[Italian guidelines for the diagnosis and treatment of Paget's disease of bone]

Paget's disease of bone is a chronic focal abnormality of bone turnover that remains totally asymptomatic over a very long period of time but that eventually ensue in bone pain and skeletal deformities. Although, in the last decade new insights have been obtained on its etiology, this remains largely obscure. Effective medical treatment (based on the use of bisphosphonates) has become available and the diagnostic procedures are now well defined. However, there remains considerable controversy regarding the hierarchy of diagnostic procedures and the medical treatment threshold. In the last few years different institution have published national guidelines, reflecting local national health systems and the available medical treatment. In this review, a working group derived from members of the SIOMMMS has examined the information available regarding the diagnosis and treatment of Paget's disease in order to develop guidelines to assist in the management of this condition. The first draft was then extensively reviewed by experts derived from the most representative scientific societies of rheumatology, internal medicine, and orthopaedic surgery. The document provides the most updated recommendations based primarily on the "evidence-based- medicine" but also on the Italian regulation for the diagnostic procedures and on the available medical treatments.

Interferon-alpha inhibits in vitro osteoclast differentiation and renal cell carcinoma-induced angiogenesis

Bone is a common site of osteolytic and richly vascularized metastases of renal cell carcinoma (RCC) and Interferon (IFN)-alpha based therapies have been considered for the treatment of patients affected by this disease. The effects of IFN-alpha on metastatic RCC patients have been related to its immunomodulatory, and cytotoxic activity on tumor cells, but there could be an effect also on tumor induced osteoclast differentiation and bone angiogenesis. When osteoclasts obtained from human peripheral blood mononuclear cells, cultured in the presence of receptor activator of nuclear factor-kappaB (RANKL) and macrophage-colony stimulating factor (M-CSF), were treated with IFN-alpha, the expression of bone tartrate resistant acid phosphatase (TRACP) type 5b was reduced, as well as calcium-phosphate resorption activity and expression of pro-osteoclatic transcription factor c-Fos. IFN-alpha modulation of angiogenesis was studied by analysis of proliferation, survival, and migration of a bone endothelial cell line (BBE), and by the analysis of pro-angiogenic factor expression in RCC cell lines. IFN-alpha inhibited bone endothelial cell proliferation and the expression of FGF-2, while the vascular endothelial growth (VEGF) did not show any significant variation. Moreover, IFN-alpha inhibited the migration induced by the RCC through the impairment of fibroblast growth factor-2 (FGF-2) secretion. These data demonstrate multiple activities of IFN-alpha on renal cancer-induced bone disease, in addition to its recognized role as a cytotoxic and immunomodulatory agent, because they indicate its ability to reduce bone resorption and to impair tumor-associated angiogenesis, and they also suggest the use of IFN-alpha to treat skeletal metastases of other carcinomas.

2006 update on genetic determinants of osteoporosis

Since the identification of vitamin D gene, the first one characterised by being related to osteoporosis, a high number of genetic studies, especially association studies, emerged to elucidate the genetic complex pattern of this disease. Osteoporosis is a skeletal chronic multifactorial disease, characterised by abnormal low bone mass and microarchitectural deterioration of bone tissue. It is getting a more and more important health problem, affecting a larger number of people, especially in developed countries. Studies demonstrated that variations in several genes, involved in bone metabolism, lead to the osteoporotic condition. Understanding the pathogenesis of osteoporosis requires the genetic characterization of the relationship among multiple gene variants, the encoded proteins, and the environmental mediators vs bone physiology. This paper pretends to give a panoramic on actual genetics of osteoporosis situation, taking into account the most important recent genetic studies in the field.

