Generation of LexA enhancer-trap lines in Drosophila by an international scholastic network

Conditional gene regulation in Drosophila through binary expression systems like the LexA-LexAop system provides a superb tool for investigating gene and tissue function. To increase the availability of defined LexA enhancer trap insertions, we present molecular, genetic, and tissue expression studies of 301 novel Stan-X LexA enhancer traps derived from mobilization of the index SX4 line. This includes insertions into distinct loci on the X, II, and III chromosomes that were not previously associated with enhancer traps or targeted LexA constructs, an insertion into ptc, and seventeen insertions into natural transposons. A subset of enhancer traps was expressed in CNS neurons known to produce and secrete insulin, an essential regulator of growth, development, and metabolism. Fly lines described here were generated and characterized through studies by students and teachers in an international network of genetics classes at public, independent high schools, and universities serving a diversity of students, including those underrepresented in science. Thus, a unique partnership between secondary schools and university-based programs has produced and characterized novel resources in Drosophila, establishing instructional paradigms devoted to unscripted experimental science.

An Interscholastic Network To Generate LexA Enhancer Trap Lines in Drosophila

Binary expression systems like the LexA-LexAop system provide a powerful experimental tool kit to study gene and tissue function in developmental biology, neurobiology, and physiology. However, the number of well-defined LexA enhancer trap insertions remains limited. In this study, we present the molecular characterization and initial tissue expression analysis of nearly 100 novel StanEx LexA enhancer traps, derived from the StanEx1 index line. This includes 76 insertions into novel, distinct gene loci not previously associated with enhancer traps or targeted LexA constructs. Additionally, our studies revealed evidence for selective transposase-dependent replacement of a previously-undetected KP element on chromosome III within the StanEx1 genetic background during hybrid dysgenesis, suggesting a molecular basis for the over-representation of LexA insertions at the NK7.1 locus in our screen. Production and characterization of novel fly lines were performed by students and teachers in experiment-based genetics classes within a geographically diverse network of public and independent high schools. Thus, unique partnerships between secondary schools and university-based programs have produced and characterized novel genetic and molecular resources in Drosophila for open-source distribution, and provide paradigms for development of science education through experience-based pedagogy.

One injection of platelet-rich plasma associated to a submaximal eccentric protocol to treat chronic jumper's knee

AIM

Jumper's knee is a frequent chronic overuse syndrome of the proximal part of the patellar tendon. Platelets contain lots of growth factors which could enhance the healing process of tendons. The aim of this study was to clarify the possible efficacy of one injection of Platelet-rich plasma (PRP) in cases of rebel jumper's knees.

METHODS

Twenty patients with chronic proximal patellar tendinopathy were enrolled. Assessments were made before infiltration of PRP, and 6 weeks and 3 months after the infiltration, using a 10-point visual analogic scale of pain, clinical examinations with a pressure algometer, algofunctional scores (IKDC and VISA-P), functional assessments (isokinetic and optojump evaluations) and imagery (ultrasounds and MRI). The PRP was obtained with an apheresis system (COMTEC®, Fresenius-Kabi, Bad Homburg, Germany). Six millilitres of PRP were injected without local anesthetic. One week after infiltration, patients started a standardized sub-maximal eccentric reeducation.

RESULTS

During daily activities pain significantly decreased with time. At functional evaluation, it decreased as well, but without significant functional improvement. No improvements in the imagery measurements were observed. Younger patients seemed to be more susceptible to have an improvement of pain by the PRP infiltration.

CONCLUSION

This study demonstrates that a local infiltration of PRP associated with a submaximal eccentric protocol can improve symptoms of chronic jumper's knee in patients non-responsive to classical conservative treatments.

Republished: Value of biomarkers in osteoarthritis: current status and perspectives

Osteoarthritis affects the whole joint structure with progressive changes in cartilage, menisci, ligaments and subchondral bone, and synovial inflammation. Biomarkers are being developed to quantify joint remodelling and disease progression. This article was prepared following a working meeting of the European Society for Clinical and Economic Aspects of Osteoporosis and Osteoarthritis convened to discuss the value of biochemical markers of matrix metabolism in drug development in osteoarthritis. The best candidates are generally molecules or molecular fragments present in cartilage, bone or synovium and may be specific to one type of joint tissue or common to them all. Many currently investigated biomarkers are associated with collagen metabolism in cartilage or bone, or aggrecan metabolism in cartilage. Other biomarkers are related to non-collagenous proteins, inflammation and/or fibrosis. Biomarkers in osteoarthritis can be categorised using the burden of disease, investigative, prognostic, efficacy of intervention, diagnostic and safety classification. There are a number of promising candidates, notably urinary C-terminal telopeptide of collagen type II and serum cartilage oligomeric protein, although none is sufficiently discriminating to differentiate between individual patients and controls (diagnostic) or between patients with different disease severities (burden of disease), predict prognosis in individuals with or without osteoarthritis (prognostic) or perform so consistently that it could function as a surrogate outcome in clinical trials (efficacy of intervention). Future avenues for research include exploration of underlying mechanisms of disease and development of new biomarkers; technological development; the ‘omics’ (genomics, metabolomics, proteomics and lipidomics); design of aggregate scores combining a panel of biomarkers and/or imaging markers into single diagnostic algorithms; and investigation into the relationship between biomarkers and prognosis.

Correction of vitamin D insufficiency with combined strontium ranelate and vitamin D3 in osteoporotic patients

OBJECTIVE

This study aims to investigate the efficacy and safety of oral fixed-dose combination of strontium ranelate 2  g/vitamin D₃ 1000  IU daily vs strontium ranelate 2  g daily for correcting vitamin D insufficiency in osteoporosis.

DESIGN

A 6-month international, randomized, double-blind, parallel-group, phase 3 study.

METHODS

A total of 518 men and postmenopausal women aged ≥50 years with primary osteoporosis (T-score ≤-2.5 s.d.) and serum 25-hydroxyvitamin D (25(OH)D) >22.5 nmol/l were included. Patients were allocated to strontium ranelate 2 g/vitamin D₃ 1000  IU daily (n=413) or strontium ranelate 2 g daily (n=105). The participants received calcium 1 g daily. The primary endpoint was serum 25(OH)D at last post-baseline evaluation during 3 months.

RESULTS

Both groups were comparable at baseline. Mean baseline of 25(OH)D was 44.1 ± 14.6 nmol/l. After 3 months, the percentage of patients with 25(OH)D ≥50 nmol/l was higher with strontium ranelate/vitamin D₃ vs strontium ranelate (84 vs 44%, P<0.001; adjusted between-group odds ratio=6.7; 95% CI, 4.2-10.9). The efficacy of the fixed-dose combination on 25(OH)D was maintained at 6 months (86 vs 40%, P<0.001). Mean 25(OH)D was 65.1 and 49.5 nmol/l, respectively, after 3 months and 66.9 and 45.4 nmol/l after 6 months. Physical performance improved in both groups. Falls were 17 and 20% in the strontium ranelate/vitamin D₃ and strontium ranelate groups respectively. Parathyroid hormone levels were inversely correlated with 25(OH)D. No clinically relevant differences in safety were observed.

CONCLUSIONS

This study confirms the efficacy and safety of fixed-dose combination of strontium ranelate 2 g/vitamin D₃ 1000 IU for correction of vitamin D insufficiency in osteoporotic patients.

Value of biomarkers in osteoarthritis: current status and perspectives

Osteoarthritis affects the whole joint structure with progressive changes in cartilage, menisci, ligaments and subchondral bone, and synovial inflammation. Biomarkers are being developed to quantify joint remodelling and disease progression. This article was prepared following a working meeting of the European Society for Clinical and Economic Aspects of Osteoporosis and Osteoarthritis convened to discuss the value of biochemical markers of matrix metabolism in drug development in osteoarthritis. The best candidates are generally molecules or molecular fragments present in cartilage, bone or synovium and may be specific to one type of joint tissue or common to them all. Many currently investigated biomarkers are associated with collagen metabolism in cartilage or bone, or aggrecan metabolism in cartilage. Other biomarkers are related to non-collagenous proteins, inflammation and/or fibrosis. Biomarkers in osteoarthritis can be categorised using the burden of disease, investigative, prognostic, efficacy of intervention, diagnostic and safety classification. There are a number of promising candidates, notably urinary C-terminal telopeptide of collagen type II and serum cartilage oligomeric protein, although none is sufficiently discriminating to differentiate between individual patients and controls (diagnostic) or between patients with different disease severities (burden of disease), predict prognosis in individuals with or without osteoarthritis (prognostic) or perform so consistently that it could function as a surrogate outcome in clinical trials (efficacy of intervention). Future avenues for research include exploration of underlying mechanisms of disease and development of new biomarkers; technological development; the ‘omics’ (genomics, metabolomics, proteomics and lipidomics); design of aggregate scores combining a panel of biomarkers and/or imaging markers into single diagnostic algorithms; and investigation into the relationship between biomarkers and prognosis.

