Low-energy electron microscopy intensity-voltage data - Factorization, sparse sampling and classification.

Low-energy electron microscopy (LEEM) taken as intensity-voltage (I-V) curves provides hyperspectral images of surfaces, which can be used to identify the surface type, but are difficult to analyse. Here, we demonstrate the use of an algorithm for factorizing the data into spectra and concentrations of characteristic components (FSC3 ) for identifying distinct physical surface phases. Importantly, FSC3 is an unsupervised and fast algorithm. As example data we use experiments on the growth of praseodymium oxide or ruthenium oxide on ruthenium single crystal substrates, both featuring a complex distribution of coexisting surface components, varying in both chemical composition and crystallographic structure. With the factorization result a sparse sampling method is demonstrated, reducing the measurement time by 1-2 orders of magnitude, relevant for dynamic surface studies. The FSC3 concentrations are providing the features for a support vector machine-based supervised classification of the surface types. Here, specific surface regions which have been identified structurally, via their diffraction pattern, as well as chemically by complementary spectro-microscopic techniques, are used as training sets. A reliable classification is demonstrated on both example LEEM I-V data sets.

Putative Anticancer Compounds from Plant-Derived Endophytic Fungi: A Review.

Endophytic fungi are microorganisms that exist almost ubiquitously inside the various tissues of living plants where they act as an important reservoir of diverse bioactive compounds. Recently, endophytic fungi have drawn tremendous attention from researchers; their isolation, culture, purification, and characterization have revealed the presence of around 200 important and diverse compounds including anticancer agents, antibiotics, antifungals, antivirals, immunosuppressants, and antimycotics. Many of these anticancer compounds, such as paclitaxel, camptothecin, vinblastine, vincristine, podophyllotoxin, and their derivatives, are currently being used clinically for the treatment of various cancers (e.g., ovarian, breast, prostate, lung cancers, and leukemias). By increasing the yield of specific compounds with genetic engineering and other biotechnologies, endophytic fungi could be a promising, prolific source of anticancer drugs. In the future, compounds derived from endophytic fungi could increase treatment availability and cost effectiveness. This comprehensive review includes the putative anticancer compounds from plant-derived endophytic fungi discovered from 1990 to 2020 with their source endophytic fungi and host plants as well as their antitumor activity against various cell lines.

Identifying subpopulations in multicellular systems by quantitative chemical imaging using label-free hyperspectral CARS microscopy.

Quantitative hyperspectral coherent Raman scattering microscopy merges imaging with spectroscopy and utilises quantitative data analysis algorithms to extract physically meaningful chemical components, spectrally and spatially-resolved, with sub-cellular resolution. This label-free non-invasive method has the potential to significantly advance our understanding of the complexity of living multicellular systems. Here, we have applied an in-house developed hyperspectral coherent anti-Stokes Raman scattering (CARS) microscope, combined with a quantitative data analysis pipeline, to imaging living mouse liver organoids as well as fixed mouse brain tissue sections xenografted with glioblastoma cells. We show that the method is capable of discriminating different cellular sub-populations, on the basis of their chemical content which is obtained from an unsupervised analysis, i.e. without prior knowledge. Specifically, in the organoids, we identify sub-populations of cells at different phases in the cell cycle, while in the brain tissue, we distinguish normal tissue from cancer cells, and, notably, tumours derived from transplanted cancer stem cells versus non-stem glioblastoma cells. The ability of the method to identify different sub-populations was validated by correlative fluorescence microscopy using fluorescent protein markers. These examples expand the application portfolio of quantitative chemical imaging by hyperspectral CARS microscopy to multicellular systems of significant biomedical relevance, pointing the way to new opportunities in non-invasive disease diagnostics.

Hyperspectral CARS microscopy and quantitative unsupervised analysis of deuterated and non-deuterated fatty acid storage in human cells.

