Irisin Protects against Loss of Trabecular Bone Mass and Strength in Adult Ovariectomized Mice by Stimulating Osteoblast Activity.

Irisin is a peptide secreted by skeletal muscle that plays a major role in bone metabolism. Experiments in mouse models have shown that administration of recombinant irisin prevents disuse-induced bone loss. In this study, we aimed to evaluate the effects of irisin treatment for the prevention of bone loss in the ovariectomized (Ovx) mouse, the animal model commonly used to investigate osteoporosis caused by estrogen deficiency. Micro-Ct analysis conducted on Sham mice (Sham-veh) and Ovx mice treated with vehicle (Ovx-veh) or recombinant irisin (Ovx-irisn) showed bone volume fraction (BV/TV) decreases in femurs (Ovx-veh 1.39± 0.71 vs. Sham-veh 2.84 ± 1.23; p = 0.02) and tibia at both proximal condyles (Ovx-veh 1.97 ± 0.68 vs. Sham-veh 3.48 ± 1.26; p = 0.03) and the subchondral plate (Ovx-veh 6.33 ± 0.36 vs. Sham-veh 8.18 ± 0.41; p = 0.01), which were prevented by treatment with a weekly dose of irisin for 4 weeks. Moreover, histological analysis of trabecular bone showed that irisin increased the number of active osteoblasts per bone perimeter (Ovx-irisin 32.3 ± 3.9 vs. Ovx-veh 23.5 ± 3.6; p = 0.01), while decreasing osteoclasts (Ovx-irisin 7.6 ± 2.4 vs. Ovx-veh 12.9 ± 3.04; p = 0.05). The possible mechanism by which irisin enhances osteoblast activity in Ovx mice is upregulation of the transcription factor Atf4, one of the key markers of osteoblast differentiation, and osteoprotegerin, thereby inhibiting osteoclast formation.

LIGHT/TNFSF14 regulates estrogen deficiency-induced bone loss.

Bone loss induced by ovariectomy is due to the direct activity on bone cells and mesenchymal cells and to the dysregulated activity of bone marrow cells, including immune cells and stromal cells, but the underlying mechanisms are not completely known. Here, we demonstrate that ovariectomy induces the T-cell co-stimulatory cytokine LIGHT, which stimulates both osteoblastogenesis and osteoclastogenesis by modulating osteoclastogenic cytokine expression, including TNF, osteoprotegerin, and the receptor activator of nuclear factor-κB ligand (RANKL). Predictably, LIGHT-deficient (Tnfsf14-/- ) mice are protected from ovariectomy-dependent bone loss, whereas trabecular bone mass increases in mice deficient in both LIGHT and T and B lymphocytes (Rag -/- Tnfsf14 -/- ) and is associated with an inversion of the TNF and RANKL/OPG ratio. Furthermore, women with postmenopausal osteoporosis display high levels of LIGHT in circulating T cells and monocytes. Taken together, these results indicate that LIGHT mediates bone loss induced by ovariectomy, suggesting that patients with postmenopausal osteoporosis may benefit from LIGHT antagonism. © 2020 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Calcium intake from different food sources in Italian women without and with non-previously diagnosed osteoporosis.

An adequate calcium and vitamin D intake may play a role in preventing osteoporosis, but the contribution of the different food sources of calcium with regards to the risk of osteoporosis been barely explored. This observational study evaluated the calcium intake through a food frequency questionnaire in 126 adult women with not previously diagnosed osteoporosis undergoing Dual-energy X-ray Absorptiometry (DXA) to screen for osteoporosis, and to correlate the calcium intake with parameters of bone density, measured by DXA. Total daily calcium intake and daily intake from food were similar among women found to have osteoporosis, osteopenia or normal condition. The main food source was milk and dairy products, while calcium supplementation was consumed by only 14% of subjects, irrespectively from osteoporosis conditions. DXA parameters were not significantly correlated with total daily calcium intake and calcium from food. The present study highlighted no qualitative and quantitative differences in the consumption of food groups contributing to calcium intakes in women with and without osteoporosis.

Deletion of the Transcription Factor PGC-1α in Mice Negatively Regulates Bone Mass.

