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Biomedical subjects

S Gnudi

Publications and source records attributed to S Gnudi.

At least 19 recordsLinked to original sources
PubMed2004

Differences in proximal femur geometry distinguish vertebral from femoral neck fractures in osteoporotic women.

Bone mineral density (BMD) is generally used to predict the risk of fracture in osteoporotic subjects. However, femoral neck BMD and spine BMD have been reported not to be significantly different among patients with hip or vertebral fractures, suggesting that other risk factors are needed to determine the different fracture types. Proximal femur geometry (PFG) parameters, such as hip axis length (HAL), femoral neck-shaft angle (NSA) and femoral neck diameter (FND) have also been shown to predict the risk of hip fracture. These parameters are statistically different in spine fractures compared with both types of hip fractures (trochanteric and femoral neck) when considered together. We wanted to assess the difference in these parameters by comparing spine fractures with a homogeneous group of hip fractures, i.e. femoral neck fractures. 807 post-menopausal women were divided into three groups; those with vertebral fractures (182), those with femoral neck fractures (134) and a control group without fractures (491). Dual X-ray absorptiometry (DXA) scans of the spine and hip were carried out to measure BMD and define the PFG parameters of the hip. Data were statistically analysed. In agreement with other authors, we found that women with femoral neck fractures had longer HAL, wider FND and larger NSA than controls, whereas there were no statistically significant differences in PFG between women with spine fractures and controls. Logistic regression showed HAL and NSA could predict the risk of femoral neck but not vertebral fracture. These data indicate specificity of some PFG parameters for hip fracture risk.

Aged↗
PubMed2002

Proximal femur geometry to detect and distinguish femoral neck fractures from trochanteric fractures in postmenopausal women.

Some proximal femur geometry (PFG) parameters, measured by dual-energy X-ray absorptiometry (DXA), have been reported to discriminate subjects with hip fracture. Relatively few studies have tested their ability to discriminate femoral neck fractures from those of the trochanter. To this end we performed a cross-sectional study in a population of 547 menopausal women over 69 years of age with femoral neck fractures (n = 88), trochanteric fractures (n = 93) or controls (n = 366). Hip axis length (HAL), neck-shaft angle (NSA), femoral neck diameter (FND) and femoral shaft diameter (FSD) were measured by DXA, as well as the bone mineral density (BMD) of the nonfractured hip at the femoral neck, trochanter and Ward's triangle. In fractured subjects, BMD was lower at each measurement site. HAL was longer and NSA wider in those with femoral neck fractures. With logistic regression the age-adjusted odds ratio (OR) for a 1 standard deviation (SD) decrease in BMD was significantly associated at each measurement site with femoral neck fracture (femoral neck BMD: OR 1.9, 95% confidence interval (95% CI): 1.4-2.5; trochanter BMD: OR 1.6, 95% CI 1.2-2.0; Ward's triangle BMD: OR 1.7, 95% CI 1.3-2.2) and trochanteric fracture (femoral neck BMD: OR 2.6, 95% CI 1.9-3.6; trochanter BMD: OR 3.0, 95% CI 2.2-4.1; Ward's triangle BMD: OR 1.8, 95% CI 1.4-2.3). Age-adjusted OR for 1 SD increases in NSA (OR 2.2, 95% CI 1.7-2.8) and HAL (OR 1.3, 95% CI 1.1-1.6) was significantly associated with the fracture risk only for femoral neck fracture. In the best predictive model the strongest predictors were site-matched BMD for both fracture types and NSA for neck fracture. Trochanteric BMD had the greatest area (0.78, standard error (SE) 0.02) under the receiver operating characteristic curve in trochanteric fractures, whereas for NSA (0.72, SE 0.03) this area was greatest in femoral neck fractures. These results confirm the association of BMD with proximal femur fracture and support the evidence that PFG plays a significant role only in neck fracture prediction, since NSA is the best predictive parameter among those tested.

Absorptiometry, Photon↗
PubMed2002

L-arginine and L-lysine stimulation on cultured human osteoblasts.