FokI polymorphism of the vitamin D receptor gene correlates with parameters of bone mass and turnover in a female population of the Italian island of Lampedusa

One of the most promising genetic approaches to dissecting a multifactorial disease is represented by genetically isolated population studies. We studied a genetic marker in a cohort of women living on the Mediterranean island of Lampedusa, a geographically isolated population. Lampedusa, located between the African coast and Sicily, consists of a young genetic isolate (<20 generations) with an exponential growth in the last generations. We analyzed the association between the FokI vitamin D receptor (VDR) gene polymorphism, previously proposed as a predictor of bone mass, with parameters of bone mass and turnover in a cohort of pre- and postmenopausal women living on Lampedusa. In 424 women (277 postmenopausal and 147 premenopausal), allelic frequencies were 49% for the F allele and 51% for the f allele. Using analysis of covariance, we found that subjects with ff genotype exhibited a significantly (P < 0.001) lower lumbar spine bone mass, by dual-energy X-ray absorptiometry, and lower values of bone ultrasonographic parameters (speed of sound and broadband ultrasound attenuation) relative to those with Ff and FF genotypes. Conversely, osteocalcin and serum cross-laps were significantly higher in ff and Ff compared to FF genotype. Our data suggest that FokI VDR polymorphism may contribute to the determination of bone mass and turnover in both pre- and postmenopausal women in this geographically isolated population.

Genistein affects adipose tissue deposition in a dose-dependent and gender-specific manner

The soy isoflavone genistein targets adipose tissue and elicits physiological effects that may vary based on dietary intake. We hypothesized that the adipose effects of genistein are dose and gender dependent. Four-week-old C57BL/6 male and female mice received daily oral doses of genistein (50-200,000 microg/kg.d) or 17beta-estradiol (E2) (5 microg/kg.d) for 15 d or a diet containing 800 ppm genistein. Genistein increased epididymal and renal fat pad and adipocyte size at doses up to 50,000 microg/kg.d or at 800 ppm in the diet in males but not in females. The alteration in adipocity correlated with changes in peripheral insulin resistance. These treatments increased genistein serum concentrations from 35+/-6 to 103+/-26 nM 12 h after treatment and lowered plasma triglycerides and cholesterol levels. The 200,000 microg/kg.d genistein dose decreased adipose tissue weight similarly to E2. This genistein dose down-regulated estrogen receptor (beta more than alpha) and progesterone receptor expression and induced estrogen-dependent adipose differentiation factors; it did not change expression of the minimal consensus estrogen-responsive element in ERE-tK-LUC mice, which was positively modulated in other tissues (e.g. the lung). E2 down-regulated almost all examined adipogenic factors. Gene microarray analysis identified factors in fat metabolism and obesity-related phenotypes differentially regulated by low and high doses of genistein, uncovering its adipogenic and antiadipogenic actions. The lower dose induced the phospholipase A2 group 7 and the phospholipid transfer protein genes; the 200,000 microg/kg.d dose inhibited them. The antiadipogenic action of genistein and down-regulation of adipogenic genes required the expression of ERbeta. In conclusion, nutritional doses of genistein are adipogenic in a gender-specific manner, whereas pharmacological doses inhibited adipose deposition.

A comparison of methods for the analysis of low abundance proteins in desmoid tumor cells

The desmoids are a group of rare clinically diverse, deep-seated fibrous neoplasms. The exact etiology is unknown, but several factors are considered to be positively correlated with their development and growth, i.e., genetic and hormonal factors and trauma. These tumors may be sporadic or associated with a genetic disease such as familial adenomatous polyposis (FAP). Devoid of metastatic potential, they tend to form large, infiltrative masses which, if not completely excised, recur repeatedly. Although surgery is widely accepted as the first-line treatment for extra-abdominal and abdominal wall desmoids, a proportion of cases are successfully palliated with either estrogen antagonists (tamoxifen, toremifene, and raloxifene) or nonsteroidal anti-inflammatory drugs. We describe and compare four methods for evaluating the expression of estrogen receptors alpha/beta and COX-1 and COX-2 in desmoid tumor-derived cells and tissues: immunocytochemistry, immunohistochemistry, RT-PCR, and two-color Western blot detection with the Odyssey infrared imaging system. Through this comparative analysis, Western blot with Odyssey was recognized as the best method to analyze the expression particularly of low expressed proteins in desmoid-derived cells. The use of a specific and reliable assessment method becomes fundamental in the evaluation of the presence and modulation of proteins which are important but weakly expressed in these rare tumors.

