Download Parathyroid hormone and bone

Clinical Science( 1986) 71, 231-238
23 1
~
EDITORIAL REVIEW
Parathyroid hormone and Lone
J. REEVE’
AND
JOAN M. ZANELLI’
I Bone
Disease Research Group, MRC Clinical Research Centre and Northwick Park Hospital, Harrow, Middlesex,
U.K., and ZHormonesDivision, National Institute for Biological Standards and Control, Harnpstead, London
Introduction
Nearly sixty years ago Mandl demonstrated that
removal of a parathyroid tumour could reverse the
associated bone softening and cyst formation of
osteitis fibrosa [ l , 21. Over the next 20 years,
various investigators showed that animals treated
with impure parathyroid extract (PTE) in moderate
dosage given daily or on alternate days could
increase their trabecular bone density [3-91. In these
experiments, in the first few days, osteoclastic
resorption and fibrous tissue proliferation were
observed; an increase in osteoblastic activity
followed later [7]. Higher doses of PTE led to the
more familiar pictures of massive continued bone
loss or osteitis fibrosa [4,9]. Considerable advances
have since been made in understanding how parathyroid peptides stimulate the cellular events leading to bone renewal, both physiologically and in
pathological states in which high plasma concentrations of parathyroid hormone (PTH) are found.
However, their precise role in the regulation of the
balance between bone formation and resorption still
remains obscure.
Within a small volume of bone, at the intermediary level between the cell and the organ, tissue
renewal is organized by a co-operating group of
cells, named the ‘basic multicellular unit’ (BMU)by
Frost [lo]. The normal skeleton contains 105-106
BMU. Some cells (eg. osteoblasts and osteocytes)
are derived from the stromal (fibroblastic) system of
bone or marrow [ll]; osteoclasts are believed to
originate in the haemopoietic system and in some
respects resemble macrophages [ 121, but do not
share their surface markers [ 131. Previous speculations that the two bone cell types shared a common
stem cell [ 141have been disproved [ 111.
Abbreviations: BMU, basic multicellular unit(s); PTE,
parathyroid extract; PTH, parathyroid hormone; hPTH
1-34, 1-34 fragment of synthetic human PTH.
Correspondence: Dr J. Reeve, Bone Disease Research
Group, Clinical Research Centre, Watford Road, Harrow,
Middlesex HA1 3UJ, U.K.
Normally, in man, iliac trabecular bone remodelling takes about 4 months. Resorption is initiated by
osteoclasts, perhaps prompted by another cell type.
First a collagen-poor cement line is laid down
during a phase when the resorption surface is predominantly populated with cells with single nuclei,
including pre-osteoblasts [ 151; bone formation then
begins 5-10 weeks after the initiation of bone
resorption [16]. Osteoid is laid down on the cement
line and the lag time to its mineralization is normally
12 days or more, being very much longer in diseases
such as osteomalacia [ 171. However, even in health
not all osteoid is mineralizing simultaneously; in
normal man 30% appears to be ‘resting’ [lo, 181.
After remodelling is complete it is thought that perhaps 30% of osteoblasts survive to transform into
resting bone surface or ‘buried‘ osteocytes, which
have distinctive responses to PTH in vivo as will be
discussed. Because osteocytes do not make bone in
significant amounts, an important functional distinction is made by histomorphometrists between
these cells and their parents, the osteoblasts. The
origin of the two functionally distinct cell types
from the same lineage presents potential difficulties
in the interpretation of studies in vitro of bone cells
grown in culture.
In this review, the influence of PTH peptides on
bone tissue in vivo and in vitro is contrasted with
their effects on isolated cells. An attempt is made to
identify those problems which must be addressed in
future research. For an excellent in-depth review of
this topic up to 1976, readers are referred to Parfitt
[19-221 and earlier information was summarized by
Parsons & Potts [23].
Effects of PTH on cultured bone tissue
Studies by Barnicot [24] and Chang [25] on the
osteolytic effects of parathyroid tissue transplanted
into close proximity to cranial bone heralded the
development of tissue culture techniques by Gail-
232
J. Reeve and J. M . Zatielli
lard [26]for studying effects of parathyroid peptides
on bone in vitro. Bone from neonates, or fetal bone
from the last third of the gestational period, was
found to dissolve over a few days in culture in the
presence of high concentrations of PTE [26-321.
The degrees of histological and biochemical
changes seen in the bone and culture fluid were in
some cases proportional to the concentration of
added parathyroid activity, leading to the development of bioassay systems [28, 321.
Gaillard showed that PTE increased both the
number and activity of osteoclasts [27]. More
recently, Stern et al. [33] have found that a calcium
ionophore, which increases intracellular calcium,
promotes osteoclast formation, and Lowik et al.
[34] using the indicator Quin 2 have demonstrated
that intracellular calcium is increased by PTH. Parathyroid hormone is well known to increase cyclic
AMP production in the kidney [35] and some bone
systems [36, 371. It may therefore act on cells by
increasing the intracellular concentrations of two
recognized secondary messengers which may act
independently or synergistically [38]. Further progress in understanding the biochemical actions of
PTH at the target cell membrane would be facilitated by the characterization of the PTH receptor
molecule(s), a task which has presented considerable techniml difficulties [39].
Using longer-term cultures, tioldhaber showed
that despite the early disappearance of osteoblasts,
spontaneous bone resorption was eventually followed by bone formation [30]. Subsequently, Herrmann-Erlee et al. [40] showed that, at low
concentrations, PTH and particularly its 1-34
human N-terminal fragment caused net increases in
the amount of bone formed in vitro. Howard et al.
obtained a soluble factor (molecular weight
approximately 83 000 daltons) released from bone
after stimulation by bone resorbing agents such as
PTH, which induced subsequent bone formation
[41], probably because it was mitogenic for osteoblast precursors [42]. This harked back to earlier
work of Bingham et al. [43], who showed that
tritiated uridine incorporation into osteoblast-like
cells showed a biphasic response to PTH.
Effects of PTH on bone cells in v i m
The difficulties of unravelling the biochemical
mechanisms of PTH actions on cell populations in
intact bone have emphasized the importance of
studying PTH effects on isolated populations of
identified bone cells. However, techniques for purifying bone cells have not yet progressed to the point
at which functionally homogeneous preparations of
osteoblastic or osteoclastic cell lines can be
obtained.