Coherent anti-Stokes Raman scattering (CARS) implemented as a vibrational micro-spectroscopy modality eradicates the need for potentially perturbative fluorescent labeling while still providing high-resolution, chemically specific images of biological samples. Isotopic substitution of hydrogen atoms with deuterium introduces minimal change to molecular structures and can be coupled with CARS microscopy to increase chemical contrast. Here, we investigate HeLa cells incubated with non-deuterated or deuterium-labeled fatty acids, using an in-house-developed hyperspectral CARS microscope coupled with an unsupervised quantitative data analysis algorithm, to retrieve Raman susceptibility spectra and concentration maps of chemical components in physically meaningful units. We demonstrate that our unsupervised analysis retrieves the susceptibility spectra of the specific fatty acids, both deuterated and non-deuterated, in good agreement with reference Raman spectra measured in pure lipids. Our analysis, using the cell-silent spectral region, achieved excellent chemical specificity despite having no prior knowledge and considering the complex intracellular environment inside cells. The quantitative capabilities of the analysis allowed us to measure the concentration of deuterated and non-deuterated fatty acids stored within cytosolic lipid droplets over a 24 h period. Finally, we explored the potential use of deuterium-labeled lipid droplets for non-invasive cell tracking, demonstrating an effective application of the technique for distinguishing between cells in a mixed population over a 16 h period. These results further demonstrate the chemically specific capabilities of hyperspectral CARS microscopy to characterize and distinguish specific lipid types inside cells using an unbiased quantitative data analysis methodology.

Quantitative morphometric analysis of single gold nanoparticles by optical extinction microscopy: Material permittivity and surface damping effects.

Quantifying the optical extinction cross section of a plasmonic nanoparticle has recently emerged as a powerful means to characterize the nanoparticle morphologically, i.e., to determine its size and shape with a precision comparable to electron microscopy while using a simple optical microscope. In this context, a critical piece of information to solve the inverse problem, namely, calculating the particle geometry from the measured cross section, is the material permittivity. For bulk gold, many datasets have been reported in the literature, raising the question of which one is more adequate to describe specific systems at the nanoscale. Another question is how the nanoparticle interface, not present in the bulk material, affects its permittivity. In this work, we have investigated the role of the material permittivities on the morphometric characterization of defect-free ultra-uniform gold nanospheres with diameters of 10 nm and 30 nm, following a quantitative analysis of the polarization- and spectrally-resolved extinction cross section on hundreds of individual nanoparticles. The measured cross sections were fitted using an ellipsoid model. By minimizing the fit error or the variation of the fitted dimensions with color channel selection, the material permittivity dataset and the surface damping parameter g best describing the nanoparticles are found to be the single crystal dataset by Olmon et al. [Phys. Rev. B 86, 235147 (2012)] and g ≈ 1, respectively. The resulting nanoparticle geometries are in good agreement with transmission electron microscopy of the same sample batches, including both 2D projection and tomography.

Early results with a bicruciate-retaining total knee arthroplasty: a match-paired study.

BACKGROUND: The aim of this study is to compare 2 groups of total knee arthroplasties (TKAs): the bicruciate-retaining (BCR-group) and cruciate-retaining total knee arthroplasty (CR-group), evaluating the functional results in the short-term follow-up. METHODS: 24 BCR were included in the study and were compared with a group of 24 TKAs performed with the same implant, but with sacrifice of the ACL and retention of the posterior cruciate ligament. For preoperative and postoperative clinical evaluation, the visual analogue score (VAS) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) were used. Radiological evaluation included weight-bearing long-leg view, a Rosemberg view, lateral view of the knee and tangential view of the patella. Hip-knee-ankle angle (HKA) was recorded pre and postoperatively. Radiolucent lines (RLLs) were evaluated according the Knee Society Roentgenographic Evaluation System (KSRES). RESULTS: At last follow-up the mean VAS score was 1.81 for BCR group and 1.43 for CR group (p = 0.61). The mean WOMAC score was 8.68 for BCR group and 12.81 for CR group (p = 0.33). As for the radiological evaluation, preoperative HKA angle was 0.53° varus for BCR group and 3.14° varus for CR group (p = 0.24); postoperative HKA was 0.72° valgus for BCR group and 0.38° valgus for CR group (p = 0.75). The percentage of RLLs was similar between the two groups (12% versus 15%). CONCLUSIONS: BCR-TKA has showed to give similar functional and radiographic outcomes compared to conventional CR-TKA in a similar cohort of patients. An higher operative times and higher number of complications respect were found in BCR group. These results can be explained by the early learning curve experiences. Future randomized controlled trials should be performed to support new implant designs such as BCR. LEVEL OF EVIDENCE: Level of evidence Case-control study, level III.

Quantitative Label-Free Imaging of Lipid Domains in Single Bilayers by Hyperspectral Coherent Raman Scattering.

