Prolonged bisphosphonate release after treatment in women with osteoporosis. Relationship with bone turnover

Bisphosphonates (BP), especially alendronate and risedronate, are the drugs most commonly used for osteoporosis treatment, being incorporated into the skeleton where they inhibit bone resorption and are thereafter slowly released during bone turnover. However, there are few data on the release of BP in patients who have received treatment with these drugs for osteoporosis. This information is essential for evaluating the possibility of BP cyclic therapy in these patients and for controlling their long-term presence in bone tissue. This study evaluated the urinary excretion of alendronate and risedronate in patients treated with these drugs for osteoporosis and analysed its relationship with bone turnover, time of previous drug exposure and time of treatment discontinuation. We included 43 women (aged 65±9.4 years) previously treated with alendronate (36) or risedronate (7) during a mean of 51±3 and 53±3 months, respectively, who had not been treated with other antiosteoporotic treatment and with a median time of discontinuation of 13.5 and 14 months, respectively. Both BP were detected in 24-hour urine by HPLC. In addition, bone formation (PINP) and resorption (NTx) markers were analysed. Both BP were also determined in a control group of women during treatment. Alendronate was detected in 41% of women previously treated with this drug whereas no patient previously treated with risedronate showed detectable urinary values. All control patients showed detectable values of both BP. In patients with detectable alendronate levels, the time of drug cessation was shorter than in patients with undetectable values (12 [6-19] versus 31 [7-72] months, p<0.001). Alendronate was not detected in any patient 19 months after treatment cessation. Alendronate levels were inversely related to time of treatment discontinuation (r=-0.403, p=0.01) and the latter was directly related to NTx (r=0.394, p=0.02). No relationship was observed with age, length of drug exposure, renal function or weight. In conclusion, contrary to risedronate, which was not detected in patients after cessation of treatment, alendronate was frequently detected in women previously treated with this agent up to 19 months after discontinuation of therapy. The relationship between alendronate levels and both bone resorption and time of treatment cessation further indicates a residual effect of this drug in bone, despite treatment discontinuation.

Influence of the preservation temperature (37, 20, 4, -196°C) and the mixing of semen over sperm quality of Majorera bucks

This study assessed the effect of different semen storage temperatures and the influence of semen pooling in semen viability. In experiment 1, semen samples (n = 30) of five Majorera bucks were individually processed [Individual semen (IS)] and after the first dilution (Tris-yolk extender), semen-diluted aliquots from each male were pooled semen (PS). Thereafter, semen samples (IS and PS) were preserved as fresh semen (37 and 20°C), chilled semen (4°C) and frozen semen. Sperm motility and the percentage of abnormal sperm cells and intact membrane acrosomes were defined. Semen preservation at 20 and 4°C did not modify the quality of spermatozoa for the first 24 h, but the conservation at 37°C caused a dramatic fall in the semen motility from 12 h onwards. Furthermore, the longevity of frozen-thawed semen was limited to 4-6 h. No differences were observed in semen parameters when PS was compared with semen from individual males in any of the preservation protocols assessed. In experiment 2, 120 goats were distributed in four experimental groups: in group fresh individual semen (FIS, n = 30) and group frozen-thawed individual semen (FTIS, n = 30), does were transcervically inseminated with fresh semen and frozen-thawed semen from each individual male, respectively, and in group fresh pooled semen (FPS, n = 30) and group frozen-thawed pooled semen (FTPS, n = 30), goats were transcervically inseminated with FPS and FTPS, respectively. The kidding rate was very close in the FIS and FPS groups (70.0% and 73.7%, respectively), and no significant differences were observed in the fertility rate between FTIS and FTPS. The results of this study confirmed that semen samples may be preserved satisfactorily for 24 h both at 20 and 4°C. In addition, the mixture of semen of different bucks did not significantly modify the semen parameters when compared with semen from individual males.

