Biomedical subjects

S Giannini

Publications and source records attributed to S Giannini.

At least 55 records · Page 3Linked to original sources

PubMed2001

Fixation strength and pin tract infection of hydroxyapatite-coated tapered pins.

In a multicenter, prospective, randomized study, the biomechanical and clinical properties of the bone-pin interface were compared with standard tapered pins and hydroxyapatite-coated tapered pins implanted in patients who underwent femoral and tibial external fixation treatments. The results showed that the hydroxyapatite-coated tapered pins are clinically effective in improving the strength of fixation of the bonepin interface. This improvement corresponded to a lower rate of pin tract infection. In the hydroxyapatite-coated pin group, there were no differences in strength of fixation between the pins removed from the infected and uninfected pin tracts. In this pin group, the mean pin extraction torque was 531 +/- 225 Ncm in the infected pin tracts and 508 +/- 233 Ncm in the uninfected pin tracts. In the standard pin group, the mean pin extraction torque was 73 +/- 142 Ncm in the infected pin tracts and 211 +/- 216 Ncm in the uninfected pin tracts. The advantages provided by the hydroxyapatite-coated pins were higher in cancellous bone than in cortical bone.

Adult↗

PubMed2001

Vertebral morphometry by X-ray absorptiometry before and after liver transplant: a cross-sectional study.

OBJECTIVES: To evaluate bone density and fracture prevalence in patients with end-stage liver diseases (ESLD) awaiting liver transplant and in orthotopic liver-transplant (OLTx) recipients by using dual energy X-ray absorptiometry. DESIGN: In a cross-sectional study 27 patients (16 males and 11 females, mean age 49.9 +/- 1.7 years) with ESLD, and 36 subjects (26 males and 10 females, mean age 50.5 +/- 1.6 years) who had undergone OLTx 1-70 months before, were recruited. METHODS: All patients underwent biochemical assessment of mineral metabolism. Bone density measurement of the spine and femur and morphometric X-ray absorptiometry (MXA) of the vertebrae were also obtained. RESULTS: Bone density was decreased in both groups as compared to the expected normal values. Spinal density did not differ between the two groups, while femoral bone mass was lower in OLTx than in ESLD patients (T-scores of: femoral neck -1.91 +/- 0.16 vs -1.12 +/- 0.22, P < 0.01; total femur -1.62 +/- 0.16 vs -0.94 +/- 0.23, P < 0.02). Bone alkaline phosphatase was the only independent predictor of femoral density (R2 = -0.21, P < 0.05). Symptomatic fractures were reported by 25% of OLTx and 15% of ESLD patients. MXA vertebral fractures were present in 28% of OLTx and 7.5% of ESLD (P < 0.05) patients. Most of these fractures had been asymptomatic. Total methylprednisolone intake was higher in patients with MXA vertebral fractures than in non-fractured patients (P < 0.05). CONCLUSIONS: Fragility fractures, especially of the spine, occur more frequently after liver transplantation, with corticosteroid treatment being the most important risk factor. Morphometric X-ray absorptiometry represents a useful technique for identifying vertebral fractures even in liver transplanted patients.

Absorptiometry, Photon↗

PubMed2001

Autologous chondrocyte transplantation in osteochondral lesions of the ankle joint.

The aim of this study was to assess the repair of osteochondral defects of the ankle joint with hyaline cartilage. For this purpose we have been using a technique of autologous chondrocyte transplantation for osteochondral defects of the talus for the last two years. Until the method described in the paper, treatment methods proposed for the repair of cartilaginous defects have not been histologically effective in restoring the hyaline cartilage sheath, and in all cases the neoformation of cartilage was of a fibrocartilaginous nature with varying cellular characteristics. Clinical and histological results obtained using this surgical technique have confirmed its validity. Furthermore, neither subjective nor objective complications have been reported. Less pain and better articular function have also been observed. According to the AOFAS score, an improvement from an average score of 32/100 points pre-op. to 91/100 points at 24 months of follow up was obtained. Laboratory data have confirmed the presence of reconstructed cartilage with chondrocytes and expression of collagen II, characteristic of hyaline cartilage.