Essential amino acids, such as L-Arginine (Arg) and L-Lysine (Lys), are involved in bone metabolism and growth. Our previous studies analyzed the effect of these amino acids on rat osteoblast cultures and in experimental animals. In this study, we evaluated the effect of L-Arg and L-Lys on cultured human osteoblasts. Primary human osteoblast cultures were divided into four groups: the Arg Group received 0.625 mg/ml per day of Arg, the Lys Group 0.587 mg/ml per day of Lys, the Arg-Lys Group received both amino acids, whereas the Control Group was sham-treated. After 7 days, the following parameters were tested in all groups: alkaline phosphatase (ALP), nitric oxide (NO), calcium (Ca), phosphorus (P), osteocalcin (OC), type I collagen (PICP), interleukin-6 (IL-6), transforming growth factor-beta 1 (TGF-beta 1) on culture supernatant, platelet derived growth factor (PDGF), insulin-like growth factor-I (IGF-I), and MTT proliferation test on cells. Arg administration significantly increased ALP, NO, PICP and IGF-I production and reduced the level of IL-6. Lys administration over the same time interval mainly affected cell proliferation, as evidenced by the MTT test and immunostaining for PDGF. The same positive effects evidenced by the single administrations of the two amino acids resulted from their simultaneous administration. However, synergism could be demonstrated only for the decrease in the level of IL-6. Arg and Lys show a positive effect on human osteoblasts, which is related partly to the production of those factors required for matrix synthesis, and partly to the direct or mediated activation of cell proliferation.

Arginine↗
PubMed2002

Brucella spondylitis with paravertebral abscess due to Brucella melitensis infection: a case report.

This report describes the case of a 45-year-old woman with a 5-month history of fever, generalized malaise, myalgia, lower back pain and difficulty in walking. Serodiagnosis for brucella, carried out at the onset of symptoms 5 months previously, was negative. When the patient was admitted to our hospital there was contracture of the paraspinal muscles but no peripheral nerve damage. Laboratory tests showed positive agglutination for Brucella and an increase in the rate of dilution from 1/160 to 1/640 over 2 weeks. Radiographs and a computed tomography scan of the spine revealed bone erosion in the posterior borders of the L4-L5 vertebral end plates and a soft tissue mass surrounding the interposed disc and protruding into the spinal canal. Magnetic resonance imaging confirmed the presence of a paraspinal abscess around the affected disc and tissue edema. Culture tests of the blood and abscess tissue, taken by biopsy, were negative. Rifampicin treatment (600 mg daily), combined with a bust cast to immobilize the spine, led to clinical healing without the need for surgery. Because onset symptoms are nonspecific and insidious, in nonrisk subjects a diagnosis of brucellosis may sometimes be suspected only if there are local symptoms. The phenomenon of the absence of positivity in patients with a high antibody titer should also be considered Cases such as that described herein demonstrate the need for culture tests and serodiagnosis, even in nonrisk patients with persistent fever and arthralgia, to prevent the later complications of brucellosis.

Abscess↗
PubMed2001

Comparison of logistic and Bayesian classifiers for evaluating the risk of femoral neck fracture in osteoporotic patients.

Femoral neck fracture prediction is an important social and economic issue. The research compares two statistical methods for the classification of patients at risk for femoral neck fracture: multiple logistic regression and Bayes linear classifier. The two approaches are evaluated for their ability to separate femoral neck fractured patients from osteoporotic controls. In total, 272 Italian women are studied. Densitometric and geometric measurements are obtained from the proximal femur by dual energy X-ray absorptiometry. The performances of the two methods are evaluated by accuracy in the classification and receiver operating characteristic curves. The Bayes classifier achieves an accuracy approximately 1% higher than that of the multiple logistic regression. However, the performances of the two methods, evaluated by the area under the curves, are not statistically different. The study demonstrates that the Bayes linear classifier can be a valid alternative to multiple logistic regression in the classification of osteoporotic patients.

Aged↗
PubMed2001

Comparison of calcitonin, alendronate and fluorophosphate effects on ovariectomized rat bone.