Serum sclerostin levels in men with idiopathic osteoporosis

OBJECTIVE

Sclerostin inhibits osteoblast differentiation and bone formation. If aberrant sclerostin action is involved in less efficient bone acquisition in men with idiopathic low bone mass, this might be reflected in higher serum sclerostin levels.

METHODS

In 116 men with idiopathic osteoporosis (≤65 years old), 40 of their sons and healthy controls, areal bone parameters were measured using dual-energy X-ray absorptiometry, and volumetric and geometric bone parameters were measured using peripheral quantitative computed tomography. Serum analytes were measured using immunoassays and estradiol (E2) levels using liquid chromatography-tandem mass spectrometry.

RESULTS

Men with idiopathic low bone mass had lower levels of sclerostin than the controls (0.54±0.17 vs 0.66±0.23 ng/ml; P<0.001). In both groups, sclerostin levels were strongly associated with age; when adjusting for age, no associations with anthropometrics were observed (P>0.14). In multivariate analyses, sclerostin levels displayed a positive association with whole-body bone mineral content (BMC) and areal BMD (aBMD), as well as with trabecular and cortical volumetric bone mineral density (vBMD) at the tibia in the probands. No clear associations were observed in the control group, neither were sclerostin levels associated with BMC at the radius or lumbar spine (all P>0.11). Testosterone, but not E2, was inversely related to sclerostin levels in the probands. No difference in sclerostin levels was found in their sons when compared with their controls.

CONCLUSION

Lower rather than higher serum sclerostin levels in the probands with idiopathic low bone mass suggest that aberrant sclerostin secretion is not involved in the pathogenesis of low bone mass in these subjects.

Relationship between 3-month changes in biochemical markers of bone remodelling and changes in bone mineral density and fracture incidence in patients treated with strontium ranelate for 3 years

SUMMARY

From two randomised controlled trials, it is shown that 3-month changes in biochemical markers of bone formation (bone-specific alkaline phosphatase and C-terminal propeptide of type I procollagen) were associated with 3-year bone mineral density (BMD) changes, but not fracture incidence in patients treated with strontium ranelate.

INTRODUCTION

The purpose of this study was to assess if short-term change in biochemical markers of bone remodelling is associated with long-term BMD change and fracture incidence observed during treatment with strontium ranelate.

METHODS

From the SOTI and TROPOS trials, bone-specific alkaline phosphatase (BALP), C-terminal propeptide of type I procollagen (PICP), serum C-terminal telopeptides (S-CTX) and urine N-terminal telopeptides of type I collagen (U-NTX) were assessed at baseline and after 3 months.

RESULTS

Two thousand three hundred seventy-three women were included in this study. Multiple regression analysis showed that 3-month changes in PICP and BALP but not s-CTX I nor s-NTX I were significantly (p < 0.001) associated with 3-year BMD changes at the lumbar spine and the femoral neck. Changes in s-CTX I, PICP and BALP were significantly associated with change in total proximal femur BMD. Changes in biochemical markers explain less than 8% of the BMD changes. The 3-month changes in BALP, PICP s-CTX I and s-NTX I were not significantly associated with fracture incidence.

CONCLUSIONS

Short-term changes in biochemical markers of bone formation are associated with future BMD changes in patients treated with strontium ranelate, suggesting a bone-forming activity of this treatment, but are not appropriate to monitor the efficacy of strontium ranelate at the individual level.

Vertebral anti-fracture efficacy of strontium ranelate according to pre-treatment bone turnover

Osteoporotic post-menopausal women patients in two randomised trials comparing the anti-fracture efficacy of strontium ranelate with placebo were separated into tertiles according to their baseline levels of biochemical markers of bone formation and resorption. The vertebral anti-fracture efficacy of strontium ranelate was shown to be independent of baseline bone turnover levels.

INTRODUCTION

Bone turnover (BTO) levels vary among women at risk of osteoporotic fracture. Strontium ranelate is an anti-osteoporotic treatment increasing bone formation and reducing bone resorption. It was hypothesised that its anti-fracture efficacy would be independent of baseline BTO levels.

METHODS

Post-menopausal women with osteoporosis from two pooled studies were stratified in tertiles according to baseline levels of two BTO markers: bone-specific alkaline phosphatase (b-ALP, n = 4995) and serum C-telopeptide cross-links (sCTX, n = 4891). Vertebral fracture risk was assessed over 3 years with strontium ranelate 2 g/day or placebo.

RESULTS

In the placebo group, relative risk of vertebral fractures increased with BTO tertiles by 32% and 24% for patients in the highest tertile for b-ALP and CTX, respectively, compared to those in the lowest tertile. In the strontium ranelate group, incidences of vertebral fracture did not differ significantly across BTO tertiles. Significant reductions in vertebral fractures with strontium ranelate were seen in all tertiles of both markers, with relative risk reductions of 31% to 47% relative to placebo. Risk reduction did not differ among tertiles (b-ALP: p = 0.513; sCTX: p = 0.290).

CONCLUSION

The vertebral anti-fracture efficacy of strontium ranelate was independent of baseline BTO levels. Strontium ranelate offers clinical benefits to women across a wide range of metabolic states.

Effects of long-term strontium ranelate treatment on vertebral fracture risk in postmenopausal women with osteoporosis

SUMMARY

Vertebral fractures are a major adverse consequence of osteoporosis. In a large placebo-controlled trial in postmenopausal women with osteoporosis, strontium ranelate reduced vertebral fracture risk by 33% over 4 years, confirming the role of strontium ranelate as an effective long-term treatment in osteoporosis.

INTRODUCTION

Osteoporotic vertebral fractures are associated with increased mortality, morbidity, and loss of quality-of-life (QoL). Strontium ranelate (2 g/day) was shown to prevent bone loss, increase bone strength, and reduce vertebral and peripheral fractures. The preplanned aim of this study was to evaluate long-term efficacy and safety of strontium ranelate.

METHODS

A total of 1,649 postmenopausal osteoporotic women were randomized to strontium ranelate or placebo for 4 years, followed by a 1-year treatment-switch period for half of the patients. Primary efficacy criterion was incidence of patients with new vertebral fractures over 4 years. Lumbar bone mineral density (BMD) and QoL were also evaluated.

RESULTS

Over 4 years, risk of vertebral fracture was reduced by 33% with strontium ranelate (risk reduction = 0.67, p < 0.001). Among patients with two or more prevalent vertebral fractures, risk reduction was 36% (p < 0.001). QoL, assessed by the QUALIOST(R), was significantly better (p = 0.025), and patients without back pain were greater (p = 0.005) with strontium ranelate than placebo over 4 years. Lumbar BMD increased over 5 years in patients who continued with strontium ranelate, while it decreased in patients who switched to placebo. Emergent adverse events were similar between groups.

CONCLUSION

In this 4- and 5-year study, strontium ranelate is an effective and safe treatment for long-term treatment of osteoporosis in postmenopausal women.

Assessment of determinants for osteoporosis in elderly men

SUMMARY

The aim of this cross-sectional study was to determine and quantify some determinants associated to low bone mineral density (BMD) in elderly men. This study showed that ageing, a lower body mass index (BMI), a higher blood level of C-terminal cross-linking telopeptides of type I collagen (CTX-1), family history of osteoporosis, and/or fracture and prior fracture were associated with bone mineral density.

INTRODUCTION

Our aims were to identify some determinants associated to low bone mineral density in men and to develop a simple algorithm to predict osteoporosis.

METHODS

A sample of 1,004 men aged 60 years and older was recruited. Biometrical, serological, clinical, and lifestyle determinants were collected. Univariate, multivariate, and logistic regression analyses were performed. Receiver operating characteristic analysis was used to assess the discriminant performance of the algorithm.