Adolescent↗

PubMed2001

Alendronate prevents further bone loss in renal transplant recipients.

The aim of this study was to investigate the effects of alendronate, calcitriol, and calcium in bone loss after kidney transplantation. We enrolled 40 patients (27 men and 13 women, aged 44.2 +/- 11.6 years) who had received renal allograft at least 6 months before (time since transplant, 61.2 +/- 44.6 months). At baseline, parathyroid hormone (PTH) was elevated in 53% of the patients and the Z scores for bone alkaline phosphatase (b-ALP) and urinary type I collagen cross-linked N-telopeptide (u-NTX) were higher than expected (p < 0.001). T scores for the lumbar spine (-2.4 +/- 1.0), total femur (-2.0 +/- 0.7), and femoral neck (-2.2 +/- 0.6) were reduced (p < 0.001). After the first observation, patients were advised to adhere to a diet containing 980 mg of calcium daily and their clinical, biochemical, and densitometric parameters were reassessed 1 year later. During this period, bone density decreased at the spine (-2.6 +/- 5.7%;p < 0.01), total femur (-1.4 +/- 4.2%; p < 0.05), and femoral neck (-2.0 +/- 3.0%; p < 0.001). Then, the patients were randomized into two groups: (1) group A-10 mg/day of alendronate, 0.50 microg/day of calcitriol, and 500 mg/day of calcium carbonate; and (2) group B-0.50 microg/day of calcitriol and 500 mg/day of calcium carbonate. A further metabolic and densitometric reevaluation was performed after the 12-month treatment period. At the randomization time, group A and group B patients did not differ as to the main demographic and clinical variables. After treatment, bone turnover markers showed a nonsignificant fall in group B patients, while both b-ALP and u-NTX decreased significantly in alendronate-treated patients. Bone density of the spine (+5.0 +/- 4.4%), femoral neck (+4.5 +/- 4.9%), and total femur (+3.9 +/- 2.8%) increased significantly only in the alendronate-treated patients. However, no trend toward further bone loss was noticed in calcitriol and calcium only treated subjects. No drug-related major adverse effect was recorded in the two groups. We conclude that renal transplanted patients continue to loose bone even in the long-term after the graft. Alendronate normalizes bone turnover and increases bone density. The association of calcitriol to this therapy seems to be advantageous for better controlling the complex abnormalities of skeletal metabolism encountered in these subjects.

Adult↗

PubMed2001

IGFBPs modulate IGF-I- and high glucose-controlled growth of human retinal endothelial cells.

Insulin-like growth factor binding proteins (IGFBPs) are important local factors in the development of proliferative diabetic retinopathy. We investigated the effects of IGF-I and increased glucose concentrations on the release of IGFBPs and the growth of human retinal endothelial cells (HRECs). HRECs secrete IGFBPs-2 to -5. IGF-I stimulated thymidine incorporation and modified the pattern of IGFBPs, decreasing the inhibitory IGFBP-4 through down-regulation of its mRNA, and increasing IGFBP-5 which, per se, was able to modulate HREC growth, exerting post-transcriptional control. Studies using an antibody (alpha IR3) against the IGF-I receptor, and compounds with low affinity for IGFBPs, such as insulin and des(1-3)IGF-I, showed that an interaction between IGF-I and IGFBP-5 was necessary to detach this IGFBP from its binding sites. The dose of IGF-I that significantly decreased the IGFBP-4/IGFBP-5 ratio was the same that stimulated HREC growth. Chronic exposure to high concentrations of glucose was able to reduce HREC mitogenesis, interacting with the IGF system through a decrease in the stimulatory IGFBPs-2, -3 and -5, leaving the concentration of the inhibitory IGFBP-4 constant. These results extend our previous observations in endothelial cells and suggest that the IGFBP-4/IGFBP-5 ratio regulates IGF-I-induced growth of HRECs, whereas a general decrease in IGFBPs (except for IGFBP-4) was the anti-proliferative effect of chronic exposure to high glucose concentrations.