The effects of calcitonin, alendronate and fluorophosphate preventive treatment on ovariectomized rat femur were studied by comparing densitometric, mechanical, mineralogical and histomorphometric data. Sixty retired breeder female Sprague-Dawley rats, aged 10 months, were randomly divided into six groups. A group (baseline) was euthanized at the beginning of the study as a baseline group; four groups were ovariectomized and one was sham-operated (sham) and considered as a sham-aged group. A group of ovariectomized rats was used as a sham-therapy control (OVX) and received only deionized drinking water, while the other three received: a) salmon calcitonin (SCN) at a dose of 2 IU/kg/d s.c. (OVX + SCN); b) alendronate sodium salt (ALN) at a dose of 6 microg/kg/d administered by gavage (OVX + ALN); and c) L-glutamine monofluorophosphate (G-MFP) and calcium at a rate of 1:30 F/Ca at a dose of 0.21 mg F/6.30 mg Ca per kg/d by gavage (OVX + MFP). Significant increases (P < 0.05) of about 15 and 27% in femoral proximal epiphysis bone mineral density (BMD) of the OVX + ALN group were observed versus healthy groups and the OVX group, respectively. The OVX + ALN group also showed significant increases in femoral mid-diaphysis BMD when compared to OVX (18%, P < 0.001), OVX + SCN (14%, P < 0.05) and OVX + MFP (18%, P < 0.001) groups. In the OVX + MFP group, the three-point bending test demonstrated significant increases (P < 0.05) in maximal load of 21 and 22% when compared to the OVX and OVX + SCN groups, respectively. Also, stiffness data showed significant increases of the OVX + MFP (17%) and sham (14%) groups in comparison with the OVX group. A decrease in Mg (42%, P < 0.05), and increases in Ca (15%, P < 0.0001) and PO4 (8%, P < 0.005) content were found by comparing OVX + MFP and OVX groups. Trabecular bone volume results showed significant increases by comparing OVX + ALN and OVX groups (12.20%, P < 0.0005), as well as control groups. Tested agents were able to reduce the bone loss due to estrogen deficiency, but this did not always produce an increase in strength of the treated bone. Alendronate treatment prevented a decrease in bone mineral density and maintained bone mechanical properties after ovariectomy without impairment of bone mineralization in aged rats.

Absorptiometry, Photon↗
PubMed2001

Bone mineral density and bone loss measured at the radius to predict the risk of nonspinal osteoporotic fracture.

Low bone mineral density (BMD) and, probably, the rate of bone loss (RBL) are associated with the risk of osteoporotic fractures. To estimate the risk of nonspinal fracture in osteoporotic women, we measured BMD and RBL in a prospective study (average follow-up, 5.38 years) in 656 postmenopausal women. The women were considered in three groups: group A (whole population), group B (women under the age of 65 years) and group C (women over the age of 65 years). At the beginning of the study, BMD was measured at the distal radius (DR) and at the proximal radius (PR) using a single-energy densitometer. BMD measurements made 2 years previously in the same patients were used to calculate RBL. Then patients were checked annually for nonspine fracture due to minor trauma. During follow-up, 121 nonspinal fractures were detected. Women with fractures were older and had lower BMD. With the Cox regression, age-corrected BMD at both DR and PR predicts fracture risk in groups A and B but not in group C. After correction for potential confounders, DR still predicts fractures in groups A and B whereas PR predicts fractures only in group B. In group C, only the RBL at the PR was predictive of the fracture risk as well as in the other two groups. Specific types of fractures are predictable in the whole population at the wrist. In conclusion, radial BMD predicts the risk of nonspine fractures except in women over the age of 65 years. The RBL at the PR is an effective predictor of fracture risk also in women over the age of 65 years.

Aged↗
PubMed2001

Effect of intramuscular clodronate on bone mass and metabolism in osteoporotic women.