Overview of physical and biophysical techniques for accident dosimetry

From feedback experience from recent radiation accident cases, in addition to biological dosimetry and physical dosimetry based on Monte Carlo calculations or experimental means, there is a need for complementary methods of dosimetry for radiation accident. Electron paramagnetic resonance (EPR) spectrometry on bones or teeth is considered as efficient but is limited by the invasive character of the sampling. Since 2005, Institute for Radiological Protection and Nuclear Safety (IRSN) develops some new approaches and methodologies based on the EPR and luminescence techniques. This article presents the overview of the different studies currently in progress in IRSN.

Reticulated vitreous carbon: a useful material for cell adhesion and tissue invasion

Diverse carbon materials have been used for tissue engineering and clinical implant applications with varying success. In this study, commercially available reticulated vitreous carbon (RVC) foams were tested in vitro and in vivo for compatibility with primary cell adhesion and tissue repair. Pores sizes were determined as 279 ± 98 μm. No hydroxyapatite deposition was detected after immersion of the foams in simulated body fluid. Nonetheless, RVC provided an excellent support for adhesion of mesenchymal stem cells (MSCs) as well as primary chondrocytes without any surface pre-treatment. Live cell quantification revealed neutral behaviour of the material with plastic adhered chondrocytes but moderate cytotoxicity with MSCs. Yet, rabbit implanted foams exhibited good integration in subcutaneous pockets and most importantly, total defect repair in bone. Probably due to the stiffness of the material, incompatibility with cartilage regeneration was found. Interestingly and in contrast to several other carbon materials, we observed a total lack of foreign body reactions. Our results and its outstanding porous interconnectivity and availability within a wide range of pore sizes convert RVC into an attractive candidate for tissue engineering applications in a variety of bone models and for ex vivo cell expansion for regenerative medical applications.

Testicular neoplasms (interstitial and Sertoli cell tumours) in a domestic ferret (Mustela putorius furo)

Unilateral testicular enlargement was detected in a 5-years-old domestic ferret during a routine sterilization. The right testicle showed two different types of proliferative lesions: (i) round nodules, well demarcated, showing a soft yellow tissue; (ii) white nodules, firm, with irregular-shaped invaginations. Microscopically, the neoplastic proliferations were identified as an interstitial neoplasm and Sertoli cell tumour, respectively. The left testicle was small and showed intense testicular atrophy. Clinical evaluation of the ferret did not show any other apparent pathological processes. This study is the first case reporting the concomitant occurrence of a Sertoli cells tumour and an interstitial cell tumour in a domestic ferret.

FLUORESCENT BERBERINE BINDING AS A MARKER OF INTERNAL GLYCOSAMINOGLYCANS SULFATE IN BOVINE OOCYTES AND SPERM CELLS

The use of berberine as a biological marker of glycosamineglycans sulfate was employed to corroborate the presence of heparin in mammalian oocytes and sperm and its distribution in all the structures, or only in some specialized zones, of the male and female gametes. Oocytes and sperms were treated with 1.8 mM berberine for the presence of heparin and examined 10, 30, 60, and 120 minutes later. We have found that heparin is homogeneously distributed in all the zones of bovine oocytes and in sperm cells. When sperm cells are first treated with 80 microM of heparin and then berberine, 40% of them display in their post acrosomal region an intense yellow fluorescence. This may be in relation to the high amount of heparin binding sites due to the presence of the reticular membranous like system in this sperm region and in its possible role whereby gametes recognize and adhere to one another. Therefore, the use of berberine as a fluorescent marker of heparin represents clear proof of the presence of GAGs and their binding sites in the outside and inside of mammalian gametes, reinforcing the importance they play in the events of the process of fertilization.