MEN1 family with a novel frameshift mutation

Multiple endocrine neoplasm type 1 (MEN1) syndrome predisposes to the development of endocrine and non-endocrine tumors with an autosomal dominant pattern of inheritance. Different mutations have been found throughout the gene with a variable phenotype expression. The proband, a Caucasian man, was admitted to our department in 2001, at the age of 51 because of a 1-yr history of diarrhoea and hypertension. He reported a previous intestinal resection for bowel occlusion with a histological diagnosis of unspecified mesenchymal neoplasia. He had also undergone a left adrenalectomy for a large nonfunctioning adrenal adenoma. Subsequently, he had suffered from gastralgia and melena; a gastroduodenoscopy showed an erosive gastritis. His family history was negative for endocrine disorders. On physical examination, multiple abdominal cutaneous lipomas and facial angiofibromas were observed. Biochemical screening revealed a primary hyperparathyroidism and an increase in circulating levels of PRL, chromogranin-A, gastrin and glucagon. The whole body computed tomography (CT) scan, the 111In-octreotide scan and the pituitary magnetic resonance imaging (MRI) did not reveal any abnormality. The presence of small neuroendocrine tumors was suspected by a positron emission tomography uptake in the epigastric region. The endoscopic ultrasound revealed a pancreatic lesion sized 1.1 cm that is under evaluation. Direct DNA sequencing analysis of the proband MEN1 gene revealed the 579delG frameshift mutation in the exon 3. The genetic screening of the family revealed the same mutation in 3 out of 5 offspring. The biochemical screening revealed some features of the MEN1 syndrome in all three of them. In conclusion, a novel frameshift MEN1 mutation was found in kindred with an apparently negative family history. Our experience confirms that MEN1 syndrome is a complex and underestimated condition, unless specifically investigated by trained specialists.

Characterization of the functional and growth properties of long-term cell cultures established from a human somatostatinoma

In somatostatinoma, a rare malignant somatostatin (SST)-secreting neoplasia, tumour regression is rarely observed, implying the need for novel antiproliferative strategies. Here, we characterized a long-term culture (SST-secreting cancer (SS-C cells)) established from a human somatostatinoma. High concentrations of SST and chromogranin A were released by SS-C cells and SST release was stimulated by depolarizing stimuli and inhibited by the SST analogue, octreotide. SS-C cells expressed mRNA for SST receptor (SSTR) subtypes 1, 2 and 4, being also able to bind native SST. Moreover, SS-C cells were positively stained with an antibody to SSTR2. SS-C cells also expressed interferon-gamma (IFN-gamma) receptor mRNA and measurable telomerase activity. Our findings indicate that in vitro exposure of SS-C cells to native SST-28, to octreotide, to IFN-gamma, or to 3'-azido-3'deoxythymidine (AZT), a telomerase inhibitor, results in inhibition of SS-C cell proliferation. Concomitant with growth inhibition, apoptosis was detected in SST-, octreotide-, IFN-gamma- or AZT-treated SS-C cell cultures. Taken together our results characterized native SST, SST analogues, IFN-gamma and a telomerase inhibitor as growth-inhibiting and proapoptotic stimuli in cultured human somatostatinoma cells. Based on these findings, the potential of SST analogues, IFN-gamma and AZT, alone or in combination, should be further explored in the medical treatment of somatostatinoma.

Superiority of alfacalcidol compared to vitamin D plus calcium in lumbar bone mineral density in postmenopausal osteoporosis