Bisphosphonates have significantly improved the treatment of postmenopausal osteoporosis. However, when administered orally, gastric intolerance is their main adverse effect. This makes patients reluctant to undergo treatment. As an alternative, intramuscular (i.m.) administration may be more acceptable to patients undergoing long-term treatment. Since clodronate has been easily available in Italy for many years, we carried out this study to evaluate its effect on bone mineral density (BMD) in 36 osteoporotic postmenopausal women who were intolerant to oral administration of bisphosphonates. Patients received 100 mg of clodronate i.m. every 10 days together with 500 mg/day of calcium orally for 2 years. A control group of 32 women received only oral calcium at the same dose and for the same length of time. In the control group a progressive but not statistically significant decrease in BMD was observed in the spine and femoral neck over the 2-year follow-up. In contrast, patients treated with clodronate had a statistically significant increase in BMD in the spine at the first yearly check-up (+2.63%) and a further but not statistically significant increase during the second year of treatment (+0.59%). The increase in BMD at the femoral neck was not statistically significant during the first and second years of treatment, being 1.21% and 0.37% respectively. In the women treated with clodronate, hydroxyproline was significantly suppressed. All the patients reported local pain at the injection site. This led 11.11% of the subjects to withdraw from treatment.

Aged↗
PubMed2000

Quantitative ultrasound and bone densitometry to evaluate the risk of nonspine fractures: a prospective study.

The ability of quantitative ultrasound (QUS) to estimate the risk of osteoporotic fractures was evaluated in a prospective study over a mean time of 5.47 years in 254 postmenopausal women (mean age 58.06+/-7.67 years). Baseline measurements of ultrasound transmission velocity (UTV) and bone mineral density (BMD) were taken at the distal radius (DR). UTV was also measured at the patella (P). Fifty nonspine fractures due to minor trauma were detected during annual check-ups with an incidence of 3.59/year. Fractures occurred in older women with a lower BMD and QUS. Using Cox regression analysis the relative risk (RR) per 1 standard deviation (SD) decrease in the unadjusted QUS and BMD measurements was: BMD-DR = 3.56, 95% confidence interval (CI) 1.57-8.09; 95% CI 2.08-9.68. The relationship between BMD and QUS variables and fracture risk persisted after adjusting for potential confounders apart from previous fractures, giving the following RR: BMD-DR = 2.99, 95% CI 1.06-8.41; UTV-DR = 3.69, 95% CI 1.18-11.49; UTV-P = 3.89, 95% CI 1.53-9.90. Correcting also for previous fractures, only UTV-P remained an effective predictor of fracture risk even after QUS measurement correction for BMD. Wrist fractures were best related to BMD-DR (RR 7.33, 95% CI 1.43-37.50) and UTV-DR (RR 10.94, 95% CI 1.10-108.45), while hip and ankle fractures were significantly associated only with UTV-P (hip: RR 32.14, 95% CI 1.83-562.80; ankle: RR 17.60, 95% CI 1.78-173.79). The combined use of BMD and QUS is a better predictor of fracture risk than either technique used separately. Comparison of the areas under the receiver operating characteristic (ROC) curves did not show differences in the ability of BMD and QUS to correctly distinguish fractures. In conclusion, QUS predicts fracture risk in osteoporotic women at least as well as BMD. UTV-DR and BMD-DR are good predictors of wrist fractures, while UTV-P is strongly related to hip and ankle fractures. QUS and BMD combined improve the diagnostic ability of each technique individually.

Absorptiometry, Photon↗
PubMed2000

Discriminant capacity of quantitative ultrasound versus dual X-ray absorptiometry to determine cancellous bone loss in ovariectomized rats.