By studying separated individual multinucleated
osteoclasts which can be shown under the microscope to resorb bone, Chambers and his colleagues
[44, 451 have circumvented some of the difficulties
associated with mixed cell cultures and shed light
on the relationship between PTH and osteoclastic
bone resorption. Whereas calcitonin inhibited the
motility of osteoclasts and prevented them from
creating resorption pits on slices of devitalized
cortical bone, PTH in various concentrations was
without any effect. Braidman and her colleagues
[46] used an enzymatic digestion procedure applied
to early postnatal calvaria followed by Percoll
density centrifugation to obtain cultures or osieoclast-like cells more homogeneous than those previously obtained with the techniques of Wong &
Cohn [47]. Whereas Wong & Cohn [48] had
observed that their ‘osteoclast-like’ cells responded
to PTH, Braidman et al. did not [46], supporting the
conclusions of Chambers et al.
Several approaches to the study of osteoblasts in
culture have been developed. The sequential
enzyme digestion technique of Wong & Cohn [48]
was applied to embryonic or neonatal bone and
used to harvest cells released late during digestion.
These cells had morphological and biochemical
characteristics of osteoblasts, and responded to
PTH, but not to calcitonin [49]. In Braidman’s
refined system these observations were confirmed
[46]. Another approach has been to culture bone
marrow cells in media which favour stromal cell
populations. Fibroblastic cells with many characteristics of osteoblasts have been grown, cloned and
serially passaged from rabbit, guinea pig and human
bone marrow [50, 511. Rabbit cells, when enclosed
within diffusion chambers implanted into the peritoneal cavities of host rabbits (separating the cells
from host cells, but not from macromolecules),
form bone, cartilage and fibrous tissue in variable
proportions [52, 531. Further experiments with
cloned cells by Friedenstein, who reimplanted them
under the kidney capsule in uivo [54], have shown
that a single clone can develop a whole stromal
environment for colonization by host haemopoietic
cells to form a marrow ‘organ’.This and other work
summarized by Owen [ 111 has led to the realizations that osteoblasts may share a common stromal
stem cell, not only with osteocytes, but with other
marrow cell types such as the fibroblastic cells of
the marrow reticular network, chondroblasts and
adipocytes [ 11, 551. It is also generally agreed that
many osteoblasts eventually transform into osteocytes in vivo, but the possibility that analogous
changes may occur in long-term bone cell cultures
in vitro has not yet received attention.
Parathyroid hormone and bone
Mixed cell cutures are well known to cause difficulties in studying single cell types because alterations occur in relative growth rates when different
cell types are grown together in vitro. Therefore it is
important to recognize that studies on ‘osteoblastlike’ cells grown in mixed cultures will require validation when techniques become available to
differentiate further cells able to form bone from
cells which are not. In particular, since the proportion of ‘osteoblasts’ in a cell culture population may
decrease under culture conditions, negative results
from experiments should be treated with caution.
As an example of this problem from another field,
Tyrrell et al. were able to show that the reported
insensitivity of many mixed cultures of pneumocytes to respiratory virus infections was due to the
relative disappearance in culture of the rather
slowly dividing type II pneumocytes; when cloned,
the vulnerability of the type II cells to infection was
demonstrable [56]. However, cell cloning alone will
not solve the problem of obtaining pure preparations of osteoblasts or osteocytes if each colony is
generated by a multipotential ‘stem’ cell.
Because of such problems, a number of groups
have used malignant cell lines derived or cloned
from induced transplantable osteogenic sarcomata
from rats, to study the biochemical interactions
between PTH peptides and the osteoblast-like cell
[57-601. These studies have been useful in defining
the actions of PTH on a number of cellular activities
[60]. However, the intrinsic growth potential of
transformed cells, with their tendency to produce
transforming growth factors, renders them unsuitable for consideration of the effect of PTH on
growth patterns of normal osteoblasts.
Based on studies with transformed and untransformed cells, certain conclusions may be drawn
[60]. Isolated osteoblast-like cells respond to PTH
with cyclic AMP production. They also respond to
the prostaglandin PGE, and calcitriol (1,25-dihydroxyvitamin D). They are capable of producing
collagenase, plasminogen activator [613, prostaglandins [60] and osteocalcin [62]. When added to the
osteoclast culture system of Chambers et al., mixed
populations of stromal cells which come in close
proximity to active osteoclasts can promote their
recovery from calcitonin-induced immobility [63].
Braidman et al., using cytochemical techniques,
have shown that PTH indirectly stimulates an
increase in osteoclast acid phosphatase activity,
provided that the osteoclast is co-cultured with an
‘osteoblast-like’ cell 1641. This evidence of an indirect effect of PTH on osteoclasts may help resolve
the paradox of the differing effects of PTH on
osteoclasts in tissue culture and on isolated osteoclasts observed in the systems of Chambers and
Braidman.
233
When continuously exposed to PTH, osteoblastlike cells reduce their synthesis of collagen [65]. On
the other hand, short ( < 24 h) exposures of such
cells to PTH increase their mitotic activity after
transfer to a PTH-free medium [66].
Studies of PTH in vivo
The intact organism integrates various processes
which determine the overall effects of PTH on the
skeleton. There is reason to believe that the first
action of PTH is to modulate the number of BMU
that are active in a given volume of bone [20].
Secondly, at the level of the individual BMU, PTH
may influence the activity [27] of the osteoclasts and
the functional lifespan of the osteoblasts [67], as
well as the birth rates of the two cell types.
The third action of PTH on bone is to promote,
via an exchange with K + [68], calcium efflux from
the so-called exchangeable pools of bone calcium in
proximity to osteocytes [69, 701, which leads to a
rapid increase in the plasma calcium level. It is
believed that this effect is the result of a direct
action of PTH on these cells, and that calcitonin
exerts its rapid hypocalcaemic action by having the
opposite effect [70]. With the action of PTH in
causing renal retention of calcium [71], the osteocytes are substantially responsible for short-term
plasma calcium homoeostasis, to which the other
actions of PTH in promoting changes in bone turnover contribute comparatively little [711. Interestingly, the immediate effect of intravenously
injected PTH on bone cells is to promote an influx
of plasma calcium into bone [72];the more familiar
calcaemic action of PTH develops subsequently,
and in chicks may be augmented by prior intravenous injection of calcium [73]. After surgical removal of a parathyroid adenoma, Mazzuoli has
observed a complementary response in that plasma
calcium transiently rises before the expected fall
[74]; termination of chronic hypercalcaemic PTH
infusions in dogs gave results compatible with these
observations [75].
