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Latanoprost (LTP) is a prostaglandin F2α analog used to lower intraocular pressure in glaucoma treatment administered daily as eye drops. In this study, a universal model based on poly(l-lactide-co-glycolide-co-trimethylene carbonate) with shape memory was proposed for the development of a solid biodegradable formulation with prolonged release administered intraconjunctivally, intravitreally, subconjunctivally, and subcutaneously. Solution casting and electron beam (EB) irradiation were applied to the matrix formulation. The properties of the native matrix and matrices degraded in a PBS buffer (pH 7.4) were monitored by NMR, DSC, GPC, and SEM. Water uptake (WU) and weight loss (WL) were also analyzed. LTP was released over 113 days in a tri-phasic and sigmoidal pattern without a burst effect and with a relatively long second release phase, in which changes were observed in the glass transition temperature, molecular weight (Mn), WU, and WL. EB irradiation decreased the initial Mn, increased WU, and accelerated LTP release with a shortened lag phase. This provides the opportunity to partially eliminate the use of drops at the start of treatment. SEM observations indicated that surface erosion is the prevalent degradation mechanism. The proposed model is an interesting solution during a preliminary study to develop final medicinal products that provide high adherence.

Background: As the World faces unprecedented pandemic caused by SARS-CoV-2 virus, repositioning of existing drugs to treatment of COVID-19 disease is urgently awaited, provided that high quality scientific evidence supporting safety and efficacy in this new indication is gathered. Efforts concerning drugs repositioning to COVID-19 were mostly focused on antiviral drugs, or drugs targeting the late phase of the disease. Methods: Based on published research, the pharmacological activities of fluvoxamine and amantadine, two well-known drugs widely used in clinical practice for psychiatric and neurological diseases, respectively, have been reviewed, with a focus on their potential therapeutic importance in the treatment of COVID-19. Result: Several preclinical and clinical reports were identified suggesting that these two drugs might exert protective effects in the early phases of COVID-19. Conclusion: Preclinical and early clinical evidence are presented indicating that these drugs hold promise to prevent COVID-19 progression when administered early during the course of infection.

In den letzten Jahren wurde in vielen experimentellen und klinischen Studien gezeigt, dass bei der Glaukomerkrankung die neuronale Degeneration nicht nur auf der Hohe von Netzhaut und Sehnerv, sondern im Verlauf der gesamten Sehbahn und des Gehirns erfolgt. Dargestellt werden die neuroprotektive Wirkung und ihre Mechanismen von Citicolin bei der Glaukomerkrankung. Vor dem Hintergrund der Neuroanatomie, des Neuroimaging und der Pathogenese der Glaukomerkrankung wird die Relevanz erlautert. Die Daten der experimentellen und klinischen Studien werden dargelegt und ein Fazit fur die klinische Anwendung gezogen. Citicolin wirkt neuroprotektiv uber glaukomrelevante Mechanismen. Die neuroprotektive Wirkung von Citicolin bei Offenwinkelglaukomen ist funktionell und morphologisch nachweisbar. Sie ist unabhangig vom Glaukomschaden und Augeninnendruck und tritt i. d. R. erst nach einem Jahr auf. Die Effekte von oralem Citicolin treten bei einer Tagesdosis von 500–1000 mg auf. Die Einnahme von Citicolin kann dauerhaft oder in Zyklen erfolgen. In den Studien traten bei der Einnahme von Citicolin keine Nebenwirkungen auf. Citicolin kann kognitive Leistungen und somit Therapieadharenz sowie die Lebensqualitat bei Glaukompatienten verbessern Diese relativ alte nootrope Substanz, welche jetzt als Nahrungserganzungsmittel vertrieben wird, scheint eine wertvolle Erganzung zur konventionellen Therapie der Glaukomerkrankung und eine rationale Option zur Neuroprotektion und Prophylaxe zu sein.

