Dim artificial light at night alters gene expression rhythms and growth in a key seagrass species (Posidonia oceanica).

Artificial light at night (ALAN) is a globally spreading anthropogenic stressor, affecting more than 20% of coastal habitats. The alteration of the natural light/darkness cycle is expected to impact the physiology of organisms by acting on the complex circuits termed as circadian rhythms. Our understanding of the impact of ALAN on marine organisms is lagging behind that of terrestrial ones, and effects on marine primary producers are almost unexplored. Here, we investigated the molecular and physiological response of the Mediterranean seagrass, Posidonia oceanica (L.) Delile, as model to evaluate the effect of ALAN on seagrass populations established in shallow waters, by taking advantage of a decreasing gradient of dim nocturnal light intensity (from < 0.01 to 4 lx) along the NW Mediterranean coastline. We first monitored the fluctuations of putative circadian-clock genes over a period of 24 h along the ALAN gradient. We then investigated whether key physiological processes, known to be synchronized with day length by the circadian rhythm, were also affected by ALAN. ALAN influenced the light signalling at dusk/night in P. oceanica, including that of shorter blue wavelengths, through the ELF3-LUX1-ZTL regulatory network, and suggested that the daily perturbation of internal clock orthologs in seagrass might have caused the recruitment of PoSEND33 and PoPSBS genes to mitigate the repercussions of a nocturnal stress on photosynthesis during the day. A long-lasting impairment of gene fluctuations in sites characterised by ALAN could explain the reduced growth of the seagrass leaves when these were transferred into controlled conditions and without lighting during the night. Our results highlight the potential contribution of ALAN to the global loss of seagrass meadows, posing questions about key interactions with a variety of other human-related stressors in urban areas, in order to develop more efficient strategies to globally preserve these coastal foundation species.

Increased Gene Expression of RUNX2 and SOX9 in Mesenchymal Circulating Progenitors Is Associated with Autophagy during Physical Activity.

Lack of physical exercise is considered an important risk factor for chronic diseases. On the contrary, physical exercise reduces the morbidity rates of obesity, diabetes, bone disease, and hypertension. In order to gain novel molecular and cellular clues, we analyzed the effects of physical exercise on differentiation of mesenchymal circulating progenitor cells (M-CPCs) obtained from runners. We also investigated autophagy and telomerase-related gene expression to evaluate the involvement of specific cellular functions in the differentiation process. We performed cellular and molecular analyses in M-CPCs, obtained by a depletion method, of 22 subjects before (PRE RUN) and after (POST RUN) a half marathon performance. In order to prove our findings, we performed also in vitro analyses by testing the effects of runners' sera on a human bone marrow-derived mesenchymal stem (hBM-MSC) cell line. PCR array analyses of PRE RUN versus POST RUN M-CPC total RNAs put in evidence several genes which appeared to be modulated by physical activity. Our results showed that physical exercise promotes differentiation. Osteogenesis-related genes as RUNX2, MSX1, and SPP1 appeared to be upregulated after the run; data showed also increased levels of BMP2 and BMP6 expressions. SOX9, COL2A1, and COMP gene enhanced expression suggested the induction of chondrocytic differentiation as well. The expression of telomerase-associated genes and of two autophagy-related genes, ATG3 and ULK1, was also affected and correlated positively with MSC differentiation. These data highlight an attractive cellular scenario, outlining the role of autophagic response to physical exercise and suggesting new insights into the benefits of physical exercise in counteracting chronic degenerative conditions.

Use of clodronate in the management of osteoarthritis: an update.

Osteoarthritis (OA) is a chronic rheumatic disease characterized by joint cartilage wear and loss of normal function. Clodronate (CLO) is a first-generation non-nitrogen-containing bisphosphonate that exerts anti-inflammatory and analgesic and modulatory effects on bone and cartilage metabolism. To date, few clinical studies have evaluated the effect of CLO in OA. Current evidence suggests that CLO may represent a new type of analgesic drug as it reduces pain in bone diseases characterized by edema such as Complex Regional Pain Syndrone type-1 and vertebral fractures. Thanks to its anti-inflammatory and analgesic effects, CLO has been shown to afford benefit in knee OA, erosive OA of the hand, painful knee hip prosthesis and veterinary practice. Transforming growth factor ß1 has also been found to play an important role in the pathogenesis of OA. The present review article examines recent evidence on the potential use of CLO in the treatment of OA.

Bone histomorphometry in acromegaly patients with fragility vertebral fractures.

