26 research outputs found

    Histologic and Histomorphometric Assessment of Eggshell-Derived Bone Graft Substitutes on Bone Healing in Rats

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    Objective: The objective of this study was to histologically and histomorphometrically evaluate the efficacy of the new formulations of eggshell-derived calcium carbonate in rats. Study Design: The study was conducted on 30 adult male rats. Four standardized and circular intra-bony defects were created in the both maxilla and mandibula of each animal. Three different graft materials were prepared as follows: 1) Material A: Eggshell-derived calcium carbonate combined with carrageenan gel, 2) Material B: Eggshellderived calcium carbonate combined with xanthan gum gel, and 3) Material C: Eggshell-derived calcium carbonate powder. The right mandibular defect sites were grafted with Material A in all animals, and defects on the left were grafted with Material B. Defects on the right side of maxilla were received Material C in all animals, and all left maxillary defects were remained untreated as controls. The animals were sacrificed either postoperatively on the 15th day, postoperatively on the 30th day or postoperatively on the 45th day. Histomorphometric measurements were made of the areas of newly formed bone, necrotic bone, fibrous tissue and residual graft material. Results: Material A exhibited the highest level of osteoid formation followed by Material B and Material C on the 45th day. In terms of osteoid formation, statistically significant differences were observed between graft materials and controls at 45th day compared to 15th and 30th day (p<0.05). Conclusions: Eggshell-derived graft substitutes in both gel and powder forms are biocompatible materials which may have the potential to enhance the new bone formation

    Comparative in vitro studies on PBN loaded nanoparticles prepared by biodegradable chitosan, PLGA polymers and their PEGylated block copolymers

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    α-phenyl-N-tert-butyl nitrone (PBN) is a neuroprotective free radical scavenger however it has low in vivo stability and blood residence time. Aim. of this study is to develop a nanoparticle formulation by using different polymeric system which enhance the blood residence time and in vivo stability of PBN and characterize in terms of particle size, zeta potential, morphology, encapsulation efficiency, in vitro release profiles. Chitosan (CS), poly(D,L-lactide-co-glycolide) (PLGA) and their poly(ethylene glycol) (PEG) block co-polymers were used for comparative study. Results showed that particle sizes of CS, CS-PEG, PLGA and PLGA-PEG nanoparticles are between 142-356 nm. PLGA nanoparticles and their block copolymers' nanoparticle have greatly monodisperse distribution. CS and CS-PEG nanoparticles have zeta potential values between 17-40 mV related to amine groups, contrariwise PLGA and PLGA-PEG nanoparticles have negative zeta potential in the range of (-8)-(-19) mV. Encapsulation efficiency and loading capacity for all formulations are between 12-54 %, 9-68 %, respectively. PLGA-PEG nanoparticles are promising for further studies due to their sufficient encapsulation efficiency and in vitro release profilesAuthors would like to acknowledge that this project was financially supported by Tubitak (Scientific Research Project Number: 110S460)S

    An aquaporin 4 antisense oligonucleotide loaded, brain targeted nanoparticulate system design

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    Aquaporins (AQPs), members of the water-channel protein family, are highly expressed in brain tissue especially in astrocytic end-feet. They are important players for water hemostasis during development of cytotoxic as well as vasogenic edema. Increased expression of AQPs is important in pathophysiology of neurological diseases such as neuroinflammation and ischemia. Unfortunately, there are a few pharmacological inhibitors of AQP4 with several side effects limiting their translation as a drug for use in clinical conditions. Another therapeutic approach is using antisense oligonucleotides (ASOs) to block AQP4 activity. These are short, synthetic, modified nucleic acids that bind RNA to modulate its function. However, they cannot pass the blood brain barrier (BBB). To overcome this obstacle we designed a nanoparticulate system made up of chitosan nanoparticles surface modified with PEG and conjugated with monoclonal anti transferrin receptor-1 antibody via streptavidin-biotin binding. The nanocarrier system could be targeted to the transferrin receptor-1 at the brain endothelial capillaries through monoclonal antibodies. It is hypothesized that the nanoparticles could pass the BBB via receptor mediated transcytosis and reach brain parenchyma. Particle size, zeta potential, loading capacity and release profiles of nanoparticles were investigated. It was observed that all types of chitosau (CS) nanoparticles had positive zeta potential values and nanoparticle particle size distribution varied between 100 and 800 nm. The association efficiency of ASOs into the nanoparticles was between 80–97% and the release profiles of the nanoparticles exhibited an initial burst effect followed by a controlled release. The results showed that the designed chitosan based nanocarriers could be a promising carrier system to transport nucleic acid based drugs to brain parenchymaThis study is supported by The Scientific and Technological Research Council of Turkey (TUBITAK, Project Number: 110S460)S