Lipid phase separation in cellular membranes is thought to play an important role in many biological functions. This has prompted the development of synthetic membranes to study lipid-lipid interactions in vitro, alongside optical microscopy techniques aimed at directly visualizing phase partitioning. In this context, there is a need to overcome the limitations of fluorescence microscopy, where added fluorophores can significantly perturb lipid packing. Raman-based optical imaging is a promising analytical tool for label-free chemically specific microscopy of lipid bilayers. In this work, we demonstrate the application of hyperspectral coherent Raman scattering microscopy combined with a quantitative unsupervised data analysis methodology developed in-house to visualize lipid partitioning in single planar membrane bilayers exhibiting liquid-ordered and liquid-disordered domains. Two home-built instruments were utilized, featuring coherent anti-Stokes Raman scattering and stimulated Raman scattering modalities. Ternary mixtures of dioleoylphosphatidylcholine, sphingomyelin, and cholesterol were used to form phase-separated domains. We show that domains are consistently resolved, both chemically and spatially, in a completely label-free manner. Quantitative Raman susceptibility spectra of the domains are provided alongside their spatially resolved concentration maps.

Quantitative Imaging of B1 Cyclin Expression Across the Cell Cycle Using Green Fluorescent Protein Tagging and Epifluorescence.

In this article, we report the number of cyclin B1 proteins tagged with enhanced green fluorescent protein (eGFP) in fixed U-2 OS cells across the cell cycle. We use a quantitative analysis of epifluorescence to determine the number of eGFP molecules in a nondestructive way, and integrated over the cell we find 104 to 105 molecules. Based on the measured number of eGFP tagged cyclin B1 proteins, knowledge of cyclin B1 dynamics through the cell cycle, and the cell morphology, we identify the stages of cells in the cell cycle. © 2020 The Authors. Cytometry Part A published by Wiley Periodicals LLC. on behalf of International Society for Advancement of Cytometry.

Label-Free Volumetric Quantitative Imaging of the Human Somatic Cell Division by Hyperspectral Coherent Anti-Stokes Raman Scattering.

Quantifying the chemical composition of unstained intact tissue and cellular samples with high spatio-temporal resolution in three dimensions would provide a step change in cell and tissue analytics critical to progress the field of cell biology. Label-free optical microscopy offers the required resolution and noninvasiveness, yet quantitative imaging with chemical specificity is a challenging endeavor. In this work, we show that hyperspectral coherent anti-Stokes Raman scattering (CARS) microscopy can be used to provide quantitative volumetric imaging of human osteosarcoma cells at various stages through cell division, a fundamental component of the cell cycle progress resulting in the segregation of cellular content to produce two progeny. We have developed and applied a quantitative data analysis method to produce volumetric three-dimensional images of the chemical composition of the dividing cell in terms of water, proteins, DNAP (a mixture of proteins and DNA, similar to chromatin), and lipids. We then used these images to determine the dry masses of the corresponding organic components. The attribution of proteins and DNAP components was validated using specific well-characterized fluorescent probes, by comparison with correlative two-photon fluorescence microscopy of DNA and mitochondria. Furthermore, we map the same chemical components under perturbed conditions, employing a drug that interferes directly with cell division (Taxol), showing its influence on cell organization and the masses of proteins, DNAP, and lipids.

Quantitative imaging of lipids in live mouse oocytes and early embryos using CARS microscopy.

Mammalian oocytes contain lipid droplets that are a store of fatty acids, whose metabolism plays a substantial role in pre-implantation development. Fluorescent staining has previously been used to image lipid droplets in mammalian oocytes and embryos, but this method is not quantitative and often incompatible with live cell imaging and subsequent development. Here we have applied chemically specific, label-free coherent anti-Stokes Raman scattering (CARS) microscopy to mouse oocytes and pre-implantation embryos. We show that CARS imaging can quantify the size, number and spatial distribution of lipid droplets in living mouse oocytes and embryos up to the blastocyst stage. Notably, it can be used in a way that does not compromise oocyte maturation or embryo development. We have also correlated CARS with two-photon fluorescence microscopy simultaneously acquired using fluorescent lipid probes on fixed samples, and found only a partial degree of correlation, depending on the lipid probe, clearly exemplifying the limitation of lipid labelling. In addition, we show that differences in the chemical composition of lipid droplets in living oocytes matured in media supplemented with different saturated and unsaturated fatty acids can be detected using CARS hyperspectral imaging. These results demonstrate that CARS microscopy provides a novel non-invasive method of quantifying lipid content, type and spatial distribution with sub-micron resolution in living mammalian oocytes and embryos.

Long Exciton Dephasing Time and Coherent Phonon Coupling in CsPbBr2Cl Perovskite Nanocrystals.