Analysis of Variance↗

PubMed2001

Improvement of the bone-pin interface strength in osteoporotic bone with use of hydroxyapatite-coated tapered external-fixation pins. A prospective, randomized clinical study of wrist fractures.

BACKGROUND: Achieving adequate fixation strength in osteoporotic bone is a challenge. In this study, we examined the use of hydroxyapatite-coated tapered external-fixation pins for the fixation of wrist fractures in patients with osteoporosis. METHODS: Twenty female patients with osteoporosis and a fracture of the wrist were divided into two paired groups and randomized to receive either standard tapered pins or hydroxyapatite-coated tapered pins. Two pins were inserted in the distal part of the radius, two pins were inserted in the second metacarpal, and an external fixation device was mounted. All fixation devices were removed six weeks after surgery. RESULTS: The mean pin-insertion torque (and standard deviation) was 461 +/- 254 Nmm in the group managed with standard pins and 332 +/- 176 Nmm in the group managed with hydroxyapatite-coated pins (p = 0.01). The mean pin-extraction torque was 191 +/- 155 Nmm in the group managed with standard pins and 600 +/- 214 Nmm in the group managed with hydroxyapatite-coated pins (p < 0.0001, power 95%). The mean extraction torque was lower than the corresponding insertion torque at each pin position in the group managed with standard pins (p < 0.05), whereas the mean extraction torque was higher than the corresponding insertion torque at each pin position in the group managed with hydroxyapatite-coated pins (p = 0.001). Two patients managed with standard pins and no patient managed with hydroxyapatite-coated pins had a pin-track infection. Pain during pin removal did not differ between the two groups. CONCLUSIONS: The present study showed that hydroxyapatite-coated tapered external-fixation pins provided improved fixation in the treatment of wrist fractures in patients with osteoporosis.

Aged↗

PubMed2001

Idiopathic pulmonary hemosiderosis in an adult. Favourable response to azathioprine.

Idiopathic pulmonary hemosiderosis (IPH) is a rare disorder characterised by intermittent, diffuse alveolar hemorrhage (DAH). Although an inflammatory pulmonary capillaritis can be evidenced in most patients with DAH, IPH is a distinct entity in which pulmonary inflammatory alterations are lacking. Most cases occur in children, although the disease has been exceptionally reported in adults too. Here, we, describe a case of IPH in a 30-year-old woman who was admitted to our hospital because of recurrent episodes of hemoptysis since the age of 21. IPH was diagnosed on the basis of: 1) an open lung biopsy showing focal alveolar edema and hemorrhage without parenchymal inflammatory alterations, 2) a bronchoalveolar lavage showing hemosiderin-laden macrophages, and 3) exclusion of infectious or immunologic causes of hemoptysis. Prednisone administration could control the disease, but every attempt to lower the dose to less than 25 mg per day was followed by recurrence of hemoptysis. Then, azathioprine was started, and after three months prednisone was gradually tapered to the dose of 10 mg per day, without any relapse of the disease. These findings indicate that azathioprine, in combination with prednisone, may be an effective therapy for IPH and suggest that an immunologic mechanism could be involved in the pulmonary capillary damage underlying alveolar bleeding.

Adult↗

PubMed2001

Persistently increased bone turnover and low bone density in long-term survivors to kidney transplantation.