    Systemically Administered Brain-Targeted Nanoparticles Transport Peptides across the Blood—Brain Barrier and Provide Neuroprotection

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    Although growth factors and anti-apoptotic peptides have been shown to be neuroprotective in stroke models, translation of these experimental findings to clinic is hampered by limited penetration of peptides to the brain. Here, we show that a large peptide like the basic fibroblast growth factor (bFGF) and a small peptide inhibitor of caspase-3 (z-DEVD-FMK) can effectively be transported to the brain after systemic administration by incorporating these peptides to brain-targeted nanoparticles (NPs). Chitosan NPs were loaded with peptides and then functionalized by conjugating with antibodies directed against the transferrin receptor-1 on brain endothelia to induce receptor-mediated transcytosis across the blood—brain barrier (BBB). Pre-ischemic systemic administration of bFGF- or z-DEVD-FMK-loaded NPs significantly decreased the infarct volume after 2-hour middle cerebral artery occlusion and 22-hour reperfusion in mice. Co-administration of bFGF- or z-DEVD-FMK-loaded NPs reduced the infarct volume further and provided a 3-hour therapeutic window. bFGF-loaded NPs were histologically detected in the brain parenchyma and also restored ischemia-induced Akt dephosphorylation. The neuroprotection was not observed when receptor-mediated transcytosis was inhibited with imatinib or when bFGF-loaded NPs were not conjugated with the targeting antibody, which enables them to cross the BBB. Nanoparticles targeted to brain are promising drug carriers to transport large as well as small BBB-impermeable therapeutics for neuroprotection against strokeTurgay Dalkara’s work is supported by the Turkish Academy of Sciences. This study is supported by The Scientific and Technological Research Council of Turkey (TUBITAK, Project Number: 109S017)S

    Neonatal tetanus in Turkey; what has changed in the last decade?

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    dikici, bunyamin/0000-0001-7572-6525WOS: 000259222800001PubMed: 18713452Background: Neonatal tetanus (NT) is still considered as one of the major causes of neonatal death in many developing countries. The aim of the present study was to assess the characteristics of sixty-seven infants with the diagnosis of neonatal tetanus followed-up in the Pediatric Infectious Diseases Ward of Dicle University Hospital, Diyarbakir, between 1991 and 2006, and to draw attention to factors that may contribute (or may have contributed) to the elimination of the disease in Diyarbakir. Methods: The data of sixty-seven infants whose epidemiological and clinical findings were compatible with neonatal tetanus were reviewed. Patients were stratified into two groups according to whether they survived or not to assess the effect of certain factors in the prognosis. Factors having a contribution to the higher rate of tetanus among newborn infants were discussed. Results: A total of 55 cases of NT had been hospitalized between 1991 and 1996 whereas only 12 patients admitted in the last decade. All of the infants had been delivered at home by untrained traditional birth attendants (TBA), and none of the mothers had been immunized with tetanus toxoid during her pregnancy. Twenty-eight (41.8%) of the infants died during their follow-up. Lower birth weight, younger age at onset of symptoms and at the time admission, the presence of opisthotonus, risus sardonicus and were associated with a higher mortality rate. Conclusion: Although the number of neonatal tetanus cases admitted to our clinic in recent years is lower than in the last decade efforts including appropriate health education of the masses, ensurement of access to antenatal sevices and increasing the rate of tetanus immunization among mothers still should be made in our region to achieve the goal of neonatal tetanus elimination

    Erratum to: 36th International Symposium on Intensive Care and Emergency Medicine

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    [This corrects the article DOI: 10.1186/s13054-016-1208-6.]