In a randomized multicenter, double-blind, double-dummy, parallel group study a comparison of the efficacy and safety of 1 microg alfacalcidol to 880 IU vitamin D plus calcium carbonate (1 g calcium) once daily per os was performed on 148 postmenopausal osteoporotic Caucasian patients with normal vitamin D serum levels for 18 months. Bone mineral density (BMD) was measured at baseline, 12 and 18 months. Safety parameters were followed during the entire study period. Sixty-nine (90.8%) in the alfacalcidol group and 67 (93.1%) in the vitamin D group were included in the ITT analysis. Lumbar BMD in the alfacalcidol group increased by 0.017 g/cm2 (2.33%) and 0.021 g/cm2 (2.87%) from baseline (P<0.001) at 12 and 18 months, respectively, whereas in the vitamin D plus calcium group the increase was 0.005 g/cm2 (0.70%) from baseline (N.S.) at both 12 and 18 months. The higher changes from baseline in the alfacalcidol group, as compared to the changes in the vitamin D plus calcium group at both 12 and 18 months, were found to be statistically significant (P=0.018, 0.005). A small increase of mean femoral BMD was achieved in both groups (N.S.). Adverse events were similar in both groups. No significant differences were noted between the groups in serum calcium. In conclusion, alfacalcidol was found to be superior in significantly increasing lumbar BMD as compared to vitamin D plus calcium while safety characteristics were found to be similar in both treatments.

Lessons from genes mutated in multiple endocrine neoplasia (MEN) syndromes

Multiple endocrine neoplasia (MEN) types 1 and 2 syndromes are rare hereditary cancer syndromes expressing a variety of endocrine and non-endocrine neoplasias and lesions. The improving of both molecular and clinical genetics knowledge helps health care providers in the whole spectrum of the clinical managements of MEN patients. The MEN1 gene, a tumour suppressor gene, is responsible of MEN1 syndrome, and is probably involved in the regulation of several cell functions, including DNA replication and repair and transcriptional machinery. RET proto-oncogene encodes for a receptor tyrosine kinase protein whose expression is fundamental for appropriate migration, development and differentiation of neuroendocrine cells originating from neural crest. Currently, DNA testing makes possible the early identification of germline mutation in asymptomatic mutant gene carriers in both MEN syndromes. Consequently, the combination of new genetic and diagnostic tools could permit a precocious detection of MEN-associated neoplasms, and in particular the identification of a strong genotype-phenotype correlations in MEN2 syndrome demonstrates an improving outcome and quality of life for affected subjects.

Thymic neuroendocrine carcinoma (carcinoid) in multiple endocrine neoplasia type 1 syndrome: the Italian series

Neuroendocrine tumors may occur in the setting of multiple endocrine neoplasia type 1 (MEN1) syndrome. Among these, a probably underestimated prevalence of well differentiated neuroendocrine thymic carcinoma (carcinoid), a neoplasm characterized by very aggressive behavior, has been described. We report characterization of the seven Italian cases in which this association occurred among a series of 221 MEN1 patients (41 sporadic and 180 familial cases; prevalence, 3.1%). All of the patients were male, and six of seven (85%) were heavy smokers. No associated hormonal hypersecretion was detected. The first diagnosis was between the second and fifth decades. Familial clusters were present in three of seven (42.8%). No genotype-phenotype correlation was found. All seven cases were associated with hyperparathyroidism. In one patient, prophylactic thymectomy revealed a small nodular lesion suggestive of a thymic carcinoid, providing evidence that preventive thymectomy might prevent additional growth of an occult thymic carcinoid. These findings confirm that thymic carcinoids are associated with a very high lethality, with a near-total prevalence in smoker males. Therefore, prophylactic thymectomy should be considered at neck surgery for primary hyperparathyroidism in MEN1 male patients, especially for smokers, and, due to the frequent familial clusters distribution of this pathology, in subjects with affected relatives presenting this feature. Thus, we recommend screening every patient affected with a neuroendocrine thymic neoplasm for MEN1 syndrome.