Current treatment protocols for myocardial infarction improve the outcome of disease to some extent but do not provide the clue for full regeneration of the heart tissues. An increasing body of evidence has shown that transplantation of cells may lead to some organ recovery. However, the optimal stem cell population has not been yet identified. We would like to propose a novel pro-regenerative treatment for post-infarction heart based on the combination of human skeletal myoblasts (huSkM) and mesenchymal stem cells (MSCs). huSkM native or overexpressing gene coding for Cx43 (huSKMCx43) alone or combined with MSCs were delivered in four cellular therapeutic variants into the healthy and post-infarction heart of mice while using molecular reporter probes. Single-Photon Emission Computed Tomography/Computed Tomography (SPECT/CT) performed right after cell delivery and 24 h later revealed a trend towards an increase in the isotopic uptake in the post-infarction group of animals treated by a combination of huSkMCx43 with MSC. Bioluminescent imaging (BLI) showed the highest increase in firefly luciferase (fluc) signal intensity in post-infarction heart treated with combination of huSkM and MSCs vs. huSkM alone (p &lt, 0.0001). In healthy myocardium, however, nanoluciferase signal (nanoluc) intensity varied markedly between animals treated with stem cell populations either alone or in combinations with the tendency to be simply decreased. Therefore, our observations seem to show that MSCs supported viability, engraftment, and even proliferation of huSkM in the post-infarction heart.

Simple Summary Treatment of osteosarcoma, apart from chemotherapy modifications, has not changed for approximately 30 years. Similarly, as in other tumors, mutations in the TP53 gene are often observed in osteosarcoma. In this article, we highlight the possibility of targeting p53 in the treatment of osteosarcoma. We collected data on mutations in this gene founded in patients-derived samples. We describe animals with TP53 dysfunction, which may constitute preclinical models. We put emphasis on several molecules which act on p53 protein or its activity. We also highlight gene therapy approaches. Although many of the therapies are at an early stage, they offer hope for a change in the approach to osteosarcoma treatment based on TP53 targeting in the future. Abstract The TP53 gene is mutated in 50% of human tumors. Oncogenic functions of mutant TP53 maintain tumor cell proliferation and tumor growth also in osteosarcomas. We collected data on TP53 mutations in patients to indicate which are more common and describe their role in in vitro and animal models. We also describe animal models with TP53 dysfunction, which provide a good platform for testing the potential therapeutic approaches. Finally, we have indicated a whole range of pharmacological compounds that modulate the action of p53, stabilize its mutated versions or lead to its degradation, cause silencing or, on the contrary, induce the expression of its functional version in genetic therapy. Although many of the described therapies are at the preclinical testing stage, they offer hope for a change in the approach to osteosarcoma treatment based on TP53 targeting in the future.

Introduction Rheumatoid arthritis (RA) and periodontitis share risk factors and inflammatory pathways that could be related to cytokines, such as interleukin (IL)-6, IL-8, IL-17A, and tumour necrosis factor-α (TNF-α). The aim of this study was to compare periodontal status and salivary levels of selected cytokines between patients diagnosed with RA and periodontitis. RA patients were assessed for the potential influence of anti-rheumatic therapy. Material and methods One hundred and six patients were enrolled in a cross-sectional study. Medical assessment and periodontal examination were performed in 35 patients with chronic periodontitis, in 35 patients with RA and chronic periodontitis, and in 36 controls. Unstimulated whole saliva samples were analysed for IL-6, IL-8, IL-17A, and TNF-α. Results Significant differences in biomarkers and periodontal parameters were found among groups. Study groups exhibited higher mean pocket depth (PD), number of PD > 4 mm, and mean clinical attachment loss, when compared with controls. The RA group had lower bleeding on probing index and PD, but higher values of plaque indices than the periodontitis group. Concentration of evaluated cytokines were higher in the RA and periodontitis groups, compared with controls. The periodontitis group showed also higher levels of IL-6, IL-17A, and TNF-α in comparison to RA. RA patients were treated with disease-modifying anti-rheumatic drugs (DMARDs) and glucocorticosteroids. Conclusions Salivary levels of IL-6, IL-8, IL-17A, and TNF-α can be affected by periodontitis, RA, and presumably DMARDs. DMARD therapy appears to reduce destructive and inflammatory processes in periodontal tissues because lower values of PD, BOP, and salivary levels of IL-6, IL-17A, and TNF-α were found in RA.

Background There has been long-term interest in cladribine as a drug for the treatment of MS. The current study focused on the effect of cladribine on oligoclonal bands (OCB) expression in the CSF in relapsing-remitting MS (RRMS) patients observed over 10 years. Methods 29 treatment-naive subjects with RRMS were prospectively enrolled and received induction therapy with subcutaneous parenteral cladribine (at a cumulative dose of 1.8 mg/kg; divided into 6 courses every 5 weeks given for 4–6 days, depending on patients’ body weight). Selected patients received maintenance doses in the follow-up period. Results Isoelectric focusing revealed that 55% of patients did not have OCB in CSF after cladribine treatment as compared to baseline testing when 100% of patients were positive for OCB. There were no significant differences in Expanded Disability Status Scale scores at baseline and at the end of treatment cycle between OCB-positive vs. OCB-negative subgroups. At the last follow-up, OCB-negative patients had lower disability compared to OCB-positive patients (p = 0.03). Conclusion Cladribine-induced immune reconstitution leads to long lasting suppression of intrathecal humoral response, which might be an additional mechanism that enhances the therapeutic effect on disease progression in RRMS patients.