Peroxisome proliferator-activated receptor-gamma coactivator (PGC1α) is a transcription coactivator that interacts with a broad range of transcription factors involved in several biological responses. Here, we show that PGC1α plays a role in skeletal homeostasis since aged PGC1α-deficient mice (PGC1α-/-) display impaired bone structure. Micro-CT of the tibial mid-shaft showed a marked decrease of cortical thickness in PGC1α-/- (- 11.9%, p < 0.05) mice compared to wild-type littermate. Trabecular bone was also impaired in knock out mice which displayed lower trabecular thickness (Tb.Th) (- 5.9% vs PGC1α+/+, p < 0.05), whereas trabecular number (Tb.N) was higher than wild-type mice (+ 72% vs PGC1α+/+, p < 0.05), thus resulting in increased (+ 31.7% vs PGC1α+/+, p < 0.05) degree of anisotropy (DA), despite unchanged bone volume fraction (BV/TV). Notably, these impairments of cortical and trabecular bone led to a dramatic ~ 48.4% decrease in bending strength (p < 0.01). These changes in PGC1α-/- mice were paralleled by a significant increase in osteoclast number at the cortical bone surface and in serum level of the bone resorption marker, namely, C-terminal cross-linked telopeptides of type I collagen (CTX-I). We also found that in cortical bone, there was lower expression of mRNA codifying for the key bone-building protein Osteocalcin (Ocn). Interestingly, Collagen I mRNA expression was reduced in mesenchymal stem cells from bone marrow of PGC1α-/-, thus indicating that differentiation of osteoblast lineage is downregulated. Overall, results presented herein suggest that PGC1α may play a key role in bone metabolism.

Claimed effects, outcome variables and methods of measurement for health claims on foods proposed under European Community Regulation 1924/2006 in the area of appetite ratings and weight management.

All the requests for authorisation to bear health claims under Articles 13(5) and 14 in the context of appetite ratings and weight management have received a negative opinion by the European Food Safety Authority (EFSA), mainly because of the insufficient substantiation of the claimed effects (CEs). This manuscript results from an investigation aimed to collect, collate and critically analyse the information related to outcome variables (OVs) and methods of measurement (MMs) in the context of appetite ratings and weight management compliant with Regulation 1924/2006. Based on the literature review, the appropriateness of OVs and MMs was evaluated for specific CEs. This work might help EFSA in the development of updated guidance addressed to stakeholders interested in bearing health claims in the area of weight management. Moreover, it could drive the applicants during the design of randomised controlled trials aimed to substantiate such claims.

Claimed effects, outcome variables and methods of measurement for health claims on foods related to the gastrointestinal tract proposed under regulation (EC) 1924/2006.

Most of the requests of authorisation to the use of health claims pursuant to Regulation EC 1924/2006 related to the gastrointestinal (GI) tract have received a negative opinion by the European Food Safety Authority (EFSA), mainly because of an insufficient substantiation of the claimed effect (CE). The present manuscript refers to the collection, collation and critical analysis of outcome variables (OVs) and methods of measurement (MMs) related to the GI tract compliant with Regulation 1924/2006. The critical evaluation of OVs and MMs was based on the literature review, with the final aim of defining their appropriateness in the context of a specific CE. The results obtained are relevant for the choice of the best OVs and MMs to be used in randomised controlled trials aimed to substantiate the claims on the GI tract. Moreover, the results can be used by EFSA for updating the guidance for the scientific requirements of such health claims.

Biomimetic coating with phosphoserine-tethered poly(epsilon-lysine) dendrons on titanium surfaces enhances Wnt and osteoblastic differentiation.