RESULTS

In the multiple regression analysis, only age, BMI, CTX-1, and family history of osteoporosis and/or fracture were able to predict the femoral neck T-score. When running the procedure with the total hip T-score, prior fracture also appeared to be significant. With the lumbar spine T-score, only age, BMI, and CTX-1 were retained. The best algorithm was based on age, BMI, family history, and CTX-1. A cut-off point of 0.25 yielded a sensibility of 78%, a specificity of 59% with an area under the curve of 0.73 in the development and validation cohorts.

CONCLUSION

Ageing, a lower BMI, higher CTX-1, family history, and prior fracture were associated with T-score. Our algorithm is a simple approach to identify men at risk for osteoporosis.

[Interest of monoclonal antibodies in biomedical laboratory analysis]

Immunoassays, or assays with antibodies as reagents, are widely used in medical laboratories. These assays are used to identify and quantify various substances in biological fluids, such as specific proteins (various tissue markers, markers of inflammation, hormones, coagulation factors...) or immunoglobulins (viral or bacterial antibodies, auto-antibodies...) and even both viral antigens and antibodies (HIV virology). The use of monoclonal antibodies allowed, through their specificity for a single epitope of the target molecule, the development of increasingly sophisticated immunoassays. In particular, the use of monoclonal antibodies with microarrays permits the simultaneous determination of various proteins (inflammatory profile, cardiac profile, specifics IgE...) quickly and accurately. Very important tools in the clinical laboratory, immunoassays techniques are, however, subject to various analytical interferences which may be responsible for significant changes in the test results.

[Production of monoclonal antibodies]

In contrast to a polyclonal antiserum, a monoclonal antibody is specific to a single epitope on the surface of a complex antigen. In 1975, Kohler and Milstein produced the first monoclonal antibodies by using a method which rapidly became a key technology in immunology. By fusing activated antibody-forming cells (B cells) with myeloma cells, they obtained hybrid cells--the so-called hydridomas--which combine the ability of the activated B cells to secrete a single species of antibody and the immortality of the myeloma cell. The selected hybridomas proliferate continuously, their clonal progeny providing an unending supply of antibody with a single specificity. These antibodies have found many applications in basic research and in vitro diagnosis. In the clinical laboratory, monoclonal antibodies are used as reagents in immunoassays, often replacing traditional antisera. Many years of development and innovation were needed to humanize monoclonal antibodies in order to make them usable in human therapy.

Comprehensive therapy in osteoporosis using a single drug: from ADFR to strontium ranelate

In vitro, strontium ranelate increases collagen and non-collagenic proteins synthesis by mature osteoblast enriched cells. The effects of strontium ranelate on bone formation were confirmed as the drug enhanced preosteoblastic cell replication. In the isolated rat osteoclast, a preincubation of bone slices with strontium ranelate induced a dose-dependent inhibition of the bone resorbing activity of treated rat osteoclast. Strontium ranelate dose-dependently inhibited preosteoclast differentiation. In a phase II dose ranging trial Strontium ranelate (500 mg, 1000 mg, 2000 mg/day) or placebo were given to 353 postmenopausal women with prevalent vertebral osteoporosis. At the conclusion of this 2-year study, the annual increase in lumbar BMD of the group receiving 2000 mg of strontium ranelate was + 7.3%, a significant increase in bone alkaline phosphatase, over a 6-month period and a significant decrease in N-telopeptide crosslinks throughout the 2-year period were seen. During the second year of treatment, the dose of 2000 mg was associated with a 44% reduction in the number of patients experiencing a new vertebral deformity. The primary analysis of the SOTI study, evaluating the effect of strontium ranelate 2000 mg on vertebral fracture rates, revealed a 41% reduction in the relative risk of patient experiencing a first new vertebral fracture with strontium ranelate throughout the 3-year study. The TROPOS study showed a significant reduction in the risk of experiencing a first non-vertebral fracture by 16% in the group treated with strontium ranelate throughout the 3-year study. A reduction in the risk of experiencing a hip fracture by 36% was also demonstrated in the patients at high risk of hip fracture (age > or =74 years and Femoral Neck T score < or = -2.4 according to NHANES normative value). All these results suggest that strontium ranelate is a new, effective and safe treatment of vertebral and non-vertebral osteoporosis, with a unique mode of action.

Osteoarthritis, magnetic resonance imaging, and biochemical markers: a one year prospective study

OBJECTIVE

To investigate the relation between biochemical markers of bone, cartilage, and synovial remodelling and the structural progression of knee osteoarthritis.

METHODS

62 patients of both sexes with knee osteoarthritis were followed prospectively for one year. From magnetic resonance imaging (MRI), done at baseline and after one year, the volume and thickness of cartilage of the femur, the medial tibia, and the lateral tibia were assessed. A whole organ magnetic resonance imaging score (WORMS) of the knee was calculated for each patient at baseline and at the one year visits. This score consists in a validated, semiquantitative scoring system for whole organ assessment of the knee in osteoarthritis using MRI. Biochemical markers (serum hyaluronic acid, osteocalcin, cartilage glycoprotein 39 (YKL-40), cartilage oligomeric matrix protein (COMP), and C-telopeptide of type I collagen (CTX-I), and urine C-telopeptide of type II collagen (CTX-II)) were measured at baseline and after three months.

RESULTS

Baseline markers were not correlated with one year changes observed in cartilage volume and thickness. However, an increase in CTX-II after three months was significantly correlated with a one year decrease in mean thickness of medial tibial and lateral tibial cartilage. Patients in the highest quartile of three month changes in CTX-II experienced a mean loss of 0.07 (0.08) mm of their medial thickness, compared with a mean increase of 0.05 (0.19) mm for patients in the lowest quartile (p = 0.04) Multiple regression analysis showed that high baseline levels of hyaluronic acid are predictive of a worsening in WORMS (p = 0.004).

CONCLUSIONS

These results suggest that a single measurement of serum hyaluronic acid or short term changes in urine CTX-II could identify patients at greatest risk of progression of osteoarthritis.

One-year increase of Coll 2-1, a new marker of type II collagen degradation, in urine is highly predictive of radiological OA progression

OBJECTIVE

To analyse the relationship between the levels of urinary biochemical markers of type II collagen degradation and the clinical and radiological severity and progression of knee osteoarthritis (OA).

METHOD

Seventy-five patients with primary knee OA were included in this 3-year follow-up study. Mean joint space width (JSW) of the medial compartment of the femorotibial joint was measured with a computer assisted method on standardized radiographs taken at baseline and after a 3-year follow-up. Pain, stiffness, and physical function subscales of the Western Ontario and McMaster Universities (WOMAC) were assessed at the same time points. Type II collagen peptides Coll 2-1 and Coll 2-1 NO(2), as well as pyridinoline (Pyr) and deoxypyridinoline (D-Pyr) were measured in urines at baseline, after 1 year and 3 years, with specific immunoassays.

RESULTS

At baseline, significant correlations were found between the urinary Coll 2-1 and Coll 2-1 NO(2) levels and the global WOMAC score (Coll 2-1: r=0.28, P=0.01; Coll 2-1 NO(2): r=0.27, P=0.02) and its subscales for pain (Coll 2-1: r=0.27, P=0.01; Coll 2-1 NO(2): r=0.30, P=0.01) and function (Coll 2-1: r=0.29, P=0.01; Coll 2-1 NO(2): r=0.27, P=0.02). Pyr and D-Pyr levels were not significantly correlated with the WOMAC scores. One-year change in Coll 2-1 and Coll 2-1 NO(2) urinary levels were negatively correlated with a 3-year change in JSW (Coll 2-1: r=-0.31, P=0.03; Coll 2-1 NO(2): r=-0.31, P=0.03), indicating that an increase of Coll 2-1 or Coll 2-1 NO(2) over 1 year is predictive of subsequent joint space narrowing. Neither Pyr nor D-Pyr was correlated with radiological OA progression.

CONCLUSIONS

At baseline, Coll 2-1 and Coll 2-1 NO(2) urinary levels were indicative of the clinical activity of knee OA and the increase of these peptides over 1 year was predictive of the radiological progression of knee OA.

Rapid improvement of bone metabolism after infliximab treatment in Crohn's disease

BACKGROUND

Crohn's disease is associated with low bone mineral density and altered bone metabolism.