CONTEXT: The high risk of vertebral fractures (VFs) in acromegaly patients despite normal bone mineral density (BMD) is well known. The reasons for this paradoxical finding of skeleton fragility are poorly understood due to the limited data on bone histomorphometry in acromegaly. OBJECTIVE: This study aimed to analyze histomorphometric parameters including bone microarchitecture in acromegaly patients with VFs and normal BMD compared to normal subjects, and also to evaluate the differences between active and controlled acromegaly patients. PATIENTS AND METHODS: Forty-seven acromegaly patients (17 active, 30 controlled), median (range) age 57 years (30-88) were evaluated for bone turnover, morphometric VFs and BMD by dual-energy X-ray absorptiometry at lumbar spine and hip; 12 patients with VFs and normal BMD underwent iliac crest bone biopsy; 12 biopsies were taken at the autopsy in healthy sex and age-matched control subjects. RESULTS: The histomorphometric evaluation of acromegaly fractured patients was compared with that of normal controls and showed significantly reduced median (range) levels of bone volume/tissue volume (BV/TV: 15.37% (7.93-26.75) vs. 18.61% (11.75-27.31), p = 0.036), trabecular thickness (TbTh: 77.6 µm (61.7-88.3) vs. 82.7 µm (72.3-92.0) p = 0.045), with increased trabecular separation (TbSp: 536.4 µm (356.2-900.6) vs. 370.3 µm (377.1-546.3) p = 0.038) and increased cortical thickness (1268 µm (752-2521) vs. 1065 µm (851-1205) p = 0.025) and porosity (11.9% (10.2-13.3) vs. 4.8% (1.6-8.8) p = 0.0008). While active acromegaly patients showed histomophometric features of increased bone turnover, patients with controlled disease presented normal bone turnover with significantly lower osteoblastic activity, expressed as osteoblast number (p = 0.001), active osteoblasts and vigor (p = 0.014) in the presence of reduced osteocyte number (p = 0.008) compared to active disease. CONCLUSIONS: The apparent paradox of bone fragility in acromegaly patients with a normal BMD can be explained by increased cortical thickness and porosity and reduced trabecular thickness with increased trabecular separation. These structural and microarchitectural abnormalities persist in the controlled phase of acromegaly despite bone turnover normalization. The main determinant of bone disease after hormonal control is severe osteoblastic dysfunction.

Multifocal osteonecrosis in a patient with anamnestic ulcerative colitis. Is there a relationship with the disease and the use of glucocorticoids twenty years before? A brief review of the literature.

In 2013 a 40 year old man came to visit in our Rheumatology Unit because of a recent bilateral shoulder and hip pain. He had been treated from 1990 to 2000 with Cyclosporin A and Sulfasalazyn because of an ulcerative colitis which was completely in remission from 2000 . Glucocorticoids at the mean daily dose of 50 mg were administered only in the first period (1990-92). X-plain rays showed a suspicious multifocal osteonecrosis of both femoral and humeral heads. Magnetic Resonance confirmed the diagnosis (stage III and IV following Ficat and Arlet's criteria). The patient was treated with a cycle of hyperbaric oxygen therapy, with two cycles of intravenous clodronate and with a 2-month cycle of teriparatide. The treatment was able to save a sufficient function for both shoulders, while for both hips arthroplasty the surgery was required. The risks of osteonecrosis linked to inflammatory bowel diseases or to its therapy are discussed.

Atypical femoral fracture as first sign of non-hodgkin lymphoma- case report with a brief review of the literature.

ABSTRACT: Atypical subtrochanteric and diaphyseal femoral fractures (AFF) have been suggested to be associated with the use of bisphosphonates (BPs), but the role of these drugs is still under debate. A 64-year old female, never treated with BPs was admitted to our Rehabilitation Institute because of a recent right AFF. The patient began suffering from low back pain radiating to the groin and to the anterior regions of the right thigh and leg, A nuclear magnetic resonance (NMR) of the lumbar spine showed disc protrusions at the L3-L4 and L5-S1 levels with impingement of the spinal nerve root. Therefore she was treated with analgesic, anti-inflammatory and muscle relaxing compounds for nine months without reduction of symptoms. Being the pain still present, the patient felt down the street breaking the right femoral neck and the femoral distal shaft. Following the ASBMR criteria the fracture was classified as a complete AFF and the patient underwent surgical ostheosynthesis with nail. A bone biopsy of the fracture site was performed showing findings consistent with B-cells non-Hodgkin lymphoma (NHL). Immuno-histochemical analysis highlighted that the atypical cells were follicolar G2 pattern diffuse large B cells. CONCLUSIONS: AFF can occur also in patients not treated with BPs. In the present case report, the cause of the fracture was a NHL. Even uncommon, this occurrence should be considered in the differential diagnosis of radicular pain.