AIMS: There are few data on the long-term outcome of bone health in renal transplant recipients. We wanted to evaluate the prevalence of osteoporosis and related clinical fractures in long-term survivals to kidney transplantation. METHODS: We carried out a cross-sectional study of 80 males and 44 females, aged 45 +/- 1 years, who had undergone kidney transplantation (KTx) 55.6 +/- 4.6 months earlier. Patients were treated according to standard immunosuppressive protocols. RESULTS: High parathyroid hormone levels were observed in 55 out of the 124 patients (44.6%) and the prevalence of secondary hyperparathyroidism (SHPT) remained similar even when subjects were grouped according to the time elapsed since transplant. The Z scores for bone alkaline phosphatase, osteocalcin, urinary N telopeptide and galactosyl-hydroxylysine were increased as compared to normal controls, both in males and females (p < 0.05). Bone formation markers normalized, while bone resorption markers remained elevated in these patients even ten years after transplant. Vertebral and femoral osteoporosis were present in 37% and 56% of the patients, respectively, and no tendency toward a recovery in bone mass was seen even in those patients who had survived the longest time since KTx. Clinical fracture rate was 0.006 and 0.031 patient years, before and after KTx, respectively. The number of fractures was lower in patients taking lower mean daily doses of corticosteroids (p < 0.025). PTH levels positively correlated with bone alkaline phosphatase, osteocalcin and N telopeptide. CONCLUSION: In conclusion, bone density is decreased and bone turnover increased even many years after KTx, with persistent SHPT and corticosteroid use being the main pathogenetic factors.

Adult↗

PubMed2000

A new folding intermediate of apomyoglobin from Aplysia limacina: stepwise formation of a molten globule.

Apomyoglobin from Aplysia limacina (al-apoMb), despite having only 20 % sequence identity with the more commonly studied mammalian globins (m-apoMbs), properties which result in an increased number of hydrophobic contacts and a loss of most internal salt bridges, shares a number of features of their folding profiles. We show here that it contains an unusually stable core which resists unfolding even at 70 degrees C. The equilibrium intermediate (I(T)) at this high temperature is distinct from the acid unfolded state I(A) which has many properties in common with the acid intermediate observed for the mammalian apoproteins (I(AGH)). It contains a smaller amount of secondary structure (27 % alpha-helical instead of 35 %) and is more highly solvated as evidenced from its fluorescence spectrum (lambda(max)=344 nm instead of 338 nm). Its stability is greatly increased (DeltaDeltaG(w)=-6.75 kcal mol(-1)) in the presence of high salt (2 M KCl), lending support to the view that hydrophobic interactions are responsible for its stability. Kinetic data show classical two-state kinetics between I(A) and the folded state both in the presence and absence of salt. Both I(A) and I(T) can be populated within the dead time of the stopped-flow apparatus, since initiating the refolding reaction from I(T) or I(A) rather than the completely unfolded state does not affect the observed refolding time-course. Our conclusion is that al-apoMb, as other "apo" proteins (including for example alpha-lactalbumin in the absence of Ca(2+)), may be described as "uncoupled" with an unusually high and exploitable tendency to populate partially folded states.

Allosteric Site↗

PubMed2000

Lumbar osteoarthritis, bone mineral density, and quantitative ultrasound.

Low bone mass is a major risk factor for osteoporotic fractures. Thus, bone density evaluation, performed by Dual Energy X-ray Absorptiometry (DXA) is important for diagnosis and monitoring treatment of osteoporosis. The accuracy of DXA, particularly at the lumbar spine, can be affected by several factors such as degenerative diseases. To evaluate the effects of vertebral osteophytosis on densitometric measurements, we examined 198 women, aged 32-81 years, who had undergone lateral X-ray of the lumbar spine. We classified patients according to different grades of osteophytosis, and evaluated bone density at the lumbar spine and the proximal femur by DXA. We also performed quantitative ultrasound at the heel (QUS). Patients with severe osteophytosis were significantly older (p < 0.0005), and values were adjusted for this parameter. We observed a significant increase in lumbar bone density with worsening osteophytosis (p < 0.02). On the contrary, no significant differences were found at the femur and QUS. According to bone density at the femoral neck, we subdivided patients into two groups: osteoporotic (group A) and non-osteoporotic (group B). Both groups showed increasingly high bone density at the spine with worsening osteophytosis (A: p < 0.01; B: p < 0.02). No differences were found in all the other evaluations. In conclusion, lumbar spine measurement is dramatically influenced by osteophytosis, particularly in the elderly. Consequently, other strategies should be performed such as evaluation of the hip and also measurement of the heel by ultrasound, which could be an interesting approach in these cases.