AIM

To assess the evolution of bone metabolism in Crohn's disease patients treated with infliximab.

METHODS

We studied 71 Crohn's disease patients treated for the first time with infliximab for refractory Crohn's disease. Biochemical markers of bone formation (type-I procollagen N-terminal propeptide, bone-specific alkaline phosphatase, osteocalcin) and of bone resorption (C-telopeptide of type-I collagen) were measured in the serum before and 8 weeks after infliximab therapy and compared with values in a matched healthy control group.

RESULTS

Eight weeks after treatment with infliximab, a normalization of bone markers was observed with a median increase in formation markers of 14-51% according to marker and a lower but significant decrease in resorption marker (median 11%). A clinically relevant increase in bone formation markers was present in 30-61% of patients according to the marker. A clinically relevant decrease in C-telopeptide of type-I collagen was present in 38% of patients. No association was found with any tested demographic or clinical parameter.

CONCLUSION

Infliximab therapy in Crohn's disease may rapidly influence bone metabolism by acting either on bone formation or bone resorption. This improvement seems to be independent of clinical response to infliximab.

Reduction in PINP, a marker of bone metabolism, with raloxifene treatment and its relationship with vertebral fracture risk

In the Multiple Outcomes of Raloxifene Evaluation (MORE) trial, 7705 postmenopausal women with osteoporosis, defined by low bone mineral density and/or prevalent vertebral fractures (VF), were randomized to placebo or raloxifene (60 or 120 mg/day). All women received daily calcium (500 mg) and vitamin D (400-600 IU) supplements. Our previous analyses found that changes in BMD and biochemical markers of bone turnover are poorly predictive of the reduction in VF risk observed with raloxifene. This present study evaluated the effects of raloxifene on type I procollagen N-terminal propeptide (PINP), a new marker of bone turnover. Logistic regression analysis models evaluated the relationships between the changes at 1 year in PINP, serum osteocalcin (OC), bone-specific alkaline phosphatase (BSAP), and urinary excretion of type I collagen C-telopeptide fragments normalized to creatinine (CTx/Cr), and the risk of new VF at 3 years for placebo and pooled raloxifene. A subset of 967 women (mean age = 68 years) from the MORE cohort had PINP, OC, BSAP, and CTx evaluated at baseline. Both doses of raloxifene significantly decreased (P < 0.001) all biochemical markers of bone turnover from baseline. Compared to baseline, PINP levels were decreased by medians of 11.0% and 40.8% in the placebo and pooled raloxifene groups, respectively. In addition, the placebo and pooled raloxifene groups decreased serum OC by 8.5% and 31.8%, BSAP by 15.8% and 34.6%, and urinary CTx/Cr excretion by 5.6% and 46.5%, respectively, from baseline. In the pooled raloxifene group, the logistic regression relationship between 3-year VF risk and 1-year percentage change for each biochemical marker was statistically significant with PINP (slope estimate = 0.0085, P = 0.009), OC (slope estimate = 0.0068, P = 0.035), and BSAP (slope estimate = 0.0056, P = 0.039), but not with CTx/Cr (slope estimate = 0.0027, P = 0.192). Furthermore, the percent decrease in PINP at 1 year could account for 28% of the total reduction in vertebral fracture risk. In conclusion, a 1-year decrease in PINP, BSAP, or OC, but not CTx/Cr, may be predictive of the 3-year VF risk reduction with raloxifene therapy in this subset of postmenopausal women with osteoporosis.

[Comparison of changes in biochemical markers of bone turnover after 6 months of hormone replacement therapy with either transdermal 17 beta-estradiol or equine conjugated estrogen plus nomegestrol acetate]

OBJECTIVE

To compare changes in biochemical markers of bone turnover in postmenopausal women who received sequential discontinuous hormone replacement therapy (HRT) with either transdermal 17 beta-estradiol gel (group 1) or oral equine sulfoconjugated estrogen (group 2), plus nomegestrol acetate.

PATIENTS AND METHOD

Prospective, open, randomized, controlled trial, conducted on 3 parallel groups of 106 postmenopausal women. All treated groups received estrogen therapy for 25 consecutive days every month. The estrogen used was either 1.5 mg/day of transdermal 17 beta-estradiol gel (group 1) [N = 42, average age (AA) = 51.6 years, average duration of menopause (ADM = 21.5 months)], or 0.625 mg/day of oral equine sulfoconjugated estrogen (group 2) [N = 39, AA = 51.3 years, ADM = 16.8 months]. In all cases nomegestrol acetate 5 mg/day was added for 12 consecutive days every month. The control group comprised 25 patients, [AA = 53.4 years, ADM = 33.7 months]. Two bone resorption markers: urinary cross-linked N-telopeptide and C-telopeptide of type I collagen (U-NTX/Cr, U-CTX/Cr), and a bone formation marker: serum bone specific alkaline phosphatase activity were measured before and 6 months after treatment start.

RESULTS

Significant decreases from baseline values were observed for the 3 biochemical markers in both treated groups compared with control (P < 0.001). There were no significant differences in changes between the 2 treated groups for the 3 biochemical markers. The mean percentage change in the 3 biochemical markers was: from -9.3 to -45.5% in group 1, from -20.5 to -39% in group 2, and from -3.3 to 2% in control group. In group 1, the mean percentage decreases in U-CTX reached optimal threshold of bone turnover change (-45%) which is considered by the International Osteoporosis Foundation as clinically relevant because it predicts an increase in BMD greater than 3% when treatment is maintained over a long term.

DISCUSSION AND CONCLUSION

Both treated groups induced a significant comparable decrease of bone turnover markers after 6 months of intervention, compared with control. The group treated with cyclic administration of transdermal 17 beta-estradiol (1.5 mg/day) and nomegestrol acetate (5 mg/day) showed a bone resorption markers decrease corresponding to the threshold of clinical relevance described in the international literature and predictive of positive BMD response in long term.

Osteoarthritic patients with high cartilage turnover show increased responsiveness to the cartilage protecting effects of glucosamine sulphate

OBJECTIVE

Glucosamine sulphate has been shown in a large double-blind, placebo-controlled clinical trial to prevent structural damage and improve clinical symptoms of osteoarthritis (OA). We investigated whether early response in a newly developed biochemical marker of collagen type II degradation (CTX-II, CartiLaps ELISA) could reflect the long-term preservation of hyaline cartilage.

METHODS

Study subjects comprised 212 knee OA patients participating in a clinical trial of the effects of glucosamine sulphate. Disease symptoms were assessed quarterly by WOMAC scoring and X-ray analysis was performed at baseline and after 3 years. Urine samples were obtained at baseline and after 1, 2 and 3 years for measurement in the CartiLaps assay. The measurements were corrected for creatinine.

RESULTS

At baseline the patients had an average concentration of urinary CTX-II of 222.4 +/- 159.5 ng/mmol creatinine. This was significantly above the CTX-II levels measured in urine samples from 415 healthy controls (169.1 +/- 92.3 ng/mmol, p < 0.0001). There was no significant difference in the CTX-II response in the placebo group and the glucosamine treated group. However, those with high cartilage turnover presented a significant decrease in CTX-II after 12-month glucosamine treatment. Thus, three group with CTX II concentrations above normal average + 1SD decreased 15.5% after 12-month therapy. The 12 months change in CTX-II in OA patients with elevated CTX-II at baseline correlated with the change in average joint space width observed after 36 months (R = 0.43, p < 0.05). Increased baseline levels of CTX-II were associated with a worsening of the WOMAC index (p < 0.01).

CONCLUSION

The data indicate that measurement of urinary collagen type II C-telopeptide fragments enables the identification of OA patients with high cartilage turnover who at the same time are most responsive to therapy with structure modifying drugs.

