Morphometry and ultrasound measurements in patients with vertebral deformittes

Bone Vol. 19, No. 3, Supplement September 1996: 129S-169s

Abstracts The 7th International

Congress

47

49

ENVELOPE AND SITE SPECIFIC BONE LOSS IN ESTROGEN DEFICIENT RATS AND THEIR RESPONSE TO ANABOLIC THERAPY WITH INTERMI’I-IENT PTH-TREATMENT.

MORPHOMETRY AND ULTRASOUND MEASUREMENTS PATIENTS WITH VERTEBRAL DEFORMITIES C. Gennari S. Gonnelli, C. Cepollaro, R. Palmieri, C. Pondrelli, -, S. Martini. Institute of Internal Medicine, University of Siena (Italy)

J.A. Gasser, Sandoz Pharma Ltd., Bale.

Switzerland

The study aimed to compare site specific changes in bone mass and architecture noninvasively

over time using pQCT

oestrogen deficient rats. Additionally

(peripheral

quantitative

computed tomography)

their response to treatment with hPTH(l-34)

green, alizarine red, calcein blue, xylenol orange and oxytetracycline.

Bone loss in I5 month old retired breeder rats was measured every two weeks ovariectomy by pQCT using 3 XCT 960 (Stratec, Germany) over a period of

I6 weeks m the distal femur metaphysis (DFM), mid diaphysis of the tilxa (MDT), (TV5).

proximal

tibia1 metaphysis (PTM),

distal tibia1 metaphysis (DTM)

Thereafter treatment with 25pg/kg hPTH(l-34)

and changes in bone mass/architecmre additional I6 weeks.

and tail vertebra 5

(3 inj/weeks s.c.) was initiated

assessed every 2 weeks by pQCT

Cancellous and endocortical bone loss occurred rapidly in the DFM

(-35%)

for an

and PTM

(-12%) wth losses reaching a new steady state at 12 to 16 weeks following OVX. Marrow cavity expansion (+8%) indicated slow bone loss in the MDT. PTH-treatment restored cortical and cancellow

bone mass at all three sites, reaching a plateau towards

the end of the study. No significant bone loss in OVX animals was detected in the DTM and TV5 but both sites responded favourably to F’I’H treatmenf (DTM +6%, TV5

+4%).

Weekly

application

of fluorochrome

labels allowed

to compare

the

dynamics of the bone formation process at the periosteal, endoconical and cancellous surface. Measurements indicated that the bone formation rate was highly envelope specific proceeding 2 to 3 times faster at endocortical and cancellow sulfates compared to the sub-periosteal surface. The onset of bone formation was very rapid reaching next to maximal speed within the first week and proceeding in a linear fashion until the plateau was reached. The magnitude of the bone loss and gain appeared to be largely determined by the surface area of the available template. Bone gam under PTH reached a plateau indicative for the existence of a negative feed-back mechanism (mechanical sensor) which served to limit the anabolic response. The DTM which responds with rapid bone loss during immobilisation was not sensittve to oestrogen deficiency. Tail vertebral bodxes could not substitute for the lumbar vertebral bodies which can not be measured by pQCT.

In addition to the quality of the bone template, the cellular composition

(adipose tissue vs. bone marrow) appears to have a profound influence magnitude of the response to mtervention in situations of bone loss and gain.

on the

Ultrasound tecnique (US) has been proposed to evaluate skeletal status. Some studies have shown that US measurement of heel is predictive of hip and vertebral fractures. In 304 postmenopausal women (age 58.8f5.5) we evaluated : bone mineral density (BMD) of lumbar spine (HOLOGIC, QDR lOOO), SOS, BUA and Stiffness ( S, which is an index derived from the combination of SOS and BUA values) in the OS calcis (Achilles, Lunar Corp). In all subjects we performed lateral lumbar and thoracic X-rays. Morphometry was used to measure the anterior, middle and posterior height of each vertebral body, obtaining a semiquantitative grading of vertebral fractures, with a score graded as follows : 0 (no vertebral deformity); 1 (any vertebral height (vh) reduced between 20 and 25%); 2 (any vh reduced between 25 and 40%); 3 (any vh reduced more than 40%). On the basis of the number and severity of vertebral deformities the women were divided in : Group 1 (n=79, normal), Group 2 (n=80, mild), Group 3 (n&5, moderate) and Group 4 (n&O, severe). Mean values of SOS, BUA, S and BMD resulted significantly (p
50