CALCIUM (HYDROGEN-1-MALATE) HEXAHYDRATE ONECHEVERIA GIBBIFLORALEAVES AND ITS EFFECT ON SPERM CELLS

Echeveria gibbiflora is a plant widely used for its contraceptive activity in traditional Mexican medicine. Data on calcium crystals in plants are not outstanding. In the case of the Echeveria gibbiflora leaves, however, its quality, quantity, and salt type are quite surprising; one striking result of its X-ray crystallographic data shows the presence of calcium bis (hydrogen-1-malate) hexahydrate [2(C4H5O(5)1), Ca(1)2+, 6(H2O1)]. This highly soluble compound might explain the rapid shape changes of calcium crystals. Because SEM-EDS analysis shows that calcium malate crystals were obtained in a highly pure state and the immobilization and agglutination pattern that OBACE show on human and bull spermatozoa are not found even when high concentrations of calcium bis (hydrogen-1-malate) hexahydrate salt are present it is not feasible to involucrate molecules as calcium malate as part of the OBACE contraceptive activity.

Lipid-modifying efficacy and tolerability of extended-release niacin/laropiprant in patients with primary hypercholesterolaemia or mixed dyslipidaemia

BACKGROUND

Improving lipids beyond low-density lipoprotein cholesterol (LDL-C) lowering with statin monotherapy may further reduce cardiovascular risk. Niacin has complementary lipid-modifying efficacy to statins and cardiovascular benefit, but is underutilised because of flushing, mediated primarily by prostaglandin D(2) (PGD(2)). Laropiprant (LRPT), a PGD(2) receptor (DP1) antagonist that reduces niacin-induced flushing has been combined with extended-release niacin (ERN) into a fixed-dose tablet.

METHODS AND RESULTS

Dyslipidaemic patients were randomised to ERN/LRPT 1 g (n = 800), ERN 1 g (n = 543) or placebo (n = 270) for 4 weeks. Doses were doubled (2 tablets/day; i.e. 2 g for active treatments) for 20 weeks. ERN/LRPT 2 g produced significant changes vs. placebo in LDL-C (-18.4%), high-density lipoprotein cholesterol (HDL-C; 20.0%), LDL-C:HDL-C (-31.2%), non-HDL-C (-19.8%), triglycerides (TG; -25.8%), apolipoprotein (Apo) B (-18.8%), Apo A-I (6.9%), total cholesterol (TC; -8.5%), TC:HDL-C (-23.1%) and lipoprotein(a) (-20.8%) across weeks 12-24. ERN/LRPT produced significantly less flushing than ERN during initiation (week 1) and maintenance (weeks 2-24) for all prespecified flushing end-points (incidence, intensity and discontinuation because of flushing). Except for flushing, ERN/LRPT had a safety/tolerability profile comparable with ERN.

CONCLUSION

Extended-release niacin/LRPT 2 g produced significant, durable improvements in multiple lipid/lipoprotein parameters. The improved tolerability of ERN/LRPT supports a simplified 1 g-->2 g dosing regimen of niacin, a therapy proven to reduce cardiovascular risk.

Idiopathic osteoporosis in premenopausal women. Clinical characteristics and bone remodelling abnormalities

OBJECTIVE

Osteoporosis is infrequent in young premenopausal women and is often associated with secondary disorders. However, idiopathic osteoporosis may be found in this setting and few data are known on this condition. Therefore, the aim of this study was to analyse the clinical characteristics and bone remodelling abnormalities in premenopausal women with idiopathic osteoporosis.

METHODS

28 premenopausal women with idiopathic osteoporosis (aged 38.3+/-7.6 years) were included. The patients had one or more fragility fractures and/or decreased bone mass (z-score <-2 in the lumbar spine or femur). In all patients, secondary causes of osteoporosis were excluded and previous skeletal fractures, family history and risk factors for osteoporosis were recorded. In addition, bone mineral density at the lumbar spine and hip, spinal x-rays, and laboratory tests including PTH, 25-hydroxyvitamin D, 1,25 (OH)<inf>2</inf> vitamin D and urinary calcium excretion were measured. Bone markers such as serum bone alkaline phosphatase (bone AP) and P1NP, and urinary hydroxyproline (HYP), NTx and CTx were measured and results were compared with those observed in a control group of 28 healthy premenopausal women.