Fully inorganic cesium lead halide perovskite nanocrystals (NCs) have shown to exhibit outstanding optical properties such as wide spectral tunability, high quantum yield, high oscillator strength as well as blinking-free single photon emission, and low spectral diffusion. Here, we report measurements of the coherent and incoherent exciton dynamics on the 100 fs to 10 ns time scale, determining dephasing and density decay rates in these NCs. The experiments are performed on CsPbBr2Cl NCs using transient resonant three-pulse four-wave mixing (FWM) in heterodyne detection at temperatures ranging from 5 to 50 K. We found a low-temperature exciton dephasing time of 24.5 ± 1.0 ps, inferred from the decay of the photon-echo amplitude at 5 K, corresponding to a homogeneous line width (fwhm) of 54 ± 5 µeV. Furthermore, oscillations in the photon-echo signal on a picosecond time scale are observed and attributed to coherent coupling of the exciton to a quantized phonon mode with 3.45 meV energy.

Bessel-Beam Hyperspectral CARS Microscopy with Sparse Sampling: Enabling High-Content High-Throughput Label-Free Quantitative Chemical Imaging.

Microscopy-based high-content and high-throughput analysis of cellular systems plays a central role in drug discovery. However, for contrast and specificity, the majority of assays require a fluorescent readout which always comes with the risk of alteration of the true biological conditions. In this work, we demonstrate a label-free imaging platform which combines chemically specific hyperspectral coherent anti-Stokes Raman scattering microscopy with sparse sampling and Bessel beam illumination. This enabled us to screen multiwell plates at high speed, while retaining the high-content chemical analysis of hyperspectral imaging. To demonstrate the practical applicability of the method we addressed a critical side effect in drug screens, namely, drug-induced lipid storage within hepatic tissue. We screened 15 combinations of drugs and neutral lipids added to human HepG2 liver cells and developed a high-content quantitative data analysis pipeline which extracted the spectra and spatial distributions of lipid and protein components. We then used their combination to train a support vector machine discriminative algorithm. Classification of the drug responses in terms of phospholipidosis versus steatosis was achieved in a completely label-free assay.

Hyperspectral analysis applied to micro-Brillouin maps of amyloid-beta plaques in Alzheimer's disease brains.

A recent investigation on the architecture and chemical composition of amyloid-ß (Aß) plaques in ex vivo histological sections of an Aß-overexpressing transgenic mouse hippocampus has shed light on the infrared light signature of cell-activation related biomarkers of Alzheimer's disease. A correlation was highlighted between the biomechanical properties detected by Brillouin microscopy and the molecular make-up of Aß plaques provided by FTIR spectroscopic imaging and Raman microscopy (with correlative immunofluorescence imaging) in this animal model of the disease. In the Brillouin spectra of heterogeneous materials such as biomedical samples, peaks are likely the result of multiple contributions, more or less overlaid on a spatial and spectral scale. The ability to disentangle these contributions is very important as it may give access to discrete components that would otherwise be buried within the Brillouin peak envelope. Here, we applied an unsupervised non-negative matrix factorization method to analyse the spontaneous Brillouin microscopy maps of Aß plaques in transgenic mouse hippocampal sections. The method has already been proven successful in decomposing chemical images and is applied here for the first time to acoustic maps acquired with a Fabry-Perot Brillouin microscope. We extracted and visualised a decrease in tissue rigidity from the core through to the periphery of the plaque, with spatially distinct components that we assigned to specific entities. This work demonstrates that it is possible to reveal the structure and mechanical properties of Aß plaques, with details visualized by the projection of the mechanical contrast into a few relevant channels.

Imaging of the thymus in myotonic dystrophy type 1.

The occurrence of thymoma in myotonic dystrophy type 1 (DM1) has been occasionally reported, and an increased risk of tumors has been observed. We performed imaging of the thymus in 22 patients carrying DMPK expansion. Clinical examination and routine instrumental exams were performed at the same time. We observed no thymic abnormalities in 13 subjects, thymic hyperplasia in eight patients, and an invasive thymoma in one case. Subjects with thymic abnormalities did not show peculiarities as regards clinical and electrophysiological features. We observed thymoma in one patient with an expansion in the higher range. Abnormalities of the thymus including hyperplasia and thymoma can be present in DM1, but do not seem to play a major role in DM1 pathogenesis. Further studies are needed to understand if some RNA splicing factors involved in DM1 and influenced by CTG expansion size could have a role in thymocytes proliferation.