Absorptiometry, Photon↗

PubMed2000

Idiopathic hypercalciuria: O2(-)NO relationship and altered bone metabolism.

The pathogenesis of idiopathic hypercalciuria (IH) has not been elucidated yet, but a correlation between IH and altered bone metabolism has been proposed. Since nitric oxide (NO) regulates osteoclasts' bone resorption, a possible role for NO can be suggested. In this study we evaluated iNOS gene expression by reverse transcription of mRNA from monocytes, followed by polymerase chain reaction in patients with IH subdivided into fasting (FH) and absorptive (AH) hypercalciuria. Since superoxide (O2-), which metabolizes NO, is overproduced by osteoclasts during bone resorption, peroxynitrite plasma level was evaluated as index of O2-. Vertebral BMD in IH as a whole group was lower vs controls (C) (Z score=-1.78+/-0.2 vs 0.51+/-0.25, p<0.001), but only FH patients showed a reduced bone density (2.13+/-0.18 vs 0.51+/-0.25, p<0.0001). PTH and calcitriol were not different. FH showed an increase in b-ALP vs AH and C (41.1+/-2.6 vs 30.1+/-3.9 vs 26.6+/-3.6 U/l p<0.02), and higher uHP, either on NCD (17.7+/-1.6 vs 11.4+/-1.3 mg/g uCr, p<0.04) or after LCD (26.7+/-2.5 vs 16.7+/-1.9, p<0.01). Cells from FH patients, but not from both AH patients and C, expressed iNOS. Peroxynitrite plasma level was elevated in FH (0.30+/-0.07) pmol/l while not detectable in AH and C. This study confirms an altered bone metabolism only in FH which shows an abnormal NO system. The increased iNOS gene expression in FH, in fact, points toward an altered NO system's activity downstream the generation of NO. A possible interaction of NO with O2-, which breaks down NO, and the role of this interaction in the pathophysiology of IH is discussed.

Adult↗

PubMed2000

Role of insulin-like growth factor-I in primary osteoporosis: a correlative study.

Osteoporosis is characterized by impairment of bone mass and deterioration of bone microscopic structure, resulting in increased bone fragility and susceptibility to fracture. Recent reports have indicated that reduced plasma levels of IGF-I are associated with osteoporosis in both males and females. Moreover, there is accumulating clinical evidence that treatment with GH or IGF-I has beneficial effects on bone mass and bone remodeling in men with idiopathic osteoporosis, in the elderly and in hypopituitary patients. As correlative studies on IGF-I, IGF-BP3 and bone mass in the elderly are lacking, we studied the relationships between serum IGF-I, IGF-BP3, bone mineral density (BMD), body mass index (BMI), calciotropic hormones and age in 102 premenopausal and postmenopausal women. Our study indicates that the reduction of the anabolic processes mediated by IGF-I may account for the slow and progressive loss of bone mass that take place after the age of 40-50 years. In addition, nutritional caloric or proteic deficit may add to the effects of GH, age and other factors in decreasing IGF-I synthesis and therefore further contribute to the development of primary osteoporosis.

Adult↗

PubMed2000

Long-term persistence of low bone density in orthotopic liver transplantation.