RESULTS

46% of the patients had previous fragility fractures, 53% had family history of osteoporosis, 36% had associated hypercalciuria and 30% had a BMI <20 Kg/m². Patients with idiopathic osteoporosis had increased bone resorption markers (NTx and HYP) but normal bone formation markers when compared with healthy controls. No significant differences in the clinical and biochemical parameters were observed between patients with or without hypercalciuria.

CONCLUSION

Young women with idiopathic osteoporosis have an increased bone resorption without changes in bone formation when assessed by biochemical markers.

Expression of neurotensin and its receptors in pituitary adenomas

The neurotensin (NT) produced in the hypothalamus and in pituitary gonadotrophs and thyrotrophs participates in neuroendocrine regulation. Recently, the involvement of this peptide in normal and neoplastic cell proliferation has been postulated. In the present study, we evaluated the expression of NT and its receptors (NTR1, 2 and 3) in a series of 50 pituitary adenomas [11 growth hormone (GH)-, eight prolactin (PRL)-, four adrenocorticotrophic hormone (ACTH)- and 27 nonfunctioning adenomas]. NT mRNA expression was significantly higher in functioning compared to nonfunctioning adenomas and with normal pituitary. Nonfunctioning pituitary adenomas showed lower expression of NT mRNA than normal pituitary. In the immunohistochemical study of functioning adenomas, NT was colocalised with GH, PRL and ACTH secreting cells. In nonfunctioning adenomas, the NT immunoreactivity intensity was variable among the samples. NTR3 mRNA expression was observed in all examined samples and was higher in the adenomas, both functioning and nonfunctioning, compared to normal pituitary. By contrast, NTR1 and NTR2 mRNA were not detected in either pituitary adenomas or normal tissue. The higher expression of NTR3, as well as the expression of NT by tumoural corticotrophs, lactotrophs and somatotrophs, which are cells types that do not express this peptide in the normal pituitary, suggests that NT autocrine and/or paracrine stimulation mediated by NTR3 may be a mechanism associated with the tumourigenesis of functioning adenomas.

Origin of adenohypophysial lobes and cells from Rathke's pouch in Swiss albino mice. Proliferation and expression of Pitx 2 and Calbindin D28K in corticotropic and somatotropic cell differentiation

A developmental study of the adenohypophysis of the mouse was carried out in response to several as yet unanswered questions about its organogenesis and differentiation. The main objectives were to establish the origin of adenohypophysial lobes and cells from the Rathke's pouch (RP) and elucidate the mechanisms of development and functional differentiation of the gland. Using diverse techniques, the morphological development, proliferation and differentiation were studied in order to delimit different proliferative regions in the RP, and provide a satisfactory explanation for the distribution of each cell type in the adult gland. Combining the proliferation and differentiation studies, corticotropic and somatotropic cells appear to mainly originate from undifferentiated precursors located within each of these proliferative regions. The involvement of transcription factor Pitx 2 and calcium-binding protein Calbindin D 28K in the differentiation of corticotropic and somatotropic cells is further clarified.

Immunohistochemical distribution of regulatory peptides in the human fetal adenohypophysis

We have studied here the cellular distribution of several regulatory peptides in hormone-producing cells of the human pituitary during the fetal period. Immunohistochemistry was used to show the expression of several regulatory peptides, namely Angiotensin-II, Neurotensin and Galanin, at successive gestational stages and their co-localization with hormones in the human fetal adenohypophysis. Somatotrophs, gonadotrophs and thyrotrophs were differentiated earliest. At gestational week 9, Angiotensin-II immunoreactivity was co-localized only with growth hormone immunoreactivity in somatotrophs, one of the first hormone-producing cells to differentiate. This co-localization remained until week 37. Neurotensin immunoreactivity was present in gonadotrophs and thyrotrophs in week 23, after FSH and TSH hormone differentiation. Galanin immunoreactivity was present in all hormone-producing cell types except corticotrophs. The different pro-opiomelanocortin-derived peptides were detected at different stages of gestation and adrenocorticotrophic hormone immunoreaction was the last to be detected. Our results show an interesting relationship between regulatory peptides and hormones during human fetal development, which could imply that these peptides play a regulatory role in the development of pituitary function.