The capacity of dual x-ray absorptiometry and quantitative ultrasound to discriminate bone loss and to predict the mechanical and microarchitectural properties of cancellous bone in an animal model of osteopenia was evaluated. Thirty-five female Sprague-Dawley rats (10 months old) were randomized into three groups: baseline group, 10 rats killed at the beginning of the study; ovx group, 15 rats ovariectomized; and sham group, 10 rats sham operated. At the beginning and end of the study, all the animals underwent osteosonography to record the proximal tail (C3 vertebra) bone speed of sound. Sixteen weeks after surgery, the animals were euthanized and the L5-6 lumbar vertebrae of each rat were excised for densitometric, biomechanical (compression test), and histomorphometric studies. Significant differences were found among the groups for final speed of sound (p = 0.01). The L5 bone mineral density of the ovx group decreased by 12.1% (p = 0.049) and 12.6% (p = 0.035) compared, respectively, with baseline and sham groups. The biomechanical parameters of the ovx group decreased by 15-47% compared with the other groups, showing significant differences between the ovx and sham groups both for maximal stress (p = 0.026) and elastic modulus (p = 0.013). Histomorphometric parameters of the ovx group showed significant decreases in comparison with other groups. Logistic regression analysis showed that dual X-ray absorptiometry and quantitative ultrasound discriminate ovariectomized and healthy rats with a similar capacity, classifying correctly all rats used in the model in a range of 61-70%. This similar capacity seems to derive from two different capacities to detect bone changes. Dual X-ray absorptiometry, depending on bone mineralization and density, is able to detect modifications in bone stiffness and strength, confirmed also by the correlation with biomechanical data. On the contrary, quantitative ultrasound seems to depend more on cancellous bone microarchitecural changes because it is correlated to histomorphometric parameters.

Absorptiometry, Photon↗
PubMed1999

The mechanical properties of fluoride-treated bone in the ovariectomized rat.

The effect of fluoride therapy on the osteopenic bone of the ovariectomized rat was studied by comparing the densitometric and biomechanical data. Forty retired breeder female Sprague-Dawley rats aged 10 months were randomly divided into five groups. One group (Group A) was killed at the beginning of the study and was used as a baseline. Three groups were ovariectomized and one was sham-operated (Group B) and observed for the same period as a sham-aged group. A group of ovariectomized rats was used as a sham therapy control (Group C) and received only deionized drinking water; the other two groups (F1 and F2) received L-glutamine monofluorophosphate and calcium at a rate of 1:30 F/Ca at different doses by gavage (0.57 mg F/17 mg Ca per kg/day-Group F1; 0.21 mg F/6.30 mg Ca per kg/day-Group F2). Densitometric and biomechanical (compression and three-point bending test) assays, X-ray diffraction, and Fourier transformed infrared spectroscopy were performed on femoral specimens. Biomechanical data showed that the femoral heads of Group F2 required a significantly greater energy-to-failure than Group C (P < 0.05) as well as treated femoral diaphysis when compared with the others (P < 0.01). Significant increases in the elastic modules were observed in fluoride-treated groups (P < 0.001) when compared with other groups. Diffractometric and spectroscopic data showed the presence of fluorine-apatite in both treated groups with a high component of carbonates. Also, fluoride therapy causes an increase of bone stiffness due to the presence of fluoroapatite. It seems to produce two opposed properties in the osteopenic rat bone: a higher resistance to compression loading and a greater frailty to flexion loading.

Animals↗
PubMed1999

Geometry of proximal femur in the prediction of hip fracture in osteoporotic women.

111 White post-menopausal women with hip fracture and 329 healthy controls were studied in order to determine whether proximal femur geometry predicts hip fracture and improves the discriminant ability of femoral neck bone mineral density (BMD) in elderly women. All subjects underwent dual X-ray photon absorptiometry (DXA) of the hip from which the femoral neck BMD, hip axis length, femoral neck width and femoral neck-shaft angle were measured. Fractured subjects had a lower femoral neck BMD, a longer hip axis length and a more valgus neck-shaft angle. The hip axis length correlated significantly with neck-shaft angle, femoral neck width and age. No significant correlation was found between neck-shaft angle and age. On standardized logistic regression, the hip axis length and the neck-shaft angle predicted fracture independently of BMD after correction for age, weight and femoral neck BMD. The femoral neck BMD significantly discriminated fractured subjects after correction for all potential confounders. The logistic models containing simultaneously one femoral geometric parameter and the neck BMD discriminated significantly better than those containing the same variables as single predictor. Our data suggest that hip axis length may play a role in fracture risk and supports a similar role for neck-shaft angle. Combining proximal femur geometric measurements and femoral neck BMD improved the discriminant ability of each measurement.