We determined bone density and metabolism in 46 patients (35 males, 11 females) who had undergone liver transplantation 1-48 months previously. Twenty-one patients were then followed for the next 24 months. At each visit, blood and urine samples for bone and liver metabolism parameters, as well as spinal and femoral dual-energy X-ray absorptiometry (DXA) scans, were obtained. Basal spinal and femoral density was low (p < 0.001). Patients with pre-transplant cholestatic diseases had lower spinal density than all the other subjects (p <0.05) and the cumulative methylprednisolone intake was an independent negative predictor of total hip density (p < 0.02). At baseline, urinary hydroxyproline and N-telopeptide were at the upper normal level and decreased only after 24 months of follow-up (p < 0.05). During the first year of follow-up, femoral density decreased (p < 0.05) and a partial recovery was observed for both spine and femur after 24 months. After 12 months, femoral bone density was negatively associated with serum cyclosporin A levels (p < 0.005) and cumulative methylprednisolone intake (p < 0.05), while the percent decrease in spinal density after the first 12 months was negatively predicted by mean daily methylprednisolone intake (p < 0.05). In patients with pre-transplant cholestatic diseases, femoral and spinal density increased after the first (p < 0.05) and second year (p < 0.05), respectively. In patients with previous post-necrotic cirrhosis, femoral density decreased after 12 months (p<0.05) and was still lower than baseline after 24 months (p < 0.05). However, at the end of the study the cumulative percentage of femoral neck osteoporosis was 43%. In conclusion, an elevated prevalence of spinal and femoral osteoporosis is present even many years after liver transplantation, with immunosuppressive treatment and pre-transplant liver disease being the most important pathogenetic factors.

Adult↗

PubMed2000

Analysis of ground reaction forces by means of wavelet transform.

OBJECTIVE: To identify details of clinical relevance in ground reaction forces by means of wavelet transform. DESIGN: A retrospective analysis of gait tests performed by total knee replacement patients and a control population has been performed. METHODS: The ground reaction forces have been processed by means of wavelet transform. Results of the wavelet analysis are represented, in a time-frequency plane, by tiles. These are coloured in different grey levels associated to the values of a suitable energy function of the expansion coefficients, resulting from the wavelet transform. RESULTS: The high frequency tiles revealed the presence of irregularities with clinical significance in the first part of the stance phase. These transients in ground reaction forces are described in a quantitative manner allowing to monitor their evolution during the patient observation time. The heel strike transient has been identified by the tile representation of the vertical component of ground reaction forces and confirmed by its correlation with corresponding irregularities in the other components. CONCLUSIONS: The tile representation allows to detect and to quantify details not easily perceivable by the examiner through traditional techniques. The wavelet transform seems particularly appealing for clinical applications such as outcome assessment or treatment evaluation and can assist in the definition of normative models of ground reaction forces. The effectiveness of the procedure suggest to try to automate it. RELEVANCE: The tile representation allows to identify and to keep the records of ground reaction forces clinically significant details, such as heel strike transient.

Arthroplasty, Replacement, Knee↗

PubMed2000

The role of the passive structures in the mobility and stability of the human ankle joint: a literature review.

The mobility and stability of the ankle joint have been extensively investigated, but many critical important issues still need to be elucidated. However, there seems to be a general agreement on several important observations. A more isometric pattern of rotation for the calcaneofibular and the tibiocalcaneal ligaments with respect to all the others has been reported. Many recent studies have found changing positions of the instantaneous axis of rotation, suggesting that the hinge joint concept is an oversimplification for the ankle joint. A few recent works have also claimed anterior shift of the contact area at the tibial mortise during dorsiflexion, which would imply combined rolling and sliding motion at this joint. Many findings from the literature support the view of a close interaction between the geometry of the ligaments and the shapes of the articular surfaces in guiding and stabilizing motion at the ankle joint.

Ankle Joint↗

PubMed2000

Surgical versus non-surgical treatment of calcaneal fractures in children: a long-term results comparative study.

This study compared surgical and non-surgical treatment of 46 calcaneal fractures in children aged 3-17 years. Patients were divided into: Group A ranging 3-14 years and Group B 15-17 years, and classified according to surgical or non-surgical treatment. Mean follow-up was 22.8 years. Extra-articular fractures were treated non-surgically and all results were satisfactory. Results of articular fractures in Group A were satisfactory regardless of the type of treatment. Articular fractures surgically treated in group B were satisfactory, and those non-surgically treated were mainly poor. Extra-articular fractures can be treated non-surgically. Articular fractures in skeletally immature children can be treated non-surgically; conversely, those in children with skeletal maturity must be treated surgically.