Pharmacodynamics of follicle stimulating hormone (FSH) in postmenopausal women during pulsed estrogen therapy: Evidence that FSH release and synthesis are controlled by distinct pathways

17 beta-Estradiol (E2) exerts negative feedback effects at the hypothalamo-pituitary level on serum FSH. This study investigated the effects of repeated daily administration of intranasal E2 (S21400) on the pharmacokinetics (PK) of E2 and estrone (E1) and the pharmacodynamics (PD) of FSH and assessed the PK/PD relationship between E2 and FSH using population model-dependent analysis. Postmenopausal volunteers (n = 24) received according to a balanced cross-over design, two 28-d treatments separated by a 2-month wash-out period: 300 microg E2, either alone or combined with oral dydrogesterone (20 mg/d) during the last 14 d of one of the treatments. Absorption of E2 was rapid, with maximal plasma concentrations at 10-30 min, returning to postmenopausal levels within 12 h. Over the 24-h period, FSH levels showed a U curve, with a minimum around 8 h after E2 administration. Moreover, over the treatment period, FSH basal values decreased by 17% between d 1 and 14 and an additional 5% between d 14 and 28. A PK/PD model described these short- and mid-term effects, possibly reflecting separate regulation mechanisms by E2 on FSH release and biosynthesis, respectively. The administration of progestin had no influence on E1, E2, and FSH model parameters. This study suggests that daily transient tissue exposure to E2 after pulsed estrogen therapy elicits short- and mid-term effects on the gonadotropin axis.

[Analysis of results taken with "tweezers": some pitfalls in clinical biological interpretation]

Like other medical investigations, laboratory tests are not free from uncertainties or errors which limit their clinical value. Usually two levels of variations are identified: the analytical and biological levels. This paper presents some sources of variations and provides different examples. The concept of reference value is also discussed, as well as the clinician's viewpoint regarding the interpretation of laboratory results.

Administration of a supplement containing both calcium and vitamin D is more effective than calcium alone to reduce secondary hyperparathyroidism in postmenopausal women with low 25(OH)vitamin D circulating levels

BACKGROUND AND AIMS

Supplementation of postmenopausal women with calcium alone or calcium-vitamin D association was suggested to have positive effects on bone turnover and bone density, as well as to lower fracture incidence. The beneficial effect appears to be mediated by a reduction in parathyroid hormone secretion. Our aim was to compare the respective efficacy of calcium and calcium-vitamin D supplements in reducing serum parathyroid hormone levels in postmenopausal women with prevalent low 25(OH)vitamin D levels.

METHODS

One hundred consecutive ambulatory postmenopausal women with serum 25(OH)vitamin D levels below 18 ng/mL were included in a randomized, prospective, open label study. For a duration of 90 days, the women were randomly assigned to a daily supplementation of either one tablet of calcium gluconolactate and carbonate (500 mg calcium), or one powder-pack of an association of calcium carbonate (500 mg calcium), citric acid (2.175 gr) and cholecalciferol (200 IU). Changes observed during the 90 days of the study in circulating PTH levels were the primary endpoint, while changes in serum 25(OH)D levels were assessed as secondary endpoint.

RESULTS

A significant difference was observed between the calcium-vitamin D (CaD) and the calcium (Ca) only groups for changes occurring during the 90 days of the study in PTH (-14.5+/-40% and +2.5+/-46%) (p=0.009) and 25(OH)D (+67+/-77% and +18+/-55%) (p<0.001) circulating levels. PTH changes between baseline and day 90 were significant in the CaD group, but not in the Ca group. The odds ratio for a patient in group Ca to experience an absolute (<12 ng/mL) deficiency in circulating 25(OH)vitamin D levels, compared to a group CaD patient was statistically increased (OR: 3.22, 95% CI: 1.33-7.80).

CONCLUSIONS

Our results support the recommendation of supplementing postmenopausal women with low circulating levels of 25(OH)vitamin D with a combination of calcium and vitamin D, rather than with calcium alone.

Bone resorption in post-menopausal women with normal and low BMD assessed with biochemical markers specific for telopeptide derived degradation products of collagen type I

Biochemical markers of bone resorption can be used clinically to predict the risk of osteoporosis-related fractures (prognostic tool) and to assess the response of an osteoporotic patient to an antiresorptive therapy (monitoring tool). Our aim was to assess the ability of four currently marketed biochemical markers of bone resorption, based on the measurement of degradation products from collage type I telopeptides to monitor the elevated resorption associated with menopause. Women (846) were stratified for menopause, age, and bone mineral density and the following markers were measured: urinary cross-linked N-telopeptides of type I collagen (NTx), the levels of breakdown products of type I collagen C-telopeptides in serum (S-CTx), and in urine, by ELISA (U-CTx-E), and RIA (U-CTx-R). Furthermore, the ratio (alpha/beta) between the alphaL form of CTx measured in the CTx RIA and the betaL form measured in the ELISA was calculated. The mean difference was calculated for each marker in women with osteopenia (Op) or osteoporosis (PMO) (WHO definition) compared with healthy premenopausal (Pre) women and postmenopausal (N Post) women with normal bone mass. Serum CTx showed the highest elevation in post- compared with premenopausal women. All marker values were significantly higher in Op and PMO subjects compared with both Pre and to N Post women. Compared with premenopausal values, the largest elevation in both Op and PMO women was observed for serum CTx. Compared with N Post, urine NTx showed the highest increase in OP subjects. The alpha/beta CTx ratio was elevated in post- compared with Pre women, but there was no difference in the ratio among N Post, Op, or PMO women. In conclusion, postmenopausal women showed elevated turnover with all bone resorption markers, but with substantial individual variation in resorption levels. Furthermore, the turnover process in postmenopausal women appears to be quantitatively different from the premenopausal stage, apparent as altered alpha/beta CTx ratios.

Thymic expression of insulin-related genes in an animal model of autoimmune type 1 diabetes

BACKGROUND

Insulin and multiple other autoantigens have been implicated in the pathogenesis of autoimmune type 1 diabetes, but the origin of immunological self-reactivity specifically oriented against insulin-secreting islet beta-cells remains obscure. The primary objective of the present study was to investigate the hypothesis that a defect in thymic central T-cell self-tolerance of the insulin hormone family could contribute to the pathophysiology of type 1 diabetes. This hypothesis was investigated in a classic animal model of type 1 diabetes, the Bio-Breeding (BB) rat.

METHODS

The expression of the mammalian insulin-related genes (Ins, Igf1 and Igf2) was analysed in the thymus of inbred Wistar Furth rats (WF), diabetes-resistant BB (BBDR) and diabetes-prone BB (BBDP) rats.

RESULTS

RT-PCR analyses of total RNA from WF, BBDP and BBDR thymi revealed that Igf1 and Ins mRNAs are present in 15/15 thymi from 2-day-old, 5-day-old and 5-week-old WF, BBDR and BBDP rats. In contrast, a complete absence of Igf2 mRNA was observed in more than 80% of BBDP thymi. The absence of detectable Igf2 transcripts in the thymus of BBDP rats is tissue-specific, since Igf2 mRNAs were detected in all BBDP brains and livers examined. Using a specific immunoradiometric assay, the concentration of thymic IGF-2 protein was significantly lower in BBDP than in BBDR rats (p<0.01).

CONCLUSIONS

The present study suggests an association between the emergence of autoimmune diabetes and a defect in Igf2 expression in the thymus of BBDP rats. This tissue-specific defect in gene expression could contribute both to the lymphopenia of these rats (by impaired T-cell development) and the absence of central T-cell self-tolerance of the insulin hormone family (by defective negative selection of self-reactive T-cells).

Effect of high doses of oral risedronate (20 mg/day) on serum parathyroid hormone levels and urinary collagen cross-link excretion in postmenopausal women with spinal osteoporosis

The present study describes the biological effects of risedronate, a pyridinyl bisphosphonate, on bone and assesses the safety and tolerability of risedronate when given at high doses, with or without calcium, to postmenopausal women with spinal osteoporosis. This single-center descriptive, double-blind, placebo-controlled, randomized, parallel group study included 32 postmenopausal white women with at least one radiographically confirmed vertebral compression fracture. Patients were randomized to one of four different dose regimen groups: (i) R-P, risedronate 20 mg/day for 14 days, followed by placebo for 42 days; (ii) R-CP-P, risedronate 20 mg/day for 14 days, followed by elemental calcium 1000 mg/day and placebo for 14 days, then by placebo for 28 days; (iii) R-CP-R-CP, risedronate 20 mg/day for 7 days, followed by elemental calcium 1000 mg/day and placebo for 21 days, then risedronate 20 mg/day for 7 days, and finally elemental calcium 1000 mg/day and placebo for 21 days; and (iv) P, placebo for 56 days. The biological response was investigated by measuring serum calcium, parathyroid hormone (PTH), and 2 h urinary pyridinoline/creatinine (Pyr/Cr) and deoxypyridinoline/creatinine (DPyr/Cr) ratios at baseline and at days 3, 7, 14, 21, 28, 35, 42, 49, 56, and 84. Overall, there were no consistent trends observed between the active group and placebo for serum calcium. In groups R-P, R-CP-P, and R-CP-R-CP, mean serum PTH levels were elevated above baseline values for the entire 56 day treatment period and remained elevated, although to a lesser extent, at the day 84 follow-up visit. The effect of calcium supplementation on PTH was variable. Urinary Pyr/Cr and DPyr/Cr ratios were decreased from baseline over the entire study period in all groups receiving risedronate. The maximum observed percent decreases from baseline for Pyr/Cr and DPyr/Cr were -46.9% and -58.8%, respectively, at day 49 in the R-CP-R-CP group. In conclusion, risedronate given orally at a dose of 20 mg/day, continuously for 7 or 14 days, resulted in the expected biological response in osteoporotic women. The time course of changes in PTH levels following cessation of dosing was unaffected by calcium supplementation. There was no evidence of a PTH-mediated rebound in bone resorption following cessation of therapy. Furthermore, based on collagen cross-link data, patients did not show an excessive reduction in bone turnover.