Purpose: Filgrastim, a recombinant human granulocyte colony-stimulating factor (rhG-CSF) produced in Escherichia coli, is indicated for treatment of neutropenia-related conditions in cancer patients. It has been marketed as Neupogen since 1991. In 2006, biosimilar rhG-CSF products have been approved in the European Union (EU). The aim of this study was to compare quality attributes of the originator filgrastim with its three biosimilars which came from the EU market in 2014 to verify whether their similarity is maintained since their market approval. Materials/Methods: Spectrophotometric analysis was used to determine protein content in analyzed products. Chromatographic and electrophoretic analyses were applied to verify the presence of high and low-molecular weight impurities. Secondary and tertiary structure of the drugs were investigated with circular dichroism and intrinsic fluorescence. Finally, biological activity of the drugs was assessed using cell proliferation assay. Results: All products displayed protein content close to the label concentration with a ±6% variation. Two oxidized forms and a deamidated form were present at Conclusion: This study shows that a high level of similarity is maintained among originator and three biosimilar filgrastims up to 5 years from their first registration in the EU.

In remitting–relapsing multiple sclerosis (RR-MS), relapses are driven by autoreactive immune cells that enter the brain and spinal cord and damage myelin sheaths of axons in white and grey matter, whereas during remissions myelin is repaired by activated oligodendroglial cells. Disease-modifying therapies (DMTs) may either retard/attenuate myelin damage or promote/enhance/speed up myelin repair. Almost all currently approved DMTs inhibit myelin damage and are considerably toxic. Enhancement of myelin repair is considered an unmet medical need of MS patients. Citicoline, known for many years as a nootropic and neuroprotective drug and recently pronounced food supplement, has been found to be significantly efficacious in two complementary rodent models of MS, experimental autoimmune encephalomyelitis (EAE) and cuprizone-induced myelin toxicity. Moreover, citicoline treatment improves visual evoked potentials (VEPs) in glaucoma patients, which is relevant because VEP monitoring is frequently used as an indicator of remyelination in MS. Although over-the-counter availability of citicoline may impede its formal translation to the clinic of MS, evaluation of its efficacy for supporting remyelination in this disease is strongly indicated.

The disease which develops following SARS-CoV-2 virus infection, known as COVID-19, in most affected countries displays mortality from 1.5% to 9.8%. When leukocytosis due to granulocytosis, thrombocytopenia, and increased level of D-dimers are detected early during the disease course, they are accurate predictors of mortality. Based on the published observations that each of the aforementioned disturbances by itself may appear as a consequence of hypoxia, a hypothesis is presented that early hypoxia consequential to sleep apnea and/or blunted respiratory response to chemical stimuli is an early determinant of COVID-19 progression to the severe and critical stage. Further, it is noted that host-directed therapies which may counteract hypoxia and its early downstream effects are initiated only upon hospitalization of COVID-19 patients, which is too late to be fully effective. An example is anticoagulation treatment with low molecular weight heparin. Repurposing drugs which could counteract some early posthypoxic events, such as fluvoxamine, amantadine and N-acetylcysteine, for post-exposure prophylaxis of SARS-CoV-2 infection and early prehospital treatment of COVID-19, is indicated.

Background: It has been shown that a possible pathogenetic mechanism of neurodegeneration in the mouse model of glaucoma (DBA/2J) may be an alteration of kynurenic acid (KYNA) in the retina. This study aimed to verify the hypothesis that alterations of tryptophan (TRP) metabolism in DBA/2J mice is not limited to the retina. Methods: Samples of the retinal tissue and serum were collected from DBA/2J mice (6 and 10 months old) and control C57Bl/6 mice of the same age. The concentration of TRP, KYNA, kynurenine (KYN), and 3-hydroxykynurenine (3OH-K) was measured by HPLC. The activity of indoleamine 2,3-dioxygenase (IDO) was also determined as a KYN/TRP ratio. Results: TRP, KYNA, L-KYN, and 3OH-K concentration were significantly lower in the retinas of DBA/2J mice than in C57Bl/6 mice. 3OH-K concentration was higher in older mice in both strains. Serum TRP, L-KYN, and KYNA concentrations were lower in DBA/2J than in age-matched controls. However, serum IDO activity did not differ significantly between compared groups and strains. Conclusions: Alterations of the TRP pathway seem not to be limited to the retina in the murine model of hereditary glaucoma.