Quantitative Spatiotemporal Chemical Profiling of Individual Lipid Droplets by Hyperspectral CARS Microscopy in Living Human Adipose-Derived Stem Cells.

There is increasing evidence showing that cytosolic lipid droplets, present in all eukaryotic cells, play a key role in many cellular functions. Yet their composition at the individual droplet level and how it evolves over time in living cells is essentially unknown due to the lack of suitable quantitative nondestructive measurement techniques. In this work, we demonstrate the ability of label-free hyperspectral coherent anti-Stokes Raman scattering (CARS) microscopy, together with a quantitative image analysis algorithm developed by us, to quantify the lipid type and content in vol/vol concentration units of individual lipid droplets in living human adipose-derived stem cells during differentiation over 9 days in media supplemented with different fatty acids. Specifically, we investigated the addition of the polyunsaturated linoleic and alpha-linolenic fatty acids into the normal differentiation medium (mostly containing monounsaturated fatty acids). We observe a heterogeneous uptake which is droplet-size dependent, time dependent, and lipid dependent. Cells grown in linoleic-acid-supplemented medium show the largest distribution of lipid content across different droplets at all times during differentiation. When analyzing the average lipid content, we find that adding linoleic or alpha-linolenic fatty acids at day 0 results in uptake of the new lipid components with an exponential time constant of 22 ± 2 h. Conversely, switching lipids at day 3 results in an exponential time constant of 60 ± 5 h. These are unprecedented findings, exemplifying that the quantitative imaging method demonstrated here could open a radically new way of studying and understanding cytosolic lipid droplets in living cells.

Optical micro-spectroscopy of single metallic nanoparticles: quantitative extinction and transient resonant four-wave mixing.

We report a wide-field imaging method to rapidly and quantitatively measure the optical extinction cross-section σ(ext) (also polarisation resolved) of a large number of individual gold nanoparticles, for statistically-relevant single particle analysis. We demonstrate a sensitivity of 5 nm(2) in σ(ext), enabling detection of single 5 nm gold nanoparticles with total acquisition times in the 1 min range. Moreover, we have developed an analytical model of the polarisation resolved σ(ext), which enabled us to extract geometrical particle aspect ratios from the measured σ(ext). Using this method, we have characterized a large number of nominally-spherical gold nanoparticles in the 10-100 nm size range. Furthermore, the method provided measurements of in-house fabricated nanoparticle conjugates, allowing distinction of individual dimers from single particles and larger aggregates. The same particle conjugates were investigated correlatively by phase-resolved transient resonant four-wave mixing micro-spectroscopy. A direct comparison of the phase-resolved response between single gold nanoparticles and dimers highlighted the promise of the four-wave mixing technique for sensing applications with dimers as plasmon rulers.

Sparse sampling for fast hyperspectral coherent anti-Stokes Raman scattering imaging.

We demonstrate a method to increase the acquisition speed in coherent anti-Stokes Raman scattering (CARS) hyperspectral imaging while retaining the relevant spectral information. The method first determines the important spectral components of a sample from a hyper-spectral image over a small number of spatial points but a large number of spectral points covering the accessible spectral range and sampling the instrument spectral resolution at the Nyquist limit. From these components we determine a small set of frequencies needed to retrieve the weights of the components with minimum error for a given measurement noise. Hyperspectral images with a large number of spatial points, for example covering a large spatial region, are then measured at this small set of frequencies, and a reconstruction algorithm is applied to generate the full spectral range and resolution. The resulting spectra are suited to retrieve from the CARS intensity the CARS susceptibility which is linear in the concentration, and apply unsupervised quantitative analysis methods such as FSC3. We demonstrate the method on CARS hyperspectral images of human osteosarcoma U2OS cell, with a reduction in the acquisition time by a factor of 25. This method is suited also for other coherent vibrational microscopy techniques such as stimulated Raman scattering, and in general for hyperspectral imaging techniques with sequential spectral acquisition.

[Chronic pain in the obese: a quali-quantitative observational study]. / Dolore cronico nell'obesità: studio osservazionale quali-quantitativo.