OBJECTIVES: Phosphoserine-based functionalization has been proposed as a tool to improve integration of endosseous implants by promoting osteoblast adhesion and differentiation in vitro. The present work investigates whether phosphoserine-tethered poly(epsilon-lysine) dendrons, when applied as a film to titanium surfaces, enhance the differentiation of osteoblastic cells and the activation of Wnt/ß-catenin signaling. MATERIALS AND METHODS: These films were tested in a murine model of calvaria-derived MC3T3 osteoblastic cells, primary bone marrow cells and mesenchymal, undifferentiated C2C12 cells. Gene expression was assayed by Real Time PCR, and activation of Wnt signaling pathway was measured with a reporter assay. RESULTS: Dendrons increased expression of alkaline phosphatase and osteocalcin, two osteoblastic markers, in both murine osteoblastic MC3T3 cells and primary bone marrow cells. The expression of osteoprotegerin, a protein opposing osteoclastogenesis was also significantly higher in cells growing on dendron-coated substrates both at 3 and 6 days of culture. Similarly, the mRNA levels of Wisp-2 and of ß-catenin, two Wnt target genes, were also markedly increased in this group at day 6. The activation of this signaling pathway in cells growing on the dendron-coated surfaces was confirmed by use of a TCF/ß-catenin reporter system in the C2C12 cell line. CONCLUSIONS: The findings of the present study show that phosphoserine-tethered poly(epsilon-lysine) dendron films act as stimuli for the activation of specific signal cascades and promote the differentiation of adhering progenitor cells into an osteoblastic phenotype.

Scientific and technical assistance to the evaluation of the safety of calcidiol monohydrate as a novel food.

EFSA was asked by the European Commission to provide scientific assistance with respect to the EFSA adopted scientific opinion on 'Safety of calcidiol monohydrate produced by chemical synthesis as a novel food pursuant to Regulation (EU) 2015/2283', including its bioavailability as a metabolite of vitamin D3 when added for nutritional purposes to food supplements. On 5 July 2023, EFSA adopted the 'Scientific opinion on the tolerable upper intake level for vitamin D, including the derivation of a conversion factor for calcidiol monohydrate'. This opinion concerns an updated exposure assessment for vitamin D and proposes a conversion factor for calcidiol monohydrate into vitamin D3 of 2.5 for labelling purposes. In addition, in reference to the EFSA opinion on the safety of calcidiol monohydrate, the Commission had received a letter from the pharmaceutical company EirGen Pharma Ltd requesting a revision of this opinion based on new data concerning calcidiol. Based on the information and data considered in this scientific technical report, EFSA concludes that the novel food calcidiol monohydrate proposed for use in food supplements is a bioavailable source of the biologically active metabolite of vitamin D, i.e. 1,25-dihydroxyvitamin D, that a conversion factor of 2.5 reflects the relative bioavailability of calcidiol vs vitamin D3 under the proposed conditions of use and use levels, and that it is safe under the proposed conditions of use and use levels, i.e. up to 10 µg/day for children ≥ 11 years old and adults, including pregnant and lactating women, and up to 5 µg/day for children 3-10 years of age.

Scientific opinion on the tolerable upper intake level for preformed vitamin A and ß-carotene.

Following two requests from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver a scientific opinion on the revision of the tolerable upper intake level (UL) for preformed vitamin A and ß-carotene. Systematic reviews of the literature were conducted for priority adverse health effects of excess vitamin A intake, namely teratogenicity, hepatotoxicity and endpoints related to bone health. Available data did not allow to address whether ß-carotene could potentiate preformed vitamin A toxicity. Teratogenicity was selected as the critical effect on which to base the UL for preformed vitamin A. The Panel proposes to retain the UL for preformed vitamin A of 3000 µg RE/day for adults. This UL applies to men and women, including women of child-bearing age, pregnant and lactating women and post-menopausal women. This value was scaled down to other population groups using allometric scaling (body weight0.75), leading to ULs between 600 µg RE/day (infants 4-11 months) and 2600 µg RE/day (adolescents 15-17 years). Based on available intake data, European populations are unlikely to exceed the UL for preformed vitamin A if consumption of liver, offal and products thereof is limited to once per month or less. Women who are planning to become pregnant or who are pregnant are advised not to consume liver products. Lung cancer risk was selected as the critical effect of excess supplemental ß-carotene. The available data were not sufficient and suitable to characterise a dose-response relationship and identify a reference point; therefore, no UL could be established. There is no indication that ß-carotene intake from the background diet is associated with adverse health effects. Smokers should avoid consuming food supplements containing ß-carotene. The use of supplemental ß-carotene by the general population should be limited to the purpose of meeting vitamin A requirements.

Serotonin: a novel bone mass controller may have implications for alveolar bone.