Aetiology and clinical characteristics of male osteoporosis. Have they changed in the last few years?

OBJECTIVE

The aim of this study was to analyse the clinical characteristics and etiological factors related to male osteoporosis in patients attending an out-patient rheumatology department during an 11-year period (1995-2006), as well as to compare them with the observed characteristics in a previous study performed 12 years ago.

METHODS

232 males aged 21-88 (mean 56.1+/-14) with osteoporosis were included in the study. Previous skeletal fractures and family history of osteoporosis were recorded. Bone mass assessment, automated biochemical profile and hormonal measurements (including PTH, 25-OH vitamin D, cortisol, thyroid and sexual hormones) were performed on most patients as well as 24 h urinary calcium, and bone markers. In patients with idiopathic osteoporosis 1-25-OH2 vitamin D was also determined. In addition, x-rays of the spine were obtained for all patients.

RESULTS

67% of the patients had previous skeletal fractures and 51% had vertebral fractures. 57% of the patients had idiopathic and 43% had secondary osteoporosis whereas in the previous series only 22% of the patients had idiopathic disease. The most frequent causes of secondary osteoporosis were corticosteroid therapy, hypogonodism and alcoholism. 38% of the patients with idiopathic osteoporosis had associated hypercalciuria. Patients with secondary osteoporosis were older, shorter, had lower femoral neck T-score and lower serum values of 25-OH vitamin D and testosterone, as well as higher gonadotrophin and PTH values than the patients with idiopathic osteoporosis, whereas patients with idiopathic osteoporosis had higher urinary calcium and more frequent family history of osteoporosis. Hypercalciuric patients were younger, had lower lumbar BMD, higher urinary calcium and greater incidence of lithiasis than normocalciuric patients with idiopathic osteoporosis. Back pain, frequently associated with vertebral fractures, was the most common cause of referral in all groups of patients.

CONCLUSION

Idiopathic osteoporosis is the most frequent cause of male osteoporosis in this study. In these patients, family history of osteoporosis and associated hypercalciuria are frequent. The most frequent causes of secondary osteoporosis in males include corticosteroid therapy, hypogonadism and alcoholism. Although clinical characteristics of male osteoporosis are similar to that previously reported, in this study the percentage of patients with idiopathic osteoporosis was higher than previously observed.

Measuring flushing symptoms with extended-release niacin using the flushing symptom questionnaire: results from a randomised placebo-controlled clinical trial

INTRODUCTION

Niacin is underutilised because of flushing. Lack of a quantitative tool to assess niacin-induced flushing has precluded the objective evaluation of flushing associated with extended-release (ER) niacin formulations. We developed the Flushing Symptom Questionnaire((c)) (FSQ), a quantitative tool to assess patient-reported flushing, and assessed its ability to characterise ER niacin-induced flushing.

METHODS

This study focused on the responses to one question in the FSQ, the Global Flushing Severity Score (GFSS), reported on a 0-10 scale (none = 0, mild = 1-3, moderate = 4-6, severe = 7-9 and extreme = 10) to assess flushing during ER niacin initiation (week 1) and maintenance (weeks 2-8).

RESULTS

Flushing severity with ER niacin was greatest during week 1 and remained greater than placebo for the study duration. During weeks 2-8, 40% of patients on ER niacin vs. 8% of those on placebo had > 1 day/week with 'moderate or greater' GFSS.

CONCLUSIONS

In conclusion, the GFSS component of the FSQ was a sensitive and responsive quantitative measure of ER niacin-induced flushing that will aid in the objective comparison of novel strategies intended to improve tolerability and adherence to niacin, an agent proven to reduce cardiovascular risk.