All of these effects of PTH are influenced by its
presentation to bone cell receptors. The pattern of
exposure, as well as the integrated dose of PTH,
might potentially affect the secondary responses of
individual bone receptors as well as their density on
individual cells. Therefore, in addition to the mean
rate of hormone secretion, the glandular secretion
pattern and the disposal dynamics of endogenous
PTH are potentially important regulators of bone
cell function. Indeed, Atkinson et al. have found
evidence for altered PTH disposal in primary
biliary cirrhosis (possibly due to Kupffer cell dysfunction) [76] and in low turnover idiopathic osteoporosis 1771.
234
J. Reeve and J. M. Zanelli
When administered to the intact mammal in
supraphysiological doses, PTH and its derivatives
produce a remarkable range of effects. Iliac trabecular bone volume in primary hyperparathyroidism is usually normal or near-normal [67], with
evidence of increased remodelling due to a corresponding increase in the rate of initiation of new
BMU. In the trabecular bone of the distal radius,
osteopenia is usually seen, as it is in the cortical
bone of the periphery [78,79].
In primary hyperparathyroidism without overt
osteitis fibrosa, the history of the osteoblastic phase
of the typical axial trabecular BMU has been reconstructed by Charhon et al. [67]. Except in premenopausal women (the only sub-group to suffer a
measurable deficit in axial trabecular bone), the
effective lifespan of the osteoblasts was increased,
although at the cell level there was a slight reduction
in the rate of work of the individual osteoblast. In
very severe hyperparathyroidism, when accompanied by osteitis fibrosa, the differing effects on
cortical and trabecular bone may become more
accentuated, with severe cortical osteopenia accompanying preserved values of axial trabecular bone
volume. In hyperparathyroidism associated with
renal failure, disordered vitamin D metabolism and
hyperphosphataemia commonly modify the effects
of excess parathyroid hormone concentrations, and
axial trabecular bone volume may be increased.
In contrast to clinical hyperparathyroidism and
continuous infusions of active N-terminal parathyroid peptides [80,811, daily subcutaneous or
intravenous injections of these peptides have been
found to cause marked effects on indices of trabecular bone mass and turnover without resulting in
more than transient post-injection hypercalcaemia
[3-9, 82-84]. The diaphyseal sclerosis of rat long
bones resulting from daily injections of a crude
parathyroid extract was also shown to be due to
PTH [84] rather than to calcitonin [85]. In patients
with osteoporosis, a trial of the 1-34 fragment of
synthetic human PTH (hPTH 1-34) given by daily
injections was found to cause a substantial increase,
to a mean of about 70% above baseline values, in
trabecular bone volume in the iliac crest as well as
increased indices of bone turnover [82]. Increases
in trabecular bone volume were found to correlate
with maximal achieved indices of bone formation
[82]. A recent report has noted similar increases in
the trabecular bone density of the lumbar spine,
measured with computed tomography [86],
although in this study calcitriol in low dosage was
added to the treatment regimen.
There have been suggestions that bone is more
responsive to N-terminal active fragments of PTH
than to the intact hormone. The synthetic 1-34 fragment caused a larger cyclic AMP response by bone
than did the intact hormone in dogs [87] and these
results have been confirmed in mice 1881. However,
cyclic AMP has not been shown to mediate the
physiological response of bone to PTH, and Herrmann-Erlee et al. found a dissociation between
bone resorption and cyclic AMP response to PTH
in tissue culture [89].
Studies were carried out in dogs and rats to
investigate the mechanisms of the anabolic effects
of hPTH 1-34. Daily injections markedly increased
iliac trabecular bone volumes in both species [81,
831just as they did in patients with idiopathic osteoporosis [82]. In rats, daily injections were also found
to result in increases in total body calcium relative
to values in controls [go]. However, when administered by continuous intravenous or subcutaneous
infusions, there were no increases in iliac trabecular
bone [80,811, and the study by Tam et al. in rats
[83] suggested that the difference was due to a relatively greater increase in resorption with the infusion regimen, associated with hypercalcaemia at
higher doses.
When given by a single subcutaneous injection to
man, the appearance of hPTH 1-34 in the circulation was found to be brief [91], and the measurable
effects on renal function to last little more than 4 h
after injection [92]. It is generally appreciated that
PTH bioassays in vivo which depend on the hypercalcaemic response to intravenously injected PTH
involve massive, if transient, elevations of plasma
PTH levels. For example, in the relatively sensitive
chick hypercalcaemia assay [73], to achieve a rise in
plasma calcium of 1.5 mmol/l it is necessary to raise
the plasma PTH concentration by 4-5 orders of
magnitude, assuming that bioactive PTH levels in
man and the chick are comparable [93]. It therefore
seems likely that the absence of hypercalcaemia
associated with daily injections of parathyroid peptides is related to the brevity of the effects of such
dose regimens on the kidney and the osteocytes
regulating the exchangeable bone pools of calcium.
In contrast, the increase in bone formation, which
takes from 4 to 7 days in the rat [7] and probably
longer than 5 weeks to develop in man [82, 941,
implies that daily injections of parathyroid peptides
require a similar period to cause a significant
increase in the number of activated BMU.
This encouraged the idea that these newly activated BMU could be further influenced by ‘coherence’ therapy [95, 961. This concept involves
increasing the birthrate of new BMU by cyclic
periods of treatment (eg. with PTH), after each of
which osteoclastic resorption should be selectively
depressed and bone formation encouraged to continue, mediated by the newly induced population of
normally relatively long-lived osteoblasts. However,
activation of a new BMU may require more than
Parathyroid hormone and bone
just a brief triggering stimulus with a parathyroid
peptide. The only trial of such an approach so far
reported with PTH,in which each of the 12 activation phases was of just 1 week‘s duration (and
osteoclast depression was attempted by 3 weeks of
PTH withdrawal), did not induce increased osteoblast activation despite clearcut success in depressing osteoclastic resorption [97].Thus the result of
a total of 12 weeks’ treatment with hPTH 1-34
spread over a year was an overall reduction in bone
turnover, in direct contrast to the daily injection
regimen.
There remain many fascinating questions concerning the interaction of other agents with the
PTH-bone cell relationship. In normal women, the
role of oestrogens in reducing bone resorption relative to formation [98]might be through a modification of the response of bone to PTH. The
biochemical basis for such an action remains
obscure; as yet there is no convincing demonstration of oestrogen receptors in bone. Thyroid hormone concentrations, besides affecting overall
levels of remodelling activity, may influence the
balance between bone formation and resorption
[95, 991, as glucocorticoids certainly do [loo].