As recent studies highlight the importance of alternative mechanisms in the control of bone turnover, new therapeutic approaches can be envisaged for bone diseases and periodontitis-induced bone loss. Recently, it has been shown that Fluoxetine and Venlafaxine, serotonin re-uptake inhibitors commonly used as antidepressants, can positively or negatively affect bone loss in rat models of induced periodontitis. Serotonin is a neurotransmitter that can be found within specific nuclei of the central nervous system, but can also be produced in the gut and be sequestered inside platelet granules. Although it is known to be mainly involved in the control of mood, sleep, and intestinal physiology, recent evidence has pointed at far reaching effects on bone metabolism, as a mediator of the effects of Lrp5, a membrane receptor commonly associated with Wnt canonical signaling and osteoblast differentiation. Deletion of Lrp5 in mice lead to increased expression of Tryptophan Hydroxylase 1, the gut isoform of the enzyme required for serotonin synthesis, thus increasing serum levels of serotonin. Serotonin, in turn, could bind to HTR1B receptors on osteoblasts and stop their proliferation by activating PKA and CREB.Although different groups have reported controversial results on the existence of an Lrp5-serotonin axis and the action of serotonin in bone remodeling, there is convincing evidence that serotonin modulators such as SSRIs can affect bone turnover. Consequently, the effects of this drug family on periodontal physiology should be thoroughly explored.

Benefits of Vitamin D in Health and Diseases.

This Special Issue of Nutrients, titled "Benefits of Vitamin D in health and diseases", includes a total of twenty-five publications that consider different aspects of vitamin D, both at the cellular/preclinical and clinical levels, in neonates or children, in pregnant women, in adults and in elderly subjects [...].

Scientific opinion on the tolerable upper intake level for vitamin D, including the derivation of a conversion factor for calcidiol monohydrate.

Following two requests from the European Commission (EC), the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver a scientific opinion on the revision of the tolerable upper intake level (UL) for vitamin D and to propose a conversion factor (CF) for calcidiol monohydrate into vitamin D3 for labelling purposes. Vitamin D refers to ergocalciferol (vitamin D2), cholecalciferol (vitamin D3), and calcidiol monohydrate. Systematic reviews of the literature were conducted to assess the relative bioavailability of calcidiol monohydrate versus vitamin D3 on serum 25(OH)D concentrations, and for priority adverse health effects of excess vitamin D intake, namely persistent hypercalcaemia/hypercalciuria and endpoints related to musculoskeletal health (i.e. falls, bone fractures, bone mass/density and indices thereof). Based on the available evidence, the Panel proposes a CF for calcidiol monohydrates of 2.5 for labelling purposes. Persistent hypercalciuria, which may be an earlier sign of excess vitamin D than persistent hypercalcaemia, is selected as the critical endpoint on which to base the UL for vitamin D. A lowest-observed-adverse-effect-level (LOAEL) of 250 µg/day is identified from two randomised controlled trials in humans, to which an uncertainty factor of 2.5 is applied to account for the absence of a no-observed-adverse-effect-level (NOAEL). A UL of 100 µg vitamin D equivalents (VDE)/day is established for adults (including pregnant and lactating women) and for adolescents aged 11-17 years, as there is no reason to believe that adolescents in the phase of rapid bone formation and growth have a lower tolerance for vitamin D compared to adults. For children aged 1-10 years, a UL of 50 µg VDE/day is established by considering their smaller body size. Based on available intake data, European populations are unlikely to exceed the UL, except for regular users of food supplements containing high doses of vitamin D.

Effect of surface treatment on cell responses to grades 4 and 5 titanium for orthodontic mini-implants.