    Evaluation of nutritional status in pediatric intensive care unit patients: the results of a multicenter, prospective study in Turkey

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    IntroductionMalnutrition is defined as a pathological condition arising from deficient or imbalanced intake of nutritional elements. Factors such as increasing metabolic demands during the disease course in the hospitalized patients and inadequate calorie intake increase the risk of malnutrition. The aim of the present study is to evaluate nutritional status of patients admitted to pediatric intensive care units (PICU) in Turkey, examine the effect of nutrition on the treatment process and draw attention to the need for regulating nutritional support of patients while continuing existing therapies.Material and MethodIn this prospective multicenter study, the data was collected over a period of one month from PICUs participating in the PICU Nutrition Study Group in Turkey. Anthropometric data of the patients, calorie intake, 90-day mortality, need for mechanical ventilation, length of hospital stay and length of stay in intensive care unit were recorded and the relationship between these parameters was examined.ResultsOf the 614 patients included in the study, malnutrition was detected in 45.4% of the patients. Enteral feeding was initiated in 40.6% (n = 249) of the patients at day one upon admission to the intensive care unit. In the first 48 h, 86.82% (n = 533) of the patients achieved the target calorie intake, and 81.65% (n = 307) of the 376 patients remaining in the intensive care unit achieved the target calorie intake at the end of one week. The risk of mortality decreased with increasing upper mid-arm circumference and triceps skin fold thickness Z-score (OR = 0.871/0.894; p = 0.027/0.024). The risk of mortality was 2.723 times higher in patients who did not achieve the target calorie intake at first 48 h (p = 0.006) and the risk was 3.829 times higher in patients who did not achieve the target calorie intake at the end of one week (p = 0.001). The risk of mortality decreased with increasing triceps skin fold thickness Z-score (OR = 0.894; p = 0.024).ConclusionTimely and appropriate nutritional support in critically ill patients favorably affects the clinical course. The results of the present study suggest that mortality rate is higher in patients who fail to achieve the target calorie intake at first 48 h and day seven of admission to the intensive care unit. The risk of mortality decreases with increasing triceps skin fold thickness Z-score

    Whole exome sequencing reveals novel candidate gene variants for MODY

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    WOS: 000582504300017PubMed: 32645390Maturity-onset diabetes of the young (MODY) is a monogenic subtype of diabetes mellitus. Although 14 genes were associated to different subtypes of MODY, 30-40% of MODY patients have unidentified genetic mutations. in this study, we conducted whole exome sequencing (WES) in four Turkish MODY suspected patients in two families who do not carry any pathological variants in four frequent MODY genes (HNF1A, GCK, HNF1B and HNF4A). Initially, the variants were scanned for the known 14 MODY genes and a gene set related to glucose metabolism. Secondly, the destructive (frameshift, inframe insertion/deletion, initiator codon variant, splice acceptor/ donor variant, stop gained/lost) and missense variants in novel candidate genes shared by two patients of the same family were assessed by different bioinformatic tools. As a result, a total of three rare and novel probably pathogenic heterozygous missense variants (p.His307Gln in c-Myc, p.Asp129Asn in CDK4 and p.Gly107Ser in ARHGDIA) in candidate genes were identified in two families. This study revealed the presence of nonsynonymous alterations in novel candidate genes which were implicated in the insulin secretion. This is the first WES study which reveals novel candidate genes in Turkish MODY patients although functional analyses are required to confirm the pathogenicity of these variants.Scientific and Technological Research Council of Turkey (TUBITAK), TurkeyTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [113S218]Research project was funded by Scientific and Technological Research Council of Turkey (TUBITAK), Turkey (Grant number: 113S218)

    4 '-tert-Butyl-5-chloro-3H-spiro[1,3-benzothiazole-2,1 '-cyclohexane]

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    In the title compound, C16H22ClNS, the nine-membered 2,3-dihydro-1,3-benzothiazole ring system is essentially planar, with a maximum deviation of 0.025 (2) angstrom for the N atom. Its plane is almost perpendicular to the main plane of the substituted cyclohexane ring, which adopts a chair conformation. In the crystal, the molecules are linked by C-H center dot center dot center dot pi interactions

    4 '-tert-Butyl-5-chloro-3H-spiro[1,3-benzothiazole-2,1 '-cyclohexane]

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    In the title compound, C16H22ClNS, the nine-membered 2,3-dihydro-1,3-benzothiazole ring system is essentially planar, with a maximum deviation of 0.025 (2) angstrom for the N atom. Its plane is almost perpendicular to the main plane of the substituted cyclohexane ring, which adopts a chair conformation. In the crystal, the molecules are linked by C-H center dot center dot center dot pi interactions
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