Presentation, diagnostic features and glucose handling in a monocentric series of insulinomas.

BACKGROUND: New aspects have emerged in the clinical and diagnostic scenarios of insulinoma: current guidelines have lowered the diagnostic insulin threshold to 3 µU/ml in the presence of hypoglycemia (<55 mg/dl); post-prandial hypoglycemia has been reported as the only presenting symptom; preexisting diabetes mellitus (DM) was recognized in some patients. AIM: To evaluate clinical features, diagnostic criteria and glucose metabolic profile in a monocentric series of patients affected by insulinomas including two subgroups: sporadic and multiple endocrine neoplasia type-1 syndrome (MEN-1). SUBJECTS AND METHODS: Clinical, pathological and biochemical data regarding 33 patients were analyzed. RESULTS: following the current guidelines the 72-h fasting test was initially positive in all cases but one. In this case the test, initially negative, became positive after a 2-yr follow-up. Nadir insulin level was ≥ 3 µU/ml but <6 µU/ml in 3 patients and ≥ 6 µU/ml in the remaining 30 cases. At presentation, 27 patients (82%) reported only fasting symptoms, 3 (9%) only post-prandial and 3 (9%) both. Seven cases (21%) had previously been affected by type 2 DM or impaired glucose metabolism. CONCLUSIONS: In our series the new cut-off of insulin increased the sensitivity of the 72-h fasting test from 87% to 97%. The absence of hypoglycemia during the test cannot definitively rule out the diagnosis and the test should be repeated in every highly suspicious case. Post-prandial hypoglycemia can be the only presenting symptom. DM may be associated with the occurrence of insulinoma. So that a possible diagnosis of insulinoma must not be ignored if previous impaired glucose handling is evident.

Zoledronic acid decreases mRNA six-transmembrane epithelial antigen of prostate protein expression in prostate cancer cells.

BACKGROUND: Zoledronic acid (Zol) is used successfully to inhibit bone resorption in tumor bone disease of various human cancer. Zol inhibits the mevalonate pathway and other potential targets include the inhibition of tyrosine phosphatase activity, disruption of metalloproteinase, secretion and down-regulation of the catalytic subunit of telomerase (hTERT). The six-transmembrane epithelial antigen of prostate protein (STEAP) is a new marker highly expressed at all phases of prostate cancer. AIM: Here, we analyzed for the first time the effect of Zol on STEAP gene expression in prostate cancer cells. MATERIAL AND METHODS: We evaluated the effects of Zol in STEAP gene expression by RT real time PCR in androgen-sensitive (LNCaP) and androgen-non-sensitive (PC3 and DU145) cell lines. To confirm the pro-apoptotic effect of Zol, we also analyzed the caspase-3 gene expression, that resulted up-regulated in cancer cell apoptosis. RESULTS: Zol strongly decreased cell viability and lowered STEAP gene expression in a dose-dependent manner. In addition, this effect was accompanied by an increase of apoptotic index and an up-regulation of caspase-3 gene expression. CONCLUSION: Zol may affect cancer cells also by targeting the gene expression of STEAP.

[Evidences of safety and tolerability of the zoledronic acid 5 mg yearly in the post-menopausal osteoporosis: the HORIZON project]. / Evidenze di sicurezza e tollerabilità dell'acido zoledronico 5 mg una volta all'anno nell'osteoporosi postmenopausale: il progetto HORIZON.