COVID-19, a disease caused by infection with the SARS-CoV-2 virus, is asymptomatic or mildly symptomatic in most cases. Some patients, usually burdened with risk factors develop acute respiratory failure and other organ dysfunction. In such cases, the mortality rate is very high despite the use of intensive therapy. Amantadine has complex activity including antiviral, antiinflammatory and dopaminergic effects. This clinical trial will assess the efficacy and safety of amantadine in the prevention of COVID-19 progression toward acute respiratory failure and neurological complications.The trial will enroll 200 patients who are positive for SARS-CoV-2 infection and have one or more risk factors for worsening the disease. These patients will be included as hospitalized or ambulatory subjects for early treatment of illness. The recruitment will take place in 8 centers covering different regions of Poland. For 14 days they will be given either 200 mg of amantadine a day or placebo. Our hypothesis is a considerable reduction in the number of patients with progression toward respiratory insufficiency or neurological complications thanks to the treatment of amantadine.Demonstrating the efficacy and safety of amantadine treatment in improving the clinical condition of patients diagnosed with COVID-19 is of great importance in combating the effects of the pandemic. It has potential to influence on the severity and course of neurological complications, which are very common and persist long after the infection as long-COVID syndrome.www.gov identification no. NCT04854759; Eudra CT number: 2021-001144-98 (dated 27 February 2021).

Highlights • We report on a questionnaire-based study performed to assess severity of COVID-19 in patients suffering from multiple sclerosis, Parkinson's disease and cognitive impairment. • All patients were receiving treatments with either amantadine or memantine on stable registered doses. • In all patients infection with SARS-CoV-2 was confirmed by rtPCR but none of them developed clinical manifestations of infectious disease. They also did not report any significant changes in neurological status in the course of primary nervous system disease., Facing the outbreak of coronavirus disease 2019 (COVID-19) pandemic, there is an urgent need to find protective or curable drugs to prevent or to stop the course of the coronavirus SARS-CoV-2 infection. Recent evidence accumulates that adamantanes, widely used in different neurological diseases, could be repurposed for COVID-19. We hereby report on a questionnaire-based study performed to assess severity of COVID-19 in patients suffering from multiple sclerosis (n=10), Parkinson's disease (n=5) or cognitive impairment (n=7). In all patients infection with SARS-CoV-2 was confirmed by rtPCR of nasopharyngeal swabs. They were receiving treatment with either amantadine (n=15) or memantine (n=7) in stable registered doses. All of them had two-week quarantine since documented exposure and none of them developed clinical manifestations of infectious disease. They also did not report any significant changes in neurological status in the course of primary nervous system disease. Above results warrant further studies on protective effects of adamantanes against COVID-19 manifestation, especially in subjects suffering from neurological disease.

Osteosarcoma (OS) is the most frequent primary bone cancer in children and adolescents and the third most frequent in adults. Many inherited germline mutations are responsible for syndromes that predispose to osteosarcomas including Li Fraumeni syndrome, retinoblastoma syndrome, Werner syndrome, Bloom syndrome or Diamond–Blackfan anemia. TP53 is the most frequently altered gene in osteosarcoma. Among other genes mutated in more than 10% of OS cases, c-Myc plays a role in OS development and promotes cell invasion by activating MEK–ERK pathways. Several genomic studies showed frequent alterations in the RB gene in pediatric OS patients. Osteosarcoma driver mutations have been reported in NOTCH1, FOS, NF2, WIF1, BRCA2, APC, PTCH1 and PRKAR1A genes. Some miRNAs such as miR-21, -34a, -143, -148a, -195a, -199a-3p and -382 regulate the pathogenic activity of MAPK and PI3K/Akt-signaling pathways in osteosarcoma. CD133+ osteosarcoma cells have been shown to exhibit stem-like gene expression and can be tumor-initiating cells and play a role in metastasis and development of drug resistance. Although currently osteosarcoma treatment is based on adriamycin chemoregimens and surgery, there are several potential targeted therapies in development. First of all, activity and safety of cabozantinib in osteosarcoma were studied, as well as sorafenib and pazopanib. Finally, novel bifunctional molecules, of potential imaging and osteosarcoma targeting applications may be used in the future.