Progression in MCF-7 breast cancer cell tumorigenicity: compared effect of FGF-3 and FGF-4

The transforming properties of fibroblast growth factor 3 (FGF-3) were investigated in MCF7 breast cancer cells and compared to those of FGF-4, a known oncogenic product. The short form of fgf-3 and the fgf-4 sequences were each introduced with retroviral vectors and the proteins were only detected in the cytoplasm of the infected cells, as expected. In vitro, cells producing FGF-3 (MCF7.fgf-3) and FGF-4 (MCF7.fgf-4) displayed an amount of estrogen receptors decreased to around 45% of the control value. However, MCF7.fgf-3 cell proliferation remained responsive to estradiol supply. The sensitivity of the MCF7.fgf-4 cells, if existant, was masked by the important mitogenic action exerted by FGF-4. In vivo, the MCF7.fgf-3 and MCF7.fgf-4 cells gave rise to tumors under conditions in which the control cells were not tumorigenic. Supplementing the mice with estrogen had the paradoxical effect of totally suppressing the start of the FGF-3 as well as the FGF-4 tumors. Tumorigenicity in the presence of matrigel was similar for MCF7.fgf-3 and control cells and was increased by estrogen supplementation. Once started, the MCF7.fgf-4 tumors grew with a characteristic high rate. Remarkably, FGF-4 but not FGF-3, stimulated the secretion of vascular endothelial growth factor (VEGF165) without altering the steady-state level of its mRNA, suggesting a possible regulation of VEGF synthesis at the translational level in MCF7 cells. The increased VEGF secretion is probably involved in the more aggressive phenotype of the MCF7.fgf-4 cells while a decreased dependence upon micro-environmental factors might be part of the increased tumorigenic potential of the MCF7.fgf-3 cells.

IGF-II in primary human colorectal tumors: peptide level, activated promoters, parental imprinting and gene rearrangement

IGF-II is a polypeptide growth factor with growth and differentiation promoting activities, involved in human development. We have reported previously IGF-II mRNA and peptide overexpression in primary human colon cancers. Here we show that the IGF-II peptide content is increased in six primary colon cancers compared to the corresponding healthy tissues. The IGF-II transcripts in healthy and cancerous colon tissues were identified by Northern blotting and RT-PCR. Promoters P3 and P4 were active in most tissues. Relaxation of parental imprinting was observed in two tumors and one healthy tissue, without any correlation with the IGF-II transcript levels. Rearrangements of the IGF-II gene in two tumors containing very high amounts of IGF-II mRNA are described. Fragments containing the breakpoints were cloned by the vectorette-PCR strategy. In both tumors, the breakpoints occurred in repetitive sequences. In one tumor (T11), the breakpoint was localized 2 kb downstream the end of exon 9. The second tumor (T18) contains two modified alleles. In one rearranged allele the breakpoint is located in exon 9. The exact position of the breakpoint in the second rearranged allele has not been identified. In future experiments, the correlation between the gene rearrangements and IGF-II mRNA overexpression will be studied.

High prevalence of low femoral bone mineral density in elderly women living in nursing homes or community-dwelling: a plausible role of increased parathyroid hormone secretion

The present study was designed to visit elderly women living in nursing homes and to compare their femoral neck bone mineral density (BMD) and circulating levels of parathyroid hormone (PTH) and 25-OH vitamin D (25-OHD) with those of subjects living at home, in the immediate vicinity of the nursing homes. Of 1483 women, aged 70 years and older, who were selected, 993 agreed to participate in this trial. Their femoral neck BMD (n = 993) was measured by dual-energy X-ray absorptiometry, with a specific device installed in a mobile truck. The circulating levels of 25-OHD and PTH were assessed after an overnight fast (n = 748). After stratification for age, there were no significant differences in mean femoral neck BMD values, prevalence of femoral neck osteoporosis, mean serum 25-OHD and prevalence of absolute or relative 25-OHD deficiency between the two groups. Serum levels of PTH were significantly higher in women over 80 years old living in nursing homes, compared with the community-dwelling women. After adjustment for age, a significant relation was found between femoral neck BMD and PTH levels in the whole population (p = 0.004) and in community-dwelling subjects (p = 0.039). When stratifying our population by quartiles of serum PTH values, the odds ratios for femoral neck osteoporosis were significantly increased for the top two quartiles compared with the lowest one both before (p = 0.00146) and after (p = 0.0013) adjustment for age and type of housing. From this study we conclude that femoral osteoporosis is largely underestimated in European women. Living in a nursing home is not, per se, a risk factor for decreased femoral BMD, and circulating PTH levels are a key determinant of low femoral bone density and osteoporosis.

FGF-3 and FGF-4 elicit distinct oncogenic properties in mouse mammary myoepithelial cells

Fibroblast Growth Factors 3 (FGF-3) and 4 (FGF-4) were compared for the effects they each exert on EF43 mouse cells. This non-transformed mammary cell line appears to be myoepithelial mainly because it expresses alpha-smooth muscle actin. The EF43 cells were infected with similar vectors that carry either the short fgf-3 sequence (the product of which goes into the secretory pathway), fgf-4 or the selection gene only as control. In syngeneic animals, EF43.fgf-3 cells were tumorigenic only when orthotopically implanted whereas EF43.fgf-4 cells invariably gave rise to aggressive tumors. However, both tumor types were metastatic as evidenced by the blue micrometastases observed when the implanted cells expressed lacZ. In vitro, the FGF-3 producing cells were strongly invasive in matrigel coated chambers whereas the EF43.fgf-4 cells only were invasive in type I-collagen gels. Interestingly, FGF-3 production greatly stimulated the synthesis of pro-MMP-9 (Matrix Metalloprotease-9) and, to a lesser extent, that of pro-MMP-2. FGF-3 also up-regulated the production of plasminogen activators. In contrast, FGF-4 had no effect on these secretions and the medium conditioned by the EF43.fgf-4 cells displayed the largest plasminogen activator-inhibitor activity. These results show that FGF-3 and FGF-4 have distinct mechanisms of action on myoepithelial cells.

The effect of sodium monofluorophosphate plus calcium on vertebral fracture rate in postmenopausal women with moderate osteoporosis. A randomized, controlled trial

BACKGROUND

Fluoride is effective in increasing trabecular bone mineral density (BMD) in the spine, but its efficacy in reducing vertebral fracture rates and its effect on BMD at cortical sites are controversial.

OBJECTIVE

To study the effect of low-dose fluoride (sodium monofluorophosphate [MFP]) plus a calcium supplement over 4 years on vertebral fractures and BMD at the lumbar spine and total hip in postmenopausal women with moderately low BMD of the spine.

DESIGN

Randomized, double-blind, controlled clinical trial.

SETTING

Outpatient clinic for osteoporosis at a university medical center.

PATIENTS

200 postmenopausal women with osteoporosis (according to the World Health Organization definition) and a T-score less than -2.5 for BMD of the spine.

INTERVENTION

Women were randomly assigned (100 patients per group) to continuous daily treatment for 4 years with 1) oral MFP (20 mg of equivalent fluoride) plus 1000 mg of calcium (as calcium carbonate) or 2) calcium only.