Molecular, biochemical and cellular biology of PTH anabolic action

PTH is a single chain polypeptide with 84 amino acids. The N-terminal region, 1-34, is a biologically active fragment. PTH has both anabolic and catabolic actions on bone. Bauer et al. demonstrated that PTH extract increased trabecular bone in some animals and Selye et al. provided histology evidence that parathyroid extract, when administered in very small doses to rat pups, stimulated osteoblasts and increased bone apposition. The first clinical trial conducted with PTH was performed in 21 patients with osteoporosis treated with human PTH (1-34) [hPTH (1-34)]. In this study, the [hPTH (1-34)] was given as once-daily subcutaneous injections with an increase of 70% above mean baseline values of trabecular bone. Intermittent treatment with PTH increases osteoblast number and bone formation. The skeletal effects of PTH depend upon the pattern of systemic exposure. Once-daily administration of PTH stimulates new bone formation on trabecular and cortical bone surfaces by preferential stimulation of osteoblastic activity over osteoclastic activity. By increasing new bone formation, PTH improves bone mass and bone strength, and thereby reduces the risk of fracture. PTH (1-34) is currently being safely and effectively used in osteoporosis, and together with novel PTH derivates agent provides more tools for the clinicians in their armamentarium for the fight against osteoporosis.

Surgery for gastroenteropancreatic tumours in multiple endocrine neoplasia type 1: review and personal experience

Multiple endocrine neoplasia type 1 (MEN1) gastro-entero-pancreatic (GEP) tumours develop from the pancreatic islets and from the endocrine cells of the duodenal and gastric mucosa. Even if GEP tumours have generally a benign course, a subgroup of them shows an aggressive behaviour and is a major cause of death amongst MEN1 patients. Diagnosis of insulinoma should lead promptly to pancreatic surgery. MEN1 gastrinomas are multiple and almost exclusively localized in the duodenum. Cure rate for Zollinger-Ellison syndrome in MEN1 is low when surgery is limited to tumour enucleation or full thickness duodenal wall resection. Conversely, pancreatoduodenectomy is followed by higher chance of cure. For nonfunctioning tumours exceeding 1 cm diameter in size a prompt treatment is recommended due to their high malignant potential. Gastroscopic surveillance is indicated for the frequent occurrence of multiple, small, type 2 fundic carcinoids. Endoscopic removal is possible for lesions growing in the mucosa-submucosa, but partial or even total gastrectomy is recommended for the small number of gastric carcinoids infiltrating the muscular layers.

Primary hyperparathyroidism: new concepts in clinical, densitometric and biochemical features

Primary hyperparathyroidism (PHPT) is characterized most commonly now as an asymptomatic disorder with hypercalcaemia and elevated levels of parathyroid hormone (PTH). The elevation in PTH is detected by both the standard immunoradiometric assays (IRMA) and a more recent IRMA that detects only the 1-84 full-length PTH molecule. The serum calcium concentration is usually <1 mg dL(-1) above normal. Recently, another variant of PHPT (normocalcaemic PHPT) has been described in which the serum calcium is normal but the serum PTH is elevated, in the absence of any secondary cause for PTH elevation. Although usually sporadic, PHPT also occurs in inherited syndromes. Skeletal manifestations are appreciated by densitometry showing a typical pattern in which cancellous bone of the lumbar spine is reasonably well preserved whilst the cortical bone of the distal third of the radius is preferentially reduced. Although reduced in incidence, renal stones remain the most common overt complication of PHPT. Other organs are theoretical targets of PHPT such as the neurobehavioural axis and the cardiovascular system. Vitamin D looms as an important determinant of the activity of the PHPT state. The 2002 NIH Workshop on asymptomatic PHPT has led to revised guidelines to help doctors determine who is best advised to have parathyroid surgery and who can be safely followed without surgery. New information about the natural history of PHPT in those who did not undergo surgery has helped to define more precisely who is at-risk for complications. At the NIH workshop, a number of items were highlighted for further investigation such as pharmacological approaches to controlling hypercalcaemia, elevated PTH levels and maintaining bone density.