Malignant cells may markedly influence responses
to endogenous PTH either locally through secretion
of cytokines [ l o l l or at a distance by secretion of
circulating factors which have some of the characteristics of PTHitself [ 1021.
Conclusions and future investigations
Despite the vast literature that has accumulated on
the action of PTH on bone, this remains a fertile
field for future investigation.There is now a general
acceptance that parathyroid peptides act directly on
cells of the stromal system leading to osteoblast
proliferation, and a variety of effects on the osteocytes which are still being explored. Thereby, PTH
is intimately involved in both the long-termregulation of bone matrix turnover and the short-term
regulation of the concentration of calcium in the
extracellular fluid. However, much remains to be
learned of the biochemical mechanisms involved in
the interaction between the hormone and its target
cells. Specifically, the biochemistry of the FTH
receptor and the significance of intracellular events
triggered by hormone-receptor interactions, such
as increases in glucose-6-phosphate dehydrogenase
activity [103], will deservedly receive attention in
the immediate future. The biochemistry of hormone-receptor interactions, incidentally, is of considerable clinical interest, not least because of the
ability of non-PTH circulating products to activate
the PTH receptor in some cases of malignant hypercalcaemia [ 1041.
235
Further studies on the interaction between bone
surface osteocytes and osteoclasts will be crucial to
understanding the role of PTH in regulating bone
resorption and the rate of initiation of new basic
multicellular units. The hypothesis of Rodan &
Martin [lo51 may generate a number of detailed
variants which will need to be examined critically.
Experimental studies have shown that PTH
increases the spaces between adjacent osteocytes
[ 1061 and this has suggested a mechanism whereby
PTH may allow the osteoclasts access to uncovered
bone surfaces, leading to the initiation of ,resorption. The thin layer of under-mineralized matrix
beneath all surface osteocytes might still inhibit
resorption unless first removed by collagenase secreted by cells related to the osteocyte-osteoblast
lineage [ 1071.
While the rate at which new BMU are initiated
determines the rate of bone turnover, it does not in
itself determine the rate of bone loss or gain. In a
given volume of bone this is determined by the product of the mean loss or gain of bone in each BMU
and the rate of initiation of new BMU. In the
Haversian systems within the cortex of bone there
is, of course, no potential room for expansion; but
patterns of both loss and gain may be seen within
the three other bony ‘envelopes’: periosteal, endosteal and trabecular [108].
At the BMU level the initial loss of bone is determined by the number of osteoclasts, the rate at
which they work individually and the duration of
the osteoclastic phase. From use of a stochastic
model of BMU dynamics to analyse the effects of
daily injections of hPTH 1-34 in patients with
osteoporosis, it was concluded that increases in
trabecular bone volume of the magnitude observed
in some patients could only have been the result of
a substantial increase in effective osteoblast lifespan
[109], a phenomenon also observed directly in
patients treated successfully with sodium fluoride
plus calcium [110]. Conversely, before treatment,
many similar patients showed evidence of a reduced
effective osteoblast lifespan [ 1113 associated with
prolonged periods when the associated osteoid was
not mineralizing [17].The relationship of parathyroid peptides to the maturation and stabilization
of osteoblast populations clearly requires further
investigation.
The application of new techniques to study the
proliferative potential of the osteoblast stem cell
and the study of the effects of parathyroid peptides
on the intermediary metabolism of bone cells and
proteins synthesized by such cells in isolation and in
tissue sections should have a profound influence on
our future understanding of the regulation of bone
in health and disease.
J. Reeve and J. M. Zanelli
236
Acknowledgments
We thank Maureen Owen, Pierre Meunier and
Michael Parfitt for helpful discussions.
References
1. Mandl, F. (1926) ThLrapeutischer Versuch bei einem Falle von
Ostitis fibrosa generalisata mittels Exstirpation eines Epithelkorperchentumors. Zentralblatrfirr Chirurgie, 5,260-264.
2 . Mandl, F. (1929) Zur Frage der Exstirpation eines Epithelkorpertumors bei der allgemeinen Ostitisfibrosa. Zentralblatt f i r
Chirurgie, 28, 1739-1745.
3. Bauer, W., Aub, J.C. & Albright, F. (1929) Studies of calcium and
phosphorus metabolism. V. A study of the bone trabeculae as a
readily available reserve supply of calcium. Journal of Experimental Medicine, 49, 145-162.
4. Selye, H. (1932) On the stimulation of new bone-formation with
parathyroid exfract and irradiated ergosterol. Endocrinology, 16,
547-558.
5. Pugsley, L.1. & Selye, H. (1933) The histological changes in the
bone responsible for the action of parathyroid hormone on the
calcium metabolism of the rat. Journal of Physiology (London).
79,113-117.
6. Shelling, D.H., Asher, D.E. & Jackson, D.A. (1933) Calcium and
phosphorus studies: (vii) the effects of variations in dosage of
parathormone and calcium and phosphorus in the diet on the
concentrations of calcium and phosphorus in the serum and on
the histology and chemical composition of the bones of rats.
Bulletin of the Johns Hopkins Hospital, 53, 348-389.
7. Burrows, R.B. (1938) Variations produced in bones of growing
rats by parathyroid extracts. American Journal of Anatomy, 62,
237-290.
8. Barnicot, N.A. (1945) Some data on the effect of parathormone
on the grey-lethal mouse. JournalofAnatomy, 79,83-93.
9. Jaffe, H.L. (1933) Hyperparathyroidism (von Recklinghausen’s
disease of bone). Archives of Pathology, 16.63- 112.
10. Frost, H.M. (1970) Tetracycline-based histological analysis of
bone remodelling. Calcified Tissue Research, 3.21 1-237.
11. Owen, M. (1985) Lineage of osteogenic cells and their relationship to the stromal system. In: Bone and Mineral Research
Annual3, pp. 1-25. Ed. Peck, W. Excerpta Medica, Amsterdam.
12. Ericsson, J.L.E. (1980) Origin and structure of the osteoclast. In:
Mononuclear Phagocyres: Functional Aspects, part 1, p. 203. Ed.
Van Furth, R. Martinus Nijhoff, The Hague/Boston/London.
13. Horton, M.A., Rimmer, E.F., Moore, A. & Chambers, T.J. (1985)
On the origin of the osteoclast: the cell surface phenotype of
rodent osteoclasts. Calcified Tissue International, 37,46-50.
14. Rasmussen, H. & Bordier. P. (1974) In: The Physiological and
Cellular Basis of Metabolic Bone Disease. pp. 41-48. Williams
and Wilkins, Baltimore.