To establish a relationship between impairment of the anterograde axonal transport (AAT) in the axons of the retinal ganglion cells and the intraocular pressure (IOP) during aging in mice with hereditary glaucoma.Quantitative in vivo approach based on manganese enhanced magnetic resonance imaging was developed in order to evaluate AAT in 3-, 6-, and 14-month old DBA/2J mice that develop age-dependent pigmentary glaucoma or age-matched C57Bl/6 mice that do not develop any retinal disease. Unilateral intravitreous administration of MnClIn C57Bl/6 mice, AAT to SC was decreasing with age, 30% decrease was noted between 3 and 14 months. The decrease in axonal transport to LGN was less pronounced in this strain. In 3-month-old DBA/2J mice, axonal transport to SC was 30% lower than in 3-month-old C57Bl/6 mice but no significant decrease was noted in 6-month-old animals. However, a decrease of over 95% in axonal transport both to SC and LGN was noted in 14-month-old DBA/2J mice. DBA/2J mice exhibited a sharp increase in IOP at 6 months, which reversed at 14 months but displayed age-dependent elongation of the eyeball and deepening of the anterior chamber.Failure of AAT to SC of DBA/2J mice during development of pigmentary glaucoma does not follow closely changes in IOP and eye morphology. The relationship between IOP and AAT in optic nerve and tract is complex and may reflect preconditioning mechanism.

Background The gene that encodes tumor protein p53, Tp53, is mutated or silenced in most human cancers and is recognized as one of the most important cancer drivers. Homozygotic Tp53 knockout mice, which develop lethal cancers early in their lives, are already used in cancer prevention studies, and now Tp53 knockout rats have also been generated. This study assessed feasibility of using homozygous Tp53 knockout rats to evaluate the possible outcome of cancer chemoprevention. Methods A small colony of Tp53 knockout rats with a Wistar strain genetic background was initiated and maintained in the animal house at our institution. Tp53 heterozygotic females were bred with Tp53 homozygous knockout males to obtain a surplus of knockout homozygotes. To evaluate the reproducibility of their lifespan, 4 groups of Tp53 homozygous knockout male rats born during consecutive quarters of the year were kept behind a sanitary barrier in a controlled environment until they reached a moribund state. Their individual lifespan data were used to construct quarterly survival curves. Results The four consecutive quarterly survival curves were highly reproducible. They were combined into a single “master” curve for use as a reference in intervention studies. The average lifespan of untreated male Tp53 homozygous knockout rats was normally distributed, with a median of 133 days. Sample size vs. effect calculations revealed that confirming a 20% and 30% increase in the lifespan would respectively require a sample size of 18 and 9 animals (when assessed using the t-test with a power of 80% and alpha set at 0.05). As an example, the Tp53 homozygous knockout rat model was used to test the chemopreventive properties of carnosine, a dipeptide with suspected anticancer properties possibly involving modulation of the mTOR pathway. The result was negative. Conclusion Further evaluation of the Tp53 homozygous knockout male rat colony is required before it can be confirmed as a viable tool for assessing new methods of cancer prevention or treatment.

Kynurenines, products of tryptophan (TRP) metabolism, display neurotoxic (e.g., 3-hydroxykynurenine; 3-HK), or neuroprotective (e.g., kynurenic acid; KYNA) properties. Imbalance between the enzymes constituting the kynurenine pathway (KP) plays a role in several disease, including neurodegeneration. In this study, we track changes in concentrations of tryptophan and its selected metabolites after damage to retinal ganglion cells and link this data with expression of KP enzymes. Brown-Norway rats were subjected to intravitreal N-methyl-D-aspartate (NMDA) injection or partial optic nerve crush (PONC). Retinas were collected 2 and 7 days after the completion of PONC or NMDA injection. Concentrations of TRP, kynurenine (KYN), and KYNA were determined by high performance liquid chromatography (HPLC). Data on gene expression in the rat retina were extracted from GEO, public microarray experiments database. Two days after NMDA injection concentration of TRP decreased, while KYN and KYNA increased. At day 7 compared to day 2 decrease of KYN, KYNA and further reduction of TRP concentration were observed, but on day 7 KYN concentration was still elevated when compared to controls. At day 2 and 7 after NMDA injection no statistically significant alterations of 3-HK were observed. TRP and 3-HK concentration was higher in PONC group than in controls. However, both KYN and KYNA were lower. At day seven concentration of TRP, 3-HK, and KYN was higher, whereas concentration of KYNA declined. In vivo experiments showed that retinal damage or optic nerve lesion affect TRP metabolism via KP. However, the pattern of changes in metabolite concentrations was different depending on the model. In particular, in PONC KYNA and KYN levels were decreased and 3-HK elevated. These observations correspond with data on expression of genes encoding KP enzymes assessed after optic nerve crush or transection. After intraorbital optic nerve crush downregulation of KyatI and KyatIII between 24 h and 3 days after procedure was observed. Kmo expression was transiently upregulated (12 h after the procedures). After intraorbital optic nerve transsection (IONT) Kmo expression was upregulated after 48 h and 7 days, KyatI and KyatIII were downregulated after 12, 48 h, 7 days and upregulated after 15 days. Collected data point to the conclusion that development of therapeutic strategies targeting the KP could be beneficial in diseases involving retinal neurodegeneration.

