Neutron activation analysis provides a useful clinical test to assess bone mass status in vivo. The neutron flux is obtained from Pu/Be sources and49Ca activity is measured by NaI detectors. For diagnostic value, the49Ca measurement is related to the mean value for normal subjects of the same body size. This normalized index, our CaBI, is used extensively to diagnose the bone loss associated with osteoporosis and to asses changes in bone mass with progression of disease and in response to treatments. Our facility operates at maximum capacity (35 tests/wk.). The hospital location and the dependability and ease of operation (provided by neutron sources) have facilitated extensive clinical use.
Authors:J. Harrison, S. Krishnan, C. Muller, A. Strauss, S. Mukherjee, and W. Sturtridge
The accuracy of dual energy X-ray absorptiometry (DEXA) for measurement of bone mass carried out by quantitative digital radiography (Hologic Inc.) was compared to results with neutron activation analysis (NAA) on 106 subjects. The accuracy with DEXA was further investigated by measurements on aluminium samples of known composition. DEXA measured 4 lumbar vertebrae by spine scan. The central third of the skeleton also was measured by whole body scan to obtain data on the same large part of the skeleton as measured by NAA. Results suggested that DEXA spine scans were more reliable than whole body scans. In addition, the measurement of total mineral content (BMC) was more reliable than the normalization of BMC to bone surface area (BMC/Area) or bone mineral density (BDM). Since the proportion of bone below detection would increase with development of osteoporosis, with osteoporosis the BMC would be increasingly underestimated, but to only a small extent, while the BMD would be more significantly overestimated.
The osteoporosis is regarded as a widespread disease all over the world. In the prevention therapy of this disease there is
a primary role of the daily calcium intake with the proper Ca:P ratio (1:1–1:2). The primary source of Ca for people the dairy
products are implied, from which only the processed cheeses have inadequate ratio of Ca:P. In cheeses processed without peptization
developed in the Hungarian Dairy Research Institute (HDRI) the Ca:P ratio meets the requirements (1.5:1), moreover these products
can be enriched with Ca.
In this study we used both processing technologies. The electronmicroscopic photographs demonstrate the differences clearly.
The traditionally processed cheese (with peptization) has a 'spongy’ structure well known from literature, while a space-net
can be seen resulting from the casein-filamentous hydrocolloid interaction in the structure of heat-treated cheese without
peptization. DSC curves are the same in the temperature range 0–40C, showing endotherm melting process in two well-distinguished
temperature interval (0–20 and 22–40C). They are different in the temperature interval 40–100C: in the case of processed
cheese with peptization the gel-sol transformation gives a higher endotherm peak in a narrow temperature range, while for
heat-treated cheese without peptization this temperature range is wider with a lower endotherm peak.
Both electronmicroscopic and DSC investigations have proved that contrary to the traditionally processed cheese where the
structure is formed by the linked peptized protein, in the heat- processed cheese without peptization the frame-forming element
is the huge hydrocolloid molecule interacted with the protein. The enthalpy change is substantially lower at the disintegration
of the latter structure.
Authors:S. Krishnan, J. Mernagh, A. Hitchman, K. McNeill, and J. Harrison
A procedure has been developed to measure fluoride concentration in bone biopsies by neutron activation analysis /NAA/. The NAA procedure is non-destructive so that the bone biopsies can be used subsequently for histological evaluation. The fluoride content is expressed as F/Ca ratio in the bone samples. The fluoride and calcium are measured using the reactions:19F/n, /20F /t=11.2 s/ and48Ca/n,/49Ca/t=8.8 m/, respectively. The F/Ca ratio normalizes the fluoride to bone mineral avoiding the use of bone weight which is unreliable with fresh biopsy samples. This ratio also corrects for variations in neutron flux and gamma counting efficiencies. Results by this procedure were compared to biochemical determinations using an ion-selective electrode for fluoride and atomic absorption for calcium. The two methods gave results which agreed within ±5% which is the precision of the NNA procedure. The NAA method provides a simple and non-destructive procedure for fluoride measurement in bone biopsies for clinical studies. The method is now routinely used in our clinical studies for the fluoride measurements on biopsies from osteoporotic patients treated with fluoride therapy for nearly four years.
Calcium may be measured in vivo by neutron activation analysis /IVNAA/, observing the 3.1 MeV -ray from the decay of49Ca. Normally the detection of this -ray is done in a heavily shielded whole body counter. It is shown that the use of shielding is unnecessary. As a result, the cost of building an IVNAA facility for Ca is very much reduced.
Authors:Luciana Malpezzi, Elisabetta Maccaroni, Giordano Carcano, and Gianpiero Ventimiglia
treatment of osteoporosis and similar diseases, which has been subjected to many pharmacological [ 1 – 3 ] and structural studies [ 4 – 8 ], in order to explore the structural basis of their activity against bone diseases and against some parasite
Authors:L. Stephens-Newsham, M. Duke, T. Overton, and D. Ng
Instrumental neutron activation analysis (INAA) was carried out on hair samples from a group of twenty patients undergoing a study of osteoporosis. Half of these were judged normal. Fourteen elements were measured but only calcium was found to have a correlation with the disease state. Calcium levels in hair were significantly lower (99% confidence level) in patients with osteoporosis. Conversely, calcium levels in the blood of osteoporotic patients were significantly higher (95% confidence level) than those in normals. Though the group studied was small it is felt that the levels of calcium in hair may be of value in diagnosing osteoporosis.
reported that psoralidin also has multiple pharmacological activities such as anti-tumor [ 2 – 7 ], anti-osteoporosis [ 8 – 12 ] and enhancement of immunity [ 13 – 15 ]. Studies have shown that psoralidin can release a large amount of Ca 2+ in the
In-vivo neutron activation analysis (IVNAA) has been used in this laboratory, approximately for the past twenty years, to determine the bone status of humans. For this purpose, the total body calcium (TBCa) is assayed and that is indicative of the bone mineral concentration of the individual. We have effectively used this method to diagnose, understand and monitor the treatment of osteoporosis among elderly women, particularly in post-menopausal women. This paper summarizes the technique and our experience in dealing with osteoporosis.