INTRODUCTION: Mini-implants are used to improve orthodontic anchorage, but optimal composition and surface characteristics have yet to be determined. We investigated the behavior of osteoblast-like cells on grade 4 commercially pure titanium and grade 5 titanium alloy with different surface treatments for mini-implants. METHODS: MC3T3 cells were plated on machined, acid-etched, or acid-etched grade 4 titanium enriched with calcium phosphate, or machined, anodized, or anodized and calcium phosphate-enriched grade 5 titanium disks. Surface and cell morphologies were assessed by scanning electron microscopy. Cell viability was measured by chemiluminescence, cytoskeletal organization was investigated by immunofluorescence, and real-time polymerase chain reaction for osteoblast-specific genes was performed to measure cell differentiation. RESULTS: Flattened shapes and strong stress fibers were observed on the machined surfaces; cells on the rough surfaces had a spindle shape, with lower cytoskeletal polarization. Cell proliferation was highest on smooth grade 4 titanium surfaces, whereas cells quickly reached a plateau on rough grade 4 titanium; no difference was observed after 72 hours in the grade 5 titanium groups. Calcium phosphate enrichment on grade 4 titanium significantly increased the messenger RNA levels for alkaline phosphatase and osteocalcin. Osteoblastic markers were higher on the grade 5 titanium machined surfaces than on the rough surfaces, and comparable with acid-etched grade 4 titanium. CONCLUSIONS: Although the grade 4 titanium enriched with calcium phosphate had the highest level of differentiation in vitro, the grade 5 titanium machined surfaces supported cell proliferation and matrix synthesis, and induced high expression of early differentiation markers. Increased mechanical resistance of grade 5 titanium makes it a potential candidate for orthodontic mini-implants.

The Immunologic Profile of Vitamin D and Its Role in Different Immune-Mediated Diseases: An Expert Opinion.

Historically, vitamin D is recognized as an essential component for the maintenance of the musculoskeletal system. The immunomodulatory role of vitamin D in health and disease has gained much interest in recent years due to the many pathologies that share underlying immunological features where vitamin D has been shown to exert a potential role. Evidence from pre-clinical studies show that vitamin D elicits biological effects on both the innate and adaptive immune systems. Furthermore, in vivo studies have shown that administration of vitamin D can lead to changes in or the development of a range of immune-related diseases. This encourages the hypothesis that data derived from clinical and epidemiological studies connect vitamin D with the incidence and severity of many immune-mediated disorders such as rheumatoid arthritis, diabetes, and infectious diseases. Since some other immune-mediated diseases share similar features to that of viral infection such as COVID-19, in this review, we examined these other areas and the role of vitamin D in these diseases.

The Potential Impact of Inducing a Restriction in Reimbursement Criteria on Vitamin D Supplementation in Osteoporotic Patients with or without Fractures.

In October 2019, the Italian Drug Agency (AIFA) restricted reimbursement criteria for vitamin D (VD) use outside the osteoporosis setting (Note 96). However, whether this restriction could also have involved patients at risk for or with osteoporotic fractures has not yet been investigated. We retrospectively analyzed databases from five Italian Local Health Units. Patients aged ≥50 years with either at least one prescription for osteoporosis treatment or with fragility fractures and evidence of osteoporosis from 2011 to 2020 were included. The proportion of subjects with an interruption in VD treatment before and after the introduction of the new reimbursement criteria and predictors of this interruption were analyzed. A total of 94,505 patients (aged 69.4 years) were included. Following the introduction of Note 96, a 2-fold (OR 1.98, 95% CI: 1.92-2.04) increased risk of VD discontinuation was observed. These findings were independent of seasonal variation, osteoporosis treatment patterns, as well as other confounding variables. However, a higher rate of interruption was observed in patients without vertebral/femur fracture (37.8%) vs. those with fracture (32.9%). Rheumatoid arthritis, dyslipidemia and previous fracture were associated with a lower risk of VD interruption, while stroke increased the risk of VD interruption. Our results highlight that a possible misinterpretation of newly introduced criteria for reimbursement restrictions in VD outside of osteoporosis have resulted in an inadequate level of VD supplementation in patients with osteoporosis. This undertreatment could reduce the effect of osteoporosis therapies leading to increased risk of negative outcome.

Testosterone Enanthate: An In Vitro Study of the Effects Triggered in MG-63 Cells.