Bisphosphonates are the most commonly prescribed medications for the treatment of osteoporosis. Despite evidence supporting the anti-fracture efficacy of aminobisphosphonates approximately 50% of patients do not follow their prescribed treatment regimen and/or discontinue treatment within the first year. Poor compliance is associated with negative outcomes, including increased fracture risk. Tolerability and safety are among the causes of poor compliance. Intravenous bisphosphonates avoids the gastrointestial intolerance and the complex dosing instruction of the oral route ensuring full compliance which may provide improved efficacy. However, there are some concerns regarding potent intravenous bisphosphonates as zoledronic acid with respect to tolerability, mainly the acute phase response and to safety, mainly a theoretical risk of over suppression of bone turnover, renal toxicity and osteonecrosis of the jaw. In the HORIZON study, 152 patients on active treatment (82) or placebo (70) underwent to a bone biopsy after double tetracycline labeling. Bone biopsies (iliac crest) were obtained at the final visit at month 36, 1 year after the last infusion. The biopsies were analyzed by histomorphometry on bone sections and by micro-CT (microCT) analysis. One hundred forthy-three biopsies (76 zoledronic acid, 67 placebo) had at least one microCT parameter measured and 111 were available for quantitative histomorphometry (59 zoledronic acid, 52 placebo). Micro-CT analysis of bone structure revealed higher trabecular bone volume (BV/TV), decreased trabecular separation (Tb.Sp), and a strong trend towards improvement in connectivity density in biopsies obtained from patients treated with zoledronic acid, indicating preservation of trabecular bone structure with respect to placebo. Histomorphometric analysis obtained from patients treated with zoledronic acid exhibited reduction of bone turnover, as suggested by decreased activation frequency (Ac.F) by 63%, mineralizing surface (MS/BS), bone formation rate (BFR/BV). In addition, mineral appositional rate (MAR), reflecting the bone-forming capacity of osteoblastic teams at the bone multicellular unit (BMU) level, was significantly higher in patients on active treatment. No sign of excessive suppression of bone turnover or mineralization impairment was detected, confirming the safety of the treatment with intravenous zoledronic acid once a year. These interesting findings are discussed in the article, particularly in terms of new histomorphometric results and clinical findings supporting the tolerability and safety of zoledronic acid.

STEAP mRNA detection in serum of patients with solid tumours.

STEAP was identified by the strategy of suppression subtractive hybridizations in Los Angeles prostate cancer xenografts. It is expressed in prostate and other cancers, and not in most normal tissue; it can be used as a marker to evaluate biological samples from individuals suspected of having a disease associated with STEAP dysregulation, such as cancers, and may provide prognostic information useful in defining appropriate therapeutic options. The aim of this study was to test the STEAP mRNA detection in the serum of patients with different malignant tumours by using Real-Time reverse transcription PCR. The results were compared with biological samples obtained by age-matched non-malignant donors. Our data demonstrated that STEAP mRNA is detectable in serum of patients with different solid tumours whereas it is not amplifiable in non-malignant donors. This marker revealed with the molecular method of quantitative PCR in serum, may be useful to discriminate normal and cancer patients.

Trabecular bone microarchitecture in mild primary hyperparathyroidism.

Primary hyperparathyroidism (PHPT) is a common endocrine disease. High levels of PTH cause demineralization of bone and increased risk of fracture. On the other hand, the effect of PHPT on bone structure is more ambiguous. The aim of this study was to evaluate the effect of PHPT on cancellous bone volume, structure, and microarchitecture. Thirteen transiliac biopsy specimens taken in untreated post-menopausal women aged 65+/-5 yr with primary hyperparathyroidism were compared with 13 biopsies taken in normal women aged 66+/-6 yr. None of the patients presented any other disorder affecting bone metabolism. In these samples we evaluated the direct and indirect histomorphometric parameters of bone microarchitecture using an image analysis system consisting of an epifluorescent microscope (Leica DMR) connected to an analogic 3 CCD camera (Sony DXC 390P) and a computer equipped with specific software for histomorphometric analyses. No significant differences between PHPT patients and controls in cancellous bone volume, trabecular thickness, and number were found. Two-dimensional parameters showed a preserved microarchitecture in PHPT patients. On the other hand, indirect parameters of microarchitecture [Marrow Star Volume (MSV) and Trabecular Bone Pattern Factor (TBPf)] showed a significant compromising of microarchitecture in these patients. PHPT patients have similar structural parameters to normal subjects. Concerning microarchitecture, indirect approach by MSV and TBPf shows a significant compromising of connectivity. These results can explain trabecular fragility observed in clinical studies on PHPT.

Risedronate prevents the loss of microarchitecture in glucocorticoid-induced osteoporosis in rats.