15. Baron, R., Vignery, A. & Horowitz, M. (1984) Lymphocytes,
macrophages and the regulation of bone remodelling. In: Bonc
and Mineral Research Annual 2, pp. 175-243. Ed. Peck, W.A.
Elsevier, Amsterdam.
16. Eriksen, E.F., Melsen, F. & Mosekilde, L. (1984) Reconstruction
of the resorptive site in iliac trabecular bone: a kinetic model for
bone resorption in 20 normal individuals. Metabolic Bone Disease
and Related Research, 5,235-242.
17. Parfitt, A.M., Mathews, C., Rao, D., Frame, B., Kleerekoper, M.
& Villanueva, A.R. (1981) Impaired osteoblast function in metabolic bone disease. In: Osteoporosis - Recent Advances in Pathogenesis and Treatment, pp. 231-330. Ed. DeLuca, H.F. et al. University Park Press, Baltimore.
18. Melsen, F. & Mosekilde, L. (1978) Tetracycline double-labeling
of iliac trabecular bone in 41 normal adults. Calcified Tissue
Research, 26.99-102.
19. Parfitt, A.M. (1976) The actions of parathyroid hormone on
bone: relation to bone remodeling and turnover, calcium homeostasis. and metabolic bone disease. Part I Mechanisms of calcium
transfer between blood and bone and their cellular basis:
morphological and kinetic approaches to bone turnover.
Metabolism, 25,809-844.
20. Parfitt, A.M. (1976) The actions of parathyroid hormone on
bone: relation to bone remodeling and turnover, calcium homeostasis, and metabolic bone disease. Part II: PTH and bone cells:
bone turnover and plasma calcium regulation. Merabolism, 25,
909-955.
21. Parfitt, A.M. (1976) The actions of parathyroid hormone on
bone: relation to bone remodelling and turnover, calcium homeostasis, and metabolic bone disease. Part Ill: PTH and osteoblasts,
the relationship between bone turnover and bone loss, and the
state of the bones in primary hyperparathyroidism. Metabolism,
25,1033-1069.
22. Parfitt, A.M. (1976) The actions of parathyroid hormone on
bone: relation to bone remodeling and turnover, calcium homeostasis, and metabolic bone disease. Part IV: The state of the bones
in uremic hyperparathyroidism - the mechanisms of skeletal
resistance to PTH in renal failure and pseudohypoparathyroidism
and the role of PTH in osteoporosis, osteopetrosis, and osteofluorosis. Metabolism, 25,1157-1188.
23. Parsons, J.A. & Potts, J.T., Jr (1972) Physiology and chemistry of
parathyroid hormone. Clinics in Endocrinology and Metabolism,
1,33-78.
24. Barnicot, N.A. (1948) The local action of the parathyroid and
other tissues on bone in intracerebral grafts. Journal
Of AllalOmJ
(London),82,233-248.
25. Chang, H.Y. (1951) Grafts of parathyroid and other tissues to
bone. Anaromical Record, 111,23-47.
26. Gaillard, P.J. (1955) Parathyroid gland tissue and bone in vitro (I)
ExperimentalCell Research, Suppl. 3,154-169.
27. Gaillard, P.J. (1961) Parathyroid and bone in tissue culture. In:
The Parathyroids, DP. 20-45. Ed. GreeD, R.O. & Talmage, R.V.
Charles C. ThomaH,Springfield, Ill.
.
28. Raisz, L.G. (1963) Stimulation of bone resorption by parathyroid
hormone in tissueculture. Nature(London),197, 1015-1017.
29. Raisz. L.G. (1965) Bone resomtion in tissue culture. Factors
influencing the response to parahyroid hormone. Journal of Clinicallnvestigation, 44, 103-1 16.
30. Goldhaber, P. (1966) Remodelling of bone in tissue culture.
Journalof Dental Research, 45,490-499.
31. Vaes, G. (1968) On the mechanisms of bone resorption. Jourtul
O f Cell Bioloby, 39,676-697.
32. Zanelli, J.M., Lea, D.J. & Nisbet, J.A. (1969) A bioassay method
in vitro for parathyroid hormone. Journal of Endocrinology, 43,
33-46.
33. Stern, P.H., Orr, M.F. & Brull, E. (1982) Ionophore A23187 pro34.
35.
36.
37.
38.
39.
motes osteoclast formation in bone organ culture. Calcified
Tissue International, 34, 31-36.
Lowik, C.W.G.M., van Leeuwen, J.P.T.M., van der Meer, J.M.,
van Zeeland, J.K., Scheven, B.A.A. & Herrmann-Erlee, M.P.M.
(1986) A two receptor model for the action of parathyroid
hormone on osteoblasts: a role for intracellular free calcium and
CAMP. Cell Calcium (In press).
Marcus, R. & Aurbach, G.D. (1969) Bioassay of parathyroid hormone in virro with a stable preparation of adenylate cyclase from
rat kidney. Endocrinology, 85,801-810.
Chase, L.R., Fedak, S.A. & Aurbach, G.D. (1966) Activation of
skeletal adenyl cyclase by parathyroid hormone in vitro. Endocrinology, 84, 761-768.
Crisp, A.J., McGuire-Goldring, M.B. & Goldring, S.R. (1984) A
system for culture of human trabecular bone and hormone
response profiles of derived cells. British Journal of ExperimentalPathology, 65,645-654.
Peck, W.A., Kohler, G. & Burr, S. (1981) Calcium mediated
enhancement of the cyclic AMP response in cultured bone cells.
Calcified Tissue International, 33,409-416.
Nissenson, R.A., Mann, E., Winer, J., Teitelbaurn, A.P. &
Arnaud, C.D. (1986) Solubilization of the renal receptor for
parathyroid hormone. Journal of Bone and Mineral Research, 1,
160.
40. Herrmann-Erlee, M.P.M., Gaillard, P.J. & Hekkelman, J.W.
(1978) Regulation of the response of embryonic bone to PTH
41.
42.
43.
44.
45.
46.
and PTH fragments. A morphological and biochemical study. In:
Endocrinology of Calcium Metabolism, pp. 253-261. Ed. Copp,
D.H. & Talmage, R.V. Excerpta Medica, Amsterdam.
Howard, G.A., Botterniller, B.L., Turner, R.T., Rader, J.1. &
Baylink, D.J. (1981) Parathyroid hormone stimulates bone formation and resorption in organ culture: evidence for a coupling
mechanism. Proceedings of the National Academy of Sciences
U.S.A.,78, 3204-3208.