MEASUREMENTS

Lateral spine radiographs were taken at enrollment and at each year of follow-up for detection of new vertebral fractures (defined as a reduction > or =20% and > or =4 mm from baseline in any of the heights of a vertebral body). Nonvertebral fractures were also recorded. All analyses were done with the intention-to-treat approach.

RESULTS

Radiologic follow-up was possible for 164 of 200 patients (82%). The rate of new vertebral fractures during the 4 years of the study was lower in the MFP-plus-calcium group (2 of 84 patients; 2.4% [95% CI, 0.3% to 8.3%]) than in the calcium-only group (8 of 80 patients; 10% [CI, 4.4% to 18.8%]). The difference between the groups was 7.6 percentage points (CI, 0.3 to 15 percentage points) (P = 0.05). A moderate but progressive increase in BMD of the spine (10.0% +/- 1.5% at 4 years) was found for MFP plus calcium compared with calcium only (P < 0.001), whereas the more modest increase in BMD of the total hip seen with MFP plus calcium (1.8% +/- 0.6%) did not differ from the increase seen with calcium only.

CONCLUSIONS

Low-dose fluoride (20 mg/d) given continuously with calcium for prolonged periods can decrease vertebral fracture rates compared with calcium alone in patients with mild to moderate osteoporosis.

Characterization of the IGF system and analysis of the possible molecular mechanisms leading to IGF-II overexpression in a mesothelioma

The expression of members of the IGF system in a mesothelioma from a patient suffering from hypoglycemia, in term placenta and HT29 colon adenocarcinoma cells were compared. Very high levels of IGF-II mRNA and protein were detected in the mesothelioma. Moreover, half of the IGF-II protein took the high-molecular-weight form. We also analyzed the parental imprinting status and the promoter usage of the IGF-II gene. Our results showed loss of imprinting (LOI) in the mesothelioma while the imprinting was maintained in HT29 cells, expressing moderate levels of the transcript. Promoter P4 was active in the three tissues we analyzed, whereas IGF-II mRNA transcription from promoter P3 was only detected in the mesothelioma and the placenta, expressing comparably high levels of the transcript. IGF-II gene structure was identical in the analyzed tissues and cells. The type-I receptor mRNA expression was very low in the tumor. IGFBP-2, -4 and -5 mRNAs were detected in the mesothelioma, while IGFBP-2, -3 and -5 transcripts were detected in the placenta. IGFBP-1 and -6 transcripts were not detected.

Prediction of bone loss rate in healthy postmenopausal women

Prevention of fractures is the only way to drastically reduce osteoporosis-related health expenditures. In order to optimize the cost/benefit ratio of a strategy of prevention, it is essential to identify, as early as possible, women who will develop fractures later in their life. Therefore, and since postmenopausal bone loss is an asymptomatic process, screening procedures should detect, at the time of the menopause, women whose postmenopausal bone loss is higher than the mean, and will, a couple of years later, exhibit a low mineral content and a subsequent high risk for fractures. For 3 years we have followed a cohort of 92 healthy women who had undergone menopause less than 36 months previously. By a multivariate discriminant analysis based on the differences in lumbar bone density, assessed by dual photon absorptiometry, and in a few routine biochemical parameters (serum phosphorus, estrone, androstenedione, and urine calcium) observed during the first 6 months of the study, we have been able to correctly predict the rate of spinal bone loss, observed at the end of the 3 years, in 76% of the subjects. All of the women who presented a bone loss higher than 10% over the 3 years were correctly isolated by our discriminant functions after 6 months of follow-up. We conclude that a measurement of lumbar bone mineral density coupled with a few routine biochemical determinations, repeated twice at a 6-month interval in healthy postmenopausal women, can isolate 100% of postmenopausal "fast bone losers" with an overall specificity of 76%.

Increase in cytokine production (IL-1 beta, IL-6, TNF-alpha but not IFN-gamma, GM-CSF or LIF) by stimulated whole blood cells in postmenopausal osteoporosis

Postmenopausal osteoporosis is a progressive disorder characterized by a decreased bone mass and increased susceptibility to fractures. Several investigations have suggested that one of the mechanisms through which estrogen prevents bone loss was a modulation on secretion or release of various cytokines that are known to influence bone remodeling, even if some recent data have challenged this hypothesis. However, in established osteoporosis, the possibility that enhanced cytokines activity may account for the progression of this disease remains unclear and controversial. We sought here to determine whether production of IL-1 beta, IL-6, TNF-alpha, IFN-gamma, GM-CSF and LIF, after direct stimulation in whole blood, was different in healthy (n = 30) or osteoporotic postmenopausal women (n = 24) and whether lumbar bone density (1-BMD) correlated with the values of cytokine production observed in these conditions. A significant difference was observed between the osteoporotic and control subjects for IL-1 beta (p < 0.0001), IL-6 (p < 0.001) and TNF-alpha (p = 0.027) productions, the values being higher in the osteoporotic women. No significant differences between the groups were observed for IFN-gamma (p = 0.51), GM-CSF (p = 0.70) or LIF (p = 0.97). In the whole population, statistically significant negative correlations were observed between lumbar BMD and IL-1 beta (r = -0.46) (p < 0.0005), IL-6 (r = -0.50) (p < 0.0001) and TNF-alpha (r = -0.39) (p < 0.005) production while no such correlations were observed for IFN-gamma, GM-CSF or LIF. In conclusion, the study of cytokine production by immune cells cultured in autologous whole blood suggests that in women more than 10 years past the menopause and presenting a decrease in lumbar bone density corresponding to the new WHO definition of "osteoporosis', production of IL-1 beta, IL-6 and TNF-alpha is still increased compared to controls matched for age and ovarian function, while no differences are reported for IFN-gamma, GM-CSF or LIF production.

Distribution of interleukin-6 in maternal and embryonic tissues during the first trimester

Interleukin-6 (IL-6) distribution was investigated in coelomic fluid, amniotic fluid, maternal serum, decidua and placental villous tissue collected from 16 normal pregnancies between 7 and 12 weeks of gestation. IL-6 levels in fluids and tissues were measured by an immunoenzymatic assay and mouse monoclonal antibodies specific for IL-6 were used to localize immunohistochemically IL-6 in decidual and placental tissue. IL-6 was detected in all samples of coelomic and amniotic fluids and in most extracts of placental and decidual tissues. IL-6 concentration was significantly (P < 0.005) higher in the coelomic fluid than in amniotic fluid and was positively correlated with gestational age. Immunostaining for IL-6 was present in both syncytiotrophoblast and extra-villous trophoblast. IL-6 was in significantly (P < 0.001) higher concentration in decidual than in placental tissues. These data indicate that IL-6 is normally present in coelomic and amniotic fluids of early pregnancy and that IL-6 concentrations mainly result from the accumulation of trophoblastic-derived IL-6. During the first trimester IL-6 could play a role in tissue remodelling associated with placentation but also in the haematopoiesis function of the secondary yolk sac and in the generation of new vessels in placental villous tissue.

Tumor necrosis factor alpha stimulates insulin-like growth factor binding protein 3 expression in cultured porcine Sertoli cells

The present study was undertaken to analyze how a cytokine, the tumor necrosis factor alpha (TNF alpha), antagonizes the stimulatory action of insulin-like growth factor-I (IGF-I) on FSH receptor levels in testicular Sertoli cells. To achieve this purpose, we measured, in a model of primary culture of porcine Sertoli cells, the effects of TNF alpha on the IGF system that includes IGF-I and IGF-II, IGF binding proteins (IGFBPs), and IGF-I receptor (IGF-I R). We report that while TNF alpha had no consistent effect on the levels of IGF-I, IGF-II, or on IGF-I receptor (protein and messenger RNA (mRNA)], it stimulated IGFBP activity and particularly IGFBP-3. TNF alpha stimulated predominantly IGFBP-3 (about 4-fold) both in terms of mRNA (a 2.6-kilobase transcript, measured by Northern blotting analysis), and protein (a doublet of 40-44 kDa, assessed by ligand blotting analysis). Such a stimulatory effect on IGFBP-3 was detected with a concentration as low as 0.1 ng/ml (5.5 pM) of TNF alpha. The stimulatory action of the cytokine was time dependent and was maximal at 7 h and 48 h, for IGFBP-3 mRNA and protein, respectively. Such an increase in IGFBP-3 in TNF alpha-treated Sertoli cells results probably in a decrease in IGF-1 bioavailability for its receptors and thus in a decrease in IGF-I action. Indeed, addition of recombinant human IGFBP-3 (10 nM) suppressed completely the stimulatory addition of IGF-I (3 nM) on FSH binding to cultured porcine Sertoli cells. Together, the present findings indicate that, in Sertoli cells, TNF alpha antagonizes IGF-I action through the modulation of IGFBPs and particularly through an increase in IGFBP-3. Because of the local production of both TNF alpha and components of the IGF system, such an interaction between the IGF system and the cytokine probably occurs in the context of physiological testicular somatic-germ cell interactions.