UNLABELLED: Osteoporosis is a severe complication of glucocorticoid treatment. Bisphosphonates are a powerful therapeutic option to prevent osteoporotic fractures. The aims of this study were: a) to determine bone alterations induced by therapy with glucocorticoids (GC); b) to establish the efficacy of risedronate (Ris) in the prevention of these effects. We studied 40 female Sprague-Dawley rats randomly divided into 4 groups of treatment, administered 3 times a week sc: 1. CONTROL: vehicle of methylprednisolone (GC) + vehicle of Ris; 2. Ris: Ris 5 mug/kg body weight vehicle of GC; 3. GC: GC 7 mg/kg + vehicle of Ris; 4. GC+Ris: GC 7 mg/kg, Ris 5 microg/kg. Animals were treated for 30 days and then were sacrificed. Densitometry was performed at baseline and at the end of the treatment. Right tibiae were removed for histomorphometric analyses. The GC group showed a 7% decrease in bone density vs controls (p<0.05), while the GC+Ris group was associated with a 3.5% increase in bone density vs controls (p<0.05). In the GC group, histomorphometric evaluations showed reduced bone volume (BV/TV) and thinning of trabeculae (Tb.Th) vs controls (BV/TV: 31+/-1 vs 35+/-1%, p<0.05; Tb.Th: 43+/-2 vs 50+/-3 microm, p<0.01; Ac.f: 1.8+/-0.2 vs 1.6+/-0.3 N/yr). The GC+Ris group had increased BV/TV and Tb.Th, and reduced Ac.f vs the GC group. Ris also maintained trabecular microarchitecture. At the histological level, glucocorticoid-induced osteoporosis was characterized by decreased bone volume, reduced osteoblastic activity, and deterioration of microarchitecture. Ris counteracted these effects both by prolonging osteoblast activity, and by maintaining bone microarchitecture.

First case of bloodstream infection due to Candida magnoliae in a Chinese oncological patient.

We report a case of fungemia caused by Candida magnoliae, a yeast never associated with human disease. The infection occurred in a 42-year-old Chinese patient with gastric cancer complicated by peritoneal carcinosis. Multiple blood cultures were positive for yeast; the species was well identified with biochemical and molecular methods. The phylogenetic analysis showed a close relationship of C. magnoliae to Candida krusei.

Effect of short-term therapy with recombinant human growth hormone (GH) on metabolic parameters and preclinical atherosclerotic markers in hypopituitary patients with growth hormone deficiency.

OBJECTIVE: This study examines the effects of growth hormone replacement on body composition, insulin sensitivity, lipid profile, endothelial dysfunction and carotid intima media thickness in patients with adult-onset growth-hormone (GH) deficiency. METHODS: Twelve patients with severe GH deficiency received GH replacement for one year. In all patients, the following parameters were evaluated before and after six and twelve months of therapy: fasting glucose, insulin levels and lipid profile, bone mineral density and body composition. Carotid intima media thickness and brachial flow-mediated dilatation were also evaluated by arterial ultrasonography at basal condition and after one year of therapy. RESULTS: No significant changes were seen in body weight and blood pressure, total fat and lean mass, or bone mineral density after six months of GH replacement. There was an increase in triglycerides (p = 0.05), while total and HDL cholesterol, blood glucose, insulin levels did not change significantly. After twelve months, an increase in lean mass and a decrease in fat mass (p < 0.01 vs. baseline), a decrease in insulin resistance (p < 0.01 vs. six months; p = 0.01 vs. baseline) and a decrease in triglycerides (p < 0.01) were observed. Intima media thickness was greater in GH deficiency than in controls (p = 0.01) before therapy, and was unchanged after twelve months of therapy, whereas the flow-mediated dilatation tended to improve (p = 0.05). CONCLUSIONS: GH replacement is able to reverse typical metabolic and body composition alterations in patients with adult GH deficiency after twelve months, but it is unable to revert the vascular alteration completely. Flow-mediated dilatation seems to be a more precocious marker of the remission of arterial damage.

Histomorphometric analysis of glucocorticoid-induced osteoporosis.

Bone histomorphometry or quantitative histology consists of counting or measuring tissue components: cells, extracellular constituents and microarchitecture. Bone histomorphometry is the only method that allows the measurement of mineralization rate and the study of bone formation at three levels: cell, remodeling unit and tissue levels. It is a useful tool to explain the pathogenesis and cellular mechanisms of different metabolic bone diseases such as glucocorticoid-induced osteoporosis (GIO). Glucocorticoids (GC) affect calcium and bone metabolism at every level, but the main effect is the osteoblastic dysfunction. Concerning the bone formation, some histomorphometric studies have shown a depressed osteoblastic activity at a cell, bone remodeling unit, and tissue levels. In addition, there is evidence of a shortening of the period in which the osteoblasts work actively forming the bone matrix. This latter effect seems to occur after high cumulative doses of GC. With regard to the resorption, the results are still debated, but histomorphometric parameters seem to be increased in the majority of studies, at least in the first period of the GC treatment. From a structural point of view, GC seem to induce a thinning of the trabeculae without their perforation, which occurs only after high cumulative doses. Anti-resorptive treatments, such as bisphosphonates, are able to counteract the negative effects of GC on bone. In particular, along with their active working period, they prolong the lifespan of osteoblasts and osteocytes. In addition, the anti-resorptive treatments seem to extend the time for secondary mineralization through a reduction of the Activation Frequency. The latter is an intriguing mechanism of bisphosphonates in GIO that needs further ad hoc investigations.