INTRODUCTION: Obesity (Ob) is one of the major issues for the public health care system with a constantly increasing prevalence. Chronic Pain (CP), on the other hand, is a pathological condition as severe and prevalent as the former. Ob and CP are not only pathological conditions, they also are important factors of risk for the onset of a number of morbid conditions. MATERIALS AND METHODS: In our study we have enrolled 182 patients with Ob, to whom we have asked to fill a brief questionnaire with the purpose of evaluating prevalence and characteristics of CP, therapeutic attitude and its results, as well as the knowledge of the Law n. 38 - 15/03/2010. RESULTS: From the analysis of gathered data, CP is present in the 39% of subjects with Ob (73.2% of females and 23.9% of males) and proportionally increases as BMI increases. The majority of patients (48%) shows pain at articular level, and a "pin" and a "gripping" pain are the two types of pain that are mostly described. Almost all the subjects enrolled (90%) suffer of a pain reported at a moderate to intense level. 15% circa of the patients do not take any therapy, while FANS have resulted to be the most used drugs among them (over 50% of the patients) and the 45% of the subjects have currently reported not to have a good control over the pain. The Law n. 38 has been reported unknown by the 8.2% of the investigated sample. CONCLUSIONS: The study has demonstrated a substantial association between the Ob and CP, particularly in the female gender, the clinical relevance of pain, its BMI-dependent tendency, the inadequacy of the therapy and the widespread lack of awareness and attention to the themes and issues of pain.

[Chronic pain in the diabetic patient: a quali-quantitative observational study]. / Dolore e diabete mellito: studio osservazionale quali-quantitativo.

AIM: The purpose of this study is to evaluate the prevalence and characteristics of pain in subjects affected by Diabetes Mellitus (DM), to assess approach and therapeutically valid outcomes as well as the knowledge of the Law n. 38/15/03/2010 of the Italian Government ("Dispositions to guarantee the access to the Palliative Cares and Pain Therapy"). MATERIALS AND METHODS: We have enrolled 462 patients affected by DM [242 (52.4%) males, 209 (42.5%) females; while in 11 (5.1%) cases the gender has not been specified], with characteristics as follows: 62 patients (13.4%) affected by T1DM (37 males and 25 females) e 400 patients (86.6%) affected by T2DM (224 males e 176 females). The average age was of 65.2 years old (range 20-91). All the patients have been presented with an original questionnaires based on 10 questions. RESULTS: 221 subjects (48%) have claimed to have experienced pain; 60% within the females, 38% within the males (p<0.001). 31% of these are to be included among the patients with T1DM, 50.5% among those with T2DM (p<0.01). The presence of chronic pain has been acknowledged by 162 subjects (35%). As per chronic pain, this has been described as articular pain by 128 patients (80%), while 63 (38%) located the pain through the spine and 29 (18%) throughout the muscles. Chronic pain was described as moderate by 73 subjects (45%), intense by 59 (36%), feeble by 15 (9%), utterly intense by 5 (3%), moderate/intense by 1 (1%). The drugs for treating the chronic pain used by the patients have been enlisted as follows: FANS (41%), paracetamol (30%), glucocorticoids (3%), weak opioids (2%); 27% of subjects have received no therapy. As for the Law 38/2010, only 8% have said they have had news of it. CONCLUSIONS: The data gathered in this study have drawn attention on the fact that the presence of pain is higher in female gender, with a prevalence of 60% compared to the 38% of the male gender. It has been observed no relation with the age range, in particular no proportional increase level of pain has been observed, although the higher peak of prevalence has been experienced in the age range between 70-79, both for pain in general and for chronic pain. Speaking about efficacy of the treatment, almost 50% of the subjects have received no improvement from the therapy.

Alendronate soluble solution: a higher adherence rate in the treatment of osteoporosis.

INTRODUCTION: Since low adherence to a long-term therapy results in a poor clinical outcome and significantly increases healthcare costs, adherence to the treatment of chronic disorders is an issue of great interest. This is particularly true of the treatment of osteoporosis (OP). PURPOSE OF STUDY: Adherence to the osteoporosis therapy in patients treated with bisphosphonates in tablet form has been evaluated in comparison with the adherence of those taking alendronate in soluble solution. METHODS AND MATERIALS: Here we present a retrospective study of 245 patients treated with alendronate, risedronate and ibandronate tablets and a prospective study of 118 patients treated with soluble alendronate. In both studies, patients have been observed for a period of 12 months. RESULTS: The analysis of patients' persistence with the treatment plan, assessed at three, six and 12 months, revealed a significantly higher adherence (p < 0.005) in the cohort of patients treated with soluble alendronate (92.37% at 12 months) compared with those who followed the course of treatment with tablets (65.4 %, 12 months). CONCLUSIONS: The investigation showed higher adherence to the oral therapy with soluble alendronate, demonstrating that a formulation obtained by this method can contribute to a higher level of persistence with the treatment of a disease such as osteoporosis, which requires a long-term therapeutic plan.