Farley, J.R. & Baylink, D.J. (1984) Evidence that skeletal growth
factor may be a paracrine effector of bone volume. In: Osteoporosis I, pp. 423-430 (Proceedings of Copenhagen International Symposium on Osteoporosis, 3-8 June 1984). Ed.
Christiansen, C., Arnaud, C.D., Nordin, B.E.C., Parfitt, A.M.,
Peck, W.A. & Riggs, B.L. Department of Clinical Chemistry,
Glostrup Hospital, Copenhagen.
Bingham, P.J., Brazell, LA. & Owen, M. (1969) The effect of
parathyroid extract on cellular activity and plasma calcium levels
in vivo. Journal ofEndocrinology, 45,387-410.
Chambers, T.J., Revell, P.A., Fuller, K. & Athanosou, N.A. (1984)
Resorption of bone by isolated osteoclasts. Journal of Cell
Science, 66,383-399.
Chambers, T.J., McSheehy, P.M.J., Thomson, B.M. & Fuller, K.
(1985) The effect of calcium-regulating hormones and prostaglandins on bone resorption by osteoclasts disaggregated from
neonatal rabbit bones. Endocrinology, 116,234-239.
Braidman,I.P., Anderson, D.C., Jones,C.J.P. & Weiss, J.B.(1983)
Separation of two bone cell populations from foetal rat calvaria
and a study of their responses to parathyroid hormone and calcitonin. Journal of Endocrinology, 99, 387-399.
Parathyroid hormone and bone
47. Wong, G.L. & Cohn, D.V. (1974) Separation of uarathvroid hormone and calcitonin-sensitive cellc from non-;espo&ve bone
cells. Nature(London),252,713-715.
48. Wong, G.L. & Cohn, D.V. (1975) Target cells in bone for parathormone and calcitonin are different: enrichment for each cell
type by sequential digestion of mouse calvaria and selective
adhesion lo polymeric surfaces. Proceedings of the National
AcademyofSciences U.S.A.,72,3167-3171.
49. Luben, R.A., Wong, G.L. & Cohn, D.V. (1976) Biochemical
characterization with parathormone and calcitonin of isolated
bone cells: provisional identification of osteoclasts and osteoblasts. Endocrinology, 99, 525-534.
50. Friedenstein, A.J., Chailakhyan, R.K., Latsinik, N.V., Panasyuk,
A.F. & Keiliss-Borok, I.V. (1974) Stromal cells responsible for
transferring the microenvironment of the hemopoietic tissues.
Transplantation, 17,331-340.
51. Ashton, B.A., Abdullah, F., Cave, J., Williamson, M., Sykes, B.C.,
Couch, M. & Poser, J.W. (1985) Characterization of cells with
high alkaline phosphatase activity derived from human bone and
marrow: Preliminary assessment of their osteogenicity. Bone, 6,
313-320.
52. Ashton, B.A., Allen, T.D., Howlett, C.R., Eaglesom, C.C.,
Hattori, A. & Owen, M. (1980) Formation of bone and cartilage
by marrow stromal cells in diffusion chambers in vivo. Clinical
Orthopaedics and Related Research, 151,294-307.
53. Bab, I., Howlett, C.R., Ashton, B.A. & Owen, M.E. (1984)Ultrastructure of bone and cartilage formed in vivo in diffusion
chambers. Clinical Orthopaedics and Related Research, 187,
243-254.
54. Friedenstein, A.J. (1980) Stromal mechanisms of bone marrow:
cloning in vitro and retransplantation in vivo. In: lmmunobiology
of Bone Marrow Transplantation, pp. 19-29. Ed. Thierenfelder,
S. Springer-Verlag,Berlin.
55. Aubin, J.E., Heersche, J.N.M., Merrilees, M.J. & Sodek, J.(1982)
Isolation of bone cell clones with differences in growth, hormone
responses and extracellular matrix proteins. Journal of Cell
Biology, 92,452-461.
56. Tyrrell, D.A.J., Mika-Johnson, M. & Chapple, P.J. (1979) Clones
of cells from a human embryo lung: their growth and susceptibility to respiratory viruses. Archives of Virology, 6 1 , 6 9 4 5 ,
57. Martin, T.J., Ingleton, P.M., Underwood, JE.C., Michelangeli,
V.P., Hunt, N.H. & Melick, R.A. (1976) Parathyroid hormoneresponsive adenylate cyclase in induced transplantable osteogenic rat sarcoma. Nature (London),260,436-438.
58. Livesey, S.A., Kemp, B.E., Re, C.A., Partridge, N.C. & Martin,
T.J. (1982) Selective hormonal activation of cyclic AMP-dependent protein kinase isohormones in normal and malignant osteoblasts. Journalof BiologicalChemistry, 257,14983-14985.
59. Majeska, R.J., Rodan, S.B. & Rodan, G.A. (1978) Maintenance
of parathyroid hormone response in clonal rat osteosarcoma
lines. Experimental Cell Research, 11 1,465-468.
60. Rodan, G.A. & Rodan, S.B. (1984) Expression of the osteoblast
phenotype. In: Bone and Mineral Research Annual 2, pp.
244-285. Ed. Peck, W.A. Elsevier, Amsterdam.
61. Hamilton, J.A., Lingelbach, S.R., Partridge, N.C. & Martin, T.J.
(1984) Stimulation of plasminogen activator in osteoblast-like
cells by bone resorbing hormones. Biochemical and Biophysical
Research Communications, 122,230-236.
62. Beresford, J.N., Gallagher, J.A., Poser, J.W. & Russell, R.G.G.
(1984) Production of osteocalcin by human bone cells in vitro.
Effects of 1,25(OH),D,, 24,25(OH),D,, parathyroid hormone
and glucocorticoids. Metabolic Bone Disease and Related
Research, 5,229-234.
63. Chambers, T.J. (1985)The pathology of the osteoclast. Journal of
Clinical Pathology, 38, 241-252.
64. Braidman, I.P., Anderson, D.C. & Robertson, W.R. (1985) Hormone responses mediated via interactions between different cell
types, effects of physiological concentrations of parathyroid hormone on cultured bone cells. Journal of Endocrinology, 104
(Suppl.), 47. Abstract 61.
65. Raisz, L.G. & Kraem, B.A. (1983) Regulation of bone formation
1. New England Journal of Medicine, 309, 29-35.
66. Kahn, A.J., Fallon, M.D. & Teitelbaum, S.L. (1984) Structure-function relationships in bone: an examination of events at
the cellular level. In: Bone and Mineral Research Annual 2, pp.