Bone microarchitecture evaluated by histomorphometry.

The increasing use of densitometric devices for assessing bone fragility has progressively strengthened the assumption that mass is the most important property determining bone mechanical competence. Nevertheless, structure and microarchitecture are relevant aspects of bone strength. The study of microarchitecture is based on the measure of width, number, and separation of trabeculae as well as on their spatial organization. There are several methods to assess bone architecture, particularly at the trabecular level. In particular, histomorphometry, based on the use of optical microscopy and on the principles of quantitative histology and stereology, evaluates microarchitecture two-dimensionally, even if these measures appear well correlated to the three-dimensional structure and properties of bone. In addition, new computerized methods allow the acquisition of more sophisticated measurements by means of a digitizer have been introduced to integrate the use of the microscope. These methods supply information on trabecular width as well as on its distribution and on the organization of the trabeculae in the marrow space. Microarchitecture seems to be a determinant of bone fragility independent of bone density and it is important for understanding the mechanisms of bone fragility as well as the action of the drugs used to prevent osteoporotic fractures. Several in vivo studies (on animals and humans) can provide an additional interpretation for the anti-fracture effect of such drugs. For instance, bisphosphonates and parathyroid hormone seem to preserve or even improve microarchitecture. The challenge for the future will be to evaluate bone quality in vivo with the same or better resolution and accuracy than the invasive methods used today.

Bone microarchitecture as an important determinant of bone strength.

Structure and microarchitecture are determinant aspects of bone strength and essential elements for the assessment of bone mechanical properties. The main structural determinants of bone mechanical strength include width and porosity in the cortical bone; shape, width, connectivity, and anisotropy in the trabecular bone. There are several methods to assess bone architecture, particularly at the trabecular level. Two different approaches can be identified. The first is based on the use of optical microscopy and on the principles of quantitative histology, which evaluate microarchitecture two-dimensionally. The second applies the most modern diagnostic techniques, employing computed tomography and magnetic resonance to obtain and analyze three-dimensional images. From a clinical point of view, microarchitecture is an interesting aspect to study and define specific patterns, such as glucocorticoid-induced osteoporosis, or to evaluate bone alterations in transplanted patients. Microarchitecture seems to be a determinant of bone fragility independent of bone density. Moreover, bone microarchitecture seems to be important to understand the mechanisms of bone fragility as well as the action of the drugs used to prevent osteoporotic fractures. Several in vivo studies (on animals and humans) showed important findings on the effects of different treatments on microarchitecture. Bisphosphonates and parathyroid hormone seemed to preserve or even improve microarchitecture. These observations can provide an additional interpretation for the anti-fracture effect of drugs from a structural viewpoint. The challenge for the future will be to evaluate bone quality in vivo with the same or better resolution and accuracy than the invasive methods in use today.

[Histologic diagnosis of metabolic bone diseases: bone histomorphometry]. / Diagnostica istologica delle malattie metaboliche dello scheletro: istomorfometria ossea.

Histomorphometry or quantitative histology is the analysis on histologic sections of bone resorption parameters, formation and structure. It is the only technique that allows a dynamic evaluation of the activity of bone modelling after labelling with tetracycline. Moreover, the new measurement procedures through the use of the computer allow an assessment of bone microarchitecture too. Histomorphometric bone biopsy is a reliable and well-tolerated procedure. Complications are reported only in 1% of the subjects (hematoma, pain, transient neuralgia). Histomorphometry is used to exclude or confirm the diagnosis of osteomalacia. It is employed in the evaluation of bone damage associated with particular treatments (for example, anticonvulsants) or in case of rare bone diseases (osteogenesis imperfecta, systemic mastocytosis). It is also an essential approach when clinical, biochemical and other diagnostic data are not consistent. Finally, it is a useful method to understand the pathophysiologic mechanisms of drugs. The bone sample is taken at the level of iliac crest under local anesthesia. It is then put into methyl-metacrilate resin where the sections are prepared for the microscopic analysis of the various histomorphometric parameters.

Alendronate prevents further bone loss in renal transplant recipients.

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