Citicoline is the generic name of a cytidine-diphospho-choline (CDPCholine), a natural intracellular precursor of phosphatidylcholine, the important membrane phospholipid. Since mid-1970s, injectable formulation of citicoline (i.e., CDPCholine from exogenous source) was used in the treatment of Parkinson's and Alzheimer's disease, some dementias and brain ischemic stroke, and its pharmacodynamic properties were characterized during drug development. In consideration of negligible toxicity and excellent bioavailability following oral intake, citicoline recently was pronounced a food ingredient. Preclinical and clinical observations indicate that it could be a valuable complement to standard therapy of primary open angle glaucoma, whereas its activity in other eye diseases, such as amblyopia and myopia, requires further studies. A cause and effect relationship has not been established between the consumption of citicoline and maintenance of normal vision, but citicoline may be recommended as a food ingredient for people suffering from or threatened by glaucoma.

Sonodynamic therapy (SDT) is a promising technique based on the ability of certain substances, called sonosensitizers, to sensitize cancer cells to non-thermal effects of low-energy ultrasound waves, allowing their destruction. Sonosensitization is thought to induce cell death by direct physical effects such as cavitation and acoustical streaming as well as by complementary chemical reactions generating oxygen free radicals. One of the promising sonosensitizers is 5-aminolevulinic acid (ALA) which upon selective uptake by cancer cells is metabolized and accumulated as protoporphyrin IX. The objective of the study was to describe ALA-mediated sonodynamic effects in vitro on a rat RG2 glioma cell line. Glioma cells, seeded at the bottom of 96-well plates and incubated with ALA (10 µg/ml) for 6 h, were exposed to the sinusoidal US pulses with a resonance frequency of 1 MHz, 1000 µs duration, 0.4 duty-cycle, and average acoustic power varying from 2 W to 6 W. Ultrasound waves were generated by a flat circular piezoelectric transducer with a diameter of 25 mm. Cell viability was determined by MTT assay. Structural cellular changes were visualized with a fluorescence microscope. Signs of cytotoxicity such as a decrease in cell viability, chromatin condensation and apoptosis were found. ALA-mediated SDT evokes cytotoxic effects of low intensity US on rat RG2 glioma cells in vitro . This cell line is indicated for further preclinical assessment of SDT in in vivo conditions.

The application of drops containing ocular medicines to the conjunctival sac is the most common method of drug delivery to the anterior segment of the eye. Although this route of application seemingly displays numerous advantages, obtaining effective drug concentration at its site of action is challenging. The bioavailability of a topically applied drug depends on various factors related to the eye, to the drug and formulation, to the drop, and to the patient. The present article discusses their relative significance. From a drop applied to an eye, at most 5% of a drug dose enters the ocular structures. Of utmost importance for effective ocular drug delivery are patient compliance and the physicochemical properties of the drug. For a given concentration of an active substance, drop size may determine drug adverse effects but does not influence its efficacy.

Sarcomas are a heterogeneous group of malignant tumors, that develop from mesenchymal cells. Sarcomas are tumors associated with poor prognosis and expected short overall survival. Efforts to improve treatment efficacy and treatment outcomes of advanced and metastatic sarcoma patients have not led to significant improvements in the last decades. In the Tp53C273X/C273X rat model we therefore aimed to characterize specific gene expression pattern of angiosarcomas with a loss of TP53 function. The presence of metabolically active tumors in several locations including the brain, head and neck, extremities and abdomen was confirmed by magnetic resonance imaging (MRI) and positron emission tomography (PET) examinations. Limb angiosarcoma tumors were selected for microarray expression analysis. The most upregulated pathways in angiosarcoma vs all other tissues were related to cell cycle with mitosis and meiosis, chromosome, nucleosome and telomere maintenance as well as DNA replication and recombination. The downregulated genes were responsible for metabolism, including respiratory chain electron transport, tricarboxylic acid (TCA) cycle, fatty acid metabolism and amino-acid catabolism. Our findings demonstrated that the type of developing sarcoma depends on genetic background, underscoring the importance of developing more malignancy susceptibility models in various strains and species to simulate the study of the diverse genetics of human sarcomas.