Genetics and pharmacogenetics of osteoporosis

Osteoporosis is a skeletal chronic multifactorial disease characterised by abnormal low bone mass and microarchitectural deterioration of bone tissue. This disorder, present in both sexes, related to environmental and genetic factors, is becoming a major public health problem in developed countries. It has a polygenic pattern of inheritance that complicates identification of disease genes [cytokines, calciotropic hormones, sex hormones pathway synthesis and their receptors, bone matrix proteins synthesis genes involved on estrogenic metabolism (CYP19) and LDL receptor-related protein 5 (LRP5) gene]. It is possible to identify associations between candidate genes polymorphisms and disease phenotype in population-based and case-control studies. This could give us promising data for earlier identification of osteoporosis susceptibility and fracture risk. Preventive therapy could be targeted to patients at risk of osteoporosis before fractures occur. Genetic polymorphisms are also starting to be used to predict drug response. A new era of pharmacogenetics represents an interesting prospective to identify the potential individuals to receive customised treatments.

Risedronate rapidly reduces the risk for nonvertebral fractures in women with postmenopausal osteoporosis

Prevention of nonvertebral fractures, which account for a substantial proportion of osteoporotic fractures, is an important goal of osteoporosis treatment. Risedronate, a pyridinyl bisphosphonate, significantly reduces clinical vertebral fracture incidence within 6 months. To determine the effect of risedronate on osteoporosis-related nonvertebral fractures, data from four large, randomized, double-blind, placebo-controlled, Phase III studies were pooled and analyzed. The population analyzed consisted of postmenopausal women, with and without vertebral fractures, who had low bone mineral density (lumbar spine T-score <-2.5). Patients received placebo (N = 608) or risedronate 5 mg daily (N = 564) for 1 to 3 years. At baseline, 58% had at least one prevalent vertebral fracture, and the mean lumbar spine T-score was -3.4. Among placebo-treated patients, the presence of prevalent vertebral fractures did not increase the risk of incident nonvertebral fractures overall, although fractures of the humerus and hip and pelvis were more common in patients who had prevalent vertebral fractures than in those who did not. Risedronate 5 mg significantly reduced the incidence of nonvertebral fractures within 6 months compared with control. After 1 year, nonvertebral fracture incidence was reduced by 74% compared with control ( P = 0.001), and after 3 years, the incidence was reduced by 59% ( P = 0.002). The results indicate that risedronate significantly reduces the incidence of osteoporosis-related nonvertebral fractures within 6 months.

Dynamic investigation for evaluation of calcium metabolism and parathyroid function

Differently from other metabolic conditions, most of calcium metabolism disorders are diagnosed through simple detection of both serum and urinary excretion (24-h urine collection), levels of calcium, total and ionized form, and phosphate, and of calciotropic hormone serum levels, such as calcitonin, PTH and vitamin D metabolites. For the diagnosis and clinical monitoring of some metabolic bone diseases, such as osteoporosis and Paget's disease, the assessment of bone turnover is offering a useful tool for the evaluation of the therapeutic response in affected individuals. Markers of bone formation are represented by bone alkaline phosphatase and osteocalcin, while principal bone resorption markers are represented by pyridinoline, deoxypyridinoline and crosslinks of collagen N-telopeptide, both in the 24-h and fasting second morning urine collection. Only in selected conditions, here briefly reviewed, dynamic tests can offer an interpretation on the pathogenetic events causing a disorder of calcium metabolism.

Cytocompatibility of polyurethane foams as biointegrable matrices for the preparation of scaffolds for bone reconstruction