Adolescent↗

PubMed2000

Muscle performance about the knee joint in patients who had distal femoral replacement after resection of a bone tumor. An objective study with use of gait analysis.

BACKGROUND: The treatment of a malignant bone tumor in the distal aspect of the femur often requires great sacrifice of bone and muscle. The extent of quadriceps removal has been reported to influence the long-term functional efficiency of a patient's gait. The objective of the present study was to determine gait function as it relates to the residual quadriceps strength and to the specific component or components of the quadriceps removed in patients treated with total knee replacement because of a malignant bone tumor in the distal aspect of the femur. METHODS: Sixteen patients were evaluated after implantation of a modular hinged cementless knee prosthesis. The patients were assigned to two groups on the basis of the different components of the quadriceps muscle that were resected. Group 1 consisted of five patients who had removal of the vastus medialis and the vastus intermedius and two who had removal of the vastus medialis only. Group 2 consisted of nine patients who had removal of the vastus lateralis and the vastus intermedius. Residual muscular strength about the treated knee was measured by voluntary maximum contraction isometric testing. Foot-ground reaction forces, kinematic and kinetic findings, and electromyographic activity during free-speed walking were recorded. RESULTS: The kinematic study showed that the patients in Group 1 tended to have a stiff-knee gait during stance, whereas those in Group 2 (in which the vastus medialis was spared) had a more regular flexion-extension knee pattern. Electromyographic findings showed that a higher percentage of patients in Group 1 had reduced or absent rectus femoris activity during the loading response. Compared with the contralateral side, knee-extension strength in the treated limb was decreased in both groups. However, there were no significant differences between the groups with respect to the pattern of strength loss. CONCLUSIONS: Good gait function can be achieved in patients with a distal femoral tumor that is treated with distal femoral resection, partial excision of the quadriceps, and total knee arthroplasty with insertion of a hinged prosthesis. Patients in whom the vastus lateralis and vastus intermedius were removed had better gait performance and a more physiological knee-loading pattern than did patients in whom the vastus medialis was removed.

Adult↗

PubMed2000

Parathyroid hormone and bone metabolism in kidney-transplanted patients.

BACKGROUND: Decreases in bone mass and increased susceptibility to fractures are well-recognized complications in organ transplants. SUBJECTS AND METHODS: We performed a cross-sectional study on 60 patients (40 males, 20 females, mean age 43.2 +/- 1.06, SE range 22 - 70) who underwent kidney transplantation (KTX) 55.6 +/- 4.5 months before. Blood and 24-hour urine samples were analyzed for the main parameters of mineral metabolism, and also for osteocalcin (BGP), bone alkaline phosphatase (b-ALP, urine N-telopeptid (u-NTx) and urine galactosyl-hydroxylysine (u-Ghyl). DEXA scan of the lumbar spine (LS) and proximal femur (PF) and ultrasound determination of the heel (stiffness) was also performed. RESULTS: T-score values for bone density (BD) were 2.14 +/- 0.11 SD's for LS, -2.56 +/- 0.09 for PF and 2.49 +/- 0.15 for stiffness. There were 29 peripheral fractures in 16 patients. The rate of fractures before KTX were 0.0011 per patient/year and 0.0005 after transplantation (p < 0.02). When expressed as number of SD's with respect to normal controls, BGP (1.48 +/- 0.23), b-ALP (0.95 +/- 0.19), u-NTx excretion correlated negatively with BD at the femoral neck (p < 0.02) and trochanter (p < 0.03). Cumulative steroids intake were negatively correlated with b-ALP positively (p < 0.05). Current CsA was positively correlated with b-ALP (p < 0.001). Both cumulative steroid (p < 0.02) and CSA (p < 0.01) intakes were negatively correlated with BD at Wards triangle. CONCLUSIONS: Our data demonstrate an important bone depletion at each stage KTX. PTH plays a major role in the observed increase in bone turnover, exacerbating the negative effects on the bone on immunosuppressive treatment. Glucocorticosteroid therapy is an important risk factor for osteoporosis in this setting also.

Adult↗