The aim of this study was to investigate the effects of the androgenic hormone testosterone enanthate (TE) on human MG-63 cells. MG-63 were cultured for 24 h in the presence of TE at increasing concentrations to assess its lethal dose. Therefore, the suitable concentration for a prolonged use of TE in vitro was assessed by viability assay over 9 days. Finally, MG-63 were exposed to TE for 14 days and assayed for differentiation by qPCR and Alizarin Red S staining. TE in the amount of 100 µM resulted as the maximum dose tolerated by MG-63 cells after 24 h. However, a prolonged exposure in culture TE in the amount of 100 µM showed a cytostatic effect on cell proliferation. On the contrary, TE 10 µM was tolerated by the cells and did not boost cell proliferation, but did enhance new bone formation, as revealed by COL1A1, ALPL, BGLAP, and IBSP gene expression after 3, 7, and 14 days, and calcium deposition by Alizarin Red S staining after 14 days. Based on the current study, 10 µM is the critical dose of TE that should be used in vitro to support bone differentiation of MG-63 cells.

Hydrogen plasma treatment confers enhanced bioactivity to silicon carbide-based nanowires promoting osteoblast adhesion.

Nanomaterials play a pivotal role in modern regenerative medicine and tissue engineering, due to their peculiar physical, optical and biological properties once they are used in the nanometric size. Many evidences are showing the importance of biomaterial micro- and nano-topography on cellular adhesion, proliferation and differentiation, and hence, tissue regeneration. It is well known that nanowires (NWs) can mimic many different tissues as a result of their shape and their surface characteristics, and that surface hydrophilicity affects early protein adsorption and cellular adhesion. Therefore a material able to induce bone regeneration might be obtained by combining optimal surface topography and hydrophilicity. Based on these evidence, we designed silicon carbide (SiC) and core/shell silicon carbide/silicon dioxide (SiC/SiOx) nanowires with modified wettability in order to analyze cell behavior, using an in-vitro osteoblastic model. First, we synthetized SiC NWs and SiC/SiOx NWs through a chemical-vapour-deposition (CVD) process, and then we used hydrogen plasma to modify their hydrophilicity. Subsequently we evaluated the four types of NWs in terms of their morphology and contact angle, and we studied their behavior in the presence of MC3T3-E1 murine osteoblasts. Cell metabolic activity, viability, morphology and focal adhesions formation were considered. Morphological data showed different dimensions between SiC and SiC/SiOx NWs. SiC NWs before the hydrogen plasma treatment showed a very low contact angle, that was absent after the treatment. Osteoblastic cells appeared healthy on all of the samples. Interestingly, both hydrophilic SiC NWs and SiC/SiOx NWs generated a favorable distribution of focal adhesions around the cell body confirmed also by scanning electron microscopy images. Moreover, osteoblasts grown on hydrogen plasma treated SiC/SiOx NWs showed an increased metabolic activity testified by a significantly higher cell number. In conclusion, we are here demonstrating that hydrogen plasma treatment of SiC and SiC/SiOx NWs induce a better osteoblastic cellular adhesion by increasing NWs wettability. We are therefore suggesting that hydrogen plasma treatment of SiC/SiOx can offer a suitable method to develop scaffolds for bone tissue engineering applications.

High renin hypertension in focal renal fibromuscular dysplasia: turn off of renin system angiotensin overactivation by renal angioplasty cured high blood pressure and quickly reversed myocardial hypertrophy.

Background Fibromuscolar dysplasia (FMD) is an idiopathic, non-atherosclerotic and non-inflammatory stenotic lesion of renal arteries causing renovascular hypertension up-regulating renin-angiotensin-aldosterone system. Case report: A 18-year-old man was referred to our Hypertension Center (Clinica e Terapia Medica) for the recent onset of hypertension, poorly controlled on calcium channel blockers, already associated to electrocardiographic and echocardiography signs of left ventricular hypertrophy and significant albuminuria (728 mg/24 h). An increased plasma renin activity (PRA), aldosterone level and a mild hypokalemia raised the suspicion of renovascular hypertension. Abdominal CT and MRI angiography showed mild kidneys asymmetry and a tubular stenosis of the right renal artery in its mid-distal portion close to renal hilum. Radionuclide renal scintigraphy documented a kidneys asymmetry of separated glomerular filtration rate. Renal FMD was diagnosed based on patient age and the absence of cardiovascular risk factors for atherosclerosis. Patient successfully underwent right renal angioplasty giving a rapid normalization of blood pressure levels without antihypertensive drugs. Plasma aldosterone and PRA rapidly normalized as well as serum potassium levels. Six months after angioplasty echocardiography showed a regression of left ventricular hypertrophy and the patient albumin urine excretion became normal (14 mg/24 h). Conclusions FMD can cause renovascular hypertension associated to organ damage such myocardial hypertrophy and albuminuria through mechanisms dependent but also independent from blood pressure levels. Renal angioplasty turned off renin-angiotensin-aldosterone overactivity allowing the cure the hypertension and a surprisingly rapid reverse of myocardial hypertrophy and of excess of albumin urine excretion not only dependent on blood pressure normalization.

