental week and the first 3 days of the healing period, mean tear LDH[2] activity was significantly lower in the eyes with the new contact lens design than in eyes with the conventional lenses.

Conclusions: The novel periphery design reduces corneal damage resulting from contact lens wear, as reflected by LDH levels in the tears. The new design probably facilitates the flow and exchange of tears under the contact lens, resulting in improved metabolism of the cornea. These findings may also prove applicable to soft contact lenses.