Propofol protects cultured rat hippocampal neurons against N-methyl-D-aspartate receptor-mediated glutamate toxicity

The effect of propofol on the toxicity induced by glutamate (GLU), N-methyl-D-aspartate (NMDA), kainate (KA), and amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) was investigated on cultured fetal rat hippocampal neurons. The degree of neuronal injury was quantified by measuring the release of the neuron-specific enolase (NSE) into the culture media. The toxicity induced by brief exposure to GLU (10(-4) M) or to NMDA (10(-4) M) was significantly reduced by propofol, whereas that elicited by KA, AMPA (10(-4) M), or long GLU exposure was unaffected. In conclusion, high concentrations of propofol significantly attenuate NMDA receptor-mediated glutamate neurotoxicity in vitro. Further studies are needed to confirm this beneficial effect in vivo and to evaluate propofol as a neuroprotective anesthetic agent in pathologies involving glutamate release and NMDA-mediated toxicity.

Effect of transforming growth factor-beta 1 on the insulin-like growth factor system in cultured porcine Leydig cells

Using as a model system, primary cultures of porcine Leydig cells, we have shown that transforming growth factor-beta 1 (TGF-beta 1) (2 ng/ml, 72 h) antagonizes the stimulatory action of insulin-like growth factor-I (IGF-I) on luteinizing hormone (LH/hCG) receptors. We therefore investigated the action of TGF-beta 1 on the different components of the IGF system, namely, IGF-I, II, IGF binding proteins (IGFBPs) and IGF-I receptor present in testicular Leydig cells. TGF-beta 1 was shown to decrease in a dose and time dependent manner the binding of 125I-IGF-I to Leydig cells. The maximal (40% decrease) effect was obtained with 1.3 ng/ml (0.05 nM) after 72 h of treatment. Such a decrease in IGF-I binding by TGF-beta 1 treatment was shown to be related to the number of receptor but not to their affinity. Affinity labeling of these receptors by covalently binding them to 125I-IGF-I with disuccinimidyl suberate and subsequent electrophoretic analysis of the labeled complex revealed that the inhibitory action of TGF-beta 1 (2 ng/ml, 72 h) occurs at the level of a 135 kDa protein which represents the classical form of the binding subunit of the IGF-I receptor. Moreover, our study indicates that TGF-beta 1 was unable to affect the other components of the IGF system in cultured porcine Leydig cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Neuron-specific enolase as a marker of in vitro neuronal damage. Part I: Assessment of neuron-specific enolase as a quantitative and specific marker of neuronal damage

Enolase in cerebrospinal fluid is a sensitive marker for many types of neurological injuries including head injury and ischemia. We assessed neuron-specific enolase (NSE) as a quantitative and specific biochemical marker of neuronal damage in an experimental model of kainate neurotoxicity. Rat hippocampal cultures were treated with various concentrations of kainate. NSE release into the culture medium was compared with neuronal death estimated either by direct cell counting or by lactate dehydrogenase (LDH) release, largely used to quantify neuronal injury. A dose-response relationship was observed between kainate concentration and the amount of NSE released (r = -0.69; p < 0.05) as well as a significant correlation between NSE release and neuronal death (r = 0.64; p < 0.05). Likewise, a significant correlation was found between LDH and NSE release (r = 0.85; p < 0.05). The specificity of NSE as an indicator of neuronal death was demonstrated using immunocyto-chemistry labeling and measurement of NSE release by pure astrocyte cultures. We concluded that NSE is a reliable, quantitative, and specific marker of neuronal injury.

Neuron-specific enolase as a marker of in vitro neuronal damage. Part II: Investigation of the astrocyte protective effect against kainate-induced neurotoxicity

The protective effect of astrocytes on hippocampal neurons against kainate-induced toxicity was investigated using neuron-specific enolase as an indicator of neuronal death. Astrocyte-rich and astrocyte-poor mixed rat hippocampal cultures were submitted to various concentrations of kainate. At each kainate concentration, the amount of NSE released by neurons was significantly greater in astrocyte-poor than in astrocyte-rich cultures (p < 0.05). This protective effect was not observed when neuronal survival was tested on astrocyte-poor cultures in astrocyte-conditioned culture medium with or without 10(-4) M kainate. In conclusion, astrocytes significantly attenuate kainate toxicity on hippocampal neurons, and this effect is not mediated by a diffusible factor.

Insulin-like growth factor II in two human colon-carcinoma cell lines: gene structure and expression, and protein secretion

Abnormal expression and structural modification of the IGF-II gene in correlation with high IGF-II production have recently been described in human colorectal tumors in comparison with normal adjacent tissues. Here, we have studied IGF-II in 2 human colon-carcinoma cell lines, HT29 and COLO 320DM. RFLP analyses revealed no apparent alteration at the IGF-II locus in these 2 cell lines. HT29 cells weakly expressed IGF-II mRNA in comparison with the high over-expression previously observed in some colorectal tumors, and only the 4.8-kb mRNA species was present. In addition, the serum-free medium conditioned by HT29 cells contained high IGF-II levels (approx. 900 ng/10(8) cells), as measured in a specific IGF-II radioimmunoassay (RIA). After chromatography on Bio-Gel P-60, we observed that 64% of the total IGF-II secreted by HT29 cells were present as a high-molecular-weight form of about 17 kDa. In contrast, no detectable expression of the IGF-II gene was observed in COLO 320DM cells, and low IGF-II levels were secreted by these cells in the serum-free medium, with only 9% total IGF-II represented by the large species.

Stimulatory effect of oestradiol-17 beta and tamoxifen on gross cystic disease fluid protein 15,000 production and mRNA levels in T47D human breast cancer cells

Oestradiol-17 beta and tamoxifen regulate the synthesis of a gross cystic disease fluid protein (GCDFP-15) in T47D human breast cancer cells. Dose-response curves of GCDFP-15 mRNA contents and GCDFP-15 levels in culture media and cells versus hormone or antihormone concentration have been established. Production of GCDFP-15 was increased by oestradiol-17 beta, tamoxifen and 4-OH tamoxifen. The effect of tamoxifen and 4-OH tamoxifen was greater than the effect of oestradiol-17 beta. Moreover, oestradiol-17 beta and 4-OH tamoxifen acted synergystically in enhancing GCDFP-15 release. The strong oestrogenic effect of the antioestrogen tamoxifen in regulating GCDFP-15 may reflect an unusual interaction between the tamoxifen-oestrogen receptor complex and the DNA oestrogen-responsive elements. As oestrogen control of GCDFP-15 depends also on the cell line studied, investigation of GCDFP-15 could extend our knowledge of the possible mechanism of action of oestrogens or antioestrogens.

Tumor IGF-II content in a patient with a colon adenocarcinoma correlates with abnormal expression of the gene

We have recently reported abnormal insulin-like growth factor-II (IGF-II) mRNA levels in a number of human colorectal adenocarcinomas. Using an IGF-II radioimmunoassay, we have now detected high levels of both 10-kDa and 7.5-kDa IGF-II species (2,370 ng/g) in a right colon tumor showing a 800-fold IGF-II gene over-expression in comparison to the normal adjacent tissue. The higher-molecular-mass form represents 74% of the total immunoreactive IGF-II detected in the tumor. This form appears to be less reactive in the radioreceptor assay than in the radioimmunoassay. The insulin-like growth factor-I (IGF-I) concentration in the tumor is low. The patient's pre-operative serum IGF-II level is not increased and the proportion of the 10-kDa species is normal. In addition, the IGF-II/IGF-I ratio is 3 in the serum and 308 in the tumor. Our results show that the very high IGF-II level produced by the tumor does not influence the seric concentration of the growth factor.