Effectiveness of In-Hospital Cholecalciferol Use on Clinical Outcomes in Comorbid COVID-19 Patients: A Hypothesis-Generating Study.

Little information is available on the beneficial effects of cholecalciferol treatment in comorbid patients hospitalized for COVID-19. The aim of this study was to retrospectively examine the clinical outcome of patients receiving in-hospital high-dose bolus cholecalciferol. Patients with a positive diagnosis of SARS-CoV-2 and overt COVID-19, hospitalized from 15 March to 20 April 2020, were considered. Based on clinical characteristics, they were supplemented (or not) with 400,000 IU bolus oral cholecalciferol (200,000 IU administered in two consecutive days) and the composite outcome (transfer to intensive care unit; ICU and/or death) was recorded. Ninety-one patients (aged 74 ± 13 years) with COVID-19 were included in this retrospective study. Fifty (54.9%) patients presented with two or more comorbid diseases. Based on the decision of the referring physician, 36 (39.6%) patients were treated with vitamin D. Receiver operating characteristic curve analysis revealed a significant predictive power of the four variables: (a) low (<50 nmol/L) 25(OH) vitamin D levels, (b) current cigarette smoking, (c) elevated D-dimer levels (d) and the presence of comorbid diseases, to explain the decision to administer vitamin D (area under the curve = 0.77, 95% CI: 0.67-0.87, p < 0.0001). Over the follow-up period (14 ± 10 days), 27 (29.7%) patients were transferred to the ICU and 22 (24.2%) died (16 prior to ICU and six in ICU). Overall, 43 (47.3%) patients experienced the combined endpoint of transfer to ICU and/or death. Logistic regression analyses revealed that the comorbidity burden significantly modified the effect of vitamin D treatment on the study outcome, both in crude (p = 0.033) and propensity score-adjusted analyses (p = 0.039), so the positive effect of high-dose cholecalciferol on the combined endpoint was significantly amplified with increasing comorbidity burden. This hypothesis-generating study warrants the formal evaluation (i.e., clinical trial) of the potential benefit that cholecalciferol can offer in these comorbid COVID-19 patients.

Adhesion pattern and growth of primary human osteoblastic cells on five commercially available titanium surfaces.

OBJECTIVE: The aim of this study is to analyze the morphology and proliferation of human osteoblastic cells in vitro on five commercially available titanium surfaces. MATERIALS AND METHODS: Human primary cells of the osteoblastic lineage were obtained from bone explants. The cells were plated on polished (T1), machined (T2), sand-blasted/acid-etched (T3), sand-blasted/acid-etched, modified with hydrogen peroxide rinse (T4), and plasma-sprayed titanium (T5) disks. Cell morphology was studied after 6, 24, 72 h, 7 and 14 days of culture by scanning electron microscopy. The formation and distribution of focal adhesions was investigated by immunocytochemical staining at 3, 6 and 24 h. Cell growth was measured by an MTT assay after 3, 7 and 9 days of culture. Moreover, the production of osteocalcin and osteoprotegerin (OPG) was evaluated in the supernatants by ELISA. RESULTS: Morphological analysis revealed that substrate topography profoundly affected cells' shape and their anchoring structures. Large lamellipodia were formed on polished and machined surfaces, while thin filopodia were more frequently observed on T3 and T4 samples. Moreover, cells formed stronger focal adhesions on T3 and T4 surfaces, and cell proliferation was higher on rough surfaces. Osteocalcin production was higher on the T4 surface, whereas OPG steadily increased on every surface. CONCLUSIONS: Taken together, these data show that all the surfaces allowed cell attachment, adhesion and proliferation, but T4 and T5 surfaces appeared to be a better substrate for the adhesion, proliferation and differentiation of cells of the osteoblastic lineage.