This work reports preliminary results on the development of biointegrable scaffolds, composed of biostable 3D polymer matrices and bioabsorbable inorganic salts, to be used for cell anchorage in bone regeneration. Three crosslinked polyurethane foams (PUFs), prepared by one-step bulk polymerisation from a polyether-polyol mixture, polymeric MDI and water as expanding agent, were tested for their ability to promote adhesion and growth of bone-derived cells. The open porosity of these foams ranged from 16 to 31% with an average pore size of 470 /600 microm, compressive strength (at 10% &#949; ) of 0.28/0.38 MPa and elastic moduli of 4.88/6.61 MPa. The human osteosarcoma line Saos-2, and primary cultures of normal human articular chondrocytes and bone marrow-derived (HBM) stromal cells were used for in vitro cytocompatibility tests. For cell adhesion and proliferation analysis, DNA synthesis was evaluated by 3 H-thymidine uptake. Osteoblastic differentiation of Saos-2 adherent cells was determined by measuring the enzymatic activity of alkaline phosphatase (ALP). All cell types were able to adhere to all tested PUFs and to synthesize DNA. At 48 hr culture, HBM stromal cells showed the maximal rate of adhesion with the highest rate of proliferation onto PUFs with the largest pore size, whereas both chondrocytes and Saos-2 appeared to adhere preferentially onto foams exhibiting the highest percentage of open porosity. Up to 8 days in culture Saos-2 cells were able to proliferate into all PUFs, with a time-dependent increase of DNA synthesis and ALP activity. At SEM, the morphology of cells adherent to PUF pores was spread with cytoplasmatic extroflessions, indicating a good metabolic activation. These results demonstrate a good cytocompatibility of the proposed 3D matrices, suggesting that their use in the preparation of composite scaffolds is worth further investigation. (Journal of Applied Biomaterials & Biomechanics 2003; 1: 58-66)ABSTRACT: This work reports preliminary results on the development of biointegrable scaffolds, composed of biostable 3D polymer matrices and bioabsorbable inorganic salts, to be used for cell anchorage in bone regeneration. Three crosslinked polyurethane foams (PUFs), prepared by one-step bulk polymerisation from a polyether-polyol mixture, polymeric MDI and water as expanding agent, were tested for their ability to promote adhesion and growth of bone-derived cells. The open porosity of these foams ranged from 16 to 31% with an average pore size of 470 /600 microm, compressive strength (at 10% &#949; ) of 0.28/0.38 MPa and elastic moduli of 4.88/6.61 MPa. The human osteosarcoma line Saos-2, and primary cultures of normal human articular chondrocytes and bone marrow-derived (HBM) stromal cells were used for in vitro cytocompatibility tests. For cell adhesion and proliferation analysis, DNA synthesis was evaluated by 3 H-thymidine uptake. Osteoblastic differentiation of Saos-2 adherent cells was determined by measuring the enzymatic activity of alkaline phosphatase (ALP). All cell types were able to adhere to all tested PUFs and to synthesize DNA. At 48 hr culture, HBM stromal cells showed the maximal rate of adhesion with the highest rate of proliferation onto PUFs with the largest pore size, whereas both chondrocytes and Saos-2 appeared to adhere preferentially onto foams exhibiting the highest percentage of open porosity. Up to 8 days in culture Saos-2 cells were able to proliferate into all PUFs, with a time-dependent increase of DNA synthesis and ALP activity. At SEM, the morphology of cells adherent to PUF pores was spread with cytoplasmatic extroflessions, indicating a good metabolic activation. These results demonstrate a good cytocompatibility of the proposed 3D matrices, suggesting that their use in the preparation of composite scaffolds is worth further investigation. (Journal of Applied Biomaterials & Biomechanics 2003; 1: 58-66).

Dose-dependent inhibition of mitochondrial ATP synthase by 17 beta-estradiol

Mitochondria produce energy through oxidative phosphorylation. A key enzyme in this pathway is F0F1-ATP synthase, catalyzing ATP production from ADP and inorganic phosphate. Recently a subunit of F0F1-ATP synthase, oligomycin sensitivity-conferring protein, was identified as a new estradiol-binding protein. Estradiol could directly modulate mitochondrial ATP synthase activity through this subunit. In addition, intracellular ATP levels play a role in apoptotic death, which is an energy-dependent process requiring functioning mitochondria. Here we examined the effect of 17 beta-estradiol on F0F1-ATP synthase directly (in permeabilized cells) and in intact osteoclastic FLG 29.1 cells, a model of inducible apoptosis. The baseline F0F1-ATP synthase activity of FLG 29.1 cells was 4.485 nmol/min per mg. Estradiol rapidly inhibited F0F1-ATP synthase activity in the physiological range (half-inhibition concentration, IC50, of 30 nmol/l). With 1 nmol/l of estradiol, the inhibition was already significant (8-10% inhibition, p < 0.01) and with 100 nmol/l residual enzyme activity was only 15% (85% inhibition, p < 0.01). In addition, the effect of estradiol appeared to be directed towards F0F1-ATP synthase, since succinate-sustained respiration, uncoupled from the electron transport chain, was unaffected by estradiol. We assayed F0F1-ATP synthase activity in FLG 29.1 cells during inducible apoptosis. No significant difference of ATP synthesis was detected in apoptotic cells versus controls. In conclusion, we showed a new non-genomic effect of estradiol on a key mitochondrial enzyme, which thereby directly modulates cellular energy metabolism.