Absorptiometry, Photon↗
PubMed1999

Calcitriol and alendronate combination treatment in menopausal women with low bone mass.

Serum calcitriol levels decrease with advancing age in relation to reduced dietary intake or poor intestinal absorption of vitamin D. These decreased levels affect the development of senile osteopenia, which can be effectively prevented by the administration of alendronate and calcium. To evaluate the effect of a combined treatment with alendronate and calcitriol on bone mineral density (BMD), we followed 152 osteopenic postmenopausal women, aged 55-75 years, for 9 months. They were divided into three groups. The first group was treated every other day with 0.25 microgram of synthetic 1,25-dihydroxyvitamin D3 plus 10 mg alendronate. The second group received the same dose of alendronate plus calcium (500 mg/day). The third group received only calcium (500 mg/day). BMD measurements were made at the level of the lumbar spine and the femoral neck. At the beginning and at the end of the period of treatment the same biochemical analyses of bone metabolism were made. There were no significant differences in the baseline values of the three groups in the biological parameters. Alendronate plus calcium treatment led to a significant reduction in total alkaline phosphatase and hydroxy prolinuria as well as to a significant increase in lumbar and femoral bone density. The same changes were observed in the group treated with alendronate plus calcitriol except that femoral BMD did not significantly improve. These results show that continuous treatment for 9 months with calcitriol or calcium in combination with alendronate significantly increases both vertebral and femoral neck density (from 3.8% to 4.5% and from 0.61% to 2.36% respectively) in osteopenic postmenopausal women. The effects of both combinations on bone mass are clearly greater than those achieved by calcium monotherapy.

Aged↗
PubMed1998

Simultaneous densitometry and quantitative bone sonography in the estimation of osteoporotic fracture risk.

759 post-menopausal women (41-80 years old), 175 with and 584 without vertebral fracture, were studied by quantitative bone sonography and densitometry of the distal radius in order to evaluate the ability of ultrasound transmission velocity (UTV) to separate fractured from healthy women independently of bone mineral density (BMD) and to test the possibility of improving the discriminant ability of BMD by the simultaneous use of UTV. A second BMD measurement was made at the mid radial shaft. Both BMD and UTV were higher in healthy subjects than in fractured women; the latter being older, shorter and having a longer postmenopausal status. On logistic regression, standardized for 1 SD from the mean value of healthy women, UTV differentiated between healthy and fractured subjects after correction for BMD. UTV was also a significant predictor of fracture in a selected subgroup of healthy and fractured women paired for BMD (144 pairs). In this same subgroup, the difference in UTV between fractured and healthy women regression lines was related to elasticity (E) variation between pairs. Simultaneously evaluating BMD and UTV as fracture predictors, logistic regression showed an odds ratio that was twice that of each predictor alone and 1.2 times higher than that derived from the simultaneous evaluation of two different BMD predictors. These data confirmed that UTV differentiates between healthy and fractured women both as well as and independent of BMD. In addition, UTV separated fractured from healthy BMD matched women by measuring non mass related differences. The simultaneous use of BMD and UTV improved the discriminant ability of each of them alone and of two simultaneous measurements of BMD detected at different skeletal sites.

Adult↗
PubMed1997

[Effects of synthetic salmon calcitonin and alendronate on bone quality in ovariectomized rats].