Myocardial infarction (MI) is one of the most frequent causes of death in industrialized countries. Stem cells therapy seems to be very promising for regenerative medicine. Skeletal myoblasts transplantation into postinfarction scar has been shown to be effective in the failing heart but shows limitations such, e.g. cell retention and survival. We synthesized and investigated superparamagnetic iron oxide nanoparticles (SPIONs) as an agent for direct cell labeling, which can be used for stem cells imaging. High quality, monodisperse and biocompatible DMSA-coated SPIONs were obtained with thermal decomposition and subsequent ligand exchange reaction. SPIONs’ presence within myoblasts was confirmed by Prussian Blue staining and inductively coupled plasma mass spectrometry (ICP-MS). SPIONs’ influence on tested cells was studied by their proliferation, ageing, differentiation potential and ROS production. Cytotoxicity of obtained nanoparticles and myoblast associated apoptosis were also tested, as well as iron-related and coating-related genes expression. We examined SPIONs’ impact on overexpression of two pro-angiogenic factors introduced via myoblast electroporation method. Proposed SPION-labeling was sufficient to visualize firefly luciferase-modified and SPION-labeled cells with magnetic resonance imaging (MRI) combined with bioluminescence imaging (BLI) in vivo. The obtained results demonstrated a limited SPIONs’ influence on treated skeletal myoblasts, not interfering with basic cell functions.

Streptozotocin (STZ), a glucosamine-nitrosourea compound derived from soil bacteria and originally developed as an anticancer agent, in 1963 has been found to induce diabetes in experimental animals. Since then, systemic application of STZ became the most frequently studied experimental model of insulin-dependent (type 1) diabetes. The compound is selectively toxic toward insulin-producing pancreatic beta cells, which is explained as the result of its cellular uptake by the low-affinity glucose transporter 2 (GLUT2) protein located in their cell membranes. STZ cytotoxicity is mainly due to DNA alkylation which results in cellular necrosis. Besides pancreatic beta cells, STZ applied systemically damages also other organs expressing GLUT2, such as kidney and liver, whereas brain is not affected directly because blood-brain barrier lacks this transporter protein. However, single or double intracerebroventricular (icv) STZ injection(s) chronically decrease cerebral glucose uptake and produce multiple other effects that resemble molecular, pathological, and behavioral features of Alzheimer's disease (AD). Taking into consideration that glucose hypometabolism is an early and persistent sign of AD and that Alzheimer's brains present features of impaired insulin signaling, icv STZ injections are exploited by some investigators as a non-transgenic model of this disease and used for preclinical testing of pharmacological therapies for AD. While it has been assumed that icv STZ produces cerebral glucose hypometabolism and other effects directly through desensitizing brain insulin receptors, the evidence for such mechanism is poor. On the other hand, early data on insulin immunoreactivity showed intense insulin expression in the rodent brain, and the possibility of local production of insulin in the mammalian brain has never been conclusively excluded. Also, there are GLUT2-expressing cells in the brain, in particular in the circumventricular organs and hypothalamus; some of these cells may be involved in glucose sensing. Thus, icv STZ may damage brain glucose insulin producing cells and/or brain glucose sensors. Mechanistic explanation of the mode of action of icv STZ, which is currently lacking, would provide a valuable contribution to the field of animal models of Alzheimer's disease.

Purpose Trace elements might play a role in the complex multifactorial pathogenesis of open-angle glaucoma. The aim of this study was to analyze concentrations of trace elements in aqueous humor samples of patients with primary open-angle glaucoma (POAG) and pseudoexfoliation glaucoma (PEXG). Patients and methods Thirty-three aqueous humor samples were obtained from patients undergoing cataract surgery: 12 patients with POAG (age 65.3 ± 10.50, female 8, male 4), 10 patients with PEXG (age 65.9 ± 11.27, female 6, male 4) and 11 patients without glaucoma (age 69.5 ± 13.70, female 7, male 4) serving as controls. Aqueous humor levels of cadmium, iron, manganese, cobalt, copper and zinc were measured by Flow-Injection-Inductively-Coupled-Plasma-Mass-Spectrometry (FI-ICP-MS). Results From the statistical evaluation, we observed that patients with POAG had significantly higher aqueous humor levels of zinc (p = 0.006) compared to controls. Increased aqueous humor levels of zinc were also observed in patients with PEXG in relation to control (p = 0.0006). For iron we observed a significantly reduction in PEXG compared to control (p = 0.002) and a significant difference between POAG and PEXG (p = 0.0091). No significant differences were observed in aqueous humor levels of manganese, cobalt, copper, cadmium between glaucoma and control patients. No differences were seen for iron (POAG vs. controls). Analysis of trace element ratios was added. Conclusion Significant differences in aqueous humor levels of zinc and iron between glaucoma and control patients support the hypothesis that these trace elements are involved in the pathogenesis of open-angle glaucoma.