Estrogen metabolism in human colorectal cancer cells

Epidemiological and "in vitro" studies support a direct role of estrogens in the pathogenesis and/or progression of colorectal cancer (CRC). Recent observations suggest a local synthesis of 17beta-estradiol (E(2)). In the present study, the CRC estrogen receptor beta (ERbeta) positive HCT8, HCT116, DLD-1 and LoVo cell lines were evaluated for expression of functional 17beta-hydroxysteroid dehydrogenase (17betaHSD) types 1, 2, 3, and 4. RT-PCR analysis revealed that while 17betaHSD1 and 17betaHSD4 were expressed in all the four cell lines, 17betaHSD2 and 17betaHSD3 were expressed in a cell-specific manner. The interconversion of tritiated estrone (E(1)) or E(2) evaluated by thin layer chromatography of conditioned media revealed that in HCT8, HCT116, and DLD-1 cells both reductive and oxidative activities were present, the latter showing K(m) values (approximately 10 microM) 40-fold higher than the former (approximately 250 nM). On the contrary, in LoVo cells, estrogens were almost (approximately 90%) completely metabolized to hydrophile compounds. Charcoal-dextrane (DC) stripped fetal calf serum (FCS) (10%), E(2) (10nM), Vitamin D(3) (100nM) and the combined E(2) and Vitamin D(3) treatment were evaluated for modulation of 17betaHSD isoenzymes gene expression and activity. Gene expression and activity of 17betaHSD reductive and oxidative isoenzymes were respectively inhibited and enhanced by Vitamin D(3) in HCT8 and LoVo cells. Surprisingly, DC-FCS induced a marked increase of estrogen metabolism toward hydrophile metabolites in all four cell lines. In conclusion, our results clearly show that metabolism of estrogens by 17betaHSD isoenzymes is functional and modulated by external stimuli in continuous neoplastic colonic epithelial cell lines.

Strontium ranelate: dose-dependent effects in established postmenopausal vertebral osteoporosis--a 2-year randomized placebo controlled trial

The aim of the strontium ranelate (SR) for treatment of osteoporosis (STRATOS) trial was to investigate the efficacy and safety of different doses of SR, a novel agent in the treatment of postmenopausal osteoporosis. A randomized, multicenter, double-blind, placebo-controlled trial was undertaken in 353 osteoporotic women with at least one previous vertebral fracture and a lumbar T-score <-2.4. Patients were randomized to receive placebo, 0.5 g, 1 g, or 2 g SR/d for 2 yr. The primary efficacy endpoint was lumbar bone mineral density (BMD), assessed by dual-energy x-ray absorptiometry. Secondary outcome measures included femoral BMD, incidence of new vertebral deformities, and biochemical markers of bone metabolism. Lumbar BMD, adjusted for bone strontium content, increased in a dose-dependent manner in the intention-to-treat population: mean annual slope increased from 1.4% with 0.5 g/d SR to 3.0% with 2 g/d SR, which was significantly higher than placebo (P < 0.01). There was a significant reduction in the number of patients experiencing new vertebral deformities in the second year of treatment with 2 g/d SR [relative risk 0.56; 95% confidence interval (0.35; 0.89)]. In the 2 g/d group, there was a significant increase in serum levels of bone alkaline phosphatase, whereas urinary excretion of cross-linked N-telopeptide, a marker of bone resorption, was lower with SR than with placebo. All tested doses were well tolerated; the 2 g/d dose was considered to offer the best combination of efficacy and safety. In conclusion, SR therapy increased vertebral BMD and reduced the incidence of vertebral fractures.