BACKGROUND: The aim of this study was to assess the effect of calcitonin (CCT) and alendronate (ALN) on bone quality through histomorphometric, histological, densitometric and crystallographic evaluations in an experimental model of osteoporosis obtained in ovariectomized rats. METHODS: The animals were randomly assigned to the treatment with CCT (2 IU/kg/day, N-12) or with ALN (6 micrograms/kg/day, N-12) given subcutaneously, starting three months after ovariectomy: treatment lasted 60 days. Six rats untreated after ovariectomy and other 6 non ovariectomized (intact) were taken as controls. At the end of treatment the animals were sacrificed and femurs explanted for laboratory examinations. Results were evaluated by an ANOVA followed by the Tukey's test when appropriate. RESULTS: The histomorphometric analysis showed a significant increase of the trabecular bone volume and of the cortical bone thickness either with CCT and ALN in comparison with the ovariectomized untreated controls. Optic and electronic microscopy examinations suggest a higher bone remodeling after ALN than after CCT, but accompanied by areas of imperfect mineralization, and more irregular osteon and collagen fibres disposition. The densitometry carried out at the femoral head and diaphysis showed a similar bone mass increase following either CCT and ALN, but significantly higher in comparison to the untreated controls. At the diaphysis level ALN was superior in increasing the bone mass also when compared to the intact rats. The mineralogic exams showed that CCT acted on the re-elaboration of the mineral phase approaching the molar ratio Ca/PO4 to the physiological values typical of senescence, and crystallography revealed that the formation of hydroxyapatite crystals follows a physiological mineral redeposition: those phenomena were not observed for ALN. CONCLUSIONS: In conclusion both CCT and ALN could reduce the bone loss due to osteoporosis, by increasing the bone mass and thickness. Nevertheless the submicroscopic and chemical bone structure are less similar to the physiologic ones after treatment with ALN.

Alendronate↗
PubMed1997

Bioabsorbable polyphosphazene matrices as systems for calcitonin controlled release.

To provide a suitable delivery system for the calcitonin controlled release 80 mg bioabsorbable polyphosphazene matrices were obtained with entrapped 50 or 250 micrograms calcitonin. The in vitro behaviour demonstrated a release burst for about 24 hours, followed by a period of slow release of the peptide lasting for weeks. Matrices containing 250 micrograms calcitonin were implanted under general anaesthesia in osteoporotic female rats, while a group of animals (control group) received unloaded matrices. After thirty days a second batch of matrices was implanted in both groups to prolong the period of treatment until two months. The explanted matrices were histologically evaluated together with the surrounding tissues, and the dosage of the residual calcitonin was also performed. Results demonstrated the good biocompatibility of the system and the complete release of the calcitonin from the matrices 30 days after implantation. The therapeutic effect, after sixty days of treatment was confirmed by the better densitometric values observed in the femoral bone of treated animals than in controls.

Animals↗
PubMed1996

Bone turnover in patients on home parenteral nutrition: a longitudinal observation by biochemical markers.

In order to characterize biochemical markers of bone turnover in home parenteral nutrition(HPN) patients, 8 adult patients on HPN for benign intestinal failure were studied at 0, 6 and 12 months by evaluating serum osteocalcin (bone formation marker), urinary hydroxylysyl pyridinoline, lysyl pyridinoline and beta-galactosyl hydroxylysine (bone resorption markers), serum PTH, Calcitonin, 25 vitD, 1-25vitD, serum and urinary minerals, body weight, rehabilitation degree and HPN characteristics. Three patients entered the study 2-3 months after the beginning of HPN. Their features of bone turnover were homogeneous, characterized by increased resorption associated with normal or increased formation, at baseline, and normalization of resorption associated with an increase or a parallel decrease of formation, at 6 months. At 12 months, the patterns were similar to those observed at 6 months. The patients were not of the same sex and age and had different underlying diseases and types of intestinal failure, HPN composition and serum vitamin D levels. They had weight gain that was already present at baseline and the positive outcomes of the rehabilitation and clinical status in common. Five patients entered the study more than 1 year after the beginning of HPN. They showed heterogeneous features of bone turnover that were stable throughout the study, characterized by increased resorption associated with low or normal formation in two cases, low normal resorption associated with low or normal formation in three. In one patient, who had increased resorption and low formation, the bone turnover appeared to be explained by the nutritional and clinical outcomes, which were negative. These results appeared consistent with those obtained in previous studies by bone histomorphometry, indicating that bone turnover of short-term HPN patients differed from that of long-term patients, and suggesting that the early months of HPN were associated with increased bone resorption.

Journal Article↗