125-174. Ed. Peck, W.A. Elsevier, Amsterdam.
67. Charhon, S.A., Edouard, C.M., Arlot, M.E. & Meunier, P.J.
(1982) Effects of parathyroid hormone on remodeling of iliac
trabecular bone packets in patients with primary hyperparathyroidism. Clinical Orthopaedics and Related Research, 162,
255-263.
68. Peterson, D.R., Heideger, W.J. & Beach, K.W. (1985) Calcium
homeostasis: the effect of PTH on bone membrane electrical
potential differences. Calcified Tissue International, 37,
307-311.
69. Grubb, S.A., Edwards, G. & Talmage, R.V. (1977) Effect of
endogenous and infused parathyroid hormone on plasma con-
237
centrations of recently administered “Ca. Calcified Tissue
Research, 24,209-214.
70. Talmage, R.V., Cooper, C.W. & Toverud, S.U. (1983)The physiological significance of calcitonin. In: Bone and Mineral Research
Annual I, pp. 74-143. Ed. Peck, W.A. Excerpta Medica, Amsterdam.
71. Parfitt, A.M. (1979) Equilibrium and disequilibrium hypercalcaemia. New light on an old concept. Metabolic Bone Disease
and Related Research. 1. 279-293.
72. Parsons, J.A. & Robikbn, C.J (1971) Calcium shift into bone
causing transient hypocalcaemia after injection of parathyroid
hormone. Nature (London),230,581-582.
73. Parsons, J.A., Reit, B. & Robinson, C.J. (1973) A bioassay for
parathyroid hormone using chicks. Endocrinology, 92,454-462.
74. Mazzuoli, G.F., D’Erasmo, E., Scarda, A,, Minisola, S., Mancini,
D. & Malaguti Aliberti, L. (1979)Significance of early increase in
stable and radioactive plasma calcium after parathyroidectomy in
primary hyperparathyroidism. Calcified Tissue International, 29,
185-191.
75. Stevenson, R.W., Parsons, J.A., Podbesek, R.D. & Reeve, J.
(1983) Changes in plasma calcium and in radiocalcium kinetics
after termination of five-week infusions of synthetic parathyroid
peptide in dogs. Acta Endocrinologica, 104,462-467.
76. Atkinson, M.J., Vido, I.,Keck, E. & Hesch, R.-D. (1983)Hepalic
osteodystrophy in primary biliary cirrhosis: a possible defect of
Kupffer cell mediated cleavage of parathyroid hormone. Clinical
Endocrinology, 18.21-28.
77. Atkinson, M.J., Schettler, T., Bodenstein, H. & Hesch, R.-D.
(1984) Osteoporosis: a bone turnover defect resulting from an
elevated parathyroid hormone concentration within the bone
marrow cavity? Klinische Wochenschrift, 62,129-132.
78. Hesp, R., Tellez, M. & Davidson, L. (1986)Trabecular and cortical bone in the radii of female patients with primary hyperparathyroidism. ClinicalScience, 70 (Suppl. 13), 2OP-21P.
79. Parfitt, A.M. (1986) Accelerated cortical bone loss in primary
and secondary hyperparathyroidism. In: Bone Fragility in Ortho
paedics and Medicine. Ed. Uhthoff, H.K. & ,Jaworski, Z.F.G.
Springer Verlag, Berlin, Heidelberg, New York. (In press).
80. Malluche, H.H., Sherman, D., Meyer, W., Ritz, E., Norman, A.W.
& Massry, S.G. (1982) Effects of long-term infusion of physiologic doses of 1-34 PTH on bone. American Journal of Physiology, 242 (Renal, Fluid and Electrolyte Physiology, 1l ) ,
F197-FZ01.
81 Podbesek, R., Edouard, C., Meunier, P.J., Parsons, J.A., Reeve, J.,
Stevenson, R.W. & Zanelli, J.M. (1983) Effects of two treatment
regimes with synthetic human parathyroid hormone fragment on
bone formation and the tissue balance of trabecular bone in erevhounds. Endocrinology, 112,1000-1006.
82. Reeve, J., Meunier, P.J., Parsons, J.A., Bernat, M., Bijvoet,
O.L.M., Courpron, P., Edouard, C., Klenerman, L., Neer, R.M.,
Renier, J.C., Slovik, D., Vismans, F.J.F.E. & Potts, J.T., Jr (1980)
The anabolic effect of human parathyroid hormone fragment
(hPTH 1-34) therapy on trabecular bone in involutional osteoporosis: report of a multi-centre trial. British Medical Journal,
280,1340-1344.
83. Tam, C.S., Heersche, J.N.M., Murray, T.M. & Parsons, J.A.
(1982) Parathyroid hormone stimulates the bone apposition rate
indeaendentlv of its resorative action: differential effects of intermittdnt and. continuous’ administration. Endocrinology,
506-512.
84. Walker, D.G. (1971) The induction of osteopetrotic changes in
hypophysectomized, thyroparathyroidectomized, and intact rats
of various ages. Endocrinology, 89, 1389-1406.
85. Kalu, D.N., Doyle, F.H., Pennock, J. & Foster, G.V. (1970) Parathyroid hormone and experimental osteosclerosis. Lancet, i,
1363-1366.
86. Slovik, D.M., Rosenthal, D.I., Doppelt, S.H., Daly, M.A., Murray,
J.A. & Neer, R.M. (1985) Reversal of idiopathic osteoporosis by
treatment with hPTH (1-34) and 1,25(OH),D,. Clinical
Research, 33,444A.
87. Martin, K.J., Hruska, K., Bellorin-Font, E. & Slatopolsky, E.
(1981) The peripheral metabolism of parathyroid hormone: activation or inactivation? In: Hormonal Control of Calcium Metabolism, pp. 64-69. Ed. Cohn, D.V., Talmage, R.V. & Matthews,
J.L. Excerpta Medica, Amsterdam.
88. ZaneUi, J.M., Lane, E., Kimura, T. & Sakakibara, S . (1985) Biological activities of synthetic human parathyroid hormone 1-84
relative to natural bovine parathyroid hormone in two different in
vivo bioassay systems. Endocrinology, 117,1962-1967.
89. Herrmann-Erlee, M.P.M., Nijweide, P.J., Van der Meer, J.M. &
Ooms, M.A.C. (1983) Action of bPTH and bPTH fragments on
embryonic bone in vitro: dissociation of the cyclic AMP and
bone resorbing response. Calcified Tissue International, 35,
70-77.
90. Hefti, E., Trechsel, U., Bonjour, J.-P., Fleisch, H. & Schenk, R.
(1982) Increase of whole body calcium and skeletal mass in
I
.
238
91.
92.
93.
Y4.
95.
96.
97.
98.
99.
J. Reeve and J. M.Zanelli
normal and osteoporotic adult rats treated with parathyroid hormone. Clinical Science, 62, 389-396.
Kent, G.N., Loveridge, N., Reeve, J. & Zanelli, J.M. (1985)
Pharmacokinetics of synthetic human parathyroid hormone (134) in man measured with cytochemical bioassay and radioimmunoassay. Clinical Science, 68, 171-177.
Reeve, J., Tregear, G.W. & Parsons, J A . (1976) Preliminary trial
of low doses of human parathyroid hormone 1-34 peptide in
treatment of osteoporosis. Calcified Tissue Research, 21
(Suppl.), 469-477.
Kent, G.N. & Zanelli, J.M. (1983) Parathyroid hormone. In: C y l o
chemical Bioassays: Techniques and Clinical Applications, pp.
255-307. Ed. Chayen, J. & Bitensky, L. Marcel Dekker Inc., New
York, Basel/Butterworths, London.
Slovik, D.M., Neer, R.M. & Potts, J.T., Jr (1981) Short-term
effects of synthetic human parathyroid hormone-( 1-34) administration on bone mineral metabolism in osteoporotic patients.
Journalof Clinical Investigation, 68, 1261-1271.
Meunier, P.J., S.-Bianchi, G.G., Edouard, C.M., Bernard, J.C.,
Courpron, P. & Vignon, G.E. (1972) Bony manifestations of
thyrotoxicosis. In: Orthopedic Clinics of North America, vol. 3,
pp. 745-774. Ed. Hohl, J.C. W.B. Saunders, Philadelphia,
London, Toronto.
Frost, H.M. (1979) Treatment of osteoporoses by manipulation
of coherent bone cell populations. Clinical Orthopaedics and
Related Research, 143,227-244.
Reeve, J., Podbesek, R.D., Price, T.R., Arlot, M., Bartlett, C.,
Deacon, A.A., Edouard, C., Green, J.R., Hesp, R., Hulme, P.,
Katz, D., Tellez, M.. Zanelli, G.D., Zanelli, J.M. & Meunier, P.J.
(1984) Studies of a ‘short-cycle’ADFR regime using parathyroid
peptide hPTH 1-34 in idiopathic osteoporosis and in a dog
model. In: Osteoporosis (Proceedings of the Copenhagen International Symposium, 3-8 June 1984), vol. 2, pp. 567-573. Ed.
Christiansen, C., Amaud, C.D., Nordin, B.E.C., Parfitt, A.M.,
Peck, W.A. & Riggs, B.L. Department of Clinical Chemistry,
Glostrup Hospital, Copenhagen.
Gallagher, J.C. (1981) Biochemical effects of estrogen and progesterone on calcium metabolism. In: Osteoporosis: Recent
Advances in Pathogenesis and Treatment, pp. 231-238. Ed. De
Luca, H.F., Frost, H.M., Jee, W.S.S.,Johnston, C.C. & Parfitt,
A.M. University Park Press, Baltimore.
Mosekilde, L. & Melsen, F. (1978) A tetracycline-based histomorphometric evaluation of bone resorption and bone turnover
in hyperthyroidism and hyperparathyroidism. Acta Medica Scandinavica, 204,97-102.
100. Bressot, C., Meunier, P.J., Chapuy, M.C., Lejeune, E., Edouard,
C. & Darby, A.J. (1979) Histomorphometric profile, patho-
physiology and reversibility of carticosteroid-induced osteoporosis. Metabolic Bone Disease and Related Research, 1, 303-31 1.
101. Mundy, G.R. & Martin, T.J. (1982) The hypercalcemia of malignancy: Pathogenesis and management. Metabolism, 3 1,
1247-1277.
102. Broadus, A.E. & Stewart, A.F. (1983) Humoral hypercalcaemia
103.
104.
105.
106.
of malignancy. In: Clinical Disorders of Bone and Mineral
Metabolism, pp. 284-287. Ed. Frame, B. & Potts, J.T., Jr.
Excerpta Medica. Amsterdam.
Dunham, J. & Chayen, J. (1983) An effect of parathyroid hormone on the epiphyseal plate and osteoblasts: studies towards a
cytochemical bioassay. Journal of Imrnunoassay, 4,329-338.
Mundy, G.R., Ibbotson, K.J., DSouza, S.M., Jacobs, J.W. &
Martin, T.J. (1984) The hypercalcaemia of cancer: clinical implications and oathoeenic mechanisms. New Ennland Journal of
Medicine, 316, 17r8-1727.
Rodan, G.A. & Martin, T.J. (1981) Role of osteoblasts in hormonal control of bone resorption - an hypothesis. Calcified
Tissue International, 33, 349-351.
Jones, S.J. & Boyde, A. (1976) Experimental study of changes in
osteoblastic shape induced by calcitonin and parathyroid extract
in an ore.an culture system. Cell and Tissue Research, 169,
449-4651
107. Chambers, T.J. & Fuller, K. (1986) Osteoblasts initiate bone
resorption by exposing bone mineral lo osteoclastic contact
(Abstract). Bone (In press).
108. Frost, H.M. (1985) The skeletal intermediary organisation: a
synthesis. In: Bone and Mineral Research Annual3, pp. 49-108.
Ed. Peck, W.A. Elsevier, Amsterdam.
109. Reeve, J. (1985) A stochastic analysis of iliac trabecular bone
dynamics. Clinical Orthopaedics and Related Research (In press).
110. Eriksen, E.F., Mosekilde, E.F. & Melsen, F. (1984) Bone balance
at the BMU level in 16 osteoporotic patients before and after 5
years treatment with calcium, vitamin D, and sodium fluoride. In:
Osteoporosis (Proceedings of the Copenhagen International Symposium, 3-8 June 1984). vol. 1, pp. 493-498. Ed. Christiansen,
C., Arnaud, C.D., Nordin, B.E.C., Parfitt, A.M., Peck, W.A. &
Riggs, B.L. Department of Clinical Chemistry, Glostrup Hospital,
Copenhagen.
111. Arlot, M., Edouard, C., Meunier, P.J., Neer, R.M. & Reeve, J.
(1984) Imoaired osteoblast function in osteovorosis: comvarison
between chcium balance and dynamic histomorphometry.. British
Medicallournal, 289,517-520.