48 SUPPRESSION CONCOMITANT

IN

in was

assessed by pQCT and the site- and envelope specificity of the bone formation measured histomorphometrically using multiple fluorochrome labelling with calcein

following

141s

of Bone Morphometry

SECRETION OF PTH DECREASE IN BONE TURNOVER

WITHOUT IN RENAL

FAILURE. Geng, M.-C. Faugere, Q. Qi, E. Slatopolsky, R.M. Fricdler, N. Kubodera, H.H. Malluche. Div of Neph. Bone & Min. Me-tab., U. of KY, Lexington, KY, Washington Univ., St Louis, MO (USA), and Chugai, Tokyo (Japan). Z.

Treatment of secondary hyperparathyroidism with calcitriol is limited by lack of response of the pan&void glands in some patients or over-suppression of bone turnover in others. The present study was designed to answer whether 22-Oxalcalcitriol (OCT) could suppress parathyroid hormone (PTH) levels without affecting bone turnover. Sixty dogs were. either nephrectomized (N, n=30) or sham-operated (S, n= 30). Five to six mos. after surgeries, half of the Nx and Sham dogs received OCT (3x/wk), the other half was given vehicle (V) for 1 year. Serum PTH levels were measured and bone biopsies were performed at baseline. and 1 year after

treatment. The mean weekly doses of OCT in N and S dogs were not different: 0.10 vs. 0.14 &kg/wk. Serum PTH was significantly lower in N+OCT than N+V dogs and not different from S dogs (Fig. 1). Activation frequency was significantly higher in N than S dogs, and no difference was seen behveen N+OCT and N+V dogs (Fig. 2).

. -I-

1I

Different from S groups, p
??

These data indicate that OCT can suppress PTH in dogs with moderate renal failure without inducing adynamic bone disease. The mechanisms of the positive effect of OCT on bone cell number in uremia awaits further studies.

THE ROLE OF ESSENTIAL AMINOACIDS IN EXPERIMENTAL BONE FRACTURE REPAIR. HISTOMORPHOMETRIC STUDY. Giardino R., Fini M., Nicoli Aldini N., Giavaresi G., Guzzardella G., Orienti L. Rocca M. Experimental Surgery Dept., Istituto di Ricerca Codivilla Putti I.0.R Bologna (Italy). The role of essential aminoacids as L-Arginine (L-Arg) and L-Lysine (L-Lys) on bone fracture repair was evaluated in an in viva experimental study.‘Under general anesthesia fifty New Zealand adult male rabbits weie submitted to transversal osteotomy of the fibula. Animals were divided in two groups. Group A (25 animals) was daily treated with a mixture of 50 mg L-Arg, 45 mg L-Lys and 100 mg lactose pro Kg. body weight per OS; group B (25 animals, control) received lactose only. The rabbits were sacrificed at 15, 30, 40, 50, 60 days. The fibula was removed and methyl metacrilate embedded samples were obtained. Histomorphometric study and decalcidfied was performed to evaluate the healing process of the bone on sections stained with Azan Mallory and modified Von Kossa. A Kontron Electronic Imagin System KS300 was used for the morphometric analisys. The trabecularflacunar rate and the amount of cartilage were measured in the bone callus as well as the cortical thickness of healed bone. While at IS days no significant differences were found between groups A and B, at 30 days control group presented a greater amount of cartilage (A: 5.6 f 7.3%, B: 16.6 f 7.4 %, p < 0.05) in the bone caJlus. At 50 days trabecular bone was 94.8 f 2.8 % in group A and 73.%5.8% in group B (p