Objective: Proton magnetic resonance spectroscopy (1H-MRS) in ultra-high magnetic field can be used for non-invasive quantitative assessment of brain glutamate (Glu) and glutamine (Gln) in vivo. Glu, the main excitatory neurotransmitter in the central nervous system, is efficiently recycled between synapses and presynaptic terminals through Glu-Gln cycle which involves glutamine synthase confined to astrocytes, and uses 60–80% of energy in the resting human and rat brain. During voluntary or involuntary exercise many brain areas are significantly activated, which certainly intensifies Glu-Gln cycle. However, studies on the effects of exercise on 1H-MRS Glu and/or Gln signals from the brain provided divergent results. The present study on rats was performed to determine changes in 1H-MRS signals from three brain regions engaged in motor activity consequential to forced acute exercise to exhaustion. Method: After habituation to treadmill running, rats were subjected to acute treadmill exercise continued to exhaustion. Each animal participating in the study was subject to two identical imaging sessions performed under light isoflurane anesthesia, prior to, and following the exercise bout. In control experiments, two imaging sessions separated by the period of rest instead of exercise were performed. 1H-NMR spectra were recorded from the cerebellum, striatum, and hippocampus using a 7T small animal MR scanner. Results: Following exhaustive exercise statistically significant increases in the Gln and Glx signals were found in all three locations, whereas increases in the Glu signal were found in the cerebellum and hippocampus. In control experiments, no changes in 1H-MRS signals were found. Conclusion: Increase in glutamine signals from the brain areas engaged in motor activity may reflect a disequilibrium caused by increased turnover in the glutamate-glutamine cycle and a delay in the return of glutamine from astrocytes to neurons. Increased turnover of Glu-Gln cycle may be a result of functional activation caused by forced endurance exercise; the increased rate of ammonia detoxification may also contribute. Increases in glutamate in the cerebellum and hippocampus are suggestive of an anaplerotic increase in glutamate synthesis due to exercise-related stimulation of brain glucose uptake. The disequilibrium in the glutamate-glutamine cycle in brain areas activated during exercise may be a significant contributor to the central fatigue phenomenon.

Introduction: In amyotrophic lateral sclerosis (ALS), progressive death of motor neurons results in denerva- tion and reinnervation of muscles. It is not clear how ALS affects the properties of motor units (MUs). Methods: Properties of single MUs in the medial gastrocnemius (MG) muscle of rats bearing the human mutated superoxide dismutase gene type 1 (SOD1) were determined at 3 stages: asymptomatic (ALS I); early symptomatic (ALS II); and terminal (ALS III). Results :I n ALS II, higher proportions of FF (fast fatigable) and S (slow) MUs were observed, whereas in ALS III higher percentages of S and lower percentages of FF MUs were noted compared with controls. S motor neurons reinnervated fast muscle fibers, and those MUs gained some properties of fast MUs, including lower fatigue resistance, greater force generation, and higher action potential amplitudes. Conclusion: Changes in MU properties of SOD1 rats have progressive and multidirectional character and speed depending on the MU type. Muscle Nerve 000:000-000, 2014 Amyotrophic lateral sclerosis (ALS) is a chronic, intractable, paralytic disease characterized by pro- gressive and relatively selective death of upper and lower motor neurons, with concomitant muscular atrophy. The majority of cases occur sporadically, but up to 10% are familial; of these, about 20% are associated with mutations in the gene encod- ing cytoplasmic Cu,Zn superoxide dismutase 1 (SOD1). The transgenic rodent models of familial ALS replicate major features of the human disease, including gradual degeneration of motor neurons, which usually begins in adulthood and is accompa- nied by progressive muscle paralysis. 1,2 The most frequently studied transgenic ALS model is based on insertion of the human SOD1 gene with the G93A mutation. 3,4 G93A mice and rats have been investigated extensively. 5-8 In the course of ALS, not only do motor neu- rons degenerate along with development of dener- vation atrophy of skeletal muscles